Wiluna Mining : Ore Reserves Update and Feasibility Progress Report

ASX Announcement

12 April 2022

ASX: WMC

ORE RESERVES UPDATE AND FEASIBILITY PROGRESS REPORT

HIGHLIGHTS

ORE RESERVES

• • Updated Ore Reserve now 36.8Mt @ 1.20g/t for 1.42Moz contained gold

• • Underground Ore Reserve at Wiluna increased by 51% (tonnes) and 31% (ounces) to 6.52Mt @ 4.11g/t for 861.9koz of contained gold

• • Increased underground Ore Reserve supports medium to long-term plans to grow gold production with a focus on high-grade underground mining areas

FEASIBILITY STUDIES

• • Feasibility Studies ongoing

• • Stage 1 metrics are positive with targeted production of 110kozpa-125kozpa, AISC of A$1,796/oz (after payable charge of ~A$400/oz), NPV $343 Million, IRR 305%

• • Based on rapidly escalating input costs, tight labour conditions and incomplete feasibility outcomes, the Board has decided to pause further expansion and focus on optimising Stage 1 and project cashflows until conditions improve

• • This allows time to drill out of the Wiluna Mining Centre which contains high-grade mineral inventory of 3.11Moz @ 5.81g/t (above 3.5g/t cut-off) to support further development

• • With further minor, lower-cost modifications, Stage 1 could increase incrementally to produce circa 150kozpa

  Wiluna Mining Corporation Limited (ASX: WMC) ("Wiluna Mining, WMC or the Company") is pleased to report an Ore Reserve update for the Wiluna Mining Centre, as well as an update on the Feasibility Studies being conducted by the Company.

  The Company has made the prudent decision to continue to work on these studies and delay the Stage 2 expansion at this time. We believe more is required for the Stage 2 studies to be considered definitive, especially with additional Resource and Reserve development drilling required, particularly at the southern end of the Wiluna Mining Centre.

  Current economic and social circumstances of rising inflation, COVID disruptions, significant shortages of skilled labour in the state of Western Australia, shipping and equipment supply constraints, as well as the uncertainty over the war in Ukraine have played a major role in convincing management and Board that launching into a two year, multi-million-dollar expansion is not prudent at this time and not in the best interest of our shareholders.

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Given the potential of the multi-million-ounce scale of the Wiluna ore body, we believe that further drilling to define the Resources and Reserves of the Wiluna Mining Centre and gain a greater understanding of the true size of the opportunity in front of us, along with the associated studies, is a far more prudent and sensible to fully optimise the potential of Wiluna. The Company will concentrate on bringing Stage 1 up to commercial production and to optimise Stage 1, which will be fully ramped up by the end of CY2022 with steady-state production estimated initially between 110,000-125,000 ounces per annum that with further minor, low-cost modifications could increase incrementally to produce circa 150,000 ounces per annum.

APRIL 2022 ORE RESERVE UPDATE - SUMMARY

Summary

• • Ore Reserves based on completed internal JORC compliant studies

• • 10% total Ore Reserve increase after depletion from 1.29Moz to 1.42Moz

• • Wiltails Ore Reserve decreased slightly by 43.3koz due to tailing dam construction impacting on a portion of tailings Ore Reserve

• • Importantly, the underground Ore Reserve at the Wiluna Mining Centre increased by 31% (202koz) to 861.9koz @ 4.11 g/t

Wiluna Mining Corporation 2021 Ore Reserve Summary
Mining Centre	Mt Proved g/t Au Koz Au	Mt Probable g/t Au Koz Au	MtTotal g/t AuKoz Au
Wiluna 3	0.20 1.80 11.8	6.58 4.09 865.2	6.78 4.02 876.9
Stockpiles	0.37 0.98 11.8	- - -	0.37 0.98 11.8
Wiltails 4	- - -	29.61 0.56 535.6	29.61 0.56 535.6
TOTAL	0.58 1.27 23.6	36.19 1.20 1400.7	36.76 1.20 1424.3
1 The reported Mineral Resources are inclusive of the Ore Reserves.

2 Tonnes are reported as million tonnes (Mt) and rounded to the nearest 10,000; grade reported in grams per tonne (g/t) to the nearest hundredth gold (Au) ounces are reported as thousands rounded to the nearest 100.

• 3 Wiluna Reserves includes mining from open pit and underground deposits.

• 4 Wiltails Ore Reserve includes reclaimed tailings material in Dam C, Dam H, TSF West and backfilled pits at Adelaide,

Golden Age, Moonlight, and Squib.

The updated Ore Reserve reaffirms the Company's strategy of underground mining and production of gold in concentrate from the newly commissioned processing flotation plant. This strategy will be supported by the operation of the Wiltails retreatment plant which remains on track for commissioning in mid-2022.

The Ore Reserve estimate (as at 31 March 2022) is based on the Mineral Resources announced on 17 November 2021 and has been updated in accordance with the JORC Code 2012 edition.

This Ore Reserve update has included an assessment of

• • Underground mining at the Wiluna Mining Centre.

• • Surface stockpiles.

• • Retreatment of historical tailings.

• • Open-pit mining of Golden Age deposit.

