HORIZONTE
MINERALS PLC

NOT FOR DISTRIBUTION IN THE UNITED STATES OF AMERICA

THIS DOCUMENT AND THE ENCLOSED FORM OF PROXY ARE IMPORTANT AND REQUIRE YOUR IMMEDIATE ATTENTION. If you are in any doubt about the contents of this document or as to the action you should take, you are recommended to seek your own personal financial advice from your stockbroker, bank manager, solicitor, accountant or other independent financial adviser duly authorised under the Financial Services and Markets Act 2000 (as amended) if you are resident in the United Kingdom or, if not, from another appropriately authorised independent financial adviser.

If you are not a shareholder in Canada and you have sold or transferred all of your Ordinary Shares in the Company, please send this document and the accompanying Form of Proxy to the purchaser or transferee or to the stockbroker, bank or other agent through whom the sale or transfer was effected for onward transmission to the purchaser or transferee. Such documents should not, however, be forwarded or transmitted in or into any jurisdiction in which such act would constitute a violation of the relevant laws in such jurisdiction. If you have sold or transferred only part of your holding of Ordinary Shares, you should retain these documents and contact your stockbroker, bank or other agent through whom the sale or transfer was effected immediately.

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 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. Neither the London Stock Exchange nor the Financial Conduct Authority has examined or approved the contents of this document.

The Existing Ordinary Shares are admitted to trading on AIM. Application will be made to the London Stock Exchange for the Fundraising Shares to be admitted to trading on AIM. It is expected that admission of the Fundraising Shares to trading on AIM will become effective and that dealings will commence upon completion of the transactions as outlined herein following approval of the Resolutions at the General Meeting. The Fundraising Shares will, on AIM Admission, rank pari passu in all respects with, and will rank in full for all dividends and other distributions declared, made or paid in respect of, the Existing Ordinary Shares after the date of AIM Admission.

HORIZONTE MINERALS PLC

(Incorporated and registered in England and Wales under the Companies Act 2006 with company number 05676866)

Notice of General Meeting and Management Information Circular with respect to the General Meeting of Shareholders to be held on 4 November 2022

Dated 7 October 2022

in connection with the following matters

Placing and Subscription of 77,945,627 new Ordinary Shares at 90.5 pence per share to raise approximately US $80 million (gross)

Nominated Adviser and Joint Bookrunner
Peel Hunt LLP

Joint Bookrunner
BMO Capital Markets Limited

You are recommended to read the whole of this document but your attention is drawn, in particular, to the letter from the Chairman of the Company explaining the background to, and reasons for, the Fundraising which is set out in Part I of this document and which recommends that you vote in favour of the Resolutions to be proposed at the General Meeting.

Notice of a General Meeting of the Company to be held at the offices of Horizonte Minerals Plc, Rex House, 4-12 Regent Street, London SW1Y 4RG, United Kingdom at 11.30 a.m. on 4 November 2022, is set out in Part II of this document. Shareholders will find enclosed with this document a Form of Proxy for use in relation to the General Meeting. To be valid, Forms of Proxy should be completed, signed and returned to the Company's Registrars:

(i) Computershare Investor Services (Ireland) Limited, (for registered shareholders outside of Canada) in accordance with the instructions printed on it as soon as possible, but in any event so as to be received not later than 48 hours (excluding non-working days) before the time of the General Meeting, being 11.30 a.m. on 2 November 2022 (or, in the case of an adjournment of the General Meeting, not later than 48 hours (excluding non-working days) before the time fixed for the holding of the adjourned meeting); and
(ii) Computershare Investor Services Inc. (for registered shareholders in Canada) in accordance with the instructions printed on it as soon as possible, but in any event so as to be received not later than 8.00 a.m. (Toronto time) on 1 November 2022, or no later than 72 hours (excluding Saturdays, Sundays and statutory holidays in the City of Toronto, Ontario) prior to the time set for any adjourned or postponed Meeting.

If you hold your Ordinary Shares in uncertificated form (i.e. in CREST) you may appoint a proxy by completing and transmitting a CREST Proxy Instruction in accordance with the procedures set out in the CREST Manual so that it is received by the Registrars (under CREST Participation ID 3RA50) by no later than 11.30 a.m on 2 November 2022. The time of receipt will be taken to be the time from which the Registrar is able to retrieve the message by enquiry to CREST in the manner prescribed by CREST.

IMPORTANT INFORMATION

The distribution of this document and/or the accompanying Form of Proxy in jurisdictions other than the UK may be restricted by law and therefore persons into whose possession this document comes should inform themselves about and observe any of those restrictions. Any failure to comply with any of those restrictions may constitute a violation of the securities laws of any such jurisdiction.

The Company and the Directors accept responsibility for the information contained in this document. To the best of the knowledge and belief of the Company and the Directors (who have taken all reasonable care to ensure that such is the case), the information contained in this document is in accordance with the facts and makes no omission likely to affect the import of such information.

The Placing Shares and Subscription Shares are only available to qualified investors for the purposes of the Prospectus Regulation Rules or otherwise in circumstances not resulting in an offer of transferable securities to the public under section 102B of FSMA. Therefore, neither the Placing nor the Subscription constitute an offer to the public requiring an approved prospectus under section 85 of FSMA and accordingly this document does not constitute a prospectus for the purposes of the Prospectus Regulation Rules and has not been pre-approved by the FCA pursuant to sections 85 and 87 of FSMA, the London Stock Exchange, any securities commission or any other authority or regulatory body and has not been approved for the purposes of section 21 of FSMA. In addition, this document does not constitute an admission document drawn up in accordance with the AIM Rules. It is emphasised that no application is being made for the admission of the Existing Ordinary Shares or the Fundraising Shares to the Official List of the United Kingdom Listing Authority.

This document should be read in its entirety and, in particular, your attention is drawn to the letter from the Chairman.

This document does not constitute or form part of any offer or invitation to buy, subscribe for, or sell Ordinary Shares in Canada or any other jurisdiction in which such offer or solicitation is unlawful. In particular, the Fundraising Shares have not been, and will not be, registered under the US Securities Act of 1933, as amended, (the "Securities Act") or qualified by prospectus or the equivalent for sale under the laws of any state of the United States of America or under the applicable laws of any of Canada, Australia, the Republic of South Africa or Japan and, subject to certain exceptions, may not be offered or sold in the United States of America or to any national, resident or citizen of Canada, Australia, the Republic of South Africa or Japan.

No person has been authorised to give any information or to make any representation about the Company and about the matters the subject of this document other than those contained in this document. If any such information or representation is given or made then it must not be relied upon as having been so authorised. The delivery of this document shall not

HORIZONTE MINERALS NOTICE OF MEETING

imply that no change has occurred in the Company's affairs since the date of issue of this document or that the information in this document is correct as at any time after the date of this document, save as shall be required to be updated by law or regulation.

Peel Hunt LLP ("Peel Hunt"), which is authorised and regulated in the United Kingdom by the FCA and is a member of the London Stock Exchange, is the Company's nominated adviser for the purposes of the AIM Rules. Peel Hunt is acting exclusively for the Company and will not regard any other person (whether or not a recipient of this document) as a client and will not be responsible to anyone other than the Company for providing the protections afforded to its clients nor for providing advice in relation to the contents of this document or any other matter referred to herein. Peel Hunt's responsibilities as the Company's nominated adviser under the AIM Rules for Nominated Advisers are owed to the London Stock Exchange and not to any other person in respect of their decision to acquire Fundraising Shares in reliance on any part of this document. Peel Hunt has not authorised the contents of this document for any purpose and no liability whatsoever is accepted by Peel Hunt nor does it make any representation or warranty, express or implied, as to the accuracy of any information or opinion contained in this document or for the omission of any information. Peel Hunt expressly disclaims all and any responsibility or liability whether arising in tort, contract or otherwise which it might otherwise have in respect of this document.

BMO Capital Markets Limited ("BMO CML"), which is authorised and regulated in the United Kingdom by the FCA and is a member of the London Stock Exchange, is the Company's joint broker for the purposes of the AIM Rules. BMO CML is acting exclusively for the Company in connection with the Placing only and will not regard any other person (whether or not a recipient of this document) as a client and will not be responsible to anyone other than the Company for providing the protections afforded to its clients nor for providing advice in relation to the contents of this document or any other matter referred to herein. BMO CML has not authorised the contents of this document for any purpose and no liability whatsoever is accepted by BMO CML nor does it make any representation or warranty, express or implied, as to the accuracy of any information or opinion contained in this document or for the omission of any information. BMO CML expressly disclaims all and any responsibility or liability whether arising in tort, contract or otherwise which it might otherwise have in respect of this document.

