No securities regulatory authority has expressed an opinion about these securities and it is an offence to claim otherwise. This prospectus supplement together with the accompanying short form base shelf prospectus dated October 29, 2021 to which it relates, as amended and supplemented, and each document incorporated or deemed to be incorporated by reference therein constitute a public offering of these securities only in those jurisdictions where they may be lawfully offered for sale and therein only by persons permitted to sell such securities in those jurisdictions. The securities offered hereby have not been and will not be registered under the United States Securities Act of 1933, as amended (the "U.S. Securities Act"), or any applicable state securities laws. The securities offered hereby may not be offered or sold in the United States. This prospectus supplement does not constitute an offer to sell or a solicitation of an offer to buy any of the securities offered hereby within the United States. See "Plan of Distribution".

This document contains no offer of transferable securities to the public in the United Kingdom ("UK") within the meaning of sections 85(1) and 102B of the Financial Services and Markets Act 2000, as amended (the "FSMA"), the Companies Act 2006 (as amended) or otherwise. This document is not a prospectus for the purposes of Section 85(1) and 102B of the FSMA. Accordingly, this document has not been examined or approved as a prospectus by the United Kingdom Financial Conduct Authority (the "FCA") under Section 85 or Section 87A of the FSMA or by the London Stock Exchange and has not been drawn up in accordance with the prospectus rules made by the FCA pursuant to section 73A of the FSMA from time to time or approved by, or filed with, the FCA or any other competent authority nor has it been approved by a person authorized under the FSMA, for the purposes of Section 21 of the FSMA. Prospective investors should read this document in its entirety. An investment in the Corporation includes a significant degree of risk and prospective investors should consider carefully the risk factors set out in this document.

Information has been incorporated by reference in this prospectus supplement and in the accompanying short form base shelf prospectus dated October 29, 2021 to which it relates from documents filed with securities commissions or similar authorities in Canada. Copies of the documents incorporated herein by reference may be obtained on request without charge from the Corporate Secretary of Horizonte Minerals Plc at Rex House, 4-12 Regent Street, London, SW1Y 4RG, United Kingdom (telephone: 44 (0)203 356 2901) and are also available electronically at www.sedar.com.

PROSPECTUS SUPPLEMENT

TO THE SHORT FORM BASE SHELF PROSPECTUS DATED OCTOBER 29, 2021

New Issue

November 24, 2021

Horizonte Minerals Plc

$15,128,687.76

126,072,398 Ordinary Shares at $0.12 per Ordinary Share

This prospectus supplement (the "Prospectus Supplement"), together with the accompanying short form base shelf prospectus dated October 29, 2021 (the "Base Shelf Prospectus"), is being filed by Horizonte Minerals Plc (the "Corporation" or "Horizonte") to qualify the distribution (the "Offering") of 126,072,398 ordinary shares (the "Offered Shares") of the Corporation at a price of $0.12 per Offered Share (the "Offering Price"). The Offering is being made pursuant to an agency agreement (the "Agency Agreement") dated as of November 24, 2021 among the Corporation and BMO Nesbitt Burns Inc., as lead agent (the "Lead Agent"), Paradigm Capital Inc., Cantor Fitzgerald Canada Corporation and Cormark Securities Inc. (collectively with the Lead Agent, the "Agents"). The Offering Price was determined by arm's length negotiation between the Corporation and the Agents with reference to the prevailing market price of the ordinary shares of the Corporation (the "Ordinary Shares"). See "Plan of Distribution".

The outstanding Ordinary Shares of the Corporation are listed and posted for trading on the Toronto Stock Exchange (the "TSX") and the AIM Market, a market operated by the London Stock Exchange ("AIM"), under the symbol "HZM". AIM is a market designed primarily for emerging or smaller companies to which a higher investment risk tends to be attached than to larger or more established companies. AIM securities are not admitted to the Official List of the United Kingdom Financial Conduct Authority. A prospective investor should be aware of the risks of investing in such companies and should make the decision to invest only after careful consideration and, if appropriate, consultation with an independent financial adviser. The London Stock Exchange has not itself examined or approved the contents of this document. On November 23, 2021, the last trading day prior to the date of this Prospectus Supplement, the closing price of the Ordinary Shares on the TSX was $0.155 and on AIM was £0.0814. The Corporation has applied to list the Offered Shares distributed under this Prospectus Supplement, together with the Base Shelf Prospectus, on the TSX. Listing will be subject to approval of the TSX and the Corporation fulfilling all of the requirements of the TSX.

Price: $0.12 per Offered Share

	Price to the Public	Agents' Fee(1)	Net Proceeds to the Corporation(2)
Per Offered Share	$0.12	$0.006	$0.114
Total	$15,128,687.76	$756,434.39	$14,372,253.37

(1) In consideration for the services rendered by the Agents in connection with the Offering and by BMO Capital Markets Limited, Peel Hunt LLP and H&P Advisory Limited (the "UK Placing Joint Bookrunners" and together with the Agents, the "Joint Bookrunners") in connection with the UK Placing (as defined herein), the Corporation has agreed to pay the Joint Bookrunners a base cash commission equal to 4% of the aggregate gross proceeds of the Offering and the UK Placing plus a discretionary commission equal to 1% of the aggregate gross proceeds of the Offering and the UK Placing to be divided between the Joint Bookrunners, which discretionary commission is payable at the sole discretion of the Corporation (the "Joint Bookrunners' Fee"). The term "Agents' Fee" in this Prospectus Supplement refers to that portion of the Joint Bookrunners' Fee resulting from the aggregate gross proceeds of the Offering and assumes it is paid out of the gross proceeds of the Offering. The terms Joint Bookrunners' Fee and Agents' Fee include, unless otherwise specified, the 4% base commission, and assumes full payment of the 1% discretionary commission.

(2) After deducting the Agents' Fee, but before deducting the expenses relating to the Offering, including the preparation and filing of this Prospectus Supplement, which expenses are estimated to be approximately $500,000 and which will be paid from the proceeds of the Offering.

The Agents have been retained to act as agents in connection with the Offering to conditionally offer the Offered Shares for sale if, as and when issued by the Corporation and accepted by the Agents on a "best efforts" basis in accordance with the terms and conditions contained in the Agency Agreement referred to under "Plan of Distribution", and subject to the approval of certain legal matters on behalf of the Corporation by Cassels Brock & Blackwell LLP and on behalf of the Agents by Bennett Jones LLP.

The Offering is being made in each of the provinces and territories of Canada, except Québec. The Offered Shares will be offered in such provinces and territories through those Agents or their affiliates who are registered to offer Offered Shares for sale in such provinces and territories and such other registered dealers as may be designated by the Agents. Subject to applicable law, the Agents may offer the Offered Shares in such other jurisdictions outside of Canada as agreed between the Corporation and the Agents. See "Plan of Distribution".

Subscriptions for the Offered Shares will be received subject to rejection or allotment, in whole or in part, and the right is reserved to close the subscription books at any time without notice. Subject to all conditions under the Agency Agreement having been satisfied or waived, closing of the Offering is expected to take place on or about December 22, 2021, or such other date as may be agreed upon by the Corporation and the Lead Agent, on behalf of the Agents. Subject to applicable laws, the Agents may, in connection with the Offering, effect transactions that are intended to stabilize or maintain the market price of the Ordinary Shares at levels other than those which might otherwise prevail in the open market. Such transactions, if commenced, may be discontinued at any time. See "Plan of Distribution".

It is anticipated that the Offered Shares will be delivered under the book-based system through CDS Clearing and Depository Services Inc. ("CDS") or its nominee and deposited in electronic form.

Prospective investors should rely only on the information contained or incorporated by reference in this Prospectus Supplement and in the Base Shelf Prospectus. The Corporation and the Agents have not authorized anyone to provide purchasers with information different from that contained or incorporated by reference in this Prospectus Supplement and the Base Shelf Prospectus. The Agents are offering to sell and seeking offers to buy the Offered Shares only in jurisdictions where, and to persons whom, offers and sales are lawfully permitted. An investment in the Offered Shares is highly speculative and involves significant risks that should be carefully considered by prospective investors before purchasing such securities. Such investment should only be made by those persons who can afford the risk of loss of their entire investment. The risks outlined in this Prospectus Supplement, the Base Shelf Prospectus and in the documents incorporated by reference herein and therein should be carefully reviewed and considered by prospective investors in connection with an investment in such securities. See "Caution Regarding Forward-Looking Information" and "Risk Factors" in this Prospectus Supplement and the Base Shelf Prospectus, "Forward-Looking Information" and "Risk Factors" in the AIF (as defined herein) and the risk factors set forth in the Interim MD&A and the Annual MD&A (each as defined herein) which are available under the Corporation's profile on SEDAR at www.sedar.com, before purchasing the Offered Shares.

Purchasers are advised that it may not be possible for investors to enforce judgements obtained in Canada against any person or company that is organized under the laws of a foreign jurisdiction or resides outside of Canada, even if the party has appointed an agent for service of process.

The registered and head office of the Corporation is located at Rex House, 4-12 Regent Street, London, SW1Y 4RG, United Kingdom.

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S-4

DESCRIPTION	PAGE NO.
ABOUT THIS PROSPECTUS	S-6
MEANING OF CERTAIN REFERENCES AND CURRENCY PRESENTATION	S-6
CAUTION REGARDING FORWARD-LOOKING STATEMENTS	S-6
DOCUMENTS INCORPORATED BY REFERENCE	S-8
NON-IFRS MEASURES	S-9
MARKETING MATERIALS	S-9
ELIGIBILITY FOR INVESTMENT	S-9
THE CORPORATION	S-10
CONSOLIDATED CAPITALIZATION	S-15
USE OF PROCEEDS	S-16
PLAN OF DISTRIBUTION	S-18
DESCRIPTION OF SECURITIES BEING DISTRIBUTED	S-20
PRIOR SALES	S-21
TRADING PRICE AND VOLUME	S-21
RISK FACTORS	S-22
CERTAIN CANADIAN FEDERAL INCOME TAX CONSIDERATIONS	S-24
UNITED KINGDOM TAX CONSIDERATIONS	S-28
AUDITOR, TRANSFER AGENT AND REGISTRAR	S-30
INTEREST OF EXPERTS	S-30
STATUTORY RIGHTS OF WITHDRAWAL AND RESCISSION	S-31
CERTIFICATE OF THE CORPORATION	C-1
CERTIFICATE OF THE AGENTS	C-2

S-5

ACCOMPANYING PROSPECTUS

DESCRIPTION	PAGE NO.
ABOUT THIS SHORT FORM BASE SHELF PROSPECTUS	1
MEANING OF CERTAIN REFERENCES AND CURRENCY PRESENTATION	1
CAUTION REGARDING FORWARD-LOOKING STATEMENTS	1
DOCUMENTS INCORPORATED BY REFERENCE	3
THE CORPORATION	5
USE OF PROCEEDS	5
EARNINGS COVERAGE RATIO	6
CONSOLIDATED CAPITALIZATION	6
DESCRIPTION OF ORDINARY SHARES	6
DESCRIPTION OF WARRANTS	6
DESCRIPTION OF SUBSCRIPTION RECEIPTS	7
DESCRIPTION OF DEBT SECURITIES	8
DESCRIPTION OF UNITS	9
PLAN OF DISTRIBUTION	9
PRIOR SALES	10
MARKET FOR SECURITIES	10
CERTAIN CANADIAN FEDERAL INCOME TAX CONSIDERATIONS	11
RISK FACTORS	11
LEGAL MATTERS	13
AUDITORS, TRANSFER AGENT AND REGISTRAR	14
INTEREST OF EXPERTS	14
AGENT FOR SERVICE OF PROCESS	14
PURCHASERS' STATUTORY RIGHTS AND STATUTORY RIGHTS OF WITHDRAWAL AND RESCISSION	15
CERTIFICATE OF THE CORPORATION	C-1

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ABOUT THIS PROSPECTUS

This document is in two parts. The first part is the Prospectus Supplement, which describes the terms of the Offering and adds to and updates information contained in the Base Shelf Prospectus and the documents incorporated by reference therein. The second part is the Base Shelf Prospectus, which gives more general information, some of which may not apply to the Offering. This Prospectus Supplement is deemed to be incorporated by reference into the Base Shelf Prospectus solely for the purpose of the Offering. To the extent that there is a conflict between information contained in this Prospectus Supplement and information contained in the Base Shelf Prospectus or any document incorporated by reference herein or therein, you should rely only on the information in this Prospectus Supplement with respect thereto.

Investors should carefully read both this Prospectus Supplement and the Base Shelf Prospectus, including the documents incorporated by reference herein and therein, and in particular the risk factors discussed in such documents, prior to investing in the Offered Shares.

Investors should rely only on the information contained or incorporated by reference in this Prospectus Supplement and the Base Shelf Prospectus and are not entitled to rely only on certain parts of the information contained or incorporated by reference in this Prospectus Supplement and the Base Shelf Prospectus to the exclusion of the remainder. The Corporation and the Agents have not authorized anyone to provide investors with different information. If anyone provides you with different or additional information, you should not rely on it. The Corporation and the Agents are not offering the securities in any jurisdiction in which the Offering is not permitted. Investors should assume that the information contained in this Prospectus Supplement and the Base Shelf Prospectus is accurate only as of the date on the front of those documents and that information contained in any document incorporated by reference is accurate only as of the date of that document, regardless of the time of delivery of this Prospectus Supplement and the Base Shelf Prospectus or of any sale of the securities pursuant thereto.

MEANING OF CERTAIN REFERENCES AND CURRENCY PRESENTATION

All references to “$”, “C$” or “Canadian dollars” included in this Prospectus Supplement (excluding the documents incorporated by reference herein) refer to values denominated in Canadian dollars. All references to “£” or “British pounds” included in this Prospectus Supplement (excluding the documents incorporated by reference herein) refer to British pounds. References to “US$” are to United States dollars.

The daily average rate of exchange for British pounds expressed in Canadian dollars on November 23, 2021 as reported by the Bank of Canada was £1.00 = $1.6992 ($1.00 = £0.5885) and the daily average rate of exchange for United States dollars expressed in Canadian dollars was US$1.00 = $1.2707 ($1.00 = US$0.7870).

CAUTION REGARDING FORWARD-LOOKING STATEMENTS

Certain statements in this Prospectus Supplement and the documents incorporated by reference herein constitute forward-looking information or forward-looking statements (collectively “Forward-looking Statements”) within the meaning of applicable securities laws. Forward-Looking Statements generally can be identified by the use of forward-looking terminology such as “plans”, “expects” or “does not expect”, “is expected”, “budget”, “scheduled”, “estimates”, “forecasts”, “intends”, “anticipates” or “does not anticipate”, or “believes”, or variations of such words and phrases or statements that certain actions, events or results “may”, “could”, “would”, “might” or “will be taken”, “occur” or “be achieved”.

Forward-Looking Statements include, but are not limited to, statements concerning the Corporation’s objectives, strategies to achieve those objectives, as well as statements with respect to management’s beliefs, plans, estimates and intentions, and similar statements concerning anticipated future events, results, circumstances, performance or expectations that are not historical facts; statements with respect to the use of proceeds of the Offering and other components of the Proposed Funding Package (as defined below); the timing for completion of the Offering and other components of the Proposed Funding Package; the satisfaction of the conditions to closing of the Offering and other components of the Proposed Funding Package, including receipt in a timely manner of required shareholder and regulatory approvals, including the approval of the TSX; the plan of distribution for the Offering; the milestones

necessary to achieve the Corporation’s business objectives and the timing thereof, including adequate project funding for the Araguaia Project (as defined below), the Corporation’s plans with respect to the advancement and development of its Araguaia Project and Vermelho Project (as defined below), budgets, expansion plans including its plan to acquire, explore and develop such other mineral rights and properties as management or the board of directors may from time to time determine have potential; the results of the feasibility and prefeasibility studies for its two main projects, including NAV, IRR, anticipated capital and operating costs, life of mine, projected production and other financial and operational metrics; metal prices; industry outlooks; mineral resource and mineral reserve estimates; expected financial results, taxes, plans and objectives of or involving the Corporation; amounts and use of available funds; anticipated developments in operations in future periods, the adequacy of financial resources and the availability of additional financing as required; the costs and timing of development of the Corporation’s business, including the Araguaia Project and the Vermelho Project; the costs, timing and receipt of approvals, consents and permits under applicable legislation, and the ability to satisfy their terms and conditions including under environmental laws and executive compensation approaches and practices.

Although the Forward-Looking Statements contained in this Prospectus Supplement and documents incorporated by reference are based upon what management believes are reasonable assumptions, there can be no assurance that actual results will be consistent with these Forward-Looking Statements. Forward-Looking Statements are subject to known and unknown risks, uncertainties and other factors that may cause the actual results, level of activity, performance or achievements of the Corporation to be materially different from those expressed or implied by such Forward-Looking Statements, including but not limited to: discretion of the Corporation with respect to the use of proceeds of the Offering and other components of the Proposed Funding Package; failure to obtain required shareholder and regulatory or other approvals with respect to the Offering and other components of the Proposed Funding Package; uncertainties with respect to the timing of the Proposed Senior Debt Facility (as defined below) and the risks inherit with respect to the Corporation meeting its covenants under any agreements to be entered into with respect to such facility; uncertainties and risks with respect to the construction and development of new mineral projects such as the Araguaia Project, which may be subject to unexpected delays and cost overruns, uncertainties inherent to the results of economic studies, including the feasibility and prefeasibility studies for the Corporation’s key projects; exploration and mining risks; competition from competitors with greater capital; fluctuations in metal prices and costs of supplies; uninsured risks; environmental and other regulatory requirements; exploration, mining and other licences; the Corporation’s future payment obligations; potential disputes with respect to the Corporation’s title to, and the area of, its mining concessions; the Corporation’s dependence on its ability to obtain sufficient financing in the future; the Corporation’s dependence on its relationships with third parties; the potential of currency fluctuations and political or economic instability in countries in which the Corporation operates; currency exchange fluctuations; the Corporation’s ability to manage its growth effectively; the trading market for the Ordinary Shares; uncertainty with respect to the Corporation’s plans to continue to develop its operations and new projects; the Corporation’s dependence on key personnel; the legal and regulatory framework within which the Corporation operates; litigation, future developments with respect to the COVID-19 pandemic, including, without limitation, the occurrence of new variants and new government measures restricting business and economic activities, and those factors discussed in the sections entitled “Risk Factors” in this Prospectus Supplement and the Base Shelf Prospectus and the risks and uncertainties discussed in the AIF, the Interim MD&A and the Annual MD&A, which are incorporated by reference herein.

This list is not exhaustive of the factors that may impact the Corporation’s Forward-Looking Statements. These and other factors should be considered carefully and readers should not place undue reliance on the Corporation’s Forward-Looking Statements. As a result of the foregoing and other factors, no assurance can be given as to any such future results, levels of activity or achievements and neither the Corporation nor any other person assumes responsibility for the accuracy and completeness of these Forward-Looking Statements. The factors underlying current expectations are dynamic and subject to change.

All Forward-Looking Statements in this Prospectus Supplement and documents incorporated by reference are qualified by these cautionary statements. Other than specifically required by applicable laws, the Corporation is under no obligation and expressly disclaims any such obligation to update or alter the Forward-Looking Statements whether as a result of new information, future events or otherwise except as may be required by law.

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DOCUMENTS INCORPORATED BY REFERENCE

This Prospectus Supplement is deemed to be incorporated by reference into the Base Shelf Prospectus solely for the purpose of the Offering.

Copies of the documents incorporated by reference in this Prospectus Supplement and the Base Shelf Prospectus may be obtained on request from the corporate secretary of the Corporation at Rex House, 4-12 Regent Street, London, United Kingdom, SW1Y 4RG.