• • Processing of free milling ore through the existing CIL circuit on a campaign basis.

• • Processing of sulphide ore primarily from underground mining initially through the 750ktpa Stage 1 Sulphide flotation plant and ramping up to processing through a 1.5Mtpa Stage 2 Sulphide flotation plant.

• • A gold price of A$2,450/oz has been used for all underground Ore Reserve design and evaluation assessments, and a gold price of $2,500/oz was used for the stockpiled, Golden Age open pit and Wiltails design and evaluation. An updated gold price of A$2,650/oz was used for the financial evaluation of the Ore Reserve estimate.

The increase in underground Ore Reserves continues to endorse the Company's strategy to expand underground Ore Reserves through methodical infill and extensional drilling around the Mineral Resource, supporting near-term production requirements for Stage 1 processing, whilst also ramping up to the planned expanded production rate.

Full details in relation to this estimate have been provided in the Appendix to this announcement titled JORC (2012) Table 1 (see Page 12 of this report). This new Ore Reserve estimate is an update from the Ore Reserve statement released on 16 March 2021 and the 2021 Company Annual Report.

Resource and Reserve drilling is ongoing at Wiluna with currently four rigs drilling at Wiluna. Further updates on our Ore Reserves will be released in the annual Ore Reserve update due in October 2022.

FEASIBILITY STUDY UPDATE - APRIL 2022

The Company has been conducting studies for the past 12 months on Stage 2 and 3 planned expansions of the Wiluna Mining Operations. Stage 1 of the overall expansion has largely been completed with:

• • Underground mine development in the northern end of the Wiluna Mining Centre,

• • The successful commissioning of the concentrator (see Figure 1) in December 2021; and

• • The Wiltails tailings retreatment operation currently under construction and shortly to be commissioned; production expected to be ramped up from July 2022

Once fully ramped up by the end of CY2022, Stage 1 steady-state production is estimated to produce initially between 110,000-125,000 ounces per annum (see variables Table 1).

Figure 1. Stage 1 sulphide flotation plant.

Targeted Stage 1 LOM Metrics (Once in Commercial Production)
Estimated Stage 1 LOM	+10 years
Estimate LOM gold price	A$2,550/oz
Target Underground Tonnes Mined	+750ktpa
Target Throughput: Concentrator	+750ktpa
Target Recovery: Concentrator	83-87%
Target Head Grade: Concentrator	5.0 g/t
Target Production: Concentrator	~100-105kozpa
Target Throughput: Wiltails & Float Tails	2.2Mtpa
Target Head grade: Wiltails & Float Tails	0.45-0.68 g/t
Target Recovery: Wiltails & Float Tails	37-44%
Target Production: Wiltails & Float Tails	~10-20kozpa
Target Gold Production	~110-125kozpa
Target Cash costs (C1)	A$1,120/oz
Target AISC	A$1,396/oz
Target AISC with payability charge included*	A$1,796/oz
*AISC includes a payability charge of ~A$400/oz
Stage 1 Targeted Key Project Outcomes	LOM Value
Gold Recovered	1.5Moz
Gold Sales Revenue at $2,650/oz	A$3.2B
Pre-Tax Project IRR	305%
Pre-Tax Project NPV (10%)	A$343 million

Table 1. Stage 1 metrics.

Notes:

• • Assumes mine grade at 5 g/t from1 July 2022 onwards in line with expectations from drilling

• • Stage 1 metrics based on completed internal JORC compliant studies

• • Underground mining costs at benchmark levels of ~A$114/t ore

• • Tailings retreatment throughput of 2.2Mtpa

ASX: WMC | wilunamining.com.au

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Table 2. Targeted Stage 1 production profile.

FEASIBILITY STUDY SCOPE AND PROGRESS

WMC's 2022 Feasibility Study (FS) of Stage 2 expansion has considered the following key components:

• • Expanding Stage 1 to include underground mining of an estimated mining inventory of 9.9 Mt at an average grade of 4.1 g/t Au at a rate of 1.5 Mtpa with mining services provided through an alliance agreement with the Byrnecut group of companies.

• • Provision of a paste backfill production facility and reticulation to the underground mine.

• • Construction and operation of a new two-stage crushing and milling circuit and expansion of the Stage 1 concentrator.

• • Ongoing wall lifts of tailings dams TSF J and K.

• • Provision of 290 new accommodation rooms in an expanded and renovated Village.

• • Provision of a wastewater treatment facility.

• • Provision of a temporary construction camp to cover the expanded workforce for approximately two years.

• • Provision of an expanded power generation facility and associated reticulation infrastructure additional to the Stage 2 expansion which included a 4MW solar array. The Stage 3 expansion may also include further addition of renewable power generation equipment including wind as well as solar.

• • A modest volume of open-pit mining at the end of the schedule encompassing the currently defined Reserves in the West Mine Area. Free milling ore is assumed to be campaigned through the free-milling circuit while sulphides are campaigned through the expanded Stage 2 flotation circuit.

• • Tailings retreatment "Wiltails". The CIL plant is assumed as being utilised for the continuous processing of tailings from the concentrator and excavation from historical tailings storage facilities.