The release, publication or distribution of this document and the accompanying Form of Proxy in or into, jurisdictions other than the United Kingdom may be restricted by law and therefore persons into whose possession this document comes who are not resident in the United Kingdom should inform themselves about, and observe, any applicable restrictions. Shareholders who are in any doubt regarding such matters should consult an appropriate independent adviser in the relevant jurisdiction without delay. Any failure to comply with such restrictions may constitute a violation of the securities laws of any such jurisdiction. In particular, this document may not be distributed, directly or indirectly, in or into the United States of America, the Republic of South Africa, Australia or Japan. Overseas Shareholders and any person (including, without limitation, nominees and trustees), who have a contractual or other legal obligation to forward this document to a jurisdiction outside the UK should seek appropriate advice before taking any action.

This document has been prepared for the purposes of complying with the AIM Rules and the information disclosed may not be the same as that which would have been disclosed if this document had been prepared in accordance with the laws or regulatory requirements of jurisdictions outside the United Kingdom. The statements contained in this document are not to be construed as legal, business, financial or tax advice.

Certain statements in this document are forward-looking statements with respect to the Company's expectations, intentions and projections regarding its future performance, strategic initiatives, anticipated events or trends and other matters that are not historical facts and which are, by their nature, inherently predictive, speculative and involve risks and uncertainty because they relate to events and depend on circumstances that may or may not occur in the future. All statements that address expectations or projections about the future, including statements about expected growth in nickel global demand, production potential, the results of the feasibility and pre-feasibility studies, including, without limitation, expected NPV, IRR, construction period, pay back period, mine life, expected costs, cash generation and operating performance and other metrics, the Company's expectations with respect to its funding package (including without limitation, ability to draw down under such funding package) and the timing of commencement of construction for the Araguaia Project, the intended use of proceeds from the Fundraising, the intended reliance on the exemption set forth in Section 602.1 of the TSX Listing Rules, strategic initiatives, objectives, market position, industry trends, general economic conditions, expected expenditures, expected cost savings and financial results, are forward - looking statements. Any statements contained in this document that are not statements of historical fact are, or may be deemed to be, forward - looking statements. These forward-looking statements, which may use words such as "aim", "anticipate", "believe", "could", "intend", "estimate", "expect", "may", "plan", "project" or words or terms of similar meaning or the negative thereof, are not guarantees of future performance and are subject to known and unknown risks and uncertainties. There are a number of factors including, but not limited to, commercial, operational, economic and financial factors, that could cause actual results, financial condition, performance or achievements to differ materially from those expressed or implied by these forward looking statements. Many of these risks and uncertainties relate to factors that are beyond the Company's ability to control or estimate precisely, such as changes in taxation or fiscal policy, approval from senior lenders to draw down under existing debt facilities, future market conditions, currency fluctuations, the behaviour of other market participants, the actions of governments or governmental regulators, or other risk factors, such as changes in the political,

HORIZONTE MINERALS

NOTICE OF MEETING

social and regulatory framework in which the Company operates or in economic or technological trends or conditions, including inflation, recession and consumer confidence, on a global, regional or national basis. Given those risks and uncertainties, readers are cautioned not to place undue reliance on forward-looking statements. Forward-looking statements speak only as of the date of this document. Each of the Company, Peel Hunt and/or BMO expressly disclaims any obligation or undertaking to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise unless required to do so by applicable law or regulation. The information in this document is subject to change. The Company expressly disclaims any obligation or undertaking to disseminate any updates or revisions to any forward-looking statements contained herein to reflect any change in the Company's expectations with regard thereto or any change in events, conditions or circumstances on which any such statements are based unless required to do so by applicable law or the AIM Rules.

In accordance with the AIM Rules, this document will be available on the Company's website (www.horizonteminerals.com) from the date of this document, free of charge, subject to certain restrictions relating to persons in any jurisdiction where release, publication or distribution of this document would constitute a violation of the securities law of such jurisdiction. Neither the content of the Company's website nor any website accessible by hyperlinks to or on the Company's website is incorporated in, or forms part of, this document.

The technical and scientific information contained in this document has been reviewed and approved by David Hall, B.A.Hons (Geology) M.Sc. Fellow S.E.G. EurGeol, a consultant to the Company, who is a "Qualified Person" under National Instrument 43-101 – Standards of Disclosure for Mineral Projects of the Canadian Securities Administrators.

For additional information with respect to technical and scientific information discussed herein, including, without limitation with respect to the economic parameters underlying the economic analysis presented in the Feasibility Study and the Preliminary Feasibility Study for the Araguaia and Vermelho projects, respectively, and the key assumptions and risks associated thereto, refer to the Company's amended technical report entitled "Amended NI 43-101 Technical Report – Vermelho Project, Pará State, Brazil" dated October 31, 2019 and the amended 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 2018 and which are available as filed on March 31, 2021 under the Company's profile at www.sedar.com.

HORIZONTE MINERALS NOTICE OF MEETING

HORIZONTE MINERALS
NOTICE OF MEETING

Clause	Heading	Page
FUNDRAISING STATISTICS		6
EXPECTED TIMETABLE OF PRINCIPAL EVENTS		7
DIRECTORS, COMPANY SECRETARY AND ADVISERS		8
DEFINITIONS		9
PART I	LETTER FROM THE CHAIRMAN	14
PART II	NOTICE OF GENERAL MEETING	22
PART III	GENERAL INFORMATION RESPECTING THE MEETING	24

HORIZONTE MINERALS
NOTICE OF MEETING

FUNDRAISING STATISTICS

Issue Price 90.5 pence

Number of Existing Ordinary Shares in issue as at the date of this document 190,468,279

Number of Placing Shares 48,681,487

Number of Subscription Shares 29,264,140

Number of Fundraising Shares (Placing Shares + Subscription Shares) 77,945,627

Enlarged Share Capital immediately following completion of the Fundraising¹ 268,413,906

Market capitalisation at the Issue Price¹ £242,914,585

Fundraising Shares as a percentage of the Existing Ordinary Shares 41 per cent.

Fundraising Shares as a percentage of the Enlarged Share Capital¹ 29 per cent.

Approximated gross proceeds of the Fundraising US$80m

ISIN of the Existing Ordinary Shares GB00BMXLQJ47

Note:
1 Assuming all the Fundraising Shares are issued and that (save for the Fundraising Shares) no other Ordinary Shares are issued following the date of this document (in particular pursuant to any conversion of the Convertible Loan Notes).

EXPECTED TIMETABLE OF PRINCIPAL EVENTS

Each of the times and dates in the below is indicative only and may be subject to change by the Company, in which event details of the new times and dates will be notified to shareholders by announcement through a Regulatory Information Service.

	2022
Record date for attendance and voting at the General Meeting for non-Canadian shareholders	6.00 p.m. on 2 November 2022
Canadian Record Date for attendance and voting at the General Meeting for Canadian shareholders	5 October
Announcement of the Fundraising	4 October
Publication of this Circular and the accompanying Form of Proxy	7 October
Latest time and date for receipt of completed Forms of Proxy and receipt of electronic proxy appointments via the CREST system	11.30 a.m on 2 November
Latest time and date for receipt of completed Forms of Proxy from Canadian shareholders and shareholders whose shares are held beneficially through the Canadian Depositary for Securities (CDS) for the General Meeting	8.00 a.m. (Toronto time) on 1 November
General Meeting	11.30 a.m on 4 November
Announcement of result of General Meeting	4 November
Subject to satisfying applicable listing conditions, AIM Admission and commencement of dealings in the Fundraising Shares on AIM	8.00 a.m. on 8 November
CREST accounts expected to be credited for the Fundraising Shares	from 8.00 a.m. on 8 November
Latest date for posting of share certificates for the Fundraising Shares in certificated form (if applicable)	by 22 November

The Company has applied to list the Fundraising Shares on the TSX. Listing will be subject to approval by the TSX and the Company fulfilling all of the requirements of the TSX. Subject to the foregoing, it is expected that TSX Admission will become effective on or about 8 November 2022.

Certain of the events in the above timetable are conditional upon, inter alia, the approval of the Resolutions to be proposed at the General Meeting.

All references to time and dates in this document are to time and dates in London unless otherwise specified.