The following documents, filed with the various securities commissions or similar authorities in each of the provinces and territories of Canada, except Quebec, are specifically incorporated by reference in and form an integral part of this Prospectus Supplement and the Base Shelf Prospectus:

the Corporation’s audited consolidated financial statements for the fiscal years ended December 31, 2020 and December 31, 2019 together with the notes thereto and the auditor’s report thereon;
the Corporation’s management’s discussion and analysis for the year ended December 31, 2020 (“Annual MD&A”);
the Corporation’s unaudited condensed consolidated interim financial statements for the three and nine months ended September 30, 2021 (“Interim Financial Statements”);
the Corporation’s management’s discussion and analysis for the three and nine months ended September 30, 2021 (“Interim MD&A”);
the Corporation’s annual information form dated March 31, 2021 for the year ended December 31, 2020 (“AIF”);
the Corporation’s management information circular dated April 9, 2021 relating to the annual general meeting of shareholders held on May 17, 2021;
the Corporation’s material change report dated February 23, 2021 pertaining to the placing of 162,718,353 new Ordinary Shares and “bought deal” private placement of 88,060,100 special warrants;
the template version of the term sheet initially dated November 23, 2021 and updated November 24, 2021 in connection with the Offering (the “Term Sheet”); and
the corporate presentation of the Corporation titled “Horizonte Minerals Plc – A Next Generation Nickel Producer” dated November 23, 2021 (the “Presentation”).

All material change reports (excluding confidential material change reports), annual information forms, annual financial statements and the auditors’ report thereon and related management’s discussion and analysis (“MD&A”), interim financial statements and related MD&A, information circulars, business acquisition reports, any news release issued by the Corporation that specifically states it is to be incorporated by reference in this Prospectus Supplement, and, any other documents as may be required to be incorporated by reference into the Base Shelf Prospectus for purposes of the Offering under applicable Canadian securities laws which are filed by the Corporation with a securities commission or any similar authority in Canada after the date of this Prospectus Supplement and prior to termination of the distribution of the Offered Shares shall be deemed to be incorporated by reference in this Prospectus Supplement and the Base Shelf Prospectus.

Notwithstanding anything herein to the contrary, any statement contained in this Prospectus Supplement or the Base Shelf Prospectus or in a document incorporated or deemed to be incorporated by reference herein or therein shall be deemed to be modified or superseded, for purposes of this Prospectus Supplement, to the extent that a statement contained herein or in the Base Shelf Prospectus or in any other subsequently filed document incorporated or deemed to be incorporated by reference herein or in the Base Shelf Prospectus modifies or supersedes such prior statement. The modifying or superseding statement need not state that it has modified or superseded a prior statement or include any other information set forth in the document that it modifies or supersedes. The making of a modifying or superseding statement shall not be deemed an admission for any purposes that the modified or superseded statement, when made, constituted a misrepresentation, an untrue

S-8

statement of a material fact or an omission to state a material fact that is required to be stated or that is necessary to make a statement not misleading in light of the circumstances in which it was made. Any statement so modified or superseded shall thereafter neither constitute, nor be deemed to constitute, a part of this Prospectus Supplement, except as so modified or superseded.

NON-IFRS MEASURES

The Corporation has included certain non-International Financial Reporting Standards (“IFRS”) financial measures in certain documents incorporated by reference in this Prospectus Supplement and the Base Shelf Prospectus, including “EBITDA” (i.e. earnings before interest, taxes, depreciation and amortization), “annual free cash flow”, “net cash flow”, “all in sustaining costs” and “NPV” (i.e. net present value). The Corporation believes that such non-IFRS measures, together with measures determined in accordance with IFRS, provide prospective investors with an improved ability to evaluate the underlying performance of the Corporation. These non-IFRS measures are not recognized under IFRS and do not have standardized meanings prescribed by IFRS. Therefore, it is unlikely that these measures will be comparable to similarly titled measures reported by other issuers. Non-IFRS financial measures should be considered in the context of the Corporation’s IFRS results. The Corporation cautions readers to consider these non-IFRS financial measures in addition to, and not as an alternative for, measures calculated in accordance with IFRS.

MARKETING MATERIALS

In connection with the Offering, the Agents used the Term Sheet and the Presentation (the “Marketing Materials”) as “marketing materials” (as such term is defined under applicable Canadian securities laws). The Marketing Materials do not form part of this Prospectus Supplement and the Base Shelf Prospectus to the extent that the contents of the Marketing Materials have been modified or superseded by a statement contained in this Prospectus Supplement or any amendment. Any “template version” (as such term is defined under applicable Canadian securities laws) of any “marketing materials” filed on SEDAR (www.sedar.com) after the date of this Prospectus Supplement and before the termination of the distribution under the Offering (including any amendments to, or an amended version of, the Marketing Materials) is deemed to be incorporated by reference into this Prospectus Supplement and the Base Shelf Prospectus solely for the purposes of the Offering.

ELIGIBILITY FOR INVESTMENT

In the opinion of Cassels Brock & Blackwell LLP, counsel to the Corporation, and Bennett Jones LLP, counsel to the Agents, based on the current provisions of the Income Tax Act (Canada) (the “Tax Act”) and the regulations thereunder, in force as of the date hereof, the Offered Shares, if issued on the date hereof, would be, at a particular time, qualified investments under the Tax Act for trusts governed by a registered retirement savings plan, registered retirement income fund, registered education savings plan, registered disability savings plan, tax-free savings account (collectively referred to as “Registered Plans”) or deferred profit sharing plan, provided that at such particular time the Offered Shares are listed on a “designated stock exchange” within the meaning of the Tax Act (which currently includes the TSX).

Notwithstanding the foregoing, the holder, subscriber or annuitant of, or under, a Registered Plan (the “Controlling Individual”) will be subject to a penalty tax as set out in the Tax Act in respect of Offered Shares acquired by the Registered Plan if such shares are a “prohibited investment” (within the meaning of the Tax Act) for the particular Registered Plan. An Offered Share generally will not be a “prohibited investment” for a Registered Plan provided the Controlling Individual deals at arm’s length with the Corporation for the purposes of the Tax Act and does not have a “significant interest” (as defined in subsection 207.01(4) of the Tax Act) in the Corporation. In addition, the Offered Shares will not be a “prohibited investment” if the Offered Shares are “excluded property” (as defined in subsection 207.01(1) of the Tax Act) for the Registered Plan. Controlling Individuals should consult their own tax advisors as to whether the Offered Shares would be a prohibited investment in their particular circumstances.

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S-10

THE CORPORATION

Horizonte Minerals Plc was formed on January 16, 2006 under the Companies Act 1985 of England and Wales. In March 2006, the Corporation adopted a new set of Articles of Association ("Articles") which, among other things, removed the requirement for a limit on the amount of authorized but unissued share capital. The Corporation amended the Articles to come into line with new legislation relating to electronic communications, the requirement for directors to give reasons for any refusal to register a transfer of shares, and other notice provisions relating to notification by directors of conflict of interests.

The registered and head office of the Corporation is located at Rex House, 4-12 Regent Street, London, SW1Y 4RG, United Kingdom.

The Corporation is a reporting issuer in each of the provinces and territories of Canada, other than Québec. The Ordinary Shares are listed on the TSX and AIM under the symbol "HZM".

The Corporation is a mineral exploration and development Corporation currently focused on the development of its 100% owned Araguaia nickel laterite project ("Araguaia Project") and Vermelho nickel cobalt project ("Vermelho Project"), both located in Brazil.

The Araguaia Project is an advanced nickel project being developed by the Corporation as the next ferronickel operation in Brazil. A feasibility study (the "FS") on the Araguaia Project showing the economics of the project with an initial 28 year mine life was published in the fourth quarter of 2018. The Vermelho Project is a low cost, long life (38 years) nickel sulphate project for which the Corporation released a preliminary feasibility study (the "PFS") in October 2019.

Further information regarding the Corporation and its business, including, without limitation, information with respect to the Araguaia Project, the Vermelho Project, the results of the FS and the results of the PFS is set out in the AIF, the Annual MD&A, the Interim MD&A and other documents which are incorporated or deemed incorporated by reference herein.

Recent Developments

On November 23, 2021, the Corporation announced that it intends to complete a funding package (the "Proposed Funding Package") of approximately US$633 million to complete the funding required for the construction of the Araguaia Project.

The Proposed Funding Package comprises:

(i) An approximately US$197 million equity fundraise (the "Equity Fundraise"): The Equity Fundraise consists of (i) strategic investments of approximately US$71 million from La Mancha Investments S.à.r.l. ("La Mancha") and approximately US$50.0 million from Orion Mine Finance Fund III LP ("Orion") in newly issued Ordinary Shares (the "Strategic Equity Investments"); (ii) a cornerstone investment of approximately US$7.0 million from Glencore International AG ("Glencore") in newly issued Ordinary Shares (the "Glencore Subscription"); and (iii) the placing of up to approximately US$68.6 million of newly issued Ordinary Shares in the United Kingdom (the "UK Placing") at a price of 7 pence per Ordinary Share (the "Fundraising Price") and pursuant to the Offering (the Offering, together with the UK Placing, the "Placing");

(ii) A US$65 million convertible loan notes issue (the "Convertible Notes Investments" and together with the Strategic Equity Investments, the "Strategic Investments"): As part of their strategic investments, Orion and La Mancha have conditionally agreed to subscribe for US$50 million and US$15 million of convertible loan notes (the "Convertible Notes") respectively;

(iii) A US$25 million proposed cost overrun debt facility (the "Proposed Cost Overrun Debt Facility"): Orion is proposing that a member of its group provides the Proposed Cost Overrun Debt Facility to be used, if required, for the construction of the Araguaia Project. The Proposed Cost Overrun Debt Facility is subject, among other things, to the negotiation of definitive documentation and would form part of a

total of US$99 million in dedicated cost overrun funding and contingency funding for the Araguaia Project; and

(iv) A US$346.2 million senior debt facility: The Corporation has received credit approvals and a signed commitment letter for US$346.2 million of senior debt (the “Proposed Senior Debt Facility”) from a syndicate of international financial institutions (BNP Paribas, BNP Paribas Fortis, ING Capital LLC, ING Bank N.V., Natixis, New York Branch, Société Générale and Swedish Export Credit Corporation (collectively, the “Lenders”)). The Proposed Senior Debt Facility, which is subject, among other things, to the completion of due diligence and the negotiation of definitive documentation, will comprise two tranches: Tranche A of US$146.2 million will be guaranteed by two Export Credit Agencies (EKF, Denmark’s Export Credit Agency (“EKF”), and Finnvera plc, Finland’s Export Credit Agency (“Finnvera”)); and Tranche B of US$200 million.

The Corporation also announced that it intends to offer up to US$8 million for subscription to eligible holders of existing Ordinary Shares at a price of 7 pence per share (the “Open Offer”).

Details of the UK Placing

The UK Placing consists of a placing in the United Kingdom and certain other jurisdictions outside Canada by the UK Placing Joint Bookrunners pursuant to a placing agreement (the “UK Placing Agreement”) through an accelerated bookbuild process pursuant to which an additional 606,123,712 Ordinary Shares will be issued at the Fundraising Price for additional gross proceeds to the Corporation of approximately US$56.8 million.

Details of the Orion Strategic Investment

Orion has entered into an investment agreement with the Corporation (the “Orion Investment Agreement”) pursuant to which Orion will subscribe for approximately US$50 million of newly issued Ordinary Shares at a price of 7 pence per Ordinary Share and will procure that one of its subsidiaries will subscribe for US$50 million of Convertible Notes. The subscription for the Ordinary Shares is conditional upon, among other things, the approval of the Corporation’s shareholders at the Shareholder Meeting (as defined below); the approval of the subscription by the TSX; the approval of Orion as a new “control person” of the Corporation; the admission of the Ordinary Shares to trading on AIM; and the Placing and Strategic Investments having become unconditional with gross proceeds of not less than US$175 million (other than inter-conditionality and admission to AIM).

The subscription for the US$50 million of Convertible Notes is conditional upon, among other things, the Equity Fundraise having occurred, and construction having commenced by the time required by the Brazilian National Mining Agency (or any extension thereof) and the long-form documentation for the project financing being signed.

Under the Orion Investment Agreement, the Corporation has agreed that Orion shall have the right to participate in any future equity or equity-linked offerings by Horizonte up to the level of its ownership at the time of that offering so long as Orion owns at least 10% of the Ordinary Shares in issue at the time. Orion shall also have the right to nominate one person to be a director of the Corporation for so long as it holds at least 10% of the Ordinary Shares in issue from time to time.

Pursuant to lock-in arrangements, Orion has agreed that it will not from the date of the Orion Investment Agreement until the date falling four months after completion of the subscription for the Ordinary Shares, sell or otherwise dispose of any Ordinary Shares, subject to certain exceptions. The lock-in arrangements do not apply to the Convertible Notes when issued.

Under the Orion Investment Agreement, the Corporation has given certain warranties and indemnities to Orion. The Corporation has also undertaken that it will not, prior to the issuance of the Convertible Notes, undertake certain corporate transactions without the consent of Orion, including issuing shares, buying back shares or declaring a dividend. The Orion Investment Agreement terminates if Orion ceases to hold an interest in Horizonte of at least 10% for at least 60 days.

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Details of the La Mancha Strategic Investment

La Mancha has entered into an investment agreement with the Corporation (the “La Mancha Investment Agreement”) pursuant to which La Mancha will subscribe for approximately US$71 million of newly issued Ordinary Shares at a price of 7 pence per Ordinary Share and subscribe for US$15 million of Convertible Notes. The subscription for the Ordinary Shares is conditional upon, among other things, the approval of the Corporation’s shareholders at the Shareholder Meeting; the approval of the subscription by the TSX; the admission of the Ordinary Shares to trading on AIM; and the Placing and Strategic Investments having become unconditional with gross proceeds of not less than US$175 million (other than inter-conditionality and admission to AIM).

The subscription for the US$15 million of Convertible Notes is conditional upon, among other things, the Equity Fundraise having occurred, Orion’s conditions to subscription having been satisfied and the long-form documentation for the project financing being signed.

Under the La Mancha Investment Agreement, the Corporation has agreed that La Mancha shall have the right to participate in any future equity or equity-linked offerings (including offerings for non-cash consideration) by Horizonte up to the level of its ownership at the time of that offering so long as La Mancha owns at least 10% of the Ordinary Shares in issue at the time. La Mancha shall also have participation rights on an annual basis to avoid dilution in respect of Ordinary Shares issued pursuant to incentive awards. La Mancha shall also have the right to nominate one person to be a director of the Corporation for so long as it holds at least 10% of the Ordinary Shares in issue from time to time. The Corporation has agreed that the director nominated by La Mancha shall also have certain consultation and approval rights to participate in the selection and appointment of an additional independent non-executive director and on any replacement of such director for so long as it holds at least 15% of the Ordinary Shares in issue from time to time.

La Mancha has further agreed that it shall not take any action that would prevent the Corporation from complying with its obligations under applicable securities laws; and that it shall not procure a shareholder resolution of the Corporation which would circumvent the proper application of the AIM rules or applicable Canadian securities laws.

Under the La Mancha Investment Agreement, the Corporation has given certain warranties and indemnities to La Mancha. The Corporation has also undertaken that it will not, prior to the issuance of the Convertible Notes, undertake certain corporate transactions without the consent of La Mancha, including issuing shares, buying back shares or declaring a dividend. The La Mancha Investment Agreement terminates if La Mancha ceases to hold an interest in Horizonte of at least 10% for at least 90 days. Pursuant to lock-in arrangements, La Mancha has agreed that it will not from the date of the La Mancha Investment Agreement until the date falling four months after completion of the subscription for the Ordinary Shares, sell or otherwise dispose of any Ordinary Shares, subject to certain exceptions. The lock-in arrangements do not apply to the Convertible Notes, when issued.

Details of the Convertible Notes

The Corporation has entered into convertible note instruments (the “Convertible Note Instruments”) with an affiliate of Orion (the “Orion Noteholder”) and La Mancha. The Convertible Notes will be issued by the Corporation at a 5.75% discount (such that the Orion Noteholder and/or La Mancha shall only be required to pay 94.25% of the principal amount) at a fixed interest rate of 11.75% per annum, which shall be capitalised until completion of the Araguaia Project (as defined in the relevant documentation, the “Project Completion”) and payable in cash (subject to available cashflows) thereafter. In the case of an event of default in accordance with the terms of the Convertible Note Instrument, the interest rate is increased to 15.00% per annum. Subject to there being available cash for distribution from the Araguaia Project and following Project Completion, the principal (including any accrued capitalised interest) shall be repayable in quarterly instalments.

At any time until the maturity date, being three months after the final maturity date of Tranche A of the Proposed Senior Debt Facility, the Orion Noteholder and/or La Mancha may, at their option, convert the Convertible Notes, partially or wholly, into Ordinary Shares up to the total amount outstanding under the Convertible Notes at a conversion price equal to 125% of the Fundraising Price (the “Conversion Price”) subject to customary anti-dilution adjustments.

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At any time after the fifth (5th) anniversary of the subscription for the Convertible Notes, the Corporation shall have a one-time right to redeem the then outstanding and unconverted Convertible Notes in whole at 105% of the par value plus accrued and unpaid interest in cash if (i) a change of control event occurs; or (ii) the 30-day volume weighted average trading price of the Ordinary Shares exceeds 200% of the Conversion Price and the aggregate average daily trading value exceeds US$2.5 million over the prior 30 trading days.

Under the Convertible Notes there is a cash sweep of 85% of excess cash (being available cash for distribution from the Araguaia Project less required interest and principal payments on the Convertible Notes) to apply on each repayment date from Project Completion onwards. In certain circumstances the Corporation has also agreed that it will utilise proceeds of any direct or any indirect sale (in whole or in part) of either the Araguaia or Vermelho Projects as available cash for the purposes of the Convertible Notes. The Corporation has also given certain warranties and undertakings under the Convertible Notes.

Details of the Proposed Senior Debt Facility

As previously announced, Horizonte has received credit approvals from the Lenders for a US$346.2 million Proposed Senior Debt Facility to fund the construction and development of the Araguaia Project. A signed commitment letter has now also been received from the Lenders.

The Proposed Senior Debt Facility will include two tranches: (i) Tranche A of US$146.2 million, to be guaranteed by EKF and Finnvera in relation to a number of key equipment and service provider contracts; and (ii) Tranche B of US$200 million.

The term of the Proposed Senior Debt Facility will be ten and a half years for Tranche A, and eight and a half years for Tranche B. The interest rate of the Proposed Senior Debt Facility will be at a rate of 3M US LIBOR + 1.80% for 95% guaranteed programs for Tranche A, and pre-project completion 3M USD LIBOR (or equivalent) + 4.75% and post-project completion 3M USD LIBOR (or equivalent) + 4.25% with a step up applicable from years six to eight of 0.50% for Tranche B.

Closing of the Proposed Senior Debt Facility is subject to a number of conditions, including the completion of due diligence, the negotiation and settlement of definitive documentation and the entry into a comprehensive intercreditor agreement, among others.

Details of the Proposed Cost Overrun Facility

Orion has obtained investment committee approval to provide a Proposed Cost Overrun Debt Facility in the amount of US$25 million, subject to the Corporation and Orion negotiating definitive documentation. The Proposed Cost Overrun Debt Facility will benefit from the same security package as the Proposed Senior Debt Facility but will be subordinated to the Proposed Senior Debt Facility. It will have a maturity date of three months after the final maturity date of Tranche A of the Proposed Senior Debt Facility and will be available for drawdown in the case of a cost overrun against the construction schedule and budget, subject to certain conditions, including the Corporation having invested 90% of the funding from the Equity Fundraise and Convertible Notes into the construction of the Araguaia Project. The Proposed Cost Overrun Debt Facility will be conditional upon, among other things, the gearing ratio of 70:30 being met. The Proposed Cost Overrun Debt Facility will bear interest at 13.00% per annum and will be subject to a commitment fee while undrawn of 2% per annum.

Vermelho Royalty

An affiliate of Orion, has also agreed to purchase a gross revenue royalty (the "Vermelho Royalty") on nickel and cobalt from the Vermelho Project over the life of the mine for US$25 million. The purchase of the Vermelho Royalty will be conditional upon, among other things, the funding of the Convertible Notes by the Orion Noteholder and the granting of security over the Vermelho Project assets in favour of the Orion royalty holder. The Vermelho Royalty will carry an initial rate of 2.1% but will increase to 2.25% if substantial construction of the Vermelho Project has not commenced within five years of the closing date of the Vermelho Royalty. When the resource covered in a Vermelho Project feasibility study has been depleted, the royalty rate shall decrease by 50%. The royalty rate will be revised to deliver an 18% IRR to the royalty holder should there be any change in the mine schedule and production profile prior

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to construction (relative to that contained in the Vermelho Project pre-feasibility study). The Vermelho Royalty rate may be reduced or otherwise revised in certain circumstances. The Corporation also has the right to buy back 50% of the royalty on the first four anniversaries of closing (provided on such date it has not already been bought back) at agreed multiples of the initial purchase price of up to 2x or thereafter for a sum which would deliver an IRR of 17% upon a change of control. Orion will also have the right to require the Corporation to repurchase the Vermelho Royalty if construction of the Vermelho Project has not commenced within ten years of the closing date at a price which generates minimum level of IRR of 15% for Orion. The proceeds of the Vermelho Royalty may only be used for the development of the Vermelho Project and cannot be used towards the Araguaia Project.

