DUKETON MINING LIMITED — Capital/Financing Update 2021

Aug 15, 2021

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ASX Announcement

16th August 2021

16m of Sulphide Mineralisation Intersected below Rosie South-East

HIGHLIGHTS

Rosie Project (100% DKM)

• Hole DKDD0028 has intersected 16m of mineralisation including 1.1m of massive/ semi-massive sulphides, 1.7m of stringer/heavily disseminated sulphides and 13.2m of disseminated sulphides .

• DKDD0028 was drilled 60m below the deepest drillhole in the south-eastern part of Rosie and below the current indicated resource.

• Mineralisation remains open at depth.

• Hole has been cased with PVC for downhole electromagnetic surveying.

• This is the first deep hole drilled in the south-eastern part of Rosie in over 6 years.

• Seventeen drillholes now completed at the Rosie Nickel Project - all intersecting mineralisation.

• Drilling continues with a second deep hole 80m lateral to DKDD0028, anticipated to finished within the next 10 days.

• First batch of assays from earlier drilling expected in 2 weeks.

Duketon Mining Ltd (DKM) is pleased to announce drilling at the Rosie Nickel Project has intersected massive sulphides at depth, 60m beyond the extent of previous drilling in the south-eastern part of Rosie. DKDD0028 intersected 16m of pyrrhotite-pentlandite-chalcopyrite mineralisation including 1.1m of massive/semi-massive sulphides, 1.7m of stringer/heavily disseminated sulphides and 13.2m of disseminated sulphides (see Table 1, Table 2, Figures 1 - 4). This intersection is beyond the current indicated resource and will add more tonnes to the resource when updated. This drillhole has been cased with PVC for downhole electromagnetic surveying once the second deep hole has been completed. This sulphide hit

Duketon Mining Limited ACN 159 084 107 Level 2 25 Richardson Street West Perth WA 6005 T: +61 8 6315 1490

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highlights the continuation of the Rosie mineralisation at depth. A second deep hole is underway, targeting a position 80m lateral to DKDD0028.

Table 1: DKDD0028 lithology and mineralisation

From	To	Style of Mineralisation
538	550.86	3% disseminated sulphides(pyrrhotite-pentlandite) in ultramafic
550.86	552	20% heavily disseminated sulphides(pyrrhotite-pentlandite) in ultramafic
552	552.73	60% semi massive sulphides(pyrrhotite-pentlandite- chalcopyrite)in ultramafic
552.73	552.98	90% massive sulphides (pyrrhotite-pentlandite-chalcopyrite)
552.98	553.19	25% blebby and stringer sulphides(pyrrhotite-pentlandite- chalcopyrite)in ultramafic
553.19	553.3	90% massive sulphides (pyrrhotite-pentlandite)
553.3	553.76	footwall basalt
553.76	554.18	10% heavily disseminated sulphides(pyrrhotite-pentlandite) in footwall basalt

Duketon’s Managing Director Stuart Fogarty commented:

“ This is a fantastic result and a very exciting time for Duketon Mining. Last time we drilled in this area was early 2015 when we intersected over 5m of massive nickel and copper sulphides, and to step off 60m down plunge from the nearest drillhole in this part of the resource will add tonnes and ultimately extend the life of the mining operation proposed in the Scoping Study. This intersection is confirmation that Rosie continues at depth and gives us a substantial area to target with further drilling.”

Duketon Mining Limited ACN 159 084 107 Level 2 25 Richardson Street West Perth WA 6005 T: +61 8 6315 1490

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Figure 1: The intersection of massive and semi-massive sulphide in DKDD0028.

Duketon Mining Limited ACN 159 084 107 Level 2 25 Richardson Street West Perth WA 6005 T: +61 8 6315 1490

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Figure 2: A close-up of the intersection of massive sulphide in DKDD0028.

Duketon Mining Limited ACN 159 084 107 Level 2 25 Richardson Street West Perth WA 6005 T: +61 8 6315 1490

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Figure 3: Semi-massive sulphides in drillhole DKDD0028

Duketon Mining Limited ACN 159 084 107 Level 2 25 Richardson Street West Perth WA 6005 T: +61 8 6315 1490

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Figure 4: Heavy disseminated sulphides in drillhole DKDD0028

Duketon Mining Limited ACN 159 084 107 Level 2 25 Richardson Street West Perth WA 6005 T: +61 8 6315 1490

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The drill program at Rosie Nickel Project is designed to increase confidence in mineralisation in the upper north area, test at depth below the south-eastern area and collect PGE rich oxide material from directly above the sulphide deposit for assay and PGE recovery/metallurgical testwork. These three areas have been identified from the Rosie Nickel Sulphide Scoping Study as having potential upside by either impacting early cash flow or extending the life of mine (see ASX announcement 28[th] April 2021).