HORIZONTE MINERALS
NOTICE OF MEETING

DIRECTORS, COMPANY SECRETARY AND ADVISERS

Directors
William Fisher (Non-Executive Chairman)
Jeremy Martin (Chief Executive Officer)
Owen Bavinton (Non-Executive Director)
Gillian Davidson (Non-Executive Director)
Vincent Benoit (Non-Executive Director)

Company Secretary
Simon Retter

Registered Office
Horizonte Minerals Plc
Rex House, 4-12 Regent Street
London SW1Y 4RG
United Kingdom

Nominated Adviser and Joint Bookrunner
Peel Hunt LLP
100 Liverpool Street,
London EC2M 2AT
United Kingdom

Joint Bookrunner
BMO Capital Markets Limited
100 Liverpool Street,
London EC2M 2AT
United Kingdom

Legal Advisers to the Company as to English Law
Gowling WLG (UK) LLP
4 More London Riverside
London SE1 2AU
United Kingdom

Legal Advisers to the Company as to United States Law
Proskauer Rose (UK) LLP
110 Bishopsgate
London EC2N 4AY
United Kingdom

Legal Advisers to the Company as to Canadian Law
Cassels Brock & Blackwell LLP
2100 Scotia Plaza
40 King Street West
Toronto, Ontario M5H 3C2
Canada

Legal Advisers to the Joint Bookrunners
Bryan Cave Leighton Paisner LLP
Governor's House
5 Laurence Pountney Hill
London EC4R 0BR
United Kingdom

Registrars and Receiving Agent
Computershare Investor Services (Ireland) Limited
3100 Lake Drive
Citywest Business Campus
Dublin 24
D24 AK82
Ireland

HORIZONTE MINERALS

NOTICE OF MEETING

DEFINITIONS

The following definitions apply throughout this document, unless the context otherwise requires:

2021 Circular	the Notice of General Meeting and Management Information Circular published by the Company on 29 November 2021
Act	the Companies Act 2006, as amended
AIM Admission	admission to trading on AIM of the Fundraising Shares becoming effective in accordance with the AIM Rules
AIM	the market of that name operated by the London Stock Exchange
AIM Rules	the AIM Rules for Companies governing the admission to and operation of AIM published by the London Stock Exchange as amended from time to time
Announcement	the announcement published by the Company on 4 October 2022 in connection with the Fundraising
Announcement Date	4 October 2022
Araguaia Project	the Araguaia ferronickel project, located south of the Carajás Mining District in the Pará State, north Brazil
Araguaia Technical Report	the amended 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 2018 and available as filed on March 31, 2021 under the Company’s profile at www.sedar.com
Articles	the articles of association of the Company in force at the date of this document
BMO CML	BMO Capital Markets Limited a Joint Bookrunner for the purposes of the Placing
Board or the Directors	the directors of the Company, as at the date of this document, whose names are set out in Part I of this document
certificated or in certificated form	an Ordinary Share recorded on the Company’s share register as being held in certificated form (namely, not in CREST)
Circular or this document	this circular, dated 7 October 2022
Company or Horizonte	Horizonte Minerals Plc, a company incorporated in England and Wales with company number 05676866 whose registered office is at Rex House, 4-12 Regent St, London, SW1Y 4RG, United Kingdom
Convertible Loan Note Instruments	the La Mancha Convertible Loan Note Instrument and the Orion Convertible Loan Note Instrument

HORIZONTE MINERALS
NOTICE OF MEETING

Convertible Loan Notes
the convertible loan notes issued and granted pursuant to the respective Convertible Loan Note Instruments

Cost Overrun Facility Agreement
the cost overrun facility agreement between the Company and Orion dated 15 March 2022

CREST
the relevant system (as defined in the CREST Regulations) for the paperless settlement of trades and the holding of uncertificated securities, operated by Euroclear, in accordance with the same regulations

CREST Manual
the rules governing the operation of CREST, as published by Euroclear

CREST Regulations
the Uncertificated Securities Regulations 2001 (SI 2001 No. 3875), as amended

Enlarged Share Capital
the issued Ordinary Share capital of the Company immediately following the issue of the Fundraising Shares

Euroclear
Euroclear UK & International Limited, the operator of CREST

Existing Ordinary Shares
the 190,468,279 Ordinary Shares being the entire issued share capital of the Company as at the date of this document

FCA
the Financial Conduct Authority of the UK

Financial Promotion Order
the Financial Services and Markets Act 2000 (Financial Promotion) Order 2005 (as amended)

Form of Proxy
the form of proxy enclosed with this document for use in relation to the General Meeting

FSMA
the Financial Services and Markets Act 2000 (as amended)

Fundraising
together, the Placing and the Subscription

Fundraising Shares
the Placing Shares and the Subscription Shares

General Meeting
the general meeting of the Company, convened for 11.30 a.m. on 4 November 2022 or any adjournment thereof

Glencore
Glencore International AG

Group
together the Company and its subsidiary undertakings

ISIN
International Securities Identification Number

Issue Price
in respect of the Placing and the Subscription 90.5 pence per Placing Share or Subscription Share (as the case may be)

Joint Bookrunners
each of BMO CML and Peel Hunt

HORIZONTE MINERALS
NOTICE OF MEETING

La Mancha
La Mancha Investments S.à r.l, a private limited liability company (société responsabilité limitée) incorporated under the laws of Luxembourg, registered with the Luxembourg Trade and Companies Register (Registre de Commerce et des Sociétés) under registration number B253567 whose registered office is at 31-33, Avenue Pasteur, L-2311 Luxembourg, Grand-Duchy of Luxembourg

La Mancha Convertible Loan Note Instrument
the convertible loan note instrument between the Company and La Mancha originally dated 23 November 2021, as novated to La Mancha Treasury Limited by way of a deed of assignment and novation between the Company, La Mancha and La Mancha Treasury Limited and as further amended and restated by an amendment and restatement agreement between the Company and La Mancha Treasury Limited dated 15 March 2022

London Stock Exchange
London Stock Exchange plc

Money Laundering Regulations
the money laundering and terrorist financing provisions of the Criminal Justice Act 1993, the Terrorism Act 2000, the Proceeds of Crime Act 2002, the Terrorism Act 2006 and the Money Laundering Regulations 2007, the Money Laundering, Terrorist Financing and Transfer of Funds (Information on the Payer) Regulations 2017

Notice of General Meeting
the notice convening the General Meeting, as set out in Part II of this document

Official List
the Official List of the FCA

Ordinary Shares
ordinary shares of £0.20 each in the capital of the Company having the rights and being subject to the restrictions contained in the Articles

Orion
Orion Mine Finance Fund III LP

Orion Convertible Loan Note Instrument
the convertible loan note instrument between the Company and Orion dated 23 November 2021, as amended

Peel Hunt
Peel Hunt LLP, the Company's nominated adviser and a Joint Bookrunner for the purposes of the Placing

Placees
persons who have agreed to subscribe for Placing Shares under the Placing

Placing
the conditional placing by the Joint Bookrunners, each as agent of and on behalf of the Company, of the Placing Shares at the Issue Price on the terms and subject to the conditions of the Placing Agreement

Placing Agreement
the conditional agreement dated 4 October 2022 between the Company and the Joint Bookrunners, relating to the Placing, a summary of which is set out

HORIZONTE MINERALS
NOTICE OF MEETING

in the letter from the Chairman of the Company set out in this document

Placing Shares
the 48,681,487 new Ordinary Shares which are to be issued under the Placing

Prospectus Rules
the prospectus rules published by the FCA pursuant to section 73A of FSMA (as amended from time to time)

Prospectus Regulation
EU Regulation 2017/1129 (which forms part of UK domestic law pursuant to the European Union (Withdrawal) Act 2018) on the requirements for a prospectus to be published when securities are offered to the public or admitted to trading

Prospectus Regulation Rules
the Prospectus Regulation Rules made in accordance with the Prospectus Regulation Rules Instrument 2019 (FCA: 2019/80)

Receiving Agents or Registrars
Computershare Investor Services (Ireland) Limited of 3100 Lake Drive, Citywest Business Campus, Dublin 24, D24 AK82, Ireland

Regulatory Information Service
a service approved by the London Stock Exchange for the distribution to the public of regulatory announcements and included within the list on the website of the London Stock Exchange

Resolutions
the resolutions to be proposed at the General Meeting, as set out in the Notice of General Meeting

Securities Act
the US Securities Act of 1933, as amended

Senior Debt Facility
the US$346.2 million of syndicated senior debt secured by the Company pursuant to agreements and loan documentation dated 15 March 2022 executed between Araguaia Níquel Metais Ltda. and the Senior Lenders, and two export credit agencies (being EKF, Denmark's Export Credit Agency and Finnvera plc, Finland's Export Credit Agency), details of which were announced by the Company on 16 March 2022

Senior Lenders
BNP Paribas, BNP Paribas Fortis, ING Capital LLC, ING Bank N.V., Natixis, New York Branch, Société Générale and SEK, Swedish Export Credit Corporation

Shareholders
registered holders of Ordinary Shares

Subscribers
together Glencore, Jeremy Martin and Simon Retter

Subscription
the subscription by the Subscribers for the Subscription Shares at the Issue Price

Subscription Agreements
Each of the subscription agreements entered into between the Company and respectively each of the Subscribers

HORIZONTE MINERALS
NOTICE OF MEETING

Subscription Shares
the 29,264,140 new Ordinary Shares to be issued pursuant to the Subscription

TSX
the Toronto Stock Exchange operated by TMX Group Limited

TSX Admission
admission to trading on TSX of the Fundraising Shares becoming effective in accordance with the TSX Listing Rules

TSX Listing Rules
the rules and regulations of the TSX as set out in the TSX Company Manual as amended from time to time

UK
the United Kingdom of Great Britain and Northern Ireland

uncertificated or in uncertificated form
a share or other security recorded on the relevant register of the share or security concerned as being held in uncertificated form in CREST and title to which, by virtue of the CREST Regulations, may be transferred by means of CREST

Vermelho Project
the Vermelho Nickel-Cobalt project located in the Carajás Mining District in the Pará State, north east Brazil

Vermelho Technical Report
amended technical report entitled “Amended NI 43-101 Technical Report – Vermelho Project, Pará State, Brazil” dated October 31, 2019, and available as filed on March 31, 2021 under the Company’s profile on SEDAR at www.sedar.com

VIF
Voting Instruction Form

A reference to £ is to pounds sterling, being the lawful currency of the UK.