Under the Vermelho Royalty, Orion has been granted a right of first refusal over future royalties/streams on the project, mining area or mining rights for ten years. The Corporation has also agreed to establish a technical committee with representatives of the Corporation, Orion, and independent technical and ESG consultants. The royalty contract contains customary termination provisions upon a default, with the termination amount being the higher of the NPV of the royalty at an 8% discount rate or the royalty purchase price multiplied by 2.4. The Corporation has agreed to guarantee its subsidiaries' obligations under the Vermelho Royalty once the Proposed Senior Debt Facility has been discharged. It has also been agreed that security for the obligations to pay all amounts under the royalty agreement (including the termination amounts) will be granted over all assets, shares and intercompany loans in the Vermelho Project group companies. Orion has unrestricted ability to assign and transfer its right and obligations under the Vermelho Royalty.

Offtake

Horizonte has also entered into a binding ten year offtake agreement with Glencore, whereby Glencore has committed to acquire 100% of the production of ferronickel from the Araguaia Project for that period (the "Offtake Agreement"). The entry into the Offtake Agreement is a key requirement of the Lenders and significantly de-risks future cash flows from the Araguaia Project. The Offtake Agreement is conditional upon, among other things, the completion of the Glencore Subscription and the entry by Glencore into a direct agreement with the Lenders in relation to typical intercreditor matters.

Conditionality and Completion

The Placing is conditional, among other things, on the following being satisfied or (in the absolute discretion of the UK Placing Joint Bookrunners) waived, to the extent capable of waiver:

(i) the passing by the requisite majority of the Corporation's shareholders of certain resolutions to approve the issue and allotment of the securities to be issued in connection with Proposed Funding Package, including (among other things) authorities to directors of the Corporation to allot further shares for cash on a non-pre-emptive basis (the "Fundraising Resolutions");
(ii) certain matters in relation to the debt financing arrangements and the Strategic Investments;
(iii) pre-completion, in accordance of the terms of the applicable agreements, of the Strategic Investments having occurred;
(iv) conditional approval of the TSX; and
(v) admission to trading on AIM of the Ordinary Shares to be issued in the Placing becoming effective on or before 8.00 a.m. (London time) on December 22, 2021 (or such later date and/or time as the Corporation and the UK Placing Joint Bookrunners may agree, being no later than 8.00 a.m. (London time) on January 14, 2022) ("AIM Admission").

The Placing Agreement and the Agency Agreement contain certain customary warranties and indemnities from the Corporation in favour of, respectively, each of the UK Placing Joint Bookrunners (in the case of the Placing Agreement) and each of the Agents (in the case of the Agency Agreement). The UK Placing Joint Bookrunners and the Agents are entitled, in certain circumstances, to terminate, respectively, the Placing Agreement and the Agency Agreement. See "Plan of Distribution".

Completion of the Placing and the Strategic Investments are conditional upon each other and are not conditional upon the completion of other parts of the Proposed Funding Package, and the Placing and Strategic Investments are expected to become unconditional on admission to trading of the Ordinary Shares to be issued pursuant to them. The issue and

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allotment of the securities to be issued in connection with Proposed Funding Package is conditional upon, among other things, the passing of the Fundraising Resolutions by the Corporation’s shareholders at a meeting of shareholders (the “Shareholder Meeting”) proposed to be convened on or around December 20, 2021.

Completion of the subscription of the Ordinary Shares relating to the Strategic Investments, the Glencore Subscription and the Placing and Open Offer is expected to take place on the second Business Day after the Shareholder Meeting.

Completion of the subscription of the Convertible Notes relating to the Strategic Investments will take place on the tenth business day after the entry into the definitive documentation relating to Proposed Senior Debt Facility (and the satisfaction or waiver of the other conditions precedent), which is expected to occur in late 2021 or the first quarter of 2022. The Vermelho Royalty is expected to be drawn after the subscription of the Convertible Notes and before March 31, 2022.

Drawdown of the Proposed Senior Debt Facility is expected to occur in late 2022 once the net proceeds of the Equity Fundraise and the Convertible Notes have been spent, and other conditions to drawdown have been satisfied.

The obligations of Orion and La Mancha to subscribe for Ordinary Shares under the Strategic Investments shall terminate if the conditions to those subscriptions are not satisfied or waived by December 31, 2021. The obligations of Orion and La Mancha to subscribe for the Convertible Notes under the Strategic Investments shall terminate if the conditions to those subscriptions are not satisfied or waived by March 31, 2022.

The Proposed Senior Debt Facility and the Proposed Cost Overrun Debt Facility are at the term sheet stage and remain conditional upon definitive documentation being agreed and the completion of due diligence. Discussions are ongoing and, while the Corporation has no reason to believe that the Proposed Funding Package will not be implemented, there can be no certainty that all of the transactions contemplated by the Proposed Funding Package will occur.

Assuming the issuance of an aggregate of 2,099,909,115 Ordinary Shares upon completion of the Offering, the UK Placing, the Strategic Equity Investments and the Glencore Subscription, it is anticipated that Orion and La Mancha will hold and/or have control or direct over approximately $14.04\%$ and $19.98\%$ of the Ordinary Shares, respectively, prior to giving effect to the exercise of any convertible securities (including the Convertible Notes) and assuming no issuance of Ordinary Shares pursuant to the Open Offer.

For the purposes of TSX approval for certain aspects of the Proposed Funding Package, the Corporation intends to rely on the exemption set forth in Section 602.1 of the TSX Company Manual, which provides that the TSX will not apply its standards to certain transactions involving eligible interlisted issuers on a recognized exchange, such as AIM.

The proceeds from the Equity Fundraise, Convertible Notes Investments and the Proposed Senior Debt Facility will be used to fund the construction and development of the Araguaia Project in Brazil as more particularly described in "Use of Proceeds".

CONSOLIDATED CAPITALIZATION

Other than as disclosed under "The Corporation – Recent Developments", there have not been any material changes in the share and loan capital of the Corporation, on a consolidated basis, since the date of the Interim Financial Statements. The following table represents the share capital of the Corporation both before and after the issuance of the Offered Shares under the UK Placing, the Strategic Equity Investments and the Offering:

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Designation of Shares	Outstanding as at the date hereof^{(1)}	Outstanding on the date hereof, after giving effect to the UK Placing, the Strategic Equity Investments, the Glencore Subscription and the Offering^{(2)}
Ordinary	1,700,155,740	3,800,064,855

Notes:
(1) As at the date hereof, there are 125,350,000 Ordinary Shares issuable upon the exercise of outstanding options of the Corporation. See also “Prior Sales”.
(2) Reflects the issuance of an aggregate of 2,099,909,115 Ordinary Shares pursuant to the UK Placing, the Strategic Equity Investments, the Glencore Subscription and the Offering. Excludes Ordinary Shares issuable upon conversion of the Convertible Notes and assumes no issuances under the Open Offer and no exercise of options.

USE OF PROCEEDS

The aggregate net proceeds to the Corporation from the Offering are estimated to be approximately $13,872,253.37 million, after deducting the payment of the Agents’ Fee of approximately $756,434.39 and the estimated expenses of the Offering of approximately $500,000.

The Corporation intends to use the net proceeds of the Offering for construction and development activities of the Araguaia Project and for working capital and general corporate purposes as outlined below.

(in millions)
Use of Net Proceeds from the Offering
Mine	$0.3
Ore Preparation	$1.7
Pyrometallurgy	$6.2
Materials Supply	$1.0
Utilities & Infrastructures	$2.0
Buildings	$0.4
Working Capital and Corporate Purposes	$2.27
Total	$13.87

The tables below summarize the funding sources and the proposed use of proceeds from the Proposed Funding Package before transaction expenses and commissions.

Funding Sources	US$ millions
Equity Fundraise
Orion	US$50.0
La Mancha	US$71.1
Glencore	US$ 7.0
Placing (UK Placing and Offering)	US$68.6

Total	US$196.7
Senior Debt Facility
Tranche A	US$146.2
Tranche B	US$200.0
Total	US$346.2
Convertible Notes Investments	US$65.0
Open Offer (assuming take up in full)	US$8.0
Other(1)	US$42.0
Total Sources of Funds	US$657.9

(1) Comprises of approximately US$17 million expected cash balance immediately prior to settlement of any funds from the Proposed Funding Package and US$25 million cost overrun loan facility from Orion.

Use of Funds	US$ millions
Araguaia Capital Expenditure (incl. US$44 million contingency)	US$477.3
Working Capital and Other(1)	US$135.5
Cost Overrun Equity and Debt Contingency	US$45.0
Total Use of Funds(2)	US$657.9

(1) Other includes pre-production operating costs, financing fees and costs, land acquisition and interest during construction.
(2) Proposed use of funds includes approximately US$100 million of contingency, comprising US$44 million contingency in the capital cost estimates for the Araguaia Project, US$45 million of equity and debt cost overrun funding and US$10 million growth allowance.

David Hall, Chairman of the Corporation, is the "qualified person" (as such term is defined in National Instrument 43-101 – Standards of Disclosure for Mineral Projects) who supervised the preparation of the above use of proceeds.

The short to medium term objectives of the Corporation are to (i) complete the Proposed Funding Package for the Araguaia Project; (ii) develop and construct the Araguaia Project to bring it into commercial production; (iii) advance the Vermelho Project towards a feasibility study; and (iv) advance the permitting for the Vermelho Project. The proceeds of the Proposed Funding Package will, in addition to the Corporation's cash on hand, enable the Corporation to pursue construction activities for the Araguaia Project, improve the Corporation's balance sheet ensuring that it enters the development phase for the Araguaia Project from a strong position. There is however no assurance that the Corporation will be able to complete all the components of the Proposed Funding Package nor reach its other objectives,

There is no assurance that the Corporation will be able to proceed with the development of the Araguaia Project. Mine development and mining operations are subject to significant risks and uncertainties. See "Risk Factors - Risks Related to the Corporation - Development of the Corporation's Mineral Projects will be Subject to all the Risks Associated with Establishing New Mining Operations" in this Prospectus Supplement and other risk factors in the documents incorporated by reference herein.

The above noted allocation represents the Corporation's intentions with respect to its use of proceeds of the Offering and the Proposed Funding Package based on current knowledge, planning and expectations of management of the Corporation. The Corporation's actual use of the net proceeds of the Offering and the Proposed Funding Package may vary depending on the Corporation's operating and capital needs from time to time. There may be circumstances where, for sound business reasons, a reallocation of funds may be necessary. See "Risk Factors - Risks Related to the Securities - Use of Proceeds".

For the fiscal year ended December 31, 2020, the Corporation had negative cash flow from operating activities. The Corporation anticipates it will continue to have negative cash flow from operating activities in future periods until profitable commercial production is achieved at the Araguaia Project. As a result, certain of the net proceeds from the Offering and the Proposed Funding Package may be used to fund such negative cash flow from operating activities in future periods. See “Risk Factors – Risks Related to the Corporation – Negative Operating Cash Flow and Additional Funding”.

PLAN OF DISTRIBUTION

Pursuant to the Agency Agreement, the Corporation has engaged the Agents to act as its agents to offer the Offered Shares for sale to the public at the Offering Price on a “best efforts” basis. The Agents have agreed to assist with the Offering on an agency basis and are not obligated to purchase any Offered Shares for their own accounts. The obligations of the Agents under the Agency Agreement are several (and not joint, nor joint and several), and may be terminated at their discretion on the basis of “disaster out”, “regulatory out”, “market out”, “material adverse change out”, “due diligence out” and “breach out” provisions in the Agency Agreement and may also be terminated upon the occurrence of certain stated events.

In consideration for the services rendered by the Agents in connection with the Offering and the UK Placing Joint Bookrunners in connection with the UK Placing, the Corporation has agreed to pay the Joint Bookrunners the Joint Bookrunners’ Fee comprised of a base commission equal to 4% of the aggregate gross proceeds of the Offering and the UK Placing plus a discretionary commission of 1% of the aggregate gross proceeds of the Offering and the UK Placing to be divided between the Joint Bookrunners, which discretionary commission is payable at the sole discretion of the Corporation.

The Offering Price and other terms of the Offering were determined by arm’s length negotiation between the Corporation and the Agents, with reference to the prevailing market price of the Ordinary Shares.

The Corporation has applied to list the Offered Shares distributed under this Prospectus Supplement, together with the Base Shelf Prospectus, on the TSX. Listing will be subject to approval by the TSX and the Corporation fulfilling all of the requirements of the TSX. Pursuant to the agreements governing the Placing, the Corporation has agreed to seek AIM Admission in respect of the Ordinary Shares to be issued under the Placing. AIM Admission will be subject to approval by AIM and the Corporation fulfilling all of the requirements of AIM.

Pursuant to policy statements of certain securities regulators, the Agents may not, throughout the period of distribution under this Prospectus Supplement, bid for or purchase Ordinary Shares. The foregoing restriction is subject to certain exceptions including: (a) a bid or purchase permitted under the Universal Market Integrity Rules for Canadian Marketplaces administered by the Investment Industry Regulatory Organization of Canada relating to market stabilization and passive market making activities, (b) a bid or purchase made for and on behalf of a customer where the order was not solicited during the period of the distribution, provided that the bid or purchase was for the purpose of maintaining a fair and orderly market and not engaged in for the purpose of creating actual or apparent active trading in, or raising the price of, such securities, or (c) a bid or purchase to cover a short position entered into prior to the commencement of the prescribed restricted period. Consistent with these requirements, and in connection with this distribution, the Agents may effect transactions that are intended to stabilize or maintain the market price of the Ordinary Shares at levels other than those which otherwise might prevail on the open market. If these activities are commenced, they may be discontinued by the Agents at any time. The Agents may carry out these transactions on the TSX, in the over-the-counter market or otherwise.

Pursuant to the Agency Agreement, the Corporation has agreed to comply with the standstill provisions in the UK Placing Agreement which provide that, for a period commencing on the date of the UK Placing Agreement and ending 90 days after AIM Admission, the Corporation will not, without the prior written consent of BMO Capital Markets Limited and Peel Hunt LLP (together, the “Joint UK Global Co-ordinators”), such consent not to be unreasonably

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withheld, conditioned or delayed, directly or indirectly issue, sell, offer, grant an option or right in respect of, or otherwise dispose of, or agree to, or announce any intention to, issue, sell, offer, grant an option or right in respect of, or otherwise dispose of, any additional Ordinary Shares or any securities exercisable for, convertible into or exchangeable for Ordinary Shares, other than pursuant to (i) the UK Placing, the Open Offer, the Offering, the Strategic Equity Investments, the Convertible Note Investments or the Glencore Subscription; or (ii) the grant or exercise of stock options and other similar issuances pursuant to any stock option plan or similar share compensation arrangements in place prior to the date of the UK Placing Agreement.

Pursuant to the Agency Agreement, the Corporation has also agreed to comply with the lock-up agreement provisions in the UK Placing Agreement, which provide that the Corporation will use commercially reasonable efforts to procure that each of the officers and directors of the Corporation enter into a lock-up agreement in a form satisfactory to the Corporation and the Joint UK Global Co-ordinators, each acting reasonably, pursuant to which each such person agrees, for a period commencing on AIM Admission and ending 90 days after AIM Admission, not to directly or indirectly offer, sell, contract to sell, grant any option to purchase, make any short sale, lend, swap, or otherwise dispose of, transfer or assign, or announce any intention to do so, any Ordinary Shares or any securities exercisable for, convertible into or exchangeable for Ordinary Shares, whether now owned, directly or indirectly, or under their control or direction, or with respect to which each has beneficial ownership or enter into any transaction or arrangement that has the effect of transferring, in whole or in part, any of the economic consequences of ownership of Ordinary Shares, whether such transaction is settled by the delivery of Ordinary Shares, other securities, cash or otherwise, other than pursuant to a bona fide take-over bid, change of control or any other similar transaction made generally to all of the shareholders of the Corporation, provided that, in the event the take-over bid, change of control or other similar transaction is not completed, such securities shall remain subject to the lock-up agreement.

The Offered Shares have not been and will not be registered under the 1933 Act or any state securities laws and may not be offered or sold within the United States (as defined in Regulation S of the 1933 Act). The Agents have agreed that they will not offer or sell the Offered Shares at any time within the United States as part of their distribution or at any time within the United States. Moreover, the Agency Agreement provides that each Agent will otherwise offer and sell the Offered Shares outside the United States only in accordance with the exclusion from the registration requirements of the 1933 Act provided by Rule 903 of Regulation S under the 1933 Act.

This Prospectus Supplement does not constitute an offer to sell or a solicitation of an offer to buy any of the Offered Shares in the United States. In addition, until 40 days after the commencement of the Offering, an offer or sale of the Offered Shares within the United States by a dealer (whether or not participating in the Offering) may violate the registration requirements of the 1933 Act if such offer or sale is made otherwise than in accordance with an exemption from registration under the 1933 Act.

Subscriptions for the Offered Shares will be received subject to rejection or allotment, in whole or in part, and the right is reserved to close the subscription books at any time without notice. Subject to all conditions under the Agency Agreement having been satisfied or waived, closing of the Offering is expected to take place on or about December 22, 2021, or such other date as may be agreed upon by the Corporation and the Lead Agent, on behalf of the Agents. It is anticipated that the Offered Shares will be delivered under the book-based system through CDS or its nominee and deposited in electronic form. A purchaser of Offered Shares will receive only a customer confirmation from the registered dealer from or through which the Offered Shares are purchased and who is a CDS depository service participant. CDS will record the CDS participants who hold Offered Shares on behalf of owners who have purchased Offered Shares in accordance with the book-based system. No definitive certificates will be issued unless specifically requested or required.

Pursuant to the terms of the Agency Agreement, the Corporation has agreed to reimburse the Agents for certain expenses incurred in connection with the Offering and to indemnify the Agents, each of their subsidiaries and affiliates, and each of their directors, officers, employees and agents against certain liabilities and expenses and to contribute to payments the Agents may be required to make in respect thereof.

Completion of the Offering and other components of the Proposed Funding Package are subject to various conditions, including, without limitation, applicable regulatory approvals (including AIM and TSX) and approval by shareholders of the Corporation at the Shareholder Meeting. As part of the closing conditions of the Offering, the UK Placing Agreement must remain in full force and effect and the conditions to completion of the transactions contemplated by

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the UK Placing Agreement must be satisfied, other than certain specified conditions. See “The Corporation - Recent Developments” for additional information.

DESCRIPTION OF SECURITIES BEING DISTRIBUTED

Each Ordinary Share has one vote attached to it. Ordinary Shares may be transferred as follows: (i) in the case of certificated shares, by instrument, in writing in any usual or ordinary form, or in such other form as the board of directors of the Corporation (the “Board”) shall from time to time approve; and (ii) in the case of uncertificated shares, in accordance with and subject to the CREST Regulations and the facilities and requirements of the relevant scheme concerned.

Except as described below, the Ordinary Shares are freely transferable provided that in relation to certificated shares the transfer is in respect of only one class of share and is accompanied by the share certificate and any other evidence of title required by the Board and that the provisions in the Articles relating to the deposit of instruments for transfer have been complied with. The Board may, in its absolute discretion and without giving any reason, refuse to register a transfer of any share: (i) to more than four joint holders; or (ii) where the share is not fully paid up provided that such action does not prevent dealings in the shares from taking place on an open and proper basis; or (iii) on which the Corporation has a lien. In addition, the Board may refuse to register a transfer if a notice has been duly served on any member or other person appearing to be interested in any shares (representing at least 0.25 per cent of the issued shares of the class in question (excluding any shares of that class held as treasury shares)) pursuant to section 793 of the 2006 Act and the notice has not been complied with within the period stipulated in the notice.

Shareholders do not have any pre-emption rights in respect of transfers of issued Ordinary Shares.

