Cobar Basin PFS Show Substantial Increase in Profit and NPV
ASX Announcement
30 January 2026
ASX: MKR
Manuka Resources Limited - Level 4 Grafton Bond Building, 201 Kent St Sydney NSW Australia 2000
ABN 80 611 963 225 Tel 02- 7253 2020 www.manukaresources.com.au
Manuka Provides Updated Cobar Basin PFS
Highlighting Substantial Increase in Profit and NPV
Highlights
• Project NPV
8
of A$805 million and IRR of 1,092% based on US$95/oz silver,
US$4,800/oz gold prices and AUD/USD of 0.7000.
• 10-Year Mine Plan to produce 13.2 million ounces of silver and 35 thousand
ounces of gold from existing stockpiles and open pits located at the
Wonawinta Silver Mine and Mt Boppy Gold Mine, Cobar Basin.
• Near term production leveraging existing plant with low capex upgrades
• Existing Wonawinta Processing Plant set to return to production in H1 2026.
• Sensitivity Analysis in Table 7 shows varying NPV outcomes from movements
in Spot Gold & Silver prices.
• The Mine Plan is forecast to generate an average EBITDA of A$127 million p.a.
at an average C1 cost of A$34.4/oz silver (including gold credits).
• Mine Plan of 10.9Mt ore, supported by existing Ore Reserves and Mineral
Resources at both Wonawinta and Mt Boppy.
• Pre-production capital costs are estimated at A$26.6 million (including a
contingency of A$2.2 million).
• The Company raised A$15 million in October 2025 and is in the final stages of
reaching a binding agreement for a US$22.5 million debt facility with Nebari
Natural Resources Credit Fund. This ensures Manuka is fully funded to
production and profitability.
• The Wonawinta plant is a highly strategic asset located within trucking
distance of multiple high grade precious and base metals deposits within the
Cobar Basin, providing the Company with significant commercial optionality.
• Ongoing exploration drilling at Mt Boppy targeting high-grade extensions to
gold mineralisation that has historically delivered ~500,000 ounces grading
~15g/t Au. Assays results due during the current quarter.
• Manuka remains fully unhedged, leaving it leveraged to further upside from
movements in precious metals prices.
Manuka’s Executive Chairman, Dennis Karp, commented:
“Manuka is uniquely positioned among junior ASX resource companies as one that is
well set to translate historically high silver and gold prices into substantial near-term
cash returns for the Company and its shareholders.
With our existing 1Mtpa processing plant set to restart within the coming months, debt
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funding to support the modest capital costs nearing finalisation, and an initial 10-year
production plan demonstrating outstanding economics, Manuka presents both as a
compelling and significantly undervalued investment opportunity.
Project execution is ramping up, and we look forward to providing updates to the
market as we progress towards first production”
Figure 1: Location Wonawinta and Mt Boppy Projects within the Cobar basin.
Page 3
Project Summary
Manuka Resources Limited (ASX: MKR, “Manuka” or the “Company”) is pleased to
announce the updated 10-Year Mine Plan for the Wonawinta Silver and Mt Boppy Gold
Mines, respectively located 80km due south and 50km due east of Cobar, within the
prolific Cobar Basin mining province of New South Wales (Figure 1).
Wonawinta was built by Cobar Consolidated Resources (“CCR”) in 2011 and acquired
by Manuka in 2016. Wonawinta comprises a granted mining lease, existing open pit
mines, an existing 1Mtpa CIL processing plant and associated infrastructure including
approved tailings dams and accommodation facilities (Figures 2 – 5).
Between 2021 and 2023, Manuka intermittently and separately processed silver ore
from Wonawinta ROM stockpiles and gold ore from the Mt Boppy Gold Mine (“Mt
Boppy”) through the Wonawinta processing plant before placing the operation on active
care and maintenance in early 2024.