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Figure 5: Stope grade heat map with areas of drilling

Duketon Mining Limited ACN 159 084 107 Level 2 25 Richardson Street West Perth WA 6005 T: +61 8 6315 1490

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Figure 6: Long Section of Rosie showing pierce points of 2021 drillholes

Duketon Mining Limited ACN 159 084 107 Level 2 25 Richardson Street West Perth WA 6005 T: +61 8 6315 1490

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Figure 7: Long Section of South-East Rosie

Duketon Mining Limited ACN 159 084 107 Level 2 25 Richardson Street West Perth WA 6005 T: +61 8 6315 1490

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Figure 8: Plan of DKM Tenements showing Ultramafic, Nickel Resources and Prospects

Duketon Mining Limited ACN 159 084 107 Level 2 25 Richardson Street West Perth WA 6005 T: +61 8 6315 1490

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Table 2: Drillhole collar details

Hole ID	Easting	Northing	RL	Depth	Azimuth	Dip	Area of Drilling
DKDD0012	402230	6944161	540	231.9	45	-60	Upper North
DKDD0013	402355	6943992	540	282.2	45	-60	Upper North
DKDD0014	402426	6944056	540	85.4	45	-60	Oxide
DKDD0015	402532	6944000	540	82.9	45	-60	Oxide
DKDD0016	402640	6943960	540	85.1	0	-60	Oxide
DKDD0017	402341	6944039	540	227.5	45	-60	Upper North
DKDD0018	402292	6944057	541	253.8	45	-60	Upper North
DKDD0019	402360	6944110	540	105.8	45	-60	Upper North
DKDD0020	402301	6944153	540	130.5	-60	45	Upper North
DKDD0021	402247	6944106	540	255.5	-60	45	Upper North
DKDD0022	402171	6944146	540	395.8	-60	45	Upper North
DKDD0023	402261	6944222	540	99.3	-60	45	Upper North
DKDD0024	402181	6944226	540	279.3	-60	45	Upper North
DKDD0025	402157	6944208	540	332.8	-60	45	Upper North
DKDD0026	402213	6944277	540	161.9	-60	45	Upper North
DKDD0027	402125	6944284	540	225.1	-60	45	Upper North
DKDD0028	402703	6943510	542	579	-60	0	South-Eastern

Authorised for release by:

Stuart Fogarty Duketon Mining Limited - Managing Director +61 8 6315 1490

Competent Person Statement:

The information in this report that relates to exploration results is based on information compiled by Ms Kirsty Culver, Member of the Australian Institute of Geoscientists (AIG) and an employee of Duketon Mining Limited. Ms Culver has sufficient experience which is relevant to the style of mineralisation and type of deposit under consideration and to the activity that is being undertaken to qualify as a competent person as defined in the JORC Code 2012.Ms Culver consents to the inclusion in the report of the matters based on the information in the form and context in which it appears.

Duketon Mining Limited ACN 159 084 107 Level 2 25 Richardson Street West Perth WA 6005 T: +61 8 6315 1490

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This announcement includes information extracted from the Company’s previous ASX announcements, which are available to view on the Company’s website (www.duketonmining.com.au) as follows:

Rosie Scoping Study – ASX announcement dated 28 April 2021.

In the case of the Rosie Scoping Study, the Company confirms that it is not aware of any new information or data that materially affects the information included in the original market announcement and that all material assumptions underpinning the production target, or the financial information derived from the production target in the relevant market announcement continue to apply and have not materially changed. The Company confirms that the form and context that the Competent Person’s findings are represented have not been materially modified from the original market announcement.

Duketon Mining Limited ACN 159 084 107 Level 2 25 Richardson Street West Perth WA 6005 T: +61 8 6315 1490

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JORC Table 1

JORC Code, 2012 Edition – Table 1 report – Duketon Project

Section 1 Sampling Techniques and Data – Rosie Diamond Drilling

(Criteria in this section apply to all succeeding sections.)