A reference to € is to Euros, being the lawful currency of the single European currency.

A reference to US$ is to US dollars, being the lawful currency of the United States of America.

A reference to CAN$ is to Canadian dollars, being the lawful currency of Canada.

All Canadian dollar equivalents are calculated using the daily average rate of exchange for GBP:CAD published by the Bank of Canada on 4 October 2022, being GBP1.00=CAD1.5504.

PART I

LETTER FROM THE CHAIRMAN

HORIZONTE MINERALS PLC

(Incorporated and registered in England and Wales with company number 05676866)

Directors:
William James Fisher (Non-Executive Chairman)
Jeremy John Martin (Chief Executive Officer)
Owen Alexander Bavinton (Non-Executive Director)
Vincent Marie Michel Benoit (Non-Executive Director)
Gillian Davidson (Non-Executive Director)

Registered office:
Horizonte Minerals Plc
Rex House
4-12 Regent Street
London SW1Y 4RG
United Kingdom
7 October 2022

To: Holders of Ordinary Shares and, for information only, to holders of options over Ordinary Shares and persons with information rights

Dear Shareholder,

Notice of General Meeting and Management Information Circular with respect to the General Meeting of Shareholders to be held on 4 November 2022

Dated 7 October 2022

in connection with the following matters

Placing and Subscription of 77,945,627 new Ordinary Shares at 90.5 pence per share to raise approximately US $80 million (gross)

1 Introduction

On 5 October 2022 the Company announced that it had conditionally raised approximately US$80 million (before expenses) through:

(a) a conditional placing of 48,681,487 Placing Shares at the Issue Price to certain existing and new institutional investors and others (the "Placing") to raise, in aggregate, approximately US$50 million (before expenses); and
(b) a conditional subscription for, in aggregate, 29,264,140 Subscription Shares at the Issue Price to the Subscribers (the "Subscription") to raise approximately US$30 million (before expenses); and

(the Subscription and the Placing, together, the "Fundraising").

The Issue Price of 90.5 pence per new Ordinary Share represents a discount of approximately 9 per cent. to the closing mid-market price of 99.5 pence per share on 4 October 2022, being the latest practicable date prior to the date of the Fundraising Announcement made on 4 October 2022.

HORIZONTE MINERALS

NOTICE OF MEETING

Each element of the Fundraising is conditional, inter alia, upon Shareholders approving the Resolutions at the General Meeting, which has been convened for 11.30 a.m. on 4 November 2022 that will grant to the Directors the authority to allot the Fundraising Shares for cash on a non-pre-emptive basis.

The Resolutions are contained in the Notice of General Meeting set out in Part II of this document.

Application will be made to the London Stock Exchange for the Fundraising Shares to be admitted to trading on AIM. Assuming the Resolutions are passed, admission of the Fundraising Shares for trading on AIM is expected to occur no later than 8.00 a.m. on 8 November 2022 or such later time and/or date as the Company may agree with the Joint Bookrunners. See also paragraph 11 of this letter (TSX Admission).

In the event that the Resolutions are not passed the Fundraising will not proceed.

The purpose of this document is to provide you with details of and the background to and reasons for the Fundraising and to explain why the Directors believe that they are in the best interests of the Company and its Shareholders as a whole.

The action that you should take to vote on the Resolutions, and the recommendation of the Board, are set out in paragraphs 9 (Action to be Taken) and 13 (Recommendation), respectively, of this letter.

2 Background to and reasons for the Fundraising

The Company has made good progress with the development of the Araguaia Project following the closing of the US$633 million funding package in 2021. The Company broke ground in May 2022 and has secured a number of key construction contracts including all major and long-lead time process equipment, EPCM, earthworks, civil works, water dam and the 230kV power line, a significant de-risking event for the Project. In addition, the Company has also appointed two industry leaders to the board.

The Company wholly owns both the advanced Araguaia nickel project and the Vermelho nickel-cobalt project, located in the south of the Carajás mineral district in northern Brazil. A feasibility study for Araguaia was published in November 2018. The study demonstrated the robust economics of Araguaia.

One will be sourced from eight open pits, with a targeted 0.9mt per annum of ore to a central processing and smelting facility. A 30+-year production schedule is envisaged with approximately 16 months of construction remaining before the initial ramp up to full scale commercial production is expected to commence. Key economic highlights of the Project from the Araguaia Technical Report and based on a nickel price of US$23,000/t are as follows:

Highly cash generative: approximately US$4.8 billion net cash flow
Post-tax NPV(8%) of US$1.5 billion
Post-tax IRR of 43.0%
Payback of approx. 2.0 years
Lowest quartile cash cost (years 1-10) of US$6,794 /t Ni

in each case based upon the same assumptions as those underlying the economic analysis presented in the feasibility study outlined in the Araguaia Technical Report, which remains current and does not include the forecast increase in the capital expenditure amount to US$537 million.

Vermelho was acquired from Vale SA and is a nickel cobalt project, located approximately 85 kilometres north west of the Company's Araguaia North nickel project. A pre-feasibility study representing the economics of developing Vermelho was released in October 2019. These two projects, which are located within close proximity of each other, create a large, high-grade flexible resource base with the combined potential to produce in excess of 60,000 tonnes of nickel per year.

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The proceeds of the Fundraising will, in addition to increasing the Company's current cash balance, enable the Company to continue construction of the Araguaia project, including covering the increased capital costs that have resulted from the current inflationary environment and escalating interest rate costs, and creates the opportunity to broaden the Company's shareholder base through the introduction of new investors. The Fundraising is anticipated to allow the Company to draw down on its senior debt facility in Q4 2022 (subject to conditions and covenants to be satisfied at each draw down customary for a financing of this nature) and complete the construction of Araguaia, which remains on schedule for first production in Q1 2024.

Senior Debt Facility

On 15 March 2022, the Company's wholly owned subsidiary, Araguaia Níquel Metais Ltda., signed binding loan documentation, including a comprehensive intercreditor agreement and loan agreements in relation to its senior secured project finance debt facility of US$346.2 million, guaranteed by the Company (the "Senior Debt Facility"). The Senior Debt Facility was entered into with a syndicate of international financial institutions (being BNP Paribas, BNP Paribas Fortis, ING Capital LLC, ING Bank N.V., Natixis, New York Branch, Société Générale and SEK, Swedish Export Credit Corporation) (together the "Senior Lenders") and two export credit agencies (being EKF, Denmark's Export Credit Agency and Finnvera plc, Finland's Export Credit Agency) ("ECA").

The Senior Debt Facility includes the following:

Commercial facility of US$200,000,000 provided by the Senior Lenders;
ECA facility of US$74,562,000 guaranteed by EKF;
ECA facility of US$71,638,000 guaranteed by Finnvera;

The Fundraising is anticipated to allow the Company to draw down on the Senior Debt Facility (subject to conditions and covenants to be satisfied at each draw down customary for a financing of this nature) and the first drawdown under the Senior Debt Facility is expected to occur in the fourth quarter of 2022.

3 Use of proceeds

The net proceeds of the Fundraising will, among other uses, be used to meet the increased capital requirements for the construction of Araguaia. The table below summarises the use of proceeds from the Fundraising:

Proposed uses for Fundraising	US$M
Capex (1)	$43.0
Additional working capital and other (2)	$19.0
Araguaia line 2	$3.0
Corporate	$5.0
Contingencies and general working capital purposes	$10.0
Total uses of funds	$80.0

Note 1: Key drivers include equipment supply, electromechanical erection and electrical materials, construction support and concrete supply, owners costs and EPCM, state and municipal road upgrades
Note 2: Includes increases to pre-production operating costs and working capital, advisor/legal costs and interest costs during construction

HORIZONTE MINERALS

NOTICE OF MEETING

HORIZONTE MINERALS
NOTICE OF MEETING

4 Details of the Placing

The Placing is conditional, amongst other things, on the following:

(a) the passing of the Resolutions at the General Meeting;

(b) the Placing Shares and the Subscription Shares having been allotted, conditional only on AIM Admission;

(c) the Placing Agreement not being terminated prior to AIM Admission and otherwise becoming unconditional in all respects (save for AIM Admission);

(d) the TSX conditionally approving the listing of all the Fundraising Shares subject to the Company fulfilling the requirements of the TSX, to be set forth in the letter from the TSX conditionally approving the listing of such new Ordinary Shares, on or before the dates stipulated in such letter;

(e) Convertible Loan Note Instruments remaining in full force and effect and the proposed terms of such instruments not having been varied or amended (other than by way of the adjustment referred to in paragraph 6 of this Part I) and no event of default occurring under the relevant Convertible Loan Note Instrument (or either of them);

(f) the Senior Debt Facility remaining in full force and effect and the terms of such agreement not having been terminated, varied or amended nor has any event of default occurred under such agreement;

(g) the Cost Overrun Facility Agreement remaining in full force and effect and the terms of such agreement not having been terminated, varied or amended nor has any event of default occurred under such agreement

(h) the Subscription Agreements having been entered into and remaining in full force and effect and having become unconditional in all respects in each case other than for AIM Admission and completion of the Placing Agreement; and

(i) AIM Admission becoming effective on or before 8.00 a.m. on 8 November 2022 (or such later date and/or time as the Company and the Joint Bookrunners may agree, being no later than 8.00 a.m. on 18 November 2022).