The Production Plan described in this announcement outlines the upgrading and
recommissioning of the Wonawinta processing plant to enhance throughput and leach
performance and deliver a Production Target that comprises:
• 10.4Mt silver ore from selected stockpiles and 5 open pits located adjacent to
the Wonawinta processing plant; and
• an initial 0.2Mt of gold ore from selected areas of larger 2.2Mt Rock Dump,
Tailings and Stockpile Resource located at Mt Boppy; and
• 0.3Mt of high-grade gold ore from the existing Open Pit at Mt Boppy.
The Production Plan estimates a capital requirement of A$26.6 million to bring the
processing plant into production, of which A$11.4 million will be spent on a new
desliming circuit to remove clays that have previously inhibited mill throughput and CIL
recoveries. The upgrade and refurbishment of the processing plant is scheduled to
commence in Q1 2026 with first production from Wonawinta Stockpiles and Mt Boppy
Stockpiles in Q2 2026. Mining is scheduled to commence in Q3 2026.
Over the 10-Year Mine Plan, the Project is forecast to generate an average
EBITDA of A$127 million p.a. at a C1 cost of A$34.4/oz silver (including gold
credits) resulting in an NPV
8
of A$805 million and an IRR of 1,092%.
The Production Target (Table 1) is supported by Reserves for Wonawinta as well as
Mineral Resource Estimates for Wonawinta in-ground deposits, Wonawinta Stockpiles,
Mt Boppy in-ground deposits and Mt Boppy Rock Dumps, Tailings and Stockpiles
(Tables A2- A6, Appendix A).
The 10.9Mt Mine Plan is underpinned by 6.9Mt Reserves and comprises 8% Measured
Resources, 54% Indicated Resources and 39% Inferred Resources. There is a low level
of geological confidence associated with Inferred Resources and there is no certainty
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that further exploration work will result in the conversion of Inferred Resources to
Indicated Resources or return the same grade and tonnage distribution.
The Company has determined that the Production Plan presented herein has been
completed at a Pre-Feasibility Study level.
The 10-Year Mine Plan comprises the mining and reclaiming of a total of 10.9Mt ore
containing 19.0Moz of silver and 46koz of gold. Commencing Q2 2026, Existing ROM
Stockpiles located at Wonawinta and Existing Stockpiles located at Mt Boppy will be
reclaimed and processed through the upgraded Wonawinta Processing Plant. Mining at
Wonawinta will commence in Q3 2026 at the existing Manuka open pit, before
progressing to the Belah, Bimble and Pothole Pits and concluding with the existing
Boundary Pit. Mining of the Mt Boppy Open Pit is scheduled to commence in 2028.
Table 1: Production Target
Source
Tonnes
(Mt)
Waste
(Mt)
Ag
(g/t)
Ag
(Moz)
Au
(g/t)
Au
(koz)
Mt Boppy Stockpiles 0.2 - - 0 1.1 7.3
Mt Boppy Open Pit 0.3 7.0 - - 4.17 39.1
Wonawinta ROM Stockpiles 0.2 - 60 0.4 0.07 0.5
Manuka Open Pit 1.4 3.4 61 2.7 - -
Belah Open Pit 1.1 5.5 67 2.4 - -
Boundary Open Pit 5.5 23.9 54 9.6 - -
Bimble Open Pit 1.8 9 57 3.2 - -
Pothole Open Pit 0.4 0.9 41 0.5 - -
Total 10.9 49.7 53.9 19.0 0.1 46.3
Note: Tonnes and Grade are rounded. Discrepancies in calculated Contained Metal are due to rounding.
A new desliming circuit added to the front end of the Processing Plant will be used to
remove the -38μm size fraction from crushed ROM feed to produce a +38μm product
for milling at a rate between 100 and 135tph (0.8-1.0Mtpa).
Milled feed will leach via an existing CIL and elution circuit with metal recovered via zinc
precipitation to a ~70% silver concentrate filter cake with gold credits that will be shipped
on a weekly basis to the ABC refinery in Sydney.
Previous processing of Wonawinta silver ore by the Company delivered a gold
credit of 1 gold ounce per 435 silver ounces over a 9-month period between
May 2022 and February 2023.