Criteria	JORC Code explanation	Commentary
Sampling	• Nature and quality of sampling (eg cut channels, random chips, or	•Diamond core was drilled triple tube HQ to competent rock and then
techniques	specific specialised industry standard measurement tools appropriate	NQ2 to end of hole.
	to the minerals under investigation, such as down hole gamma	•The sample interval is cut in half using a diamond core saw and half
	sondes, or handheld XRF instruments, etc). These examples should	core sampled for assay. Each sample provides between 2.0-3.0kg of
	not be taken as limiting the broad meaning of sampling.	material. The core is cut to the left of the orientation line, with the
	• Include reference to measures taken to ensure sample representivity	same half sampled to ensure sample is representative.
	and the appropriate calibration of any measurement tools or systems	•Diamond core is sampled to geological boundaries, no greater than
	used.	1m and no less than 20cm per sample.
	• Aspects of the determination of mineralisation that are Material to the	•Certified samples and blanks are inserted every 25thsample for
	Public Report.	diamond drilling.
	• In cases where ‘industry standard’ work has been done this would be	•Mineralisation is determined qualitatively by geological logging and
	relatively simple (eg ‘reverse circulation drilling was used to obtain 1	quantitatively through assaying.
	m samples from which 3 kg was pulverised to produce a 30 g charge
	for fire assay’). In other cases more explanation may be required,
	such as where there is coarse gold that has inherent sampling
	problems. Unusual commodities or mineralisation types (eg
	submarine nodules) may warrant disclosure of detailed information.
Drilling	• Drill type (eg core, reverse circulation, open-hole hammer, rotary air	•Rock roll or rough core to refusal then diamond drilling using HQ3
techniques	blast, auger, Bangka, sonic, etc) and details (eg core diameter, triple	(61.1mm) sized core to competent rock and then NQ2 (50.6mm) to
	or standard tube, depth of diamond tails, face-sampling bit or other	end of hole.
	type, whether core is oriented and if so, by what method, etc).	•Core is oriented using a Boart Longyear TruCore UPIX orientation
		tool.

Duketon Mining Limited ACN 159 084 107

Level 2 25 Richardson Street West Perth WA 6005 T: +61 8 6315 1490

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Criteria	JORC Code explanation	Commentary
Drill sample	• Method of recording and assessing core and chip sample recoveries	•Recoveries qualitatively noted at the time of drilling and recorded.
recovery	and results assessed.	•Core is metre marked and orientated. Run recoveries are recorded.
	• Measures taken to maximise sample recovery and ensure	•Triple tube HQ is used to maximise recovery through the weathered
	representative nature of the samples.	zone and ensure a representative sample.
	• Whether a relationship exists between sample recovery and grade
	and whether sample bias may have occurred due to preferential
	loss/gainof fine/coarse material.
Logging	• Whether core and chip samples have been geologically and	•All core is logged to a level of detail to support future use in a mineral
	geotechnically logged to a level of detail to support appropriate	resource calculation.
	Mineral Resource estimation, mining studies and metallurgical	•Qualitative: Lithology, alteration, mineralisation.
	studies.	•Quantitative: Vein percentage, sulphide percentage.
	• Whether logging is qualitative or quantitative in nature. Core (or	•All holes for their entire length are logged.
	costean, channel, etc) photography.	•All core is photographed.
	• _The total length and percentage of the relevant intersections logged. _
Sub-	• If core, whether cut or sawn and whether quarter, half or all core	•The core is cut using an automatic core saw, half core is sampled.
sampling	taken.	•The entire sample (approx. 2kg) is dried, pulverised to 85% passing
techniques	• If non-core, whether riffled, tube sampled, rotary split, etc and	75µm.
and sample	whether sampled wet or dry.	•Pulp duplicates are taken at the pulverising stage and selective
preparation	• For all sample types, the nature, quality and appropriateness of the	repeats conducted at the laboratories discretion.
	sample preparation technique.	•Sample sizes are considered appropriate for the grainsize of the
	• Quality control procedures adopted for all sub-sampling stages to	material sampled.
	maximise representivity of samples.
	• Measures taken to ensure that the sampling is representative of the in
	situ material collected, including for instance results for field
	duplicate/second-half sampling.
	• Whether sample sizes are appropriate to the grain size of the material
	_being sampled. _
Quality of	• The nature, quality and appropriateness of the assaying and	•Samples are analysed using a Fire Assay 40g charge with MS finish
assay data	laboratory procedures used and whether the technique is considered	for Au, Pt & Pd and a multi-acid digest with ICP-AES finish for 17
and	partial or total.	elements.
	• For geophysical tools, spectrometers, handheld XRF instruments, etc,	•This techniqueisindustry standardfor nickeland considered