The Placing Agreement contains certain customary warranties and indemnities from the Company in favour of each of the Joint Bookrunners. The Joint Bookrunners are entitled, in certain limited circumstances, to terminate the Placing Agreement prior to AIM Admission and will also be entitled to the payment of outstanding expenses on such termination.

Under the Placing Agreement, the Company has agreed to pay the Joint Bookrunners a commission based on the value of the Placing Shares placed under the Placing Agreement and the costs and expenses of the Placing together with any applicable VAT.

5 Details of the Subscription

Pursuant to the Subscription Agreements the Subscribers have conditionally agreed to subscribe for the Subscription Shares at the Issue Price. Each of the Subscription Agreements is conditional on Admission of the Subscription Shares and the Placing Agreement becoming unconditional in all respects, other than the conditions relating to the completion of the relevant Subscription Agreement.

Convertible Loan Notes

On Admission of the Fundraising Shares an adjustment under the terms of the Convertible Loan Notes to Orion and La Mancha will be triggered, to ensure that following the Fundraising the percentage of new Ordinary Shares in the Company's share capital to be issued on conversion will remain the same as if the Fundraising had not taken place. Pursuant to the terms of the Convertible Loan Instruments, in the event of an Adjustment Event (as defined therein) taking place, the price at which the Convertible Loan Notes may be converted ("Conversion Price") and/or the number of Ordinary Shares into which the Convertible Loan Notes may convert ("Conversion Shares") must be adjusted such that after the adjustment the total number of Conversion Shares carries (as nearly as possible) the same entitlement to participate in the profits and assets of the Company (including on liquidation) and the same proportion of the voting rights attached to all the issued and outstanding Ordinary Shares (on a fully diluted basis) as if there had been no such Adjustment Event. The Fundraising is an Adjustment Event and will result in the Conversion Price being decreased and the number of Conversion Shares being increased. The adjustments to the Conversion Price are dependent on, amongst other things, the amount of accrued interest under the Convertible Loan Notes at the time of the relevant Adjustment Event and as such it is not possible to confirm what the adjustments will be following completion of the Fundraising at this time.

7 Related Parties

La Mancha holds shares representing approximately 19.9% of the Existing Share Capital as at the date hereof, is a related party of the Company and will be participating in the Placing by subscribing pursuant thereto for 24,340,744 Placing Shares at the Issue Price, which will represent, together with its holding of Existing Ordinary Shares, 23.21% of the Enlarged Share Capital. This constitutes a related party transaction under Rule 13 of the AIM Rules for Companies.

Jeremy Martin as a director and Chief Executive Officer of the Company, and Simon Retter, as a director of a subsidiary of the Company and Chief Financial Officer of the Company are also considered to be related parties of the Company and their participation in the Fundraising also constitutes related party transactions under Rule 13 of the AIM Rules for Companies. Each of Jeremy Martin and Simon Retter have conditionally subscribed for 27,624 new ordinary shares at the Issue Price (the "Director Participation"). As such William Fisher, Owen Bavinton and Gillian Davidson, who are not participating in the Fundraising and therefore considered to be independent for the purposes of the participation by La Mancha and the Director Participation consider, having consulted with the Company's Nominated Adviser, Peel Hunt, that the terms of each of the participation by La Mancha and the Director Participation is fair and reasonable insofar as the Company's shareholders are concerned.

Participation by each of Jeremy Martin, Simon Retter and La Mancha also constitutes a related party transaction under Canadian Multilateral Instrument 61-101 – Protection of Minority Security Holders in Special Transactions ("MI 61-101"). The Company has determined that the participation in the Fundraising by the related parties is exempt from the formal valuation and minority shareholder approval requirements of MI 61-101 by virtue of the exemptions contained in Sections 5.5(a) and 5.7(1)(a) of MI 61-101, as neither the fair market value of securities issued to the related parties nor the consideration paid by the related parties exceeded 25 per cent. of the Company's market capitalisation. The Company also intends to rely on the exemption in section 602.1 of the TSX Listing Rules in respect of the Fundraising as an Eligible Interlisted Issuer.

8 General Meeting

The General Meeting of the Company, notice of which is set out in Part II of this document, is to be held at 11.30 a.m. (London time) on 4 November 2022 at the offices of Horizonte Minerals plc, Rex House, 4-12 Regent Street, London, SW1Y 4RG, United Kingdom. The General Meeting is being held for the purpose of considering and, if thought fit, passing the Resolutions which are summarised below:

(i) Resolution 1 is proposed as an ordinary resolution, to authorise the Directors, in accordance with Section 551 of the Act, to allot and issue the Fundraising Shares in connection with the Fundraising. In addition, this Resolution will ensure that there is sufficient additional authority to

HORIZONTE MINERALS NOTICE OF MEETING

allow the Directors to issue and allot and any additional Ordinary Shares which may be required to be issued pursuant to the adjustments referred to in paragraph 6. To be passed, more than half of the votes cast must be in favor of the resolution;

(ii) Resolution 2 is subject to the passing of Resolution 1 and is proposed as a special resolution to authorise the Directors, under section 570(1) of the Act, to allot and issue the Fundraising Shares pursuant to the Fundraising, and any additional Ordinary Shares which may be required to be issued pursuant to the adjustments referred to in paragraph 7, in each case for cash on a non-pre-emptive basis and. To be passed, at least three quarters of the votes cast must be in favour of the resolution.

Save in respect of the allotment of the Fundraising Shares, and the issue of any Ordinary Shares pursuant to the Convertible Loan Note Instruments, Directors have no current intention to allot new Ordinary Shares, or rights to subscribe for or convert into Ordinary Shares, in the capital of the Company.

Further information on the General Meeting is set out in Part III.

9 Action to be taken

Record Date

The record date for the determination of Shareholders within Canada entitled to receive notice of and to vote at the General Meeting or any adjournments or postponements thereof is 5 October 2022 (the "Canadian Record Date"). Canadian Shareholders whose names have been entered in the register of members at the close of business on the Canadian Record Date will be entitled to receive notice of and to vote at the General Meeting or any adjournments or postponements thereof. Such Canadian shareholders who become holders of record of Ordinary Shares after the Canadian Record Date and who wish to vote at the General Meeting must make arrangements with the person(s) from whom they acquired the Ordinary Shares to direct how such Ordinary Shares are to be voted at the General Meeting. See also "Voting by Non-Registered Shareholders in Canada" below.

The record date for the determination of Shareholders outside Canada entitled to receive notice of and to vote at the General Meeting or any adjournments or postponements thereof is 6.00 p.m. on 2 November 2022.

Shareholders will find enclosed with this document a Form of Proxy for use in relation to the General Meeting.

See also Part II (Notice of General Meeting) and Part III (General Information Respecting the Meeting).

Forms of Proxy

Outside Canada

To be valid, the Form of Proxy must be completed in accordance with the instructions set out in the form and returned as soon as possible to the offices of our Registrars, Computershare Investor Services (Ireland) Limited, 3100 Lake Drive, Citywest Business Campus, Dublin 24, D24 AK82, Ireland, so as to be received no later than 11.30 p.m. (London time) on 2 November 2022.

Canadian Shareholders should refer to Part III (General Information Respecting the Meeting).

If you are in any doubt as to what action you should take, you should immediately seek your own personal financial advice from your stockbroker, bank manager, solicitor, accountant or other independent professional adviser duly authorised under the FSMA if you are resident in the United Kingdom or, if not, from another appropriately authorised independent financial adviser.

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20
HORIZONTE MINERALS
NOTICE OF MEETING

Further Information

Further information in respect of the General Meeting, in particular for shareholders within Canada and in respect of disclosures required by Canadian Securities laws can be found in Part III.

10 Admission, settlement and CREST

Application will be made to the London Stock Exchange for the Fundraising Shares to be admitted to trading on AIM. It is expected that AIM Admission will become effective at 8.00 a.m. on 8 November 2022.