Shareholders have the benefit of statutory pre-emption rights in respect of the issue and allotment of new Ordinary Shares for cash under the Companies Act 2006 of England and Wales (“2006 Act”). The Corporation may not allot Ordinary Shares or grant rights to subscribe for, or convert any security into, Ordinary Shares for cash without first offering such shares or rights to subscribe to existing shareholders in proportion to their holdings, unless shareholders resolve to disapply those rights. The rights may be disapplied by a special resolution of the Corporation (being a majority of not less than 75% of those of the Corporation’s shareholders who have voted (in person or by proxy) at a general meeting of the Corporation).

Shareholders have the right to receive dividends to the extent declared by the Corporation.

The Ordinary Shares may, subject to a resolution of the Corporation’s shareholders, be converted into stock or paid up shares of any denomination. The Ordinary Shares may, subject to a resolution of the Corporation’s shareholders, be consolidated, divided, cancelled or sub-divided. The Ordinary Shares rank equally for capital and on any winding up.

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PRIOR SALES

During the 12-month period before the date of this Prospectus Supplement, the Corporation has issued the following Ordinary Shares and securities convertible into Ordinary Shares:

Date of Issuance	Number of Securities Issued	Type of Security	Exercise Price / Price Per Security
February 19, 2021	162,718,353	Ordinary Shares	$0.133
March 9, 2021	88,060,100	Special Warrants	$0.133
April 14, 2021	88,060,100	Ordinary Shares(1)	$0.133

Note:
(1) On April 14, 2021, 88,060,100 Special Warrants were converted into 88,060,100 Ordinary Shares.

TRADING PRICE AND VOLUME

The Ordinary Shares are listed and posted for trading on the TSX and AIM under the symbol "HZM". The following table sets forth the price range and trading volumes of the Ordinary Shares on the TSX on a monthly basis for the 12-month period prior to the date of this Prospectus Supplement, as reported by the TSX:

Date	High ($)	Low ($)	Volume
November 2020	0.125	0.095	714,323
December 2020	0.135	0.110	1,417,233
January 2021	0.175	0.130	2,207,150
February 2021	0.170	0.135	4,052,336
March 2021	0.140	0.100	2,807,345
April 2021	0.155	0.125	5,663,828
May 2021	0.150	0.110	1,809,871
June 2021	0.125	0.100	2,788,429
July 2021	0.120	0.100	13,754,506
August 2021	0.140	0.105	7,329,415
September 2021	0.165	0.120	4,274,353
October 2021	0.155	0.130	1,833,220
November 1, 2021 – November 23, 2021	0.180	0.130	943,748

On November 23, 2021, the last trading day prior to the date of this Prospectus Supplement, the closing price of the Ordinary Shares on the TSX was $0.155 and on AIM was £0.0814.

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RISK FACTORS

An investment in the Offered Shares being distributed under this Prospectus Supplement is speculative and involves a high degree of risk. Any prospective investor should carefully consider the risk factors set forth in this Prospectus Supplement, the Base Shelf Prospectus, the AIF, the Annual MD&A and the Interim MD&A, which are incorporated by reference in this Prospectus Supplement, and all of the other information contained in this Prospectus Supplement (including, without limitation, the documents incorporated by reference herein) before acquiring the Offered Shares distributed under this Prospectus Supplement. The risks described herein and therein are not the only risks facing the Corporation. Additional risks and uncertainties not currently known to the Corporation, or that the Corporation currently deems to be immaterial, may also materially and adversely affect its business.

Risks Related to the Securities

Use of Proceeds

The Corporation intends to allocate the net proceeds it will receive from the Offering and other components of the Proposed Funding Package as described under “Use of Proceeds” in this Prospectus Supplement, however, the Corporation will have discretion in the actual application of the net proceeds of the Offering. The Corporation may elect to allocate the net proceeds differently from that described in “Use of Proceeds” in this Prospectus Supplement if the Corporation believes it would be in the Corporation’s best interests to do so. The Corporation’s investors may not agree with the manner in which the Corporation chooses to allocate and spend the net proceeds described herein. The failure by the Corporation to apply these funds effectively could have a material adverse effect on the business of the Corporation.

Risks Related to the Proposed Funding Package

Completion of the components of the Proposed Funding Package are subject to various conditions, including, without limitation, applicable regulatory approvals (including AIM and the TSX) and approval by the Corporation’s shareholders of certain matters, including the Equity Fundraise and the Convertible Notes Investments. Completion of the Placing and the Strategic Investments are conditional upon each other and are not conditional upon the completion of other parts of the Proposed Funding Package. The Proposed Senior Debt Facility is subject to a number of conditions, including the completion of due diligence, the negotiation and settlement of definitive documentation and the entry into a comprehensive intercreditor agreement, among others. There is no certainty that the Corporation will be able to meet all of these conditions and obtain all approvals required, and the timing of meeting such conditions and obtaining such approvals may vary from what the Corporation anticipates. If the Corporation is unable to complete all the elements of the Proposed Funding Package, it may need to seek alternative financing, which if obtained, may not be on terms advantageous to the Corporation compared to those contemplated under Proposed Funding Package. In addition, as part of the Proposed Funding Package the Corporation will be party to various debt documentation increasing materially the debt component of its loan and capital structure and the Corporation will be subject to various restrictions and covenants, and it will have material assets subject to security interests. Any failure of the Corporation to service its debt or meet its covenants under debt documentation of the Proposed Funding Package may result in an event of default or other adverse effect on the Corporation.

Potential Volatility of Share Price

The market price for Ordinary Shares may be volatile and subject to wide fluctuations in response to numerous factors, many of which are beyond the Corporation’s control, including the following: (i) actual or anticipated fluctuations in the Corporation’s quarterly results of operations; (ii) recommendations by securities research analysts; (iii) changes in the economic performance or market valuations of other issuers that investors deem comparable to the Corporation; (iv) addition or departure of the Corporation’s executive officers and other key personnel; (v) release or expiration of lock-up or other transfer restrictions on outstanding Ordinary Shares; (vi) sales or perceived sales of additional Ordinary Shares; (vii) significant acquisitions or business combinations, strategic partnerships, joint ventures or capital commitments by or involving the Corporation or its competitors; and (viii) news reports relating to trends, concerns, technological or competitive developments, regulatory changes and other related issues in the Corporation’s industry or target markets.

Financial markets have recently experienced significant price and volume fluctuations that have particularly affected the market prices of equity securities of public entities and that have, in many cases, been unrelated to the operating performance, underlying asset values or prospects of such entities. Accordingly, the market price of the Ordinary Shares may decline even if the Corporation’s operating results, underlying asset values or prospects have not changed. Additionally, these factors, as well as other related factors, may cause decreases in asset values that are deemed to be other than temporary, which may result in impairment losses. As well, certain institutional investors may base their investment decisions on consideration of the Corporation’s environmental, governance and social practices and performance against such institutions’ respective investment guidelines and criteria, and failure to satisfy such criteria may result in limited or no investment in the Ordinary Shares by those institutions, which could materially adversely affect the trading price of the Ordinary Shares. There can be no assurance that continuing fluctuations in price and volume will not occur. If such increased levels of volatility and market turmoil continue for a protracted period of time, the Corporation’s operations and the trading price of the Ordinary Shares may be materially adversely affected.

Risks Related to the Corporation

COVID-19 Outbreak

The current and ongoing global uncertainty with respect to the spread of COVID-19, the rapidly evolving nature of the pandemic, including the emergence of new variants of the virus, in Brazil and elsewhere, and local and international developments related thereto and its effect on the broader global economy and capital markets may have a negative effect on the Corporation and the advancement of the Araquaia Project and Vermelho Project. While the precise impact of the continued COVID-19 outbreak on the Corporation remains unknown, rapid spread of COVID-19 and declaration of the outbreak as a global pandemic has resulted in travel advisories and restrictions, certain restrictions on business operations, social distancing precautions and restrictions on group gatherings which are having direct impacts on businesses around the world and could result in travel bans, closure of assay labs, work delays, difficulties for contractors and employees getting to site, and diversion of management attention all of which in turn could have a negative impact on the advancement of the Araquaia Project and Vermelho Project and the Corporation generally. The continued spread of COVID-19 may also have further material adverse effects on global economic activity and could result in additional volatility and disruptions to global supply chains and the financial and capital markets, which could negatively affect the business, financial condition, results of operations, prospects and other factors relevant to the Corporation. There can be no assurance that COVID-19 or any other public health crises will not have a material adverse effect on the Corporation and its business and operations.

Development of the Corporation’s Mineral Projects will be Subject to all the Risks Associated with Establishing New Mining Operations

Development of the Corporation’s Araguaia Project and Vermelho Project will require the construction and operation of mines, processing plants and related infrastructure. As a result, the Corporation is and will continue to be subject to all of the risks associated with establishing new mining operations, including:

the timing and cost, which can be significant, of the construction of mining and processing facilities;
the availability and cost of skilled labour, mining equipment and principal supplies needed for operations;
the availability and cost of appropriate smelting and refining arrangements;
the need to obtain and maintain necessary environmental and other governmental permits and authorizations and the timing of the receipt of those permits and authorizations;
the availability of funds to finance construction and development activities;
potential opposition from non-governmental organizations, indigenous organizations, environmental groups, local groups or other stakeholders which may delay or prevent development activities; and
potential increases in construction and operating costs due to changes in the cost of labour, fuel, power, materials and supplies.

The costs, timing and complexities of developing the Corporation’s mineral projects may be greater than anticipated.

Cost estimates may increase as more detailed engineering work is completed on the projects. It is ordinary in new mining operations to experience unexpected costs, problems and delays during construction, development and mine start-up. Accordingly, the Corporation cannot provide assurance that its activities will result in profitable mining operations at its mineral properties.

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Feasibility and Pre-Feasibility Studies may not be Realized

Although the feasibility studies and pre-feasibility studies for the Corporation’s main project are comprehensive third-party expert studies in respect of the development of its deposits, there can be no assurance that the projects can or will be developed in accordance with the specifications set out in the studies. Feasibility and other mining studies are inherently based on estimates and cannot provide certainty with respect to the development of and production from a mine given the uncertainties associated with Mineral Reserve and Mineral Resource estimates and associated with construction and development of a project. Construction costs and timelines can be impacted by a wide variety of factors, many of which are beyond the control the Corporation, including the COVID-19 pandemic, weather conditions, ground conditions, availability of appropriate rock and other material required for construction, availability and performance of contractors and suppliers, delivery and installation of equipment, design changes, accuracy of estimates and availability of accommodations for the workforce. A delay in startup of commercial production would increase capital costs and delay generating revenues. Given the inherent risks and uncertainties associated with construction, there can be no assurance that the development will occur in accordance with the project’s study and current expectations (or at all), that construction costs will be consistent with the budget, that production will be achieved on schedule, or that the mine will operate as planned.

Negative Operating Cash Flow and Additional Funding

The Corporation has no history of revenue from its operating activities. For the fiscal year ended December 31, 2020, the Corporation had negative cash flow from operating activities. The Corporation anticipates it will continue to have negative cash flow from operating activities and net losses in future periods unless and until commercial sales are achieved for the Corporation’s products. A portion of the proceeds from the Offering may be used to fund negative cash flow from operating activities in future periods. Furthermore, significant additional financing, whether through the issuance of additional securities and/or debt, will be required to continue the development of the Corporation’s Araguaia Project (in the event the Proposed Funding Package is not completed in full, or the project encounters cost overruns), the Vermelho Project and/or other projects. There can be no assurance that the Corporation will be able to obtain adequate additional financing in the future or that the terms of such financing will be favourable. Failure to obtain such additional financing could result in delay or indefinite postponement of further development of the Corporation’s key projects.

Effecting Service of Process

The Corporation and certain of the Corporation’s directors and officers reside outside of Canada. Substantially all of the assets of these persons are located outside of Canada. It may also not be possible to enforce against the Corporation, certain of its directors and officers, and certain experts named in this Prospectus Supplement or documents incorporated by reference herein, judgments obtained in Canadian courts predicated upon the civil liability provisions of applicable securities laws in Canada.

CERTAIN CANADIAN FEDERAL INCOME TAX CONSIDERATIONS

The following is, as of the date hereof, a summary of the principal Canadian federal income tax considerations generally applicable to a purchaser who acquires Offered Shares pursuant to this Offering. This summary applies only to a purchaser who is a beneficial owner of Offered Shares acquired pursuant to this Offering and who, for the purposes of the Tax Act, and at all relevant times: (i) acquires and holds the Offered Shares as capital property; (ii) deals at arm’s length with the Corporation and the Agents; and (iii) is not affiliated with the Corporation or the Agents (a “Holder”).

Offered Shares will generally be considered to be capital property to a Holder unless the Holder holds such securities in the course of carrying on a business of trading or dealing in securities or has acquired them in one or more transactions considered to be an adventure or concern in the nature of trade.

This summary is not applicable to a Holder: (i) that is a “financial institution” (as defined in the Tax Act) for purposes of the mark-to-market provisions of the Tax Act; (ii) that is a “specified financial institution” as defined in the Tax Act; (iii) that has made a functional currency reporting election under section 261 of the Tax Act to report its “Canadian tax results” as defined in the Tax Act in a currency other than Canadian currency; (iv) an interest in which is, or for

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whom an Offered Share would be, a “tax shelter investment” for the purposes of the Tax Act; (v) that has entered into or will enter into a “derivative forward agreement” or “synthetic disposition arrangement”, as those terms are defined in the Tax Act, in respect of Offered Shares; (vi) that receives dividends on Offered Shares under or as part of a “dividend rental arrangement” (as defined in the Tax Act); or (vii) in relation to which the Corporation or any of its subsidiaries is or will be a “foreign affiliate” (as defined in the Tax Act). Such Holders should consult their own tax advisors.

In addition, this summary does not address the deductibility of interest by a purchaser who has borrowed money to acquire Offered Shares pursuant to the Offering.

This summary is based upon the current provisions of the Tax Act and the regulations thereunder (“Regulations”) in force as of the date hereof, all specific proposals (“Proposed Amendments”) to amend the Tax Act and the Regulations that have been publicly announced by, or on behalf of, the Minister of Finance (Canada) prior to the date hereof and counsel’s understanding of the current published administrative policies and assessing practices of the Canada Revenue Agency (“CRA”). No assurance can be given that the Proposed Amendments will be enacted or otherwise implemented in their current form, if at all. If the Proposed Amendments are not enacted or otherwise implemented as presently proposed, the tax consequences may not be as described below in all cases. Other than the Proposed Amendments, this summary does not take into account or anticipate any changes in law, administrative policy or assessing practice, whether by legislative, regulatory, administrative, governmental or judicial decision or action, nor does it take into account the tax laws of any province or territory of Canada or of any jurisdiction outside of Canada. Holders that are not residents of Canada for the purposes of the Tax Act should consult with their own tax advisors with respect to the tax consequences of acquiring, holding and disposing of Offered Shares in any jurisdiction in which they may be subject to tax, including Canada.

This summary assumes that the Corporation is, and at all relevant times will be, a non-resident of Canada for the purposes of the Tax Act. If the Corporation is (or becomes) a resident of Canada for the purposes of the Tax Act, the Canadian federal income tax consequences to a Holder may be materially different from those described in this summary.

This summary is of a general nature only, is not exhaustive of all possible Canadian federal income tax considerations and is not intended to be, nor should it be construed to be, legal or tax advice to any particular Holder. Accordingly, Holders should consult their own tax advisors with respect to their particular circumstances.

Currency Conversion

For purposes of the Tax Act, all amounts related to the acquisition, holding or disposition of Offered Shares (including dividends, adjusted cost base and proceeds of disposition) must be expressed in Canadian dollars. Amounts denominated in a foreign currency must be converted into Canadian dollars using the appropriate exchange rate determined in accordance with the detailed rules contained in the Tax Act in this regard.

Holders Resident in Canada

This section of the summary applies to a Holder who, at all relevant times, is, or is deemed to be, resident in Canada for the purposes of the Tax Act (a “Resident Holder”). The Offered Shares are not “Canadian securities” for the purpose of the irrevocable election under subsection 39(4) of the Tax Act. Consequently, a Resident Holder will not be entitled to make or rely on such an election to have the Offered Shares deemed to be capital property. Resident Holders who do not hold Offered Shares as capital property should consult their own tax advisors regarding their particular circumstances.

Dividends

A Resident Holder will be required to include in computing such Resident Holder’s income for a taxation year the amount of any dividends received (or deemed to be received) on the Offered Shares, including amounts deducted for any foreign withholding tax. Dividends received on Offered Shares by a Resident Holder who is an individual will

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not be subject to the gross-up and dividend tax credit rules in the Tax Act normally applicable to taxable dividends received from “taxable Canadian corporations” (as defined in the Tax Act). A Resident Holder that is a corporation will not be entitled to deduct the amount of such dividends in computing its taxable income.

To the extent that foreign withholding tax is payable by a Resident Holder in respect of any dividends received on the Offered Shares, the Resident Holder may be eligible for a foreign tax credit or deduction under the Tax Act to the extent and under the circumstances described in the Tax Act. Resident Holders should consult their own tax advisors regarding the availability of a foreign tax credit or deduction, having regard to their particular circumstances.

Disposition of Offered Shares

A Resident Holder who disposes of or is deemed to have disposed of an Offered Share will generally realize a capital gain (or capital loss) in the taxation year of the disposition equal to the amount by which the proceeds of disposition of the Offered Share, net of any reasonable costs of disposition, are greater (or are less) than the adjusted cost base to the Resident Holder of the Offered Share immediately before the disposition or deemed disposition. Such capital gain (or capital loss) will be subject to the tax treatment described below under “Holders Resident in Canada - Capital Gains and Capital Losses”.

Capital Gains and Capital Losses

A Resident Holder will generally be required to include in computing its income for the taxation year of disposition, one-half of the amount of any capital gain (a “taxable capital gain”) realized in such year. Subject to and in accordance with the provisions of the Tax Act, a Resident Holder will be required to deduct one-half of the amount of any capital loss (an “allowable capital loss”) against taxable capital gains realized in the taxation year of disposition. Allowable capital losses in excess of taxable capital gains for the taxation year of disposition may be carried back and deducted in any of the three preceding taxation years or carried forward and deducted in any subsequent taxation year against net taxable capital gains realized in such years, to the extent and under the circumstances specified in the Tax Act.

Capital gains realized by a Resident Holder that is an individual or trust, other than certain specified trusts, may give rise to a liability for minimum tax under the Tax Act.

Foreign tax, if any, levied on any gain realized on a disposition of Offered Shares may be eligible for a foreign tax credit under the Tax Act to the extent and under the circumstances described in the Tax Act. Resident Holders should consult their own tax advisors with respect to the availability of a foreign tax credit, having regard to their particular circumstances.

Offshore Investment Fund Property Rules

The Tax Act contains rules which, in certain circumstances, may require a Resident Holder to include an amount in income in each taxation year in respect of the acquisition and holding of Offered Shares if (a) the value of the Offered Shares may reasonably be considered to be derived, directly or indirectly, primarily from portfolio investments in: (i) shares of the capital stock of one or more corporations, (ii) indebtedness or annuities, (iii) interests in one or more corporations, trusts, partnerships, organizations, funds or entities, (iv) commodities, (v) real estate, (vi) Canadian or foreign resource properties, (vii) currency of a country other than Canada, (viii) rights or options to acquire or dispose of any of the foregoing, or (ix) any combination of the foregoing (collectively “Investment Assets”) and (b) it may reasonably be concluded that one of the main reasons for the Resident Holder acquiring, or holding Offered Shares was to derive a benefit from portfolio investments in Investment Assets in such a manner that the taxes, if any, on the income, profits and gains from such Investment Assets for any particular year are significantly less than the tax that would have been applicable under Part I of the Tax Act if the income, profits and gains had been earned directly by the Resident Holder.

In determining whether these rules may apply, regard must be had to all of the circumstances, including (i) the nature, organization and operation of any non-resident entity, including the Corporation, and the form of, and the terms and conditions governing, the Resident Holder’s interest in, or connection with, any such non-resident entity, (ii) the extent

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to which any income, profit and gains that may reasonably be considered to be earned or accrued, whether directly or indirectly, for the benefit of any non-resident entity, including the Corporation, are subject to an income or profits tax that is significantly less than the income tax that would be applicable to such income, profits and gains if they were earned directly by the Resident Holder, and (iii) the extent to which any income, profits and gains of any non-resident entity, including the Corporation, for any fiscal period are distributed in that or the immediately following fiscal period.