Duketon Mining Limited ACN 159 084 107

Level 2 25 Richardson Street West Perth WA 6005 T: +61 8 6315 1490

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Criteria	JORC Code explanation	Commentary
laboratory	the parameters used in determining the analysis including instrument	appropriate.
tests	make and model, reading times, calibrations factors applied and their	•Samples are analysed for the following elements: Al, As, Au, Ca, Co,
	derivation, etc.	Cr, Cu, Fe, K, Mg, Na, Ni, Pd, Pt, S, Sc, Ti, V, Zn, Zr
	• Nature of quality control procedures adopted (eg standards, blanks,	•Selected samples are also analysed using a Fire Assay 25g charge
	duplicates, external laboratory checks) and whether acceptable levels	with MS finish for Au, Pt, Pd, Rh, Ru, Os, Ir to a 1ppb detection limit.
	of accuracy (ie lack of bias) and precision have been established.	•Certified Reference Material (Standards) and blanks were submitted
		withbatches (1 inevery25 samples).
Verification	• The verification of significant intersections by either independent or	•All data is checked internally for correctness by senior DKM
of sampling	alternative company personnel.	geological and corporate staff.
and	• The use of twinned holes.	•All data is collected via Ocris software and uploaded into the DKM
assaying	• Documentation of primary data, data entry procedures, data	Datashed Database following validation.
	verification, data storage (physical and electronic) protocols.	•No adjustments are made to assay data.
	• _Discuss any adjustment to assay data. _	•No twinnedholeshave beendrilled to date.
Location of	• Accuracy and quality of surveys used to locate drill holes (collar and	•All location points are collected using a handheld GPS in MGA 94 –
data points	down-hole surveys), trenches, mine workings and other locations	Zone 51
	used in Mineral Resource estimation.	•Downhole surveying (azimuth and dip of the drillhole) of diamond
	• Specification of the grid system used.	drillholes was measured by the drilling contractors using an Axis
	• Quality and adequacy of topographic control.	Champ Gyro.
		•A topographic surface has been created from airborne geophysical
		data. Drillholes are corrected to this surface.
Data spacing	• Data spacing for reporting of Exploration Results.	•Holes are drilled at various spacing depending upon the holes drilled
and	• Whether the data spacing and distribution is sufficient to establish the	previously in the area of interest.
distribution	degree of geological and grade continuity appropriate for the Mineral	•Hole spacing is appropriate for drilling at this stage in the exploration
	Resource and Ore Reserve estimation procedure(s) and	process.
	classifications applied.	•Sample compositing has been applied.
	• _Whether sample compositing has been applied. _
Orientation	• Whether the orientation of sampling achieves unbiased sampling of	•The orientation of the geology and mineralization at Rosie is steeply
of data in	possible structures and the extent to which this is known, considering	dipping to the south and striking NNW to W.
relation to	the deposit type.
	• If the relationship between the drilling orientation and the orientation
	of key mineralised structures is considered to have introduced a

Duketon Mining Limited ACN 159 084 107 Level 2 25 Richardson Street West Perth WA 6005 T: +61 8 6315 1490

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Criteria	JORC Code explanation	Commentary
geological	sampling bias, this should be assessed and reported if material.
structure
Sample	• The measures taken to ensure sample security.	•Chain of custody is managed by company representatives and is
security		considered appropriate. All samples are bagged in a tied numbered
		calico bag, grouped into larger polyweave bags and cable tied.
		Polyweave bags are placed into larger bulky bags with a sample
		submission sheet and tied shut. Consignment note and delivery
		address details are written on the side of the bag and delivered to Toll
		in Laverton. The bags are delivered directly to Bureau Veritas in
		Canning Vale, WA who are NATA accredited for compliance with
		ISO/IEC17025:2005.
Audits or	• The results of any audits or reviews of sampling techniques and data.	•No external audits or reviews have been conducted apart from
reviews		internal company review.

Section 2 Reporting of Exploration Results

(Criteria listed in the preceding section also apply to this section.)