The Articles permit the Company to issue shares in uncertificated form. CREST is a computerised paperless share transfer and settlement system which allows shares and other securities to be held in electronic rather than paper form. The Existing Ordinary Shares are already admitted to CREST and therefore the Fundraising Shares will also be eligible for settlement in CREST. CREST is a voluntary system and Shareholders who wish to retain certificates will be able to do so upon request. It is expected that the Placing Shares and Subscription Shares due to uncertificated holders will be delivered in CREST on 8 November 2022.

11 TSX Admission

12 Canadian Securities Law and TSX Matters

Participation by any insiders (such as directors, officers or 10 per cent. holders of the Company) in the Fundraising may be considered a "related party transaction" pursuant to Multilateral Instrument 61-101 – Protection of Minority Security Holders in Special Transactions ("MI 61-101"). In such event, the Company expects to rely upon the exemptions from the requirements to obtain a formal valuation and minority shareholder approval in connection with the insiders' participation in the Fundraising in sections 5.5(a) and 5.7(1)(a) of MI 61-101 as neither the fair market value of the subject matter of, nor the fair market value of the consideration for, the Fundraising Shares, insofar as it shall involve the insiders, will exceed 25 per cent. of the Company's market capitalisation (calculated in accordance with MI 61-101).

The participation by La Mancha in the Fundraising as outlined herein will result in La Mancha holding greater than 19.9 per cent. of the Ordinary Shares on a partially diluted, as converted, basis. Accordingly, and as result of the issuance of a number of Ordinary Shares in the Fundraising that will be greater than 25 per cent. of the number of Existing Ordinary Shares, the Company will be relying upon section 602.1 of the TSX Listing Rules in connection with the Fundraising, which exempts the Company from obtaining shareholder approval under sections 604(a)(i) and (ii) and 607(g)(i) of the TSX Listing Rules, on the basis that the Fundraising is being completed in accordance with the standards of AIM and the volume of trading of the Ordinary Shares on all Canadian marketplaces in the 12 months immediately preceding the date of the application by the Company to the TSX is less than 25 per cent.

13 Recommendation

The Directors believe that the passing of the Resolutions is in the best interests of the Company and the Shareholders, taken as a whole. Accordingly, the Directors unanimously recommend Shareholders to vote in favour of the Resolutions, as they will so do in respect of their holdings of Ordinary Shares in the Company, representing approximately 0.1576 per cent., in aggregate, of the Existing Ordinary Shares.

In addition La Mancha, Orion and Glencore have irrevocably undertaken to vote in favour of the Resolutions in respect of their holdings of Ordinary Shares in the Company, representing approximately 44.58 per cent., in aggregate, of the Existing Ordinary Shares.

Each element of the Fundraising is conditional, inter alia, upon the passing of the Resolutions at the General Meeting. Shareholders should be aware that if the Resolutions are not approved at the General Meeting the Fundraising will not proceed and the Company will not receive the proceeds thereof. Furthermore, if the Fundraising does not proceed then the Company will not have sufficient funds to meet the forecast costs to complete construction of the Araguaia project and will be unlikely to be able to access the funding available from the Senior Debt Facility.

Yours faithfully

William Fisher
Non-Executive Chairman
for and on behalf of
Horizonte Minerals Plc

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HORIZONTE MINERALS
NOTICE OF MEETING

PART II

NOTICE OF GENERAL MEETING

Company Number: 05676866

HORIZONTE MINERALS PLC

NOTICE OF GENERAL MEETING OF SHAREHOLDERS

Notice is hereby given that a general meeting (the 'Meeting') of the shareholders of Horizonte Minerals PLC (the 'Company') will be held at the offices of Horizonte Minerals plc, Rex House, 4-12 Regent St, London, SW1Y 4RG, United Kingdom, on 4 November 2022 at 11.30 a.m. (London time). Unless otherwise indicated the definitions set out in the circular to which this notice is attached apply in this notice, the business of the meeting will be to consider and if thought fit pass the following resolutions:

Ordinary resolution

THAT the Directors of the Company be and are hereby generally and unconditionally authorised and empowered in accordance with Section 551 of the Companies Act 2006 (the 'Act') to exercise all powers of the Company to allot shares in the Company and grant rights to subscribe for, or convert any securities into, shares in the Company up to an aggregate nominal amount of £20,298,149.80 pursuant to the Fundraising provided that this authority shall expire (unless renewed, varied or revoked by the Company in general meeting) on 31 December 2022 save that the Company may, before such expiry, make offers or agreements which would or might require it to allot shares in the Company and grant rights to subscribe for, or convert any security into, shares in the Company and the directors may allot such securities in pursuance of such offer or agreement notwithstanding that the authority conferred by this resolution has expired. The authority granted by this resolution shall be in addition to the existing authority to allot shares in the Company and to grant rights to subscribe for or convert any security into shares in the Company previously granted to the Directors at the annual general meeting of the Company held on 24 May 2022 pursuant to section 551 of the Act but without prejudice to any allotment of shares or grant of rights already made, offered or agreed to be made pursuant to such authorities.

Special Resolution

THAT, subject to and conditional upon the passing of resolution 1, the Directors be and they are hereby empowered (in addition and without prejudice to all existing powers) pursuant to Section 570 of the Act to allot equity securities (within the meaning of Section 560(1) of the Act) in the capital of the Company for cash pursuant to the authority conferred on them in accordance with Section 551 of the Act by resolution 1 as if Section 561(1) of the Act did not apply to such allotment provided that this power shall be limited to the allotment up to an aggregate nominal amount of £20,298,149.80 pursuant to the Fundraising provided that this authority shall expire (unless renewed, varied or revoked by the Company in general meeting) on 31 December 2022 save that the Company may, before such expiry, make offers or agreements which would or might require it to allot equity securities and the directors may allot such equity securities in pursuance of such offer or agreement notwithstanding that the authority conferred by this resolution has expired. The authority granted by this resolution shall be in addition to the existing authority to allot equity securities previously granted to the Directors at the annual general meeting of the Company held on 24 May 2022 pursuant to section 551 of the Act but without prejudice to any allotment of shares or grant of rights already made, offered or agreed to be made pursuant to such authorities.

7 October 2022

By order of the Board of Directors

Jeremy Martin
Chief Executive Officer
Registered Office:
Rex House, 4-12 Regent Street, London, SW1Y 4RG United Kingdom

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NOTICE OF MEETING

Notes:

A shareholder of the Company (each a 'Shareholder') may attend the Meeting in person or may be represented by one or more proxies provided each proxy is appointed to exercise rights attached to different shares. Members of the Company may not appoint more than one proxy to exercise rights attached to any one share. Shareholders who are unable to attend the Meeting or any adjournments or postponements thereof in person are requested to date, sign and return the accompanying Form of Proxy or VIF (as defined later), as applicable, for use at the Meeting or any adjournments or postponements thereof. In the case of a member which is a company, the Proxy Form must be executed under its common seal or signed on its behalf by an officer or attorney duly authorised. A proxy need not be a member of the Company. Completion and return of a Form of Proxy will not prevent a member from attending and voting at the General Meeting in person should he/she wish to do so.
A corporation which is a member can appoint one or more corporate representatives who may exercise, on its behalf, all its powers as a member provided that no more than one corporate representative exercises powers over the same share.
In the case of joint holders, the signature of only one of the joint holders is required on the Form of Proxy but the vote of the first named on the register of members of the Company will be accepted to the exclusion of the other joint holders.
The following documents will be available for inspection at the registered office of the Company from the date of this notice until the time of the General Meeting during normal business hours and at the place of the General Meeting for at least 15 minutes prior to and during the General Meeting until its conclusion:

4.1. copies of the executive directors' service contracts; and

4.2. copies of the letters of appointment of the non-executive directors.

Within Canada:

The record date for the determination of Shareholders within Canada entitled to receive notice of and to vote at the Meeting or any adjournments or postponements thereof is 5 October 2022 (the 'Canadian Record Date'). Such Canadian shareholders whose names have been entered in the register of members/Shareholders at the close of business on the Record Date will be entitled to receive notice of and to vote at the Meeting or any adjournments or postponements thereof. Such Canadian shareholders who become holders of record of shares of the Company after the Canadian Record Date and who wish to vote at the Meeting must make arrangements with the person(s) from whom they acquired the shares to direct how such shares are to be voted at the Meeting.
To be effective, the enclosed Form of Proxy as sent to Registered Holders must be mailed so as to reach or be deposited with Computershare Investor Services Inc., Attention: Proxy Department, 100 University Avenue, 8th Floor, Toronto, Ontario M5J 2Y1. Non-Registered Holders may register their vote either on-line through www.proxyvote.com using the 16-digit control number that is indicated on the Voting Instruction Form ('VIF'), or by telephone voting – English – 1-800-474-7493 or French 1-800-474-7501, or by mail using the business reply envelope provided. Forms of Proxy from Registered Holders or on-line, telephone or postal voting from Non-Registered Holders must be received not later than 8.00 a.m. (Toronto time) on 1 November 2022, or no later than seventy-two (72) hours (excluding Saturdays, Sundays and statutory holidays in the City of Toronto, Ontario) prior to the time set for any adjourned or postponed Meeting.