If applicable, these rules would generally require a Resident Holder to include in income for each taxation year in which the Resident Holder owns an Offered Share (i) an imputed return for the taxation year computed on a monthly basis and determined by multiplying the Resident Holder's "designated cost" (as defined in the Tax Act) of the Offered Share at the end of the month, by 1/12th of the sum of the applicable prescribed rate for the period that includes such month plus 2%, less (ii) the Resident Holder's income for the year (other than a capital gain) from the Offered Share determined without reference to these rules. Any amount required to be included in computing a Resident Holder's income under these rules will be added to the adjusted cost base to the Resident Holder of the Offered Shares.

The CRA has taken the position that the term "portfolio investment" should be given a broad interpretation. While it should be unlikely that the value of the Offered Shares should be regarded as being derived primarily from portfolio investments in Investment Assets, there is a possibility that the CRA may take a different view. Even if the value of the Offered Shares may reasonably be considered to be derived, directly or indirectly, primarily from portfolio investments in Investment Assets, these rules will apply to a Resident Holder only if it is reasonable to conclude that one of the main reasons for the Resident Holder acquiring, holding or having the Offered Shares was to derive a benefit from Investment Assets in such a manner that the taxes, if any, on the income, profits and gains from such Investment Assets for any particular year are significantly less than the tax that would have been applicable under Part I of the Tax Act if the income, profits and gains had been earned directly by the Resident Holder.

These rules are complex and their application depends, in part, on the reasons for a Resident Holder acquiring or holding Offered Shares. Resident Holders are urged to consult their own tax advisors regarding the application and consequences of these rules in their own particular circumstances.

Additional Refundable Tax

A Resident Holder that is, throughout its taxation year, a "Canadian-controlled private corporation" (as defined in the Tax Act) may be subject to pay a tax (which generally is refundable, subject to the detailed rules of the Tax Act) on its "aggregate investment income" (as defined in the Tax Act) for the year, including amounts in respect of taxable capital gains and dividends.

Foreign Property Information Reporting

In general, a Resident Holder that is a "specified Canadian entity" (as defined in the Tax Act) for a taxation year or a fiscal period and whose total "cost amount" (as defined in the Tax Act) of "specified foreign property" (as defined in the Tax Act), including Offered Shares, at any time in the year or fiscal period exceeds C$100,000 will be required to file an information return with the CRA for the taxation year or fiscal period disclosing certain prescribed information in respect of such property. Subject to certain exceptions, a taxpayer resident in Canada, other than a corporation or trust exempt from tax under Part I of the Tax Act, will be a "specified Canadian entity," as will certain partnerships. The Offered Shares will be "specified foreign property" to a Resident Holder. Penalties may apply where a Resident Holder fails to file the required information return in respect of such Resident Holder's "specified foreign property" on a timely basis in accordance with the Tax Act.

The reporting rules in the Tax Act relating to "specified foreign property" are complex and this summary does not purport to address all circumstances in which reporting may be required by a Resident Holder. Resident Holders should consult their own tax advisors regarding the reporting rules contained in the Tax Act.

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Holders Not Resident in Canada

This portion of the summary is generally applicable to a Holder who, at all relevant times, for purposes of the Tax Act: (i) is not, and is not deemed to be, resident in Canada; and (ii) does not use or hold and is not deemed to use or hold the Offered Shares in connection with carrying on a business in Canada (a “Non-Resident Holder”). Special rules, which are not discussed in this summary, may apply to a Non-Resident Holder that is an insurer that carries on, or is deemed to carry on, an insurance business in Canada and elsewhere or that is an “authorized foreign bank” (as defined in the Tax Act). Such Holders should consult their own tax advisors.

Dividends

Dividends paid or credited on Offered Shares to a Non-Resident Holder will not be subject to Canadian withholding tax or other income tax under the Tax Act.

Disposition of Offered Shares

A Non-Resident Holder will not be subject to tax under the Tax Act in respect of any capital gain realized on a disposition or deemed disposition of an Offered Share, nor will capital losses arising therefrom be recognized under the Tax Act, unless the Offered Share is, or is deemed to be, “taxable Canadian property” of the Non-Resident Holder for the purposes of the Tax Act and the Non-Resident Holder is not entitled to an exemption pursuant to the terms of an applicable tax treaty or convention.

Generally, an Offered Share will not constitute taxable Canadian property of a Non-Resident Holder provided that the Offered Shares are listed on a “designated stock exchange” for the purposes of the Tax Act (which currently includes the TSX) at the time of disposition, unless at any time during the 60 month period immediately preceding the disposition, (i) 25% or more of the issued shares of any class or series of the capital stock of the Corporation were owned by or belonged to one or any combination of (a) the Non-Resident Holder, (b) persons with whom the Non-Resident Holder did not deal at arm’s length (for purposes of the Tax Act), and (c) partnerships in which the Non-Resident Holder or a person described in (b) holds a membership interest directly or indirectly through one or more partnerships; and (ii) at such time, more than 50% of the fair market value of the Offered Shares was derived, directly or indirectly, from any combination of real or immovable property situated in Canada, “Canadian resource property” (as defined in the Tax Act), “timber resource property” (as defined in the Tax Act), or options in respect of, interests in, or for civil law rights in such properties, whether or not such property exists. Notwithstanding the foregoing, an Offered Share may also be deemed to be “taxable Canadian property” in certain other circumstances set out in the Tax Act. Non-Resident Holders should consult their own tax advisors as to whether their Offered Shares constitute “taxable Canadian property” in their own particular circumstances.

In cases where a Non-Resident Holder disposes (or is deemed to have disposed) of an Offered Share that is taxable Canadian property to that Non-Resident Holder and the Non-Resident Holder is not entitled to an exemption under an applicable income tax treaty or convention, the consequences described above under the headings “Holders Resident in Canada - Disposition of Offered Shares” and “Holders Resident in Canada - Capital Gains and Capital Losses” will generally be applicable to such disposition.

Non-Resident Holders whose Offered Shares are taxable Canadian property should consult their own tax advisors.

UNITED KINGDOM TAX CONSIDERATIONS

The following is, as of the date hereof, a summary of certain of the principal United Kingdom tax consequences generally applicable to persons who acquire Offered Shares under the Offering. This summary is applicable only to persons who hold Ordinary Shares as capital assets and who are not resident for UK tax purposes or domiciled in the UK and does not purport to address all United Kingdom tax consequences of acquiring, holding or disposing of Ordinary Shares. This summary is based on an interpretation of current United Kingdom tax law and HM Revenue & Customs (“HMRC”)’s published practice (which may not be binding), each of which is subject to change (or changes in interpretation) possibly with retroactive effect.

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This summary assumes that the Corporation is and has always been a resident solely of the United Kingdom for United Kingdom tax purposes. This summary is of a general nature only. It is not exhaustive of all United Kingdom income tax considerations and is not intended to be and should not be construed to be legal or tax advice to any particular person. Accordingly, prospective investors must consult their own tax advisers with respect to their particular circumstances. Any person who is in any doubt as to their taxation position or who is liable to taxation in the United Kingdom should consult their professional advisers.

United Kingdom Taxation on the Corporation

A company resident in the United Kingdom for tax purposes is liable to UK corporation tax on its world-wide profits regardless of where they arise. Such a company may also be liable to UK tax under the UK's Diverted Profits Tax regime (which can apply, broadly, in cases where arrangements between connected parties lack economic substance, and in cases where a UK permanent establishment has been avoided) and under the UK's Controlled Foreign Companies ("CFC") regime (under which, broadly, a CFC charge may arise where a non-UK resident company is controlled by a UK resident person or persons and certain other conditions are met, such that all or part of the non-UK company's profits are attributed to the UK resident company).

The rate of UK corporation tax for the tax year 2021/22 is 19%. However, this rate is currently due to rise to 25% on 1 April 2023 for profits over £250,000, with companies whose profits are between £50,000 and £250,000 paying tax at the main rate reduced by marginal relief, and companies whose profits are £50,000 or less continuing to pay corporation tax at a rate of 19%.

UK Withholding Tax of Dividends

The Corporation will not be required under UK law to withhold UK tax at source when it pays a dividend to its shareholders in respect of the Ordinary Shares.

Taxation on a Disposal of Ordinary Shares

Shareholders who are not resident in the United Kingdom (and, in the case of an individual shareholder, not temporarily non-resident) (for United Kingdom tax purposes) will not normally be liable to United Kingdom taxation on chargeable gains arising from a disposal of their Ordinary Shares unless the Ordinary Shares are used, held or acquired for the purposes of a trade, profession or vocation carried on in the United Kingdom through a permanent establishment (in the case of a corporate shareholder) or branch or agency (in the case of an individual shareholder).

UK Stamp Duty and Stamp Duty Reserve Tax ("SDRT")

The following comments are intended as a guide to the general United Kingdom stamp duty and SDRT position and (except insofar as expressly referred to below) do not relate to persons such as market makers, brokers, dealers, intermediaries, persons connected with depository receipt arrangements or clearance services or persons who enter into sale and repurchase transactions in respect of the Ordinary Shares, to whom special rules apply. Shareholders should note that certain categories of person are not liable to UK stamp duty or SDRT and others may be liable at a higher rate or may, although not primarily liable for tax, be required to notify and account for UK SDRT under the Stamp Duty Reserve Tax Regulations 1986. There is generally no UK stamp duty or SDRT on the issue of shares by companies incorporated in the UK. Accordingly, no UK stamp duty or SDRT should arise on the issue of Ordinary Shares by the Corporation.

As regards the transfer (as opposed to issue) of Ordinary Shares, it should be noted that there is an exemption from UK stamp duty and SDRT where shares are admitted to trading on a recognised growth market but not listed on any recognised stock exchange. AIM currently qualifies as a recognised growth market, but the Offered Shares are intended to be listed on both AIM and TSX, and TSX is currently a recognised stock exchange. Accordingly, to the extent that the Ordinary Shares are listed on the TSX, they will not benefit from this exemption.

Any conveyance or transfer on sale of Ordinary Shares will generally be subject to UK stamp duty at the rate of 0.5% of the consideration given for the transfer, rounded up to the nearest £5, subject to the availability of certain exemptions and reliefs.

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An unconditional agreement to transfer Ordinary Shares will normally give rise to a charge to UK SDRT at the rate of 0.5% of the amount or value of the consideration payable for the transfer. If an instrument of transfer is executed pursuant to the agreement and duly stamped within six years of the date on which the agreement is made (or, if the agreement is conditional, the date on which the agreement becomes unconditional) any UK SDRT paid is generally repayable, generally with interest, and otherwise the UK SDRT charge is cancelled.

Paperless transfers of Ordinary Shares within the CREST system will generally be liable to UK SDRT, rather than stamp duty, at the rate of 0.5% of the amount or value of the consideration payable. CREST is obliged to collect UK SDRT on relevant transactions settled within the CREST system. Deposits of Ordinary Shares into CREST will not generally be subject to UK SDRT, unless the transfer into CREST is itself for consideration.

Special rules apply where listed securities are transferred between connected companies (or their nominees). Shareholders of Ordinary Shares should consult an appropriate professional adviser if they intend to transfer Ordinary Shares at less than full market value to a company with which they are connected.

The issue of Ordinary Shares into a clearance or depositary service should not give rise to a UK stamp duty charge on general principles. The issue of Ordinary Shares into a clearance or depositary service should not give rise to a UK SDRT charge on the basis that, although such a charge may prima facie arise, HMRC has accepted that where shares in a UK incorporated company are issued to a clearance service or to a depositary receipt issuer anywhere in the world, the imposition of a 1.5% SDRT charge is incompatible with EU law and, as a result, HMRC will not seek to collect such charge. Further, HMRC has stated that the 1.5% charge on issues will remain disapplied under the terms of the European Union (Withdrawal) Act 2018 following the end of the transition period and this will remain the position unless stamp taxes on shares legislation is amended.

Transfers within a clearance system will not normally give rise to a charge to stamp duty or SDRT (assuming that the clearance service in question has not entered into a section 97A Finance Act 1986 election).

Transfers (as opposed to issues) of Ordinary Shares into a clearance service will give rise to a charge to stamp duty or SDRT at 1.5% of (broadly) the amount or value of the consideration given for the transfer, except to the extent that the transfer is an integral part of an issue and raising of share capital, in which case HMRC is understood not to seek to impose the 1.5% charge. (It should be noted that the parameters of a transfer being integral to the raising of capital are imprecisely understood, so that generally any transfer of shares into a clearance service should be approached with caution.)

As a result, any Ordinary Shares which are held outside CDS and then transferred into CDS may give rise to UK stamp duty or SDRT at the 1.5% rate.

AUDITOR, TRANSFER AGENT AND REGISTRAR

BDO LLP is the auditor of the Corporation and has confirmed that it is independent with respect to the Corporation in accordance with the International Ethics Standards Board for Accountants Code of Ethics for Professional accountants.

The principal share registry for the Ordinary Shares is Computershare Investor Services (Ireland) Limited at its principal offices in Dublin, Ireland and the transfer agent and registrar for the Ordinary Shares in Canada is Computershare Investor Services Inc. at its principal offices in Toronto, Ontario.

INTEREST OF EXPERTS

Anthony Finch, Andrew Ross and Simon Walsh are the qualified persons responsible for the technical report titled "Amended NI 43-101 Technical Report – Vermelho Project, Pará State, Brazil" dated October 31, 2019, amended March 31, 2021 with an effective date of October 31, 2019, and Frank Blanchfield, Andrew Ross, Matheus Palmieri, Nicholas Adrian Barcza, David Haughton and Robin Kalanchey are the qualified persons responsible for the technical report titled "Amended NI 43-101 Technical Report Feasibility Study for the Araguaia Nickel Project Federative Republic of Brazil Project Number AU9867" dated November 30, 2018, amended March 31, 2021, with an effective date of November 20, 2018, which have been incorporated by reference into the AIF. Each of the foregoing individuals

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is “independent” as such term is defined in National Instrument 43-101 – Standards of Disclosure for Mineral Projects of the Canadian Securities Administrators.

The aforementioned persons held no securities of the Corporation or of any associate or affiliate of the Corporation at or following the time when they, as applicable: (i) prepared the technical reports above; and/or (ii) reviewed and approved the scientific and technical information set forth in the AIF and, in each case, did not receive any direct or indirect interest in any securities of the Corporation or of any associate or affiliate of the Corporation in connection with the preparation, review, confirmation and/or approval, as applicable, of the foregoing. None of the aforementioned persons, nor any directors, officers or employees of the aforementioned firms, are currently expected to be elected, appointed or employed as a director, officer or employee of the Corporation or of any associate or affiliate of the Corporation.

The scientific and technical information in this Prospectus Supplement, the Presentation, the AIF and the MD&A has been reviewed and approved by David Hall, who is a “Qualified Person” as defined in National Instrument 43-101 – Standards of Disclosure for Mineral Projects of the Canadian Securities Administrators. Mr. Hall is the Chairman of the Corporation and owns 1,039,955 Ordinary Shares and 16,000,000 options to purchase Ordinary Shares.

Certain legal matters in connection with this Offering will be passed upon on behalf of the Corporation by Cassels Brock & Blackwell LLP, and on behalf of the Agents by Bennett Jones LLP. As at the date hereof, the partners and associates of Cassels Brock & Blackwell LLP and the partners and associates of Bennett Jones LLP, each as a group, beneficially own, directly and indirectly, in the aggregate, less than 1% of the outstanding Ordinary Shares.

STATUTORY RIGHTS OF WITHDRAWAL AND RESCISSION

Securities legislation in certain of the provinces and territories of Canada provides purchasers with the right to withdraw from an agreement to purchase securities. This right may be exercised within two business days after receipt or deemed receipt of a prospectus and any amendment. In several of the provinces and territories of Canada, the securities legislation further provides a purchaser with remedies for rescission or, in some jurisdictions, revisions of the price or damages if the prospectus and any amendment contains a misrepresentation or is not delivered to the purchaser, provided that the remedies for rescission, revision of the price or damages are exercised by the purchaser within the time limit prescribed by the securities legislation of the purchaser’s province. The purchaser should refer to any applicable provisions of the securities legislation of the purchaser’s province for the particulars of these rights or consult with a legal adviser.

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C-1

CERTIFICATE OF THE CORPORATION

Dated: November 24, 2021

The short form prospectus, together with the documents incorporated in the prospectus by reference, as supplemented by the foregoing, constitutes full, true and plain disclosure of all material facts relating to the securities offered by the prospectus and this supplement as required by the securities legislation of each of the provinces and territories of Canada, except Québec.

(signed) “Jeremy Martin”
Jeremy Martin
Chief Executive Officer

(signed) “Simon Retter”
Simon Retter
Chief Financial Officer

On behalf of the Board of Directors:

(signed) “David John Hall”
David John Hall
Director

(signed) “William Fisher”
William Fisher
Director

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CERTIFICATE OF THE AGENTS

Dated: November 24, 2021

To the best of our knowledge, information and belief, the short form prospectus, together with the documents incorporated in the prospectus by reference, as supplemented by the foregoing, constitutes full, true and plain disclosure of all material facts relating to the securities offered by the prospectus and this supplement as required by the securities legislation of each of the provinces and territories of Canada, except Québec.

BMO NESBITT BURNS INC.	PARADIGM CAPITAL INC.
(signed) “John Manning”	(signed) “Andrew Partington”
John Manning
Managing Director, Equity Capital Markets	Andrew Partington
Managing Director
CANTOR FITZGERALD CANADA CORPORATION	CORMARK SECURITIES INC.
(signed) “Elan Shevel”	(signed) “Darren Wallace”
Elan Shevel
Chief Compliance Officer	Darren Wallace
Managing Director, Investment Banking

This short form prospectus is referred to as a short form base shelf prospectus and has been filed under legislation in each of the provinces and territories of Canada, other than Quebec, that permits certain information about these securities to be determined after this prospectus has become final and that permits the omission from this prospectus of that information. The legislation requires the delivery to purchasers of a prospectus supplement containing the omitted information within a specified period of time after agreeing to purchase any of these securities, except in cases where an exemption from such delivery requirements is available.

No securities regulatory authority has expressed an opinion about these securities and it is an offence to claim otherwise. This short form base shelf prospectus constitutes a public offering of these securities only in those jurisdictions where they may be lawfully offered for sale and therein only by persons permitted to sell such securities in those jurisdictions. The securities offered hereby have not been and will not be registered under the United States Securities Act of 1933, as amended (the "U.S. Securities Act"), or any applicable state securities laws. Accordingly, the securities offered hereby may not be offered or sold in the United States unless an exemption from such registration is available. This short form prospectus does not constitute an offer to sell or a solicitation of an offer to buy any of the securities offered hereby within the United States. See "Plan of Distribution"

This document contains no offer of transferable securities to the public in the United Kingdom ("U.K.") within the meaning of sections 85(1) and 102B of the Financial Services and Markets Act 2000, as amended, (the "FSMA"), the Companies Act 2006 (as amended) or otherwise. This document is not a prospectus for the purposes of Section 85(1) and 102B of the FSMA. Accordingly, this document has not been examined or approved as a prospectus by the United Kingdom Financial Conduct Authority (the "FCA") under Section 85 or Section 87A of the FSMA or by the London Stock Exchange and has not been drawn up in accordance with the prospectus rules made by the FCA pursuant to section 73A of the FSMA from time to time (the "U.K. Prospectus Rules") or approved by, or filed with, the FCA or any other competent authority nor has it been approved by a person authorized under the FSMA, for the purposes of Section 21 of the FSMA. Prospective investors should read this document in its entirety. An investment in the Corporation includes a significant degree of risk and prospective investors should consider carefully the risk factors set out in this document.

Information has been incorporated by reference in this short form base shelf prospectus from documents filed with securities commissions or similar authorities in Canada. Copies of the documents incorporated herein by reference may be obtained on request without charge from the Corporate Secretary of Horizonte Minerals Plc at Rex House, 4-12 Regent Street, London, SW1Y 4RG, United Kingdom (telephone: 44 (0)203 356 2901) and are also available electronically at www.sedar.com.