Criteria	JORC Code explanation	Commentary
Mineral	• Type, reference name/number, location and ownership including	•The tenement (M38/1252) is 100% owned by Duketon Mining Limited
tenement	agreements or material issues with third parties such as joint	and is in good standing and there are no known impediments to
and land	ventures, partnerships, overriding royalties, native title interests,	obtaining a licence to operate in the area.
tenure status	historical sites, wilderness or national park and environmental
	settings.
	• The security of the tenure held at the time of reporting along with any
	_known impediments to obtaining a licence to operate inthe area. _

Duketon Mining Limited ACN 159 084 107 Level 2 25 Richardson Street West Perth WA 6005 T: +61 8 6315 1490

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Criteria	JORC Code explanation	Commentary
Exploration	• Acknowledgment and appraisal of exploration by other parties.	•Previous drilling at The Bulge Complex was completed by
done by		Independence Group (IGO) and South Boulder Mines Ltd. This work
other parties		has been checked for quality as far as possible and formed the basis
		of the follow-up conducted as part of the drilling programme
		presented.
Geology	• Deposit type, geological setting and style of mineralisation.	•The Rosie Nickel Deposit is a komatiite-hosted nickel sulphide
		deposit. The mineralisation is characterised by accumulations of
		massive, matrix, breccia and disseminated sulphides at the basal
		contact overlying a basalt footwall.
Drill hole	• A summary of all information material to the understanding of the	•Significant intercepts are provided in a table within the text of this
Information	exploration results including a tabulation of the following information	announcement.
	for all Material drill holes:
	o easting and northing of the drill hole collar
	o elevation or RL (Reduced Level – elevation above sea level in
	metres) of the drill hole collar
	o dip and azimuth of the hole
	o down hole length and interception depth
	o hole length.
Data	• In reporting Exploration Results, weighting averaging techniques,	•No top-cuts have been applied when reporting results.
aggregation	maximum and/or minimum grade truncations (eg cutting of high	•First assay from the interval in question is reported (i.e. Ni1).
methods	grades) and cut-off grades are usually Material and should be stated.	•Aggregate sample assays calculated using a length weighted
	• Where aggregate intercepts incorporate short lengths of high grade	average.
	results and longer lengths of low grade results, the procedure used	•Significant grade intervals are based on intercepts > 4000ppm nickel.
	for such aggregation should be stated and some typical examples of	•No metal equivalent values have been used for reporting of results.
	such aggregations should be shown in detail.
	• The assumptions used for any reporting of metal equivalent values
	_should be clearly stated. _
Relationship	• If the geometry of the mineralisation with respect to the drill hole	•Downhole length is reported for the drillholes.
between	angle is known, its nature should be reported.
mineralisatio	• If it is not knownand only the down hole lengths are reported, there

Duketon Mining Limited ACN 159 084 107 Level 2 25 Richardson Street West Perth WA 6005 T: +61 8 6315 1490

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Criteria	JORC Code explanation	Commentary
n widths and	should be a clear statement to this effect (eg ‘down hole length, true
intercept	width not known’).
lengths
Diagrams	• Appropriate maps and sections (with scales) and tabulations of	•Refer to figures in document.
	intercepts should be included for any significant discovery being
	reported These should include, but not be limited to a plan view of
	_drill hole collar locations and appropriate sectional views. _
Balanced	• Where comprehensive reporting of all Exploration Results is not	•All drillhole locations are reported and a table of significant intervals is
reporting	practicable, representative reporting of both low and high grades	provided in the release text.
	and/or widths should be practiced to avoid misleading reporting of
	_Exploration Results. _
Other	• Other exploration data, if meaningful and material, should be reported	•Refer to document.
substantive	including (but not limited to): geological observations; geophysical
exploration	survey results; geochemical survey results; bulk samples – size and
data	method of treatment; metallurgical test results; bulk density,
	groundwater, geotechnical and rock characteristics; potential
	_deleterious or contaminating substances. _
Further work	• The nature and scale of planned further work (eg tests for lateral	•A discussion of further work underway is contained within the body to
	extensions or depth extensions or large-scale step-out drilling).	this ASX release.
	• Diagrams clearly highlighting the areas of possible extensions,
	including the main geological interpretations and future drilling areas,
	_provided this information is not commercially sensitive. _

Duketon Mining Limited ACN 159 084 107 Level 2 25 Richardson Street West Perth WA 6005 T: +61 8 6315 1490