Outside of Canada:

Pursuant to Regulation 41(1) of the Uncertificated Securities Regulations 2001, the Company has specified that only the holders of Ordinary Shares registered in the register of members of the Company at 6.00 p.m. on the date which is two days prior to the General Meeting or any adjournment of it shall be entitled to attend and vote or appoint a proxy or proxies to attend and vote on their behalf at the General Meeting or any adjourned General Meeting. Entries on the register of members after 6.00 p.m. on that date shall be disregarded in determining the rights of any person to attend or vote at the General Meeting.
A Form of Proxy is enclosed with this document for use in relation to the Meeting. To be valid, the Form of Proxy must be completed in accordance with the instructions set out in the form and returned as soon as possible to the offices of our Registrars, Computershare Investor Services (Ireland) Limited, 3100 Lake Drive, Citywest Business Campus, Dublin 24, D24 AK82, Ireland, so as to be received no later than 11.30 a.m. (London time) on 2 November 2022.

See further information in relation to the General Meeting and Use of Proxies in Part III (General Information Respecting the Meeting).

HORIZONTE MINERALS NOTICE OF MEETING

PART III

GENERAL INFORMATION RESPECTING THE MEETING

Solicitation of Proxies

This management information circular (the ‘Circular’) is furnished in connection with the solicitation of proxies by the management of Horizonte Minerals PLC (the ‘Company’) for use at the general meeting (the ‘Meeting’) to be held 11.30 a.m. (London time) on 4 November 2022 at the offices of Horizonte Minerals plc, Rex House at 4-12 Regent Street, London, SW1Y 4RG, United Kingdom, for the purposes set forth in the accompanying Notice of Meeting. The Letter from the Chairman in Part I forms an integral of this Circular. It is expected that the solicitation of proxies will be primarily by mail, however, proxies may also be solicited by the officers, directors and employees of the Company by telephone, electronic mail, facsimile or personally. These persons will receive no compensation for such solicitation other than their regular fees or salaries. The cost of soliciting proxies in connection with the Meeting will be borne directly by the Company.
Notwithstanding the following, the Chairman at the Meeting has the discretion to accept Forms of Proxy or VIFs, as applicable, after such deadlines.
In this Circular, references to ‘£’ are to British pounds sterling.
Unless otherwise stated, the information contained in this Circular is correct as of 6 October 2022.

Who can participate at the Meeting:

Within Canada:

The board of directors of the Company (the ‘Board’) has fixed the close of business on 5 October 2022 as the record date (the ‘Canadian Record Date’), being the date for the determination of the registered shareholders based in Canada entitled to receive notice of and to vote at the Meeting. Canadian shareholders who become holders of record of shares of the Company after the Canadian Record Date and who wish to vote at the Meeting must make arrangements with the person(s) from whom they acquired the shares to direct how such shares are to be voted at the Meeting.
The Board has resolved that duly completed and executed Forms of Proxy, as sent to Registered Holders, must be received by the Company’s registrar and transfer agent, Computershare Investor Services Inc., Attention: Proxy Department, 100 University Avenue, 8th Floor, Toronto, Ontario M5J 2Y1 not later than 8.00 a.m. (Toronto time) on 1 November 2022, or no later than seventy-two (72) hours (excluding Saturdays, Sundays and statutory holidays in the City of Toronto, Ontario) prior to the time set for any adjourned or postponed Meeting.

Non-Registered Holders may register their vote on-line through www.proxyvote.com using the 16-digit control number that is indicated on the VIF, or by telephone voting – English – 1-800-474-7493 or French 1-800-474-7501, or by mail using the business reply envelope provided. On-line, telephone or postal voting from Non-Registered Holders must be received not later than forty-eight (48) hours (excluding Saturdays, Sundays and statutory holidays in the City of Toronto, Ontario) prior to the time set for the Meeting or any adjournments or postponements thereof.

Outside of Canada:

7 Pursuant to Regulation 41(1) of the Uncertificated Securities Regulations 2001, the Company has specified that only the holders of Ordinary Shares registered in the register of members of the Company at 6.00 p.m. on the date which is two days prior to the General Meeting or any adjournment of it shall be entitled to attend and vote or appoint a proxy or proxies to attend and vote on their behalf at the General Meeting or any adjourned General Meeting. Entries on the register of members after 6.00 p.m. on that date shall be disregarded in determining the rights of any person to attend or vote at the General Meeting.

8 The Board has resolved that duly completed and executed Forms of Proxy must be received at the offices of our Registrars, Computershare Investor Services (Ireland) Limited, 3100 Lake Drive, Citywest Business Campus, Dublin 24, D24 AK82, Ireland, so as to be received no later than 11.30 a.m. (London time) on 2 November 2022.

Voting of Proxies

9 The shares represented by the accompanying Form of Proxy (if same is properly executed and is received in accordance with the instructions set forth herein, prior to the time set for the Meeting or any adjournments or postponements thereof), will be voted at the Meeting, and, where a choice is specified in respect of any matter to be acted upon, will be voted or withheld from voting in accordance with the specification made. In the absence of such specification, proxies in favour of the Chairman of the meeting or management will be voted in favour of all resolutions described below. The enclosed Form of Proxy or VIF, as applicable, confers discretionary authority upon the persons named therein with respect to amendments or variations to matters identified in the Notice of Meeting and with respect to other matters which may properly come before the Meeting. At the time of printing of this Circular, management knows of no such amendments, variations or other matters to come before the Meeting. However, if any other matters that are not now known to management should properly come before the Meeting, the Form of Proxy or VIF, as applicable, will be voted on such matters in accordance with the best judgment of the named proxies.

Appointment of Proxies

10 The persons named in the enclosed Form of Proxy are officers and/or directors of the Company. A Shareholder desiring to appoint some other person, who need not be a Shareholder, to represent him or her at the Meeting, may do so by inserting such person's name in the blank space provided in the enclosed Form of Proxy or by completing another proper form of proxy and, in either case, depositing the completed and executed proxy in accordance with the instructions set out below.

Within Canada:

11 To be effective, the enclosed Form of Proxy completed by a Canadian registered holder must be mailed so as to reach or be deposited with Computershare Investor Services Inc., Attention: Proxy Department, 100 University Avenue, 8th Floor, Toronto, Ontario M5J 2Y1not later than 8.00 a.m. (Toronto time) on 1 November 2022, or no later than seventy-two (72) hours (excluding Saturdays, Sundays and statutory holidays in the City of Toronto, Ontario) prior to the time set for any adjourned or postponed Meeting.

Outside of Canada

12 A Form of Proxy is enclosed with this document for use in relation to the Meeting. To be valid, the Form of Proxy must be completed in accordance with the instructions set out in the form and returned as soon as possible to the offices of our Registrars, Computershare Investor

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Services (Ireland) Limited, 3100 Lake Drive, Citywest Business Campus, Dublin 24, D24 AK82, Ireland, so as to be received no later than 11.30 a.m (London time) on 2 November 2022.

13 A Shareholder forwarding the enclosed Form of Proxy may indicate the manner in which the appointee is to vote with respect to any specific item by checking the appropriate space. If the Shareholder giving the proxy wishes to confer a discretionary authority with respect to any item of business, then the space opposite the item is to be left blank. The shares represented by the Form of Proxy submitted by a Shareholder will be voted in accordance with the directions, if any, given in the Form of Proxy.

14 To be valid, a Form of Proxy must be executed by a Shareholder or a Shareholder's attorney duly authorised in writing or, if the Shareholder is a body corporate, under its corporate seal or, by a duly authorised officer or attorney.

Revocation of Proxies

15 A proxy given pursuant to this solicitation may be revoked at any time prior to its use. A Shareholder who has given a proxy may revoke the proxy by:

(i) completing and signing a proxy bearing a later date and depositing it at the offices of Computershare Investor Services Inc., Attention: Proxy Department, 100 University Avenue, 8th Floor, Toronto, Ontario M5J 2Y1, or if the Shareholder is outside of Canada, at our Registrars, Computershare Investor Services (Ireland) Limited 3100 Lake Drive, Citywest Business Campus, Dublin 24, D24 AK82, Ireland;

(ii) depositing an instrument in writing executed by the Shareholder or by the Shareholder's attorney duly authorised in writing or, if the Shareholder is a body corporate, under its corporate seal or, by a duly authorised officer or attorney either with Computershare Investor Services Inc., Attention: Proxy Department, 100 University Avenue, 8th Floor, Toronto, Ontario M5J 2Y1 or at our Registrars, Computershare Investor Services (Ireland) Limited, 3100 Lake Drive, Citywest Business Campus, Dublin 24, D24 AK82, Ireland, at any time up to and including the last Business Day preceding the day of the Meeting or any adjournments or postponements thereof or with the Chairman of the Meeting prior to the commencement of the Meeting on the day of the Meeting or any adjournments or postponements thereof; or

(iii) in any other manner permitted by law.