SHORT FORM BASE SHELF PROSPECTUS

New Issue

October 29, 2021

HORIZONTE MINERALS PLC

$125,000,000

Ordinary Shares

Warrants

Subscription Receipts

Debt Securities

Units

Horizonte Minerals Plc ("Horizonte" or the "Corporation") may from time to time offer and issue the following securities: (i) Ordinary shares of the Corporation (the "Ordinary Shares"); (ii) warrants exercisable to acquire Ordinary Shares and/or other securities of the Corporation ("Warrants"); (iii) subscription receipts ("Subscription Receipts") exchangeable for Ordinary Shares and/or other securities of the Corporation; (iv) debt securities of the Corporation ("Debt Securities"); and (v) securities comprised of more than one of Ordinary Shares, Warrants, Subscription Receipts and/or Debt Securities together offered as a unit ("Units") or any combination thereof having an offer price of up to $125,000,000 in aggregate (or the equivalent thereof, at the date of issue, in any other currency or currencies, as the case may be) at any time during the 25-month period that this short form base shelf prospectus (including any amendments hereto, the "Prospectus") remains valid. The Ordinary Shares, Warrants, Subscription Receipts, Debt Securities and Units (collectively, the "Securities") offered hereby may be offered

separately or together, in separate series, in amounts, at prices and on terms to be set forth in one or more prospectus supplements (collectively or individually, as the case may be, “Prospectus Supplements”). This Prospectus qualifies the distribution of Securities by the Corporation, as described below. The specific terms of any offering of Securities will be set forth in the applicable Prospectus Supplement and may include, without limitation, where applicable: (i) in the case of Ordinary Shares, the number of Ordinary Shares being offered, the offering price, whether the Ordinary Shares are being offered for cash, and any other terms specific to the Ordinary Shares being offered; (ii) in the case of Warrants, the number of such Warrants offered, the offering price, whether the Warrants are being offered for cash, the terms, conditions and procedures for the exercise of such Warrants into or for Ordinary Share and/or other securities of the Corporation and any other specific terms; (iii) in the case of Subscription Receipts, the number of Subscription Receipts being offered, the offering price, whether the Subscription Receipts are being offered for cash, the terms, conditions and procedures for the exchange of the Subscription Receipts into or for Ordinary Shares and/or other securities of the Corporation and any other terms specific to the Subscription Receipts being offered; and (iv) in the case of Debt Securities, the specific designation, aggregate principal amount, the currency or the currency unit for which the Debt Securities may be purchased, maturity, interest provisions, authorized denominations, offering price, whether the Debt Securities are being offered for cash, the covenants, the events of default, any terms for redemption or retraction, any exchange or conversion rights attached to the Debt Securities, and any other terms specific to the Debt Securities being offered and (v) in the case of Units, the number of Units being offered, the offering price, the terms of the Ordinary Shares, Warrants, Subscription Receipts and/or Debt Securities underlying the Units, and any other specific terms.

All shelf information permitted under applicable securities legislation to be omitted from this Prospectus will be contained in one or more Prospectus Supplements that will be delivered to purchasers together with this Prospectus, unless an exemption from the prospectus delivery requirements has been granted. Each Prospectus Supplement will be incorporated by reference into this Prospectus as of the date of such Prospectus Supplement and only for the purposes of the distribution of the Securities covered by that Prospectus Supplement.

This Prospectus does not qualify for issuance Debt Securities, or Securities convertible or exchangeable into Debt Securities, in respect of which the payment of principal and/or interest may be determined, in whole or in part, by reference to one or more underlying interests including, for example, an equity or debt security, a statistical measure of economic or financial performance including, without limitation, any currency, consumer price or mortgage index, or the price or value of one or more commodities, indices or other items, or any other item or formula, or any combination or basket of the foregoing items. This Prospectus may qualify for issuance Debt Securities, or Securities convertible or exchangeable into Debt Securities in respect of which the payment of principal and/or interest may be determined, in whole or in part, by reference to published rates of a central banking authority or one or more financial institutions, such as a prime rate or bankers’ acceptance rate, or to recognized market benchmark interest rates such as CDOR (the Canadian Dollar Offered Rate) or LIBOR¹ (the London Interbank Offered Rate), and/or convertible into or exchangeable for Ordinary Shares.

The Corporation may sell the Securities to or through underwriters or dealers purchasing as principals and may also sell the Securities to one or more purchasers directly, through applicable statutory exemptions, or through agents designated by the Corporation from time to time. The Prospectus Supplement relating to a particular offering of Securities will identify each underwriter, dealer or agent engaged in connection with the offering and sale of the Securities, as well as the method of distribution and the terms of the offering of such Securities, including the net proceeds to the Corporation and, to the extent applicable, any fees, discounts, concessions or any other compensation payable to underwriters, dealers or agents and any other material terms. See “Plan of Distribution”.

In connection with any offering of the Securities, the underwriters or agents may over-allot or effect transactions that stabilize or maintain the market price of the offered Securities at a level above that which might otherwise prevail on the open market. Such transactions, if commenced, may be interrupted or discontinued at any time. See “Plan of Distribution”.

The outstanding Ordinary Shares of the Corporation are listed and posted for trading on the Toronto Stock Exchange (the “TSX”) and the AIM Market, a market operated by the London Stock Exchange (the "AIM") under the symbol

¹ On July 27, 2017 the U.K. Financial Conduct Authority (“FCA”) announced that after the end of 2021, the FCA would no longer use its power to persuade or compel banks to submit the rate information used to determine LIBOR. Accordingly, the Corporation will monitor new developments in this area and will include in the relevant indenture (or other contract) a fallback mechanism for LIBOR if it ceases to be available, and such mechanism will be disclosed in any Prospectus Supplement filed for the distribution of Debt Securities, including the risks associated thereto.

"HZM". AIM is a market designed primarily for emerging or smaller companies to which a higher investment risk tends to be attached than to larger or more established companies. AIM securities are not admitted to the Official List of the United Kingdom Listing Authority. A prospective investor should be aware of the risks of investing in such companies and should make the decision to invest only after careful consideration and, if appropriate, consultation with an independent financial adviser. The London Stock Exchange has not itself examined or approved the contents of this document. Unless otherwise specified in the applicable Prospectus Supplement, the Warrants, Subscription Receipts, Debt Securities and Units will not be listed on any securities exchange. There is no market through which these Securities may be sold and purchasers may not be able to resell such Securities purchased under this Prospectus. This may affect the pricing of the Securities in the secondary market, the transparency and availability of trading prices, the liquidity of the Securities, and the extent of issuer regulation.

The Corporation is organized under the laws of a foreign jurisdiction, and Jeremy Martin, the Chief Executive Officer and a director of the Corporation, Simon Retter, the Chief Financial Officer of the Corporation, and David Hall, Owen Bavinton and Allan Walker, directors of the Corporation, reside outside of Canada. Although each of the Corporation and the aforementioned individuals have appointed Cassels Brock & Blackwell LLP, 2100 Scotia Plaza, 40 King Street West, Toronto, Ontario M5H 3C2, as agent for service in Canada, purchasers are advised that it may not be possible for investors to enforce judgements obtained in Canada against any person who resides outside of Canada, even if the party has appointed an agent for service of process.

Investing in Securities involves a high degree of risk. A prospective purchaser should therefore review this Prospectus and the documents incorporated by reference in their entirety and carefully consider the risk factors described under "Risk Factors" prior to investing in such Securities.

No underwriter, agent, or dealer has been involved in the preparation of this Prospectus or performed any review of the contents of this Prospectus.

On October 28, 2021 the last trading day prior to the date of this Prospectus, the closing price of the Ordinary Shares on the TSX was $0.145 and on AIM £0.082 respectively. See "Plan of Distribution".

The registered and head office of the Corporation is located at Rex House, 4-12 Regent Street, London, SW1Y 4RG, United Kingdom.

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TABLE OF CONTENTS

ABOUT THIS SHORT FORM BASE SHELF PROSPECTUS ...1
MEANING OF CERTAIN REFERENCES AND CURRENCY PRESENTATION ...1
CAUTION REGARDING FORWARD-LOOKING STATEMENTS ...1
DOCUMENTS INCORPORATED BY REFERENCE ...3
THE CORPORATION ...5
USE OF PROCEEDS ...5
EARNINGS COVERAGE RATIO ...6
CONSOLIDATED CAPITALIZATION ...6
DESCRIPTION OF ORDINARY SHARES ...6
DESCRIPTION OF WARRANTS ...7
DESCRIPTION OF SUBSCRIPTION RECEIPTS ...8
DESCRIPTION OF DEBT SECURITIES ...8
DESCRIPTION OF UNITS ...9
PLAN OF DISTRIBUTION ...9
PRIOR SALES ...10
MARKET FOR SECURITIES ...10
CERTAIN CANADIAN FEDERAL INCOME TAX CONSIDERATIONS ...11
RISK FACTORS ...11
LEGAL MATTERS ...13
AUDITORS, TRANSFER AGENT AND REGISTRAR ...14
INTEREST OF EXPERTS ...14
AGENT FOR SERVICE OF PROCESS ...14
PURCHASERS' STATUTORY RIGHTS AND STATUTORY RIGHTS OF WITHDRAWAL AND RESCISSION ...15
CERTIFICATE OF THE CORPORATION ...1

iv -

ABOUT THIS SHORT FORM BASE SHELF PROSPECTUS

An investor should rely only on the information contained in this Prospectus (including the documents incorporated by reference herein) and is not entitled to rely on parts of the information contained in this Prospectus (including the documents incorporated by reference herein) to the exclusion of others. The Corporation has not authorized anyone to provide investors with additional or different information. The Corporation is not offering to sell the Securities in any jurisdictions where the offer or sale of the Securities is not permitted. The information contained in this Prospectus (including the documents incorporated by reference herein) is accurate only as of the date of this Prospectus (or the date of the document incorporated by reference herein, as applicable), regardless of the time of delivery of this Prospectus or any sale of the Ordinary Shares, Warrants, Subscription Receipts, Debt Securities and/or Units. The Corporation's business, financial condition, results of operations and prospects may have changed since the date of this Prospectus.

MEANING OF CERTAIN REFERENCES AND CURRENCY PRESENTATION

All references to “$”, “C$” or “Canadian dollars” included in this Prospectus (excluding the documents incorporated by reference herein) refer to values denominated in Canadian dollars. All references to “£” or “British pounds” included in this Prospectus (excluding the documents incorporated by reference herein) refer to British pounds values.

The daily average rate of exchange for British pounds expressed in Canadian dollars on October 28, 2021 as reported by the Bank of Canada was £1.00 = $1.7025.

CAUTION REGARDING FORWARD-LOOKING STATEMENTS

Certain statements in this Prospectus and the documents incorporated by reference herein constitute forward-looking information or forward-looking statements (collectively "Forward-looking Statements") within the meaning of applicable securities laws. Forward-Looking Statements generally can be identified by the use of forward-looking terminology such as "plans", "expects" or "does not expect", "is expected", "budget", "scheduled", "estimates", "forecasts", "intends", "anticipates" or "does not anticipate", or "believes", or variations of such words and phrases or statements that certain actions, events or results "may", "could", "would", "might" or "will be taken", "occur" or "be achieved".

Forward-Looking Statements include, but are not limited to, statements concerning the Corporation's objectives, strategies to achieve those objectives, as well as statements with respect to management's beliefs, plans, estimates, and intentions, and similar statements concerning anticipated future events, results, circumstances, performance or expectations that are not historical facts; statements with respect to the use of proceeds the milestones necessary to achieve the Corporation's business objectives and the timing thereof, including adequate project funding for the Araguaia Project, the Corporation's plans with respect to the advancement and development of its Araguaia and Vermelho Projects, budgets, expansion plans including its plan to acquire, explore and develop such other mineral rights and properties as management or the board of directors may from time to time determine have potential; the results of the feasibility and prefeasibility studies for its two main projects, including NAV, IRR, anticipated capital and operating costs, life of mine, projected production and other financial and operational metrics; metal prices; industry outlooks; mineral resource and mineral reserves estimates; expected financial results, taxes, plans and objectives of or involving the Corporation; amounts and use of available funds; anticipated developments in operations in future periods, the adequacy of financial resources and the availability of additional financing as required; the costs and timing of development of the Corporation's business, including the Araguaia Project and the Vermelho Project; the costs, timing and receipt of approvals, consents and permits under applicable legislation, and the ability to satisfy their terms and conditions including under environmental laws and executive compensation approaches and practices.

Although the Forward-Looking Statements contained in this Prospectus and documents incorporated by reference are based upon what management believes and/or its Qualified Persons are reasonable assumptions, there can be no assurance that actual results will be consistent with these Forward-Looking Statements. Forward-Looking Statements are subject to known and unknown risks, uncertainties and other factors that may cause the actual results, level of activity, performance or achievements of the Corporation to be materially different from those expressed or implied by such Forward-Looking Statements, including but not limited to: discretion of the Corporation with respect to the use of proceeds; uncertainties inherent to the results of economic studies, including the feasibility and prefeasibility studies for the Corporation's key projects; exploration and mining risks; competition from competitors

with greater capital; fluctuations in metal prices and costs of supplies; uninsured risks; environmental and other regulatory requirements; exploration, mining and other licences; the Corporation's future payment obligations; potential disputes with respect to the Corporation's title to, and the area of, its mining concessions; the Corporation's dependence on its ability to obtain sufficient financing in the future; the Corporation's dependence on its relationships with third parties; the potential of currency fluctuations and political or economic instability in countries in which the Corporation operates; currency exchange fluctuations; the Corporation's ability to manage its growth effectively; the trading market for the Ordinary Shares; uncertainty with respect to the Corporation's plans to continue to develop its operations and new projects; the Corporation's dependence on key personnel; the legal and regulatory framework within which the Corporation operates; litigation, and those factors discussed in the sections entitled "Risk Factors" in this Prospectus and the risks and uncertainties discussed in the AIF and in the Interim MD&A (as defined herein), which are incorporated by reference herein.

This list is not exhaustive of the factors that may impact the Corporation's Forward-Looking Statements. These and other factors should be considered carefully and readers should not place undue reliance on the Corporation's Forward-Looking Statements. As a result of the foregoing and other factors, no assurance can be given as to any such future results, levels of activity or achievements and neither the Corporation nor any other person assumes responsibility for the accuracy and completeness of these Forward-Looking Statements. The factors underlying current expectations are dynamic and subject to change.

All Forward-Looking Statements in this Prospectus and documents incorporated by reference are qualified by these cautionary statements. Other than specifically required by applicable laws, the Corporation is under no obligation and expressly disclaims any such obligation to update or alter the Forward-Looking Statements whether as a result of new information, future events or otherwise except as may be required by law.

DIFFERENCES IN REPORTING OF MINERAL RESOURCE ESTIMATES

This Prospectus and the documents incorporated by reference have been prepared in accordance with the requirements of Canadian securities laws, which differ from the requirements of United States securities laws. Canadian reporting requirements for disclosure of mineral properties are governed by National Instrument 43-101 – Standards of Disclosure for Mineral Projects (“NI 43-101”). Subject to the SEC Modernization Rules described below, the United States reporting requirements are currently governed by the United States Securities and Exchange Commission (“SEC”) Industry Guide 7 (“SEC Industry Guide 7”) under the U.S. Securities Act. The definitions used in NI 43-101 are incorporated by reference from the Canadian Institute of Mining, Metallurgy and Petroleum (“CIM”) – Definition Standards adopted by CIM Council on May 10, 2014 (the “CIM Definition Standards”). For example, the terms “mineral reserve”, “proven mineral reserve” and “probable mineral reserve” are Canadian mining terms as defined in NI 43-101, and these definitions differ from the definitions in SEC Industry Guide 7. Furthermore, while the terms “mineral resource”, “measured mineral resource”, “indicated mineral resource” and “inferred mineral resource” are defined in NI 43-101, these terms are not defined terms under SEC Industry Guide 7. Under SEC Industry Guide 7 standards, a “final” or “bankable” feasibility study is required to report reserves and the primary environmental analysis or report must be filed with the appropriate governmental authority. Further, under SEC Industry Guide 7, mineralization may not be classified as a “reserve” unless the determination has been made that the mineralization could be economically and legally produced or extracted at the time the reserve determination is made. Any reserves reported by the Corporation in the future and in compliance with NI 43-101 may not qualify as “reserves” under SEC Industry Guide 7. Further, until recently, the SEC has not recognized the reporting of mineral deposits which do not meet the SEC Industry Guide 7 definition of “reserve”.

The SEC adopted amendments to its disclosure rules to modernize the mineral property disclosure requirements for issuers whose securities are registered with the SEC under the Securities Exchange Act of 1934, as amended. These amendments became effective February 25, 2019 (the "SEC Modernization Rules") with compliance required for the first fiscal year beginning on or after January 1, 2021. The SEC Modernization Rules replace the historical disclosure requirements for mining issuers that were included in SEC Industry Guide 7, which will be rescinded from and after the required compliance date of the SEC Modernization Rules. As a result of the adoption of the SEC Modernization Rules, the SEC now recognizes estimates of "measured mineral resources", "indicated mineral resources" and "inferred mineral resources". In addition, the SEC has amended its definitions of "proven mineral reserves" and "probable mineral reserves" to be "substantially similar" to the corresponding CIM Definition Standards, incorporated by reference in NI 43-101.

Readers are cautioned that while the above terms are "substantially similar" to the corresponding CIM Definition Standards, there are differences in the definitions under the SEC Modernization Rules and the CIM Definition Standards. Accordingly, there is no assurance any mineral reserves or mineral resources that the Corporation may

report as “proven mineral reserves”, “probable mineral reserves”, “measured mineral resources”, “indicated mineral resources” and “inferred mineral resources” under NI 43-101 would be the same had the Corporation prepared the reserve or resource estimates under the standards adopted under the SEC Modernization Rules.

Readers are also cautioned that while the SEC will now recognize “measured mineral resources”, “indicated mineral resources” and “inferred mineral resources”, it should not be assumed that any part or all of the mineralization in these categories will ever be converted into a higher category of mineral resources or into mineral reserves. Mineralization described using these terms has a greater amount of uncertainty as to their existence and feasibility than mineralization that has been characterized as reserves. Accordingly, readers are cautioned not to assume that any “measured mineral resources”, “indicated mineral resources” or “inferred mineral resources” that the Corporation reports are or will be economically or legally mineable. Further, “inferred mineral resources” have a greater amount of uncertainty as to their existence and as to whether they can be mined legally or economically. Therefore, readers are also cautioned not to assume that all or any part of the “inferred mineral resources” exist. In accordance with Canadian securities laws, estimates of “inferred mineral resources” cannot form the basis of feasibility or other economic studies, except in limited circumstances where permitted under NI 43-101.

For the above reasons, information contained in this Prospectus and documents incorporated by reference containing descriptions of the Corporation’s mineral deposits may not be comparable to similar information made public by United States companies subject to the reporting and disclosure requirements under the United States federal securities laws and the rules and regulations thereunder.

DOCUMENTS INCORPORATED BY REFERENCE

Information has been incorporated by reference in this short form base shelf prospectus from documents filed with securities commissions or similar authorities in Canada. Copies of the documents incorporated herein by reference may be obtained on request from our corporate secretary at Rex House, 4-12 Regent Street, London, United Kingdom, SW1Y 4RG.

the Corporation's audited consolidated financial statement for the fiscal year ended December 31, 2020 and 2019 together with the notes thereto and the auditor's report thereon (“Annual Financial Statement”);
the Corporation's management's discussion and analysis for the year ended December 31, 2020 (“Annual MD&A”);
the Corporation's unaudited amended condensed consolidated interim financial statements for the six months ended June 30, 2021 (“Interim Financial Statement”);
the Corporation's management's discussion and analysis for the six months ended June 30, 2021 (“Interim MD&A”);
the Corporation's annual information form dated March 31, 2021 for the year ended December 31, 2020 (“AIF”);
the Corporation's management information circular dated April 9, 2021 relating to the annual meeting of shareholders held on May 17, 2021 (“Circular”); and
the Corporation's material change report dated February 23, 2021 pertaining to the private placing of 162,718,353 new Ordinary Shares and bought deal private placement of 88,060,100 special warrants (“Material Change Report”).

All material change reports (excluding confidential material change reports), annual information forms, annual financial statements and the auditors' report thereon and related management's discussion and analysis (“MD&A”), interim financial statements and related MD&A, information circulars, business acquisition reports, any news release issued by the Corporation that specifically states it is to be incorporated by reference in this Prospectus and any other documents as may be required to be incorporated by reference herein under applicable Canadian securities laws which are filed by the Corporation with a securities commission or any similar authority in Canada after the

date of this Prospectus, during the 25-month period this Prospectus remains valid, shall be deemed to be incorporated by reference into this Prospectus.

Upon a new interim financial report and related MD&A of the Corporation being filed with the applicable securities regulatory authorities during the currency of this Prospectus, the previous interim financial report and related MD&A of the Corporation most recently filed shall be deemed no longer to be incorporated by reference into this Prospectus for purposes of future offers and sales of Securities hereunder. Upon new annual financial statements and related MD&A of the Corporation being filed with the applicable securities regulatory authorities during the currency of this Prospectus, the previous annual financial statements and related MD&A and the previous interim financial report and related MD&A of the Corporation most recently filed shall be deemed no longer to be incorporated by reference into this Prospectus for purposes of future offers and sales of Securities hereunder. Upon a new annual information form of the Corporation being filed with the applicable securities regulatory authorities during the currency of this Prospectus, notwithstanding anything herein to the contrary, the following documents shall be deemed no longer to be incorporated by reference into this Prospectus for purposes of future offers and sales of Securities hereunder: (i) the previous annual information form; (ii) material change reports filed by the Corporation prior to the end of the financial year in respect of which the new annual information form is filed; (iii) business acquisition reports filed by the Corporation for acquisitions completed prior to the beginning of the financial year in respect of which the new annual information form is filed; and (iv) any information circular of the Corporation filed prior to the beginning of the Corporation's financial year in respect of which the new annual information form is filed. Upon a new management information circular prepared in connection with an annual general meeting of the Corporation being filed with the applicable securities regulatory authorities during the currency of this Prospectus, the previous management information circular prepared in connection with an annual general meeting of the Corporation shall be deemed no longer to be incorporated by reference into this Prospectus for purposes of future offers and sales of Securities hereunder.

A Prospectus Supplement to this Prospectus containing the specific variable terms in respect of an offering of the Securities will be delivered to purchasers of such Securities together with this Prospectus, unless an exemption from the prospectus delivery requirements has been granted or is otherwise available, and will be deemed to be incorporated by reference into this Prospectus as of the date of such Prospectus Supplement only for the purposes of the offering of the Securities covered by such Prospectus Supplement.

Notwithstanding anything herein to the contrary, any statement contained in this Prospectus or in a document incorporated or deemed to be incorporated by reference herein shall be deemed to be modified or superseded, for purposes of this Prospectus, to the extent that a statement contained herein or in any other subsequently filed document incorporated or deemed to be incorporated by reference herein modifies or supersedes such prior statement. The modifying or superseding statement need not state that it has modified or superseded a prior statement or include any other information set forth in the document that it modifies or supersedes. The making of a modifying or superseding statement shall not be deemed an admission for any purposes that the modified or superseded statement, when made, constituted a misrepresentation, an untrue statement of a material fact or an omission to state a material fact that is required to be stated or that is necessary to make a statement not misleading in light of the circumstances in which it was made. Any statement so modified or superseded shall thereafter neither constitute, nor be deemed to constitute, a part of this Prospectus, except as so modified or superseded.

THE CORPORATION

Horizonte Minerals PLC was formed on January 16, 2006 under the Companies Act 1985 of England and Wales. In March 2006, the Corporation adopted a new set of Articles of Association ("Articles") which, among other things, removed the requirement for a limit on the amount of authorized but unissued share capital. The Corporation amended the Articles to come into line with new legislation relating to electronic communications, the requirement for directors to give reasons for any refusal to register a transfer of shares, and other notice provisions relating to notification by directors of conflict of interests.

The registered and head office of the Corporation is located at Rex House, 4-12 Regent Street, London, SW1Y 4RG, United Kingdom.

The Corporation is a reporting issuer in Ontario and British Columbia. The Ordinary Shares are listed on the TSX and AIM under the symbol "HZM".

Horizonte is a mineral exploration and development Corporation currently focused on the development of its 100% owned Araguaia nickel laterite project ("Araguaia Project") and Vermelho nickel cobalt project ("Vermelho Project"), both located in Brazil.

The Araguaia Project is an advanced nickel project being developed by Horizonte as the next ferronickel operation in Brazil. A feasibility study (the "FS") on the Araguaia Project showing the economics of the project with an initial 28 year mine life was published in the fourth quarter of 2018. The Vermelho Project is a low cost, long life (38 years) nickel sulphate project for which the Corporation released a preliminary feasibility study (the "PFS") in October 2019.

On 30 September 2021, the Company announced that it has received credit approvals from a syndicate of five international financial institutions (the "Senior Lenders") in addition to its previously announced approval by the two export credit agencies (the "ECAs") for a senior secured project finance facility (the "Senior Debt Facility") of up to US$346.2 million to fund the construction and development of its Araguaia Project. The Senior Lenders are BNP Paribas Securities Corp ("BNPP"), ING Capital LLC ("ING"), Natixis, New York Branch ("Natixis"), Société Générale ("SocGen"), and Swedish Export Credit Corporation ("SEK"). The ECAs are EKF, Denmark's Export Credit Agency ("EKF") and Finnvera plc, Finland's Export Credit Agency ("Finnvera"). The Senior Debt Facility will include two tranches: (i) Tranche A of US$146.2 million, to be guaranteed by the ECAs in relation to a number of key equipment and service provider contracts; and (ii) Tranche B of US$200 million. The term of the Senior Debt Facility will be ten and a half years for Tranche A, and eight and a half years for Tranche B. The interest rate of the Senior Debt Facility will be at a rate of LIBOR plus 1.80% for Tranche A, and LIBOR plus 4.25 to 4.75% for Tranche B. Closing of the Senior Debt Facility is subject to customary conditions, including the negotiation and settlement of definitive documentation and the entry into a comprehensive intercreditor agreement, among others.

Further information regarding the Corporation and its business, including without limitation, information with respect to the Araguaia Project, the Vermelho Project, the results of the FS and the results of the PFS, is set out in the AIF and the Interim MD&A which are incorporated herein by reference.

USE OF PROCEEDS

Unless otherwise specified in the applicable Prospectus Supplement, the net proceeds from the sale of securities will be used to advance our business objectives, including the pre-development and development activities of our two main mineral projects, for general corporate purposes and/or working capital requirements and/or potential future acquisitions.

Specific information about the use of net proceeds of any offering of Securities under this Prospectus will be set forth in the applicable Prospectus Supplement. The Corporation may invest funds which it does not immediately use. Such investments may include short-term marketable investment grade securities denominated in Canadian dollars, United States dollars, British pounds or other currencies. The Corporation may, from time to time, issue securities other than pursuant to this Prospectus.

To date, the Corporation has not generated significant revenues from operations. The Corporation had negative cash flow for the fiscal year ended December 31, 2020 and the Corporation may continue to incur negative cash flow in future periods. The Corporation may need to allocate a portion of its existing working capital or a portion of the proceeds of any offering of Securities to fund any such negative cash flow.

The short to medium term objectives of the Corporation are to (i) progress the Araguaia Project through to development by securing project financing; (ii) advance the Vermelho Project towards a feasibility study; and (iii) advance the permitting for the Vermelho Project. The Corporation's cash balance of £22.2 million as at 30 June 2021, enables the Corporation to commence initial plans for construction of the Araguaia Project and provides a strong balance sheet for the next 12 months and thereby ensuring that it enters the next, critical phase of securing project financing for the Araguaia Project from a strong position.

The primary long-term objective of the Corporation is to develop the Araguaia Project. Significant additional financing will be required for the Corporation for the development stage of Araguaia Project, which may include raising capital under this Prospectus. There is no assurance that the Corporation will be able to secure the required project financing and proceed to the development of the project. Mine development and mining operations are subject to significant risks and uncertainties. See "Risk Factors" in this Prospectus and the documents incorporated by reference herein.

The Corporation's actual use of the net proceeds disclosed in any Prospectus Supplement may vary depending on the Corporation's operating and capital needs from time to time. There may be circumstances where, for sound business reasons, a reallocation of funds may be necessary. See "Risk Factors – Use of Proceeds".

EARNINGS COVERAGE RATIO

Earnings coverage ratios will be provided in the applicable Prospectus Supplement relating to the issuance of Debt Securities having a term to maturity in excess of one year, as required by applicable securities laws.

CONSOLIDATED CAPITALIZATION

There have been no material changes in the loan and capital structure of the Corporation since the date of the Interim Financial Statements, which have not been disclosed in this Prospectus or the documents incorporated by reference herein. See "Prior Sales" and "The Corporation".

As of the date of this Prospectus, the Corporation has 1,700,155,740 Ordinary Shares issued and outstanding and 125,350,000 options to acquire Ordinary Shares outstanding.

DESCRIPTION OF ORDINARY SHARES

Each Ordinary Share has one vote attached to it. Ordinary Shares may be transferred as follows: (i) in the case of certificated shares, by instrument, in writing in any usual or common form, or in such other form as the board of directors of the Corporation (the "Board") shall from time to time approve; and (ii) in the case of uncertificated shares, in accordance with and subject to the CREST Regulations and the facilities and requirements of the relevant scheme concerned.

Except as described below, the Ordinary Shares are freely transferable provided that in relation to certificated shares the transfer is in respect of only one class of share and is accompanied by the share certificate and any other evidence of title required by the Board and that the provisions in the Articles relating to the deposit of instruments for transfer have been complied with. The Board may, in its absolute discretion and without giving any reason, refuse to register a transfer of any share: (i) to more than four joint holders; or (ii) where the share is not fully paid up provided that such action does not prevent dealings in the shares from taking place on an open and proper basis; or (iii) on which the Corporation has a lien. In addition, the Board may refuse to register a transfer if a notice has been duly served on any member or other person appearing to be interested in any shares (representing at least 0.25 per cent of the issued shares of the class in question (excluding any shares of that class held as treasury shares) pursuant to section 793 of the Companies Act 2006 of England and Wales (the "2006 Act") and the notice has not been complied with within the period stipulated in the notice.

Shareholders do not have any pre-emption rights in respect of transfers of issued Ordinary Shares

Shareholders have the benefit of statutory pre-emption rights in respect of the issue and allotment of new Ordinary Shares for cash under the 2006 Act. The Corporation may not allot Ordinary Shares or grant rights to subscribe for, or convert any security into, Ordinary Shares for cash without first offering such shares or rights to subscribe to existing shareholders in proportion to their holdings, unless shareholders resolve to disapply those rights. The rights may be disapplied by a special resolution of the Corporation (being a majority of not less than seventy five per cent. of those of the Corporation's shareholders who have voted (in person or by proxy) at a general meeting of the Corporation).

Shareholders have the right to receive dividends to the extent declared by the Corporation.

DESCRIPTION OF WARRANTS

The following sets forth certain general terms and provisions of the Warrants. The Corporation may issue Warrants for the purchase of Ordinary Shares and/or other Securities of the Corporation. Warrants may be issued independently or together with Ordinary Shares, Subscription Receipts, Debt Securities and/or Units offered by any Prospectus Supplement and may be attached to, or separate from, any such offered Securities. Warrants will be issued under one or more warrant agreements entered into between the Corporation and a warrant agent named in the applicable Prospectus Supplement.

Selected provisions of the Warrants and the warrant agreements are summarized below. This summary is not complete. The statements made in this Prospectus relating to any warrant agreement and Warrants to be issued thereunder are summaries of certain anticipated provisions thereof and are subject to, and are qualified in their entirety by reference to, all provisions of the applicable warrant agreement.

Any Prospectus Supplement will contain the terms and other information relating to the Warrants being offered including:

the exercise price of the Warrants;
the designation of the Warrants;
the aggregate number of Warrants offered and the offering price;
the designation, number and terms of the Ordinary Shares and/or other Securities of the Corporation purchasable upon exercise of the Warrants, and procedures that will result in the adjustment of those numbers;
the dates or periods during which the Warrants are exercisable;
the designation and terms of any securities with which the Warrants are issued;
if the Warrants are issued as a unit with another security, the date on and after which the Warrants and the other security will be separately transferable;
the currency or currency unit in which the exercise price is denominated;
any minimum or maximum amount of Warrants that may be exercised at any one time;
whether such Warrants will be listed on any securities exchange;
any terms, procedures and limitations relating to the transferability, exchange or exercise of the Warrants;
any rights, privileges, restrictions and conditions attaching to the Warrants; and
any other specific terms.

Prior to the exercise of their Warrants, holders of Warrants will not have any of the rights of holders of the Securities subject to the Warrants.

DESCRIPTION OF SUBSCRIPTION RECEIPTS

The following sets forth certain general terms and provisions of the Subscription Receipts. The Corporation may issue Subscription Receipts that may be exchanged by the holders thereof for Ordinary Shares and/or other Securities of the Corporation upon the satisfaction of certain conditions. The particular terms and provisions of the Subscription Receipts offered pursuant to this Prospectus will be set forth in the applicable Prospectus Supplement, and the extent to which the general terms described below apply to those Subscription Receipts, will be described in the Prospectus Supplement.

The Corporation may offer Subscription Receipts separately or together with Ordinary Shares, Warrants, Debt Securities and/or Units as the case may be. The Corporation will issue Subscription Receipts under one or more subscription receipt agreements. Under each subscription receipt agreement, a purchaser of Subscription Receipts will have a contractual right of rescission following the issuance of the Ordinary Shares and/or other Securities of the Corporation, as the case may be, to such purchaser, entitling the purchaser to receive the amount paid for the Subscription Receipts upon surrender of the Ordinary Shares and/or other Securities of the Corporation, as the case may be, if this Prospectus, the relevant Prospectus Supplement, and any amendment thereto, contains a misrepresentation, provided such remedy for rescission is exercised within 180 days of the date the Subscription Receipts are issued.

Any Prospectus Supplement will contain the terms and conditions and other information relating to the Subscription Receipts being offered including:

the number of Subscription Receipts;
the price at which the Subscription Receipts will be offered and whether the price is payable in installment;
any conditions to the exchange of Subscription Receipts into Ordinary Shares, and/or other Securities of the Corporation, as the case may be, and the consequences of such conditions not being satisfied;
the procedures for the exchange of the Subscription Receipts into Ordinary Shares and/or other Securities of the Corporation, as the case may be;
the number of Ordinary Shares and/or other Securities of the Corporation, as the case may be, that may be exchanged upon exercise of each Subscription Receipt;
the designation and terms of any other Securities with which the Subscription Receipts will be offered, if any, and the number of Subscription Receipts that will be offered with each Security;
the dates or periods during which the Subscription Receipts may be exchanged into Ordinary Shares and/or other Securities of the Corporation;
whether such Subscription Receipts will be listed on any securities exchange;
any other rights, privileges, restrictions and conditions attaching to the Subscription Receipts; and
any other specific terms.

Prior to the exchange of their Subscription Receipts, holders of Subscription Receipts will not have any of the rights of holders of the securities issuable on the exchange of the Subscription Receipts.

DESCRIPTION OF DEBT SECURITIES

The following sets forth certain general terms and provisions of the Debt Securities. The particular terms and provisions of Debt Securities offered by a Prospectus Supplement, and the extent to which the general terms and provisions described below may apply to such Debt Securities, will be described in such Prospectus Supplement.

The Debt Securities will be issued in series under one or more trust indentures to be entered into between the Corporation and a financial institution to which the Trust and Loan Companies Act (Canada) applies or a financial

institution organized under the laws of any province of Canada and authorized to carry on business as a trustee. Each such trust indenture, as supplemented or amended from time to time, will set out the terms of the applicable series of Debt Securities. The statements in this prospectus relating to any trust indenture and the Debt Securities to be issued under it are summaries of anticipated provisions of an applicable trust indenture and do not purport to be complete and are subject to, and are qualified in their entirety by reference to, all provisions of such trust indenture, as applicable.

Each trust indenture may provide that Debt Securities may be issued thereunder up to the aggregate principal amount which may be authorized from time to time by the Corporation. Any Prospectus Supplement for Debt Securities will contain the terms and other information with respect to the Debt Securities being offered, including (i) the designation, aggregate principal amount and authorized denominations of such Debt Securities, (ii) the currency for which the Debt Securities may be purchased and the currency in which the principal and any interest is payable (in either case, if other than Canadian dollars), (iii) the percentage of the principal amount at which such Debt Securities will be issued, (iv) the date or dates on which such Debt Securities will mature, (v) the rate or rates at which such Debt Securities will bear interest (if any), or the method of determination of such rates (if any), (vi) the dates on which any such interest will be payable and the record dates for such payments, (vii) any redemption term or terms under which such Debt Securities may be defeated, (viii) any exchange or conversion terms, and (ix) any other specific terms.

Each series of Debt Securities may be issued at various times with different maturity dates, may bear interest at different rates and may otherwise vary.

The Debt Securities will be direct obligations of the Corporation. The Debt Securities will be senior or subordinated indebtedness of the Corporation as described in the relevant Prospectus Supplement.

DESCRIPTION OF UNITS

Units are a security comprised of more than one of the other Securities described in this Prospectus offered together as a "Unit". A Unit is typically issued so the holder thereof is also the holder of each Security included in the Unit. Thus, the holder of a Unit will have the rights and obligations of a holder of each Security comprising the Unit. The agreement, if any, under which a Unit is issued may provide that the Securities comprising the Unit may not be held or transferred separately at any time or at any time before a specified date.

The particular terms and provisions of Units offered by any Prospectus Supplement, and the extent to which the general terms and provisions described below may apply to them, will be described in the Prospectus Supplement filed in respect of such Units. This description will include, where applicable: (i) the designation and terms of the Units and of the Securities comprising the Units, including whether and under what circumstances those Securities may be held or transferred separately; (ii) any provisions for the issuance, payment, settlement, transfer or exchange of the Units or of the Securities comprising the Units; (iii) whether the Units will be issued in registered or global form; and (iv) any other material terms and conditions of the Units.

PLAN OF DISTRIBUTION

The Corporation may sell the Securities, separately or together: (a) to one or more underwriters or dealers; (b) through one or more agents; or (c) directly to one or more purchasers through applicable statutory exemptions. The Prospectus Supplement relating to a particular offering of Securities will identify each underwriter, dealer or agent engaged in connection with the offering and sale of the Securities, as well as the method of distribution and the terms of the offering of such Securities, including the net proceeds to the Corporation and, to the extent applicable, any fees, discounts, concessions or any other compensation payable to underwriters, dealers or agents and any other material terms. Only underwriters so named in the Prospectus Supplement are deemed to be underwriters in connection with the Securities offered thereby.

The Securities may be sold, from time to time in one or more transactions at a fixed price or prices which may be changed or at market prices prevailing at the time of sale, at prices related to such prevailing market prices or at negotiated prices, including sales made directly on the TSX. The prices at which the Securities may be offered may vary as between purchasers and during the period of distribution. If, in connection with the offering of Securities at a fixed price or prices, the underwriters have made a bona fide effort to sell all of the Securities at the initial offering price fixed in the applicable Prospectus Supplement, the public offering price may be decreased and thereafter further changed, from time to time, to an amount not greater than the initial public offering price fixed in such Prospectus Supplement, in which case the compensation realized by the underwriters will be decreased by the

amount that the aggregate price paid by purchasers for the Securities is less than the gross proceeds paid by the underwriters to the Corporation.

Underwriters, dealers and agents who participate in the distribution of the Securities may be entitled under agreements to be entered into with the Corporation to indemnification by the Corporation against certain liabilities, including liabilities under securities legislation, or to contribution with respect to payments which such underwriters, dealers or agents may be required to make in respect thereof. Such underwriters, dealers and agents may be customers of, engage in transactions with, or perform services for, the Corporation in the ordinary course of business.

Any offering of Warrants, Subscription Receipts, Debt Securities or Units will be a new issue of securities with no established trading market. Unless otherwise specified in the applicable Prospectus Supplement, the Warrants, Subscription Receipts, Debt Securities or Units will not be listed on any securities exchange. Certain dealers may make a market in these Securities but will not be obligated to do so and may discontinue any market making at any time without notice. No assurance can be given that any dealer will make a market in these Securities or as to the liquidity of the trading market, if any, for these Securities.