Such instrument will not be effective with respect to any matter on which a vote has already been cast pursuant to such proxy.

Voting by Non-Registered Shareholders in Canada

16 Only registered Shareholders or the persons they appoint as their proxies are permitted to vote at the Meeting. Certain Shareholders are 'non-registered' Shareholders in Canada ('Non-Registered Shareholders') because the shares they own are not registered in their names but are instead registered in the name of the brokerage firm, bank or trust company through which they purchased the shares. Shares beneficially owned by a Non-Registered Shareholder are registered either: (i) in the name of an intermediary ('Intermediary') that the Non-Registered Shareholder deals with in respect of the shares; or (ii) in the name of a clearing agency (such as CDS Clearing and Depository Services Inc.) of which the Intermediary is a participant ('Clearing Agency'). In accordance with applicable securities law requirements, the Company will have distributed copies of the Notice of Meeting and Management Circular, VIF and a request card for relevant materials, as applicable (collectively, the 'Meeting Materials') to the Clearing Agencies and Intermediaries for distribution to Non-Registered Shareholders.

HORIZONTE MINERALS NOTICE OF MEETING

Intermediaries and Clearing Agencies are required to forward the Meeting Materials to Non-Registered Shareholders unless a Non-Registered Shareholder has waived the right to receive them. Intermediaries and Clearing Agencies often use service companies to forward the Meeting Materials to Non-Registered Shareholders. Non-Registered Shareholders who have not waived the right to receive Meeting Materials will be given a VIF which is not signed by the Intermediary and which, when properly completed and signed by the Non-Registered Shareholder and returned to the Intermediary or its service company, will constitute voting instructions which the Intermediary must follow. Typically, the VIF will consist of a one page pre-printed form. The majority of brokers now delegate responsibility for obtaining instructions from clients to Broadridge Financial Solutions, Inc. ('Broadridge') in Canada. Broadridge typically prepares a machine-readable VIF, mails those forms to Non-Registered Shareholders and asks Non-Registered Shareholders to return the forms to Broadridge or otherwise communicate voting instructions to Broadridge (by way of the Internet or telephone, for example). Broadridge then tabulates the results of all instructions received and provides appropriate instructions respecting the voting of the shares to be represented at the Meeting. Sometimes, instead of the one page pre-printed form, the VIF will consist of a regular printed proxy form accompanied by a page of instructions which contains a removable label with a barcode and other information. In order for this form of proxy to validly constitute a VIF, the Non-Registered Shareholder must remove the label from the instructions and affix it to the form of proxy, properly complete and sign the form of proxy and submit it to the Intermediary or its service company in accordance with the instructions of the Intermediary or its service company. A Non-Registered Shareholder who receives a VIF cannot use that form to vote his or her shares at the Meeting.

The purpose of these procedures is to permit Non-Registered Shareholders to direct the voting of the shares they beneficially own. Should a Non-Registered Shareholder who receives a VIF wish to vote at the Meeting, or any adjournments or postponements thereof, (or have another person attend and vote on behalf of the Non-Registered Shareholder), the Non-Registered Shareholder should strike out the persons named in the VIF and insert the Non-Registered Shareholder or such other person's name in the blank space provided. Non-Registered Shareholders should carefully follow the instructions of their Intermediary, including those regarding when and where the VIF is to be delivered.

A Non-Registered Shareholder may revoke a VIF or a waiver of the right to receive Meeting Materials and to vote which has been given to an Intermediary at any time by written notice to the Intermediary provided that an Intermediary is not required to act on a revocation of a VIF or of a waiver of the right to receive Meeting Materials and to vote which is not received by the Intermediary at least seven days prior to the Meeting.

Overseas Shareholders

The distribution of this document and the Form of Proxy to persons who have registered addresses in, or who are resident or ordinarily resident in, or citizens of, or which are corporations, partnerships or other entities created or organised under the laws of countries other than the UK or Canada or to persons who are nominees of or custodians, trustees or guardians for citizens, residents in or nationals of, countries other than the UK may be affected by the laws or regulatory requirements of the relevant jurisdictions.

Accordingly, any persons into whose possession this document comes should inform themselves about and observe any applicable restrictions or requirements. No action has been taken by the Company that would permit possession or distribution of this document in any jurisdiction where action for that purpose is required. Any failure to comply with such restrictions or requirements may constitute a violation of the securities laws of any such jurisdiction.

HORIZONTE MINERALS
NOTICE OF MEETING

Voting Securities and Principal Holders of Voting Securities

22 As at the date hereof, the Company's issued share capital comprises 190,468,279 ordinary shares ('Ordinary Shares') of £0.20 each. Each Ordinary Share carries the right to one vote per share at all meetings of Shareholders.

23 To the knowledge of the directors and executive officers of the Company, no person beneficially owns or exercises control or direction over, directly or indirectly, 10 per cent. or more of the outstanding Ordinary Shares as of the date of this Circular, with the exception of those set out in the table below:

Shareholder	Number of Ordinary Shares^{1}		Percentage of issued share capital
	As at the date of this document	On Admission^{2}	As at the date of this document	On Admission^{2}
La Mancha	37,956,438	62,297,182	19.93%	23.21%
Orion Resource Partners	28,292,291	28,292,291	14.85%	10.54%
Glencore	18,662,914	47,871,806	9.80%	17.84

The information as to Ordinary Shares beneficially owned, controlled or directed, not being within the knowledge of the Company, has been obtained by the Company from publicly disclosed information and/or furnished by the Shareholder listed above.
Assuming that La Mancha and Glencore each participate in the Fundraising as set out in this document.

Indebtedness of Directors and Executive Officers

24 There is currently no outstanding indebtedness owing to either the Company or any of its subsidiaries, or to any other entity which is the subject of a guarantee, support agreement, letter of credit or similar arrangement provided by the Company or any of its subsidiaries, of (i) any director, executive officer or employee; (ii) any former director, executive officer or employee; or (iii) any associate of any current or former director or executive officer of the Company.

Interest of Certain Persons in Matters to be Acted Upon

25 As at the date hereof, save for Jeremy Martin's and Simon Retter's participation in the Fundraising, no director or executive officer of the Company who has held such position at any time since the beginning of the Company's financial year ended 31 December 2021, or associate or affiliate of the foregoing has any material interest, direct or indirect, by way of beneficial ownership of securities or otherwise, in any matter to be acted upon at the General Meeting.

Interest of Informed Persons in Material Transactions

26 Since the commencement of the Company's most recently completed financial year, no informed person or proposed director of the Company, nor any associate or affiliate thereof, has or had any material interest, direct or indirect, in any transaction or any proposed transaction which has materially affected or will materially affect the Company or any of its subsidiaries.

HORIZONTE MINERALS

NOTICE OF MEETING

Additional Information

27 Additional information relating to the Company may be found under the Company's profile on SEDAR at www.sedar.com. Inquiries including requests for copies of the Company's financial statements and management's discussion and analysis for the year ended 31 December 2021 may be directed to Company Secretary at the Company's head office and registered office is at Rex House, 4-12 Regent Street, London, SW1Y 4RG, United Kingdom.

28 Additional financial information is provided in the Company's comparative financial statements and management's discussion and analysis for the year ended 31 December 2021 which is also available on SEDAR.

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Horizonte Minerals PLC — Proxy Solicitation & Information Statement 2022

46840_rns_2022-10-12_e4c37a90-b3c5-48f3-82f3-60d8a949e3e2.pdf

NOT FOR DISTRIBUTION IN THE UNITED STATES OF AMERICA

HORIZONTE MINERALS PLC

IMPORTANT INFORMATION

CONTENTS

FUNDRAISING STATISTICS

EXPECTED TIMETABLE OF PRINCIPAL EVENTS

DEFINITIONS

LETTER FROM THE CHAIRMAN

HORIZONTE MINERALS PLC

1 Introduction

2 Background to and reasons for the Fundraising

Senior Debt Facility

3 Use of proceeds

4 Details of the Placing

5 Details of the Subscription

7 Related Parties

8 General Meeting

9 Action to be taken

Record Date

Forms of Proxy

Outside Canada

Further Information

10 Admission, settlement and CREST

11 TSX Admission

12 Canadian Securities Law and TSX Matters

13 Recommendation

PART II

NOTICE OF GENERAL MEETING

HORIZONTE MINERALS PLC

NOTICE OF GENERAL MEETING OF SHAREHOLDERS

Ordinary resolution

Special Resolution

Notes:

Within Canada:

Outside of Canada:

PART III

GENERAL INFORMATION RESPECTING THE MEETING

Solicitation of Proxies

Who can participate at the Meeting:

Within Canada:

Revocation of Proxies

Voting by Non-Registered Shareholders in Canada

Overseas Shareholders

Indebtedness of Directors and Executive Officers

Interest of Certain Persons in Matters to be Acted Upon

Interest of Informed Persons in Material Transactions

Additional Information

More from Horizonte Minerals PLC

Horizonte Minerals PLC Proxy Solicitation & Information Statement 2022