In connection with any offering of the Securities, the underwriters or agents may over-allot or effect transactions which stabilize or maintain the market price of the Securities offered at a higher level than that which might exist in the open market. Such transactions, if commenced, may be interrupted or discontinued at any time.

The Securities have not been, and will not be, registered under the 1933 Act or the securities laws of any states in the United States and, subject to certain exceptions, may not be offered or sold or otherwise transferred or disposed of in the United States absent registration or pursuant to an applicable exemption from the 1933 Act and applicable state securities laws. In addition, until 40 days after closing of an offering of Securities, an offer or sale of the Securities within the United States by any dealer (whether or not participating in such offering) may violate the registration requirement of the 1933 Act if such offer or sale is made other than in accordance with an exemption under the 1933 Act.

PRIOR SALES

During the 12-month period before the date of this Prospectus, the Corporation has issued the following Ordinary Shares and securities convertible into Ordinary Shares:

Date of Issuance	Number of Securities Issued	Type of Security	Exercise Price/ Price Per Security
February 19, 2021	162,718,353	Ordinary Shares	$0.133
March 9, 2021	88,060,100	Special Warrant	$0.133
April 14, 2021	88,060,100	Ordinary Shares (1)	$0.133

Notes:
(1) On April 14, 2021, 88,060,100 Special Warrants were converted into 88,060,100 Ordinary Shares.

MARKET FOR SECURITIES

Date	High ($)	Low ($)	Volume
October 2020	0.135	0.095	1,782,246
November 2020	0.125	0.095	714,323

December 2020	0.135	0.110	1,417,233
January 2021	0.175	0.130	2,207,150
February 2021	0.170	0.135	4,052,336
March 2021	0.140	0.100	2,807,345
April 2021	0.155	0.125	5,663,828
May 2021	0.150	0.110	1,809,871
June 2021	0.125	0.100	2,788,429
July 2021	0.120	0.100	13,754,506
August 2021	0.140	0.105	7,329,415
September 2021	0.165	0.120	4,274,353
October 1- October 28, 2021	0.155	0.130	1,494,620

CERTAIN CANADIAN FEDERAL INCOME TAX CONSIDERATIONS

The applicable Prospectus Supplement may describe certain Canadian federal income tax considerations generally applicable to investors described therein of purchasing, holding and disposing of applicable Securities, including, in the case of an investor who is not a resident of Canada, Canadian non-resident withholding tax consideration.

RISK FACTORS

Prospective investors in a particular offering of the Securities should carefully consider, in addition to information contained in the Prospectus Supplement relating to that offering and the information incorporated by reference herein for the purposes of that offering, the risk factors listed below and risks described in the Corporation's then-current AIF, as well as the Corporation's then-current interim MD&A to the extent incorporated by reference herein for the purposes of that particular offering of Securities.

Risks Related to the Securities

Use of Proceeds

The Corporation intends to allocate the net proceeds it will receive from any offering as described under "Use of Proceeds" in this Prospectus and the applicable Prospectus Supplement, however, the Corporation will have discretion in the actual application of the net proceeds. The Corporation may elect to allocate the net proceeds differently from that described in "Use of Proceeds" in this Prospectus and the applicable Prospectus Supplement if the Corporation believes it would be in the Corporation's best interests to do so. The Corporation's investors may not agree with the manner in which the Corporation chooses to allocate and spend the net proceeds from an offering. The failure by the Corporation to apply these funds effectively could have a material adverse effect on the business of the Corporation.

No Market for the Securities

There is currently no trading market for any Warrants, Subscription Receipts, Debt Securities or Units that may be offered. No assurance can be given that an active or liquid trading market for these securities will develop or be sustained. If an active or liquid market for these securities fails to develop or be sustained, the prices at which these securities trade may be adversely affected. Whether or not these securities will trade at lower prices depends on many factors, including liquidity of these securities, prevailing interest rates and the markets for similar securities,

the market price of the Corporation, general economic conditions and the Corporation's financial condition, historic financial performance and future prospects.

Potential Volatility of Share Price

The market price for Ordinary Shares may be volatile and subject to wide fluctuations in response to numerous factors, many of which are beyond the Corporation's control, including the following: (i) actual or anticipated fluctuations in the Corporation's quarterly results of operations; (ii) recommendations by securities research analysts; (iii) changes in the economic performance or market valuations of other issuers that investors deem comparable to the Corporation; (iv) addition or departure of the Corporation's executive officers and other key personnel; (v) release or expiration of lock-up or other transfer restrictions on outstanding Ordinary Shares; (vi) sales or perceived sales of additional Ordinary Shares; (vii) significant acquisitions or business combinations, strategic partnerships, joint ventures or capital commitments by or involving the Corporation or its competitors; and (viii) news reports relating to trends, concerns, technological or competitive developments, regulatory changes and other related issues in the Corporation's industry or target markets.

Financial markets have recently experienced significant price and volume fluctuations that have particularly affected the market prices of equity securities of public entities and that have, in many cases, been unrelated to the operating performance, underlying asset values or prospects of such entities. Accordingly, the market price of the Ordinary Shares may decline even if the Corporation's operating results, underlying asset values or prospects have not changed. Additionally, these factors, as well as other related factors, may cause decreases in asset values that are deemed to be other than temporary, which may result in impairment losses. As well, certain institutional investors may base their investment decisions on consideration of the Corporation's environmental, governance and social practices and performance against such institutions' respective investment guidelines and criteria, and failure to satisfy such criteria may result in limited or no investment in the Ordinary Shares by those institutions, which could materially adversely affect the trading price of the Ordinary Shares. There can be no assurance that continuing fluctuations in price and volume will not occur. If such increased levels of volatility and market turmoil continue for a protracted period of time, the Corporation's operations and the trading price of the Ordinary Shares may be materially adversely affected.

Risks Related to the Corporation

COVID-19 Outbreak

The current and ongoing global uncertainty with respect to the spread of COVID-19, the rapidly evolving nature of the pandemic, including the emergence of new variants of the virus, in Brazil and elsewhere, and local and international developments related thereto and its effect on the broader global economy and capital markets may have a negative effect on the Corporation and the advancement of the Vermelho Project and Araguaia Project. While the precise impact of the continued COVID-19 outbreak on the Corporation remains unknown, rapid spread of COVID-19 and declaration of the outbreak as a global pandemic has resulted in travel advisories and restrictions, certain restrictions on business operations, social distancing precautions and restrictions on group gatherings which are having direct impacts on businesses around the world and could result in travel bans, closure of assay labs, work delays, difficulties for contractors and employees getting to site, and diversion of management attention all of which in turn could have a negative impact on the advancement of the Vermelho Project and Araguaia Project and the Corporation generally. The continued spread of COVID-19 may also have a further material adverse effects on global economic activity and could result in additional volatility and disruptions to global supply chains and the financial and capital markets, which could negatively affect the business, financial condition, results of operations, prospects and other factors relevant to the Corporation. There can be no assurance that COVID-19 or any other public health crises will not have a material adverse effect on the Corporation and its business and operations.

Development of the Corporation's Mineral Projects will be Subject to all the Risks Associated with Establishing New Mining Operations

Development of the Corporation's Araguaia Project and Vermelho Project will require the construction and operation of mines, processing plants and related infrastructure. As a result, the Corporation is and will continue to be subject to all of the risks associated with establishing new mining operations, including:

the timing and cost, which can be significant, of the construction of mining and processing facilities;
the availability and cost of skilled labour, mining equipment and principal supplies needed for operations;
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the availability and cost of appropriate smelting and refining arrangements;
the need to obtain and maintain necessary environmental and other governmental permits and authorizations and the timing of the receipt of those permits and authorizations;
the availability of funds to finance construction and development activities;
potential opposition from non-governmental organizations, indigenous organizations, environmental groups, local groups or other stakeholders which may delay or prevent development activities; and
potential increases in construction and operating costs due to changes in the cost of labour, fuel, power, materials and supplies.

The costs, timing and complexities of developing the Corporation’s mineral projects may be greater than anticipated. Cost estimates may increase as more detailed engineering work is completed on the projects. It is common in new mining operations to experience unexpected costs, problems and delays during construction, development and mine start-up. Accordingly, the Corporation cannot provide assurance that its activities will result in profitable mining operations at its mineral properties.

Feasibility and Pre-Feasibility Studies may not be realized.

Although the feasibility studies and pre-feasibility studies for the Corporation's main project are comprehensive third-party expert studies in respect of the development of its deposits, there can be no assurance that the projects can or will be developed in accordance with the specifications set out in the studies. Feasibility and other mining studies are inherently based on estimates and cannot provide certainty with respect to the development of and production from a mine given the uncertainties associated with Mineral Reserve and Mineral Resource estimates and associated with construction and development of a project. Construction costs and timelines can be impacted by a wide variety of factors, many of which are beyond the control the Corporation, including the COVID-19 pandemic, weather conditions, ground conditions, availability of appropriate rock and other material required for construction, availability and performance of contractors and suppliers, delivery and installation of equipment, design changes, accuracy of estimates and availability of accommodations for the workforce. A delay in startup of commercial production would increase capital costs and delay generating revenues. Given the inherent risks and uncertainties associated with construction, there can be no assurance that the development will occur in accordance with the project's study and current expectations (or at all), that construction costs will be consistent with the budget, that production will be achieved on schedule, or that the mine will operate as planned.

Negative Operating Cash Flow and Additional Funding

The Corporation has no history of revenue from its operating activities. For the fiscal year ended December 31, 2020 the Corporation had negative cash flow from operating activities. The Corporation anticipates it will continue to have negative cash flow from operating activities and net losses in future periods unless and until commercial sales are achieved for the Corporation’s products. A portion of the proceeds from the Offering will be used to fund negative cash flow from operating activities in future periods. Furthermore, significant additional financing, whether through the issuance of additional securities and/or debt, will be required to continue the development of its key mineral projects. There can be no assurance that the Corporation will be able to obtain adequate additional financing in the future or that the terms of such financing will be favourable. Failure to obtain such additional financing could result in delay or indefinite postponement of further development of the Corporation’s key projects.

Effecting service of process

The Corporation and certain of the Corporation’s directors and officers reside outside of Canada. Substantially all of the assets of these persons are located outside of Canada. It may also not be possible to enforce against the Corporation, certain of its directors and officers, and certain experts named in this Prospectus or documents incorporated by reference herein, judgments obtained in Canadian courts predicated upon the civil liability provisions of applicable securities laws in Canada.

LEGAL MATTERS

Unless otherwise specified in the Prospectus Supplement relating to an offering of Securities, certain legal matters relating to the offering of Securities will be passed upon on behalf of the Corporation by Cassels Brock & Blackwell

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LLP with respect to matters of Canadian law. In addition, certain legal matters in connection with any offering of Securities will be passed upon for any underwriters, dealers or agents by counsel to be designated at the time of the offering by such underwriters, dealers or agents with respect to matters of Canadian and, if applicable, United Kingdom or other foreign law.

AUDITORS, TRANSFER AGENT AND REGISTRAR

BDO LLP is the auditor of the Corporation and has confirmed that it is independent with respect to the Corporation within the meaning of the relevant rules and related interpretations prescribed by the relevant professional bodies in Canada and any applicable legislation or regulation.

The transfer agent and registrar for the Ordinary Shares is Computershare Investor Services (Ireland) Limited at its principal offices in Dublin, Ireland.

INTEREST OF EXPERTS

Anthony Finch, Andrew Ross and Simon Walsh are the qualified persons responsible for the technical report titled "Amended NI 43-101 Technical Report – Vermelho Project, Pará State, Brazil October 31, 2019" and Frank Blanchfield, Andrew Ross, Matheus Palmieri, Nicholas Adrian Barcza, David Haughton, and Robin Kalanchey are the qualified persons responsible for the technical report titled "Amended 43-101 Technical Report Feasibility Study for the Araguaia Nickel Project Federative Republic of Brazil Project Number AU9867 November 2018" which have been incorporated by reference into the AIF. Each of the forgoing individuals is "independent" as such term is defined in National Instrument 43-101 – Standards of Disclosure for Mineral Projects of the Canadian Securities Administrators.

The aforementioned persons held no securities of the Corporation or of any associate or affiliate of the Corporation at or following the time when they, as applicable: (i) prepared the technical reports above; and/or (ii) reviewed and approved the scientific and technical information set forth in the AIF and, in each case, did not receive any direct or indirect interest in any securities of the Corporation or of any associate or affiliate of the Corporation in connection with the preparation, review, confirmation and/or approval, as applicable, of the foregoing. None of the aforementioned persons, nor any directors, officers, or employees of the aforementioned firms, are currently expected to be elected, appointed or employed as a director, officer or employee of the Corporation or of any associate or affiliate of the Corporation.

The scientific and technical information in this Prospectus, the AIF and the MD&A has been reviewed and approved by David Hall, who is a "Qualified Person" as defined in National Instrument 43-101 – Standards of Disclosure for Mineral Projects of the Canadian Securities Administrators. Mr. Hall is the Chairman of the Corporation and owns 1,039,955 Ordinary Shares and 16,000,000 options to purchase Ordinary Shares.

AGENT FOR SERVICE OF PROCESS

The Corporation is organized under the laws of a foreign jurisdiction, and Jeremy Martin, the Chief Executive Officer and a director of the Corporation, Simon Retter, the Chief Financial Officer of the Corporation, and David Hall, Owen Bavinton and Allan Walker, directors of the Corporation reside outside of Canada. Although each of the Corporation and the aforementioned individuals have appointed Cassels Brock & Blackwell LLP, 2100 Scotia Plaza, 40 King Street West, Toronto, Ontario M5H 3C2, as agent for service in Canada, purchasers are advised that it may not be possible for investors to enforce judgements obtained in Canada against any person who resides outside of Canada, even if the party has appointed an agent for service of process.

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PURCHASERS' STATUTORY RIGHTS AND CONTRACTUAL RIGHTS OF WITHDRAWAL AND RESCISSION

Unless provided otherwise in a Prospectus Supplement, the following is a description of a purchaser's statutory rights. Securities legislation in certain of the provinces and territories of Canada provides purchasers with the right to withdraw from an agreement to purchase securities. This right may be exercised within two business days after receipt or deemed receipt of a prospectus and any amendment. In several of the provinces and territories, the securities legislation further provides a purchaser with remedies for rescission or, in some jurisdictions, revisions of the price or damages if the prospectus and any amendment contains a misrepresentation or is not delivered to the purchaser, provided that the remedies for rescission, revision of the price or damages are exercised by the purchaser within the time limit prescribed by the securities legislation of the purchaser's province or territory. The purchaser should refer to any applicable provisions of the securities legislation of the purchaser's province or territory for the particulars of these rights or consult with a legal advisor.

Original purchasers of Securities which are convertible, exchangeable or exercisable for other securities of the Corporation will have a contractual right of rescission against the Corporation in respect of the conversion, exchange or exercise of such Securities. The contractual right of rescission will entitle such original purchasers to receive, upon surrender of the underlying securities, the amount paid for the applicable convertible, exchangeable or exercisable Securities in the event that this Prospectus, the relevant Prospectus Supplement or an amendment thereto contains a misrepresentation, provided that: (i) the conversion, exchange or exercise takes place within 180 days of the date of the purchase of such Securities under this Prospectus and the applicable Prospectus Supplement; and (ii) the right of rescission is exercised within 180 days of the date of the purchase of such Securities under this Prospectus and the applicable Prospectus Supplement. This contractual right of rescission will be consistent with the statutory right of rescission described under Section 130 of the Securities Act (Ontario), and is in addition to any other right or remedy available to original purchasers under Section 130 of the Securities Act (Ontario) or otherwise at law.

Original purchasers are further advised that in certain provinces and territories the statutory right of action for damages in connection with a prospectus misrepresentation is limited to the amount paid for the convertible, exchangeable or exercisable securities that were purchased under a prospectus and, therefore, a further payment at the time of conversion, exchange or exercise may not be recoverable in a statutory action for damages. The purchaser should refer to any applicable provisions of the securities legislation of the province or territory in which the purchaser resides for the particulars of these rights, or consult with a legal adviser.

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CERTIFICATE OF THE CORPORATION

Dated: October 29, 2021

This short form prospectus, together with the documents incorporated in this prospectus by reference, will, as of the date of the last supplement to this prospectus relating to the securities offered by this prospectus and the supplement(s), constitute full, true and plain disclosure of all material facts relating to the securities offered by this prospectus and the supplement(s) as required by the securities legislation of each of the provinces and territories of Canada, except Québec.

HORIZONTE MINERALS PLC

(signed) "Jeremy Martin"
By: Jeremy Martin
Chief Executive Officer

(signed) "Simon Retter"
By: Simon Retter
Chief Financial Officer

On behalf of the Board of Directors

(signed) "David John Hall"
By: David John Hall
Director

(signed) "William Fisher"
By: William Fisher
Director

C-1 -

AI assistant

Horizonte Minerals PLC — Capital/Financing Update 2021

46840_rns_2021-11-24_4f2bfc72-f2bc-400f-9a44-0282969b9f2c.pdf

PROSPECTUS SUPPLEMENT

Horizonte Minerals Plc

ACCOMPANYING PROSPECTUS

TABLE OF CONTENTS

ABOUT THIS PROSPECTUS

MEANING OF CERTAIN REFERENCES AND CURRENCY PRESENTATION

CAUTION REGARDING FORWARD-LOOKING STATEMENTS

DOCUMENTS INCORPORATED BY REFERENCE

NON-IFRS MEASURES

MARKETING MATERIALS

ELIGIBILITY FOR INVESTMENT

THE CORPORATION

Recent Developments

Details of the Proposed Senior Debt Facility

Details of the Proposed Cost Overrun Facility

Vermelho Royalty

Offtake

Conditionality and Completion

CONSOLIDATED CAPITALIZATION

USE OF PROCEEDS

PLAN OF DISTRIBUTION

DESCRIPTION OF SECURITIES BEING DISTRIBUTED

PRIOR SALES

TRADING PRICE AND VOLUME

RISK FACTORS

Risks Related to the Securities

Use of Proceeds

Risks Related to the Proposed Funding Package

Potential Volatility of Share Price

Risks Related to the Corporation

COVID-19 Outbreak

Development of the Corporation’s Mineral Projects will be Subject to all the Risks Associated with Establishing New Mining Operations

Currency Conversion

Holders Resident in Canada

Dividends

Disposition of Offered Shares

Capital Gains and Capital Losses

Offshore Investment Fund Property Rules

Additional Refundable Tax

Foreign Property Information Reporting

United Kingdom Taxation on the Corporation

UK Withholding Tax of Dividends

Taxation on a Disposal of Ordinary Shares

UK Stamp Duty and Stamp Duty Reserve Tax ("SDRT")

AUDITOR, TRANSFER AGENT AND REGISTRAR

INTEREST OF EXPERTS

STATUTORY RIGHTS OF WITHDRAWAL AND RESCISSION

CERTIFICATE OF THE CORPORATION

CERTIFICATE OF THE AGENTS

HORIZONTE MINERALS PLC

ABOUT THIS SHORT FORM BASE SHELF PROSPECTUS

MEANING OF CERTAIN REFERENCES AND CURRENCY PRESENTATION

CAUTION REGARDING FORWARD-LOOKING STATEMENTS

DIFFERENCES IN REPORTING OF MINERAL RESOURCE ESTIMATES

DOCUMENTS INCORPORATED BY REFERENCE

THE CORPORATION

USE OF PROCEEDS

EARNINGS COVERAGE RATIO

CONSOLIDATED CAPITALIZATION

DESCRIPTION OF ORDINARY SHARES

DESCRIPTION OF WARRANTS

DESCRIPTION OF SUBSCRIPTION RECEIPTS

DESCRIPTION OF DEBT SECURITIES

DESCRIPTION OF UNITS

PLAN OF DISTRIBUTION

PRIOR SALES

MARKET FOR SECURITIES

Potential Volatility of Share Price

Risks Related to the Corporation

COVID-19 Outbreak

Development of the Corporation's Mineral Projects will be Subject to all the Risks Associated with Establishing New Mining Operations

Feasibility and Pre-Feasibility Studies may not be realized.

Negative Operating Cash Flow and Additional Funding

Effecting service of process

LEGAL MATTERS

AUDITORS, TRANSFER AGENT AND REGISTRAR

INTEREST OF EXPERTS

Horizonte Minerals PLC Capital/Financing Update 2021