No gold credit has been applied to ore mined from the Wonawinta open pits and
therefore represents a significant potential upside to project cashflows over the
Mine Plan should it continue to be recovered.
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An annual summary of the Mine Plan and forecast cashflows are outlined in Table 2 and
Table 3 respectively.
Figure 2: Location of existing infrastructure, ROM Stockpiles and existing and
proposed open pits at Wonawinta.
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Figure 3: The existing Wonawinta Processing Plant.
Figure 4: ROM Stockpiles adjacent to the Wonawinta Processing Plant.
Page 7
Figure 5: Existing Manuka Open Pit.
Figure 6: Mt Boppy stockpiles and open pit mine.
Page 8
Table 2: Annual Summary of Mine Plan - Physicals
Calendar Year Units Total 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035
WWTA Open Pit Waste Mt 42.7 1.3 6.4 6.7 3.6 4.0 6.5 6.9 5.1 1.6 0.5
WWTA In-Ground Mt 10.2 0.5 1.3 1.0 1.0 1.1 1.2 0.9 1.4 1.4 0.5
Silver Grade g/t Ag 56.5 51 64 59 60 56 54 55 53 53 61
WWTA Stockpiles Mt 0.2 0.2 - - - - - - - - -
Silver Grade g/t Ag 60.3 60 - - - - - - - - -
Mt Boppy Stockpiles Mt 0.2 0.1 0.1 - - - - - - - -
Gold Grade g/t Au 1.1 1.11 1.07 - - - - - - - -
Mt Boppy Open Pit Waste Mt 7.0 - - 2.2 4.2 0.6 - - - - -
Mt Boppy In-Ground Mt 0.3 - - 0.0 0.1 0.2 - - - - -
Gold Grade g/t Au 4.2 - - 1.25 3.26 5.00 - - - - -
Total Ore Mined Mt 10.9 0.8 1.4 1.0 1.1 1.3 1.2 0.9 1.4 1.4 0.5
Total Silver Mined Moz 19.0 1.3 2.6 1.9 1.8 2.0 2.0 1.6 2.4 2.4 1.0
Total Gold Mined koz 46.3 2.8 4.5 0.1 14.1 24.9 - - - - -
Measured % 8% 40% 5% 0% 8% 5% - 9% 15% 1% -
Indicated % 54% 55% 80% 88% 82% 85% 22% 35% 58% 5% -
Inferred % 39% 5% 15% 12% 11% 10% 78% 56% 27% 94% 100%
ROM Feed Mt 10.9 0.6 1.2 1.1 1.2 1.3 1.2 1.0 1.2 1.2 1.0
Milled / Leached Mt 7.8 0.4 0.9 0.8 0.9 0.9 0.8 0.7 0.8 0.8 0.7
Milled/Leached Silver Moz 16.3 0.7 1.7 1.8 1.9 1.8 1.7 1.6 1.6 1.7 1.6
Recovered Silver Moz 13.2 0.6 1.3 1.5 1.6 1.4 1.4 1.3 1.4 1.5 1.4
Recovered Gold koz 35.2 2.9 2.9 - 4.6 18.2 6.6 - - - -
There is a low level of geological confidence associated with Inferred Resources and there is no certainty that further exploration work will
result in the conversion of Inferred Resources to Indicated Resources or return the same grade and tonnage distribution.
Page 9
Table 3: Annual Summary of Mine Plan – Financials
Calendar Year Units Total 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035
Payable Silver Moz 13.2 0.6 1.3 1.5 1.6 1.4 1.4 1.3 1.4 1.5 1.4
Payable Gold koz 35.2 2.4 3.4 - 4.1 18.2 7.1 - - - -
Silver Price US$/oz
95.0 95.0 95.0 95.0 95.0 95.0 95.0 95.0 95.0 95.0
Gold Price US$/oz
4,800 4,800 4,800 4,800 4,800 4,800 4,800 4,800 4,800 4,800
Exchange Rate A$:US$
0.70 0.70 0.70 0.70 0.70 0.70 0.70 0.70 0.70 0.70
Net Silver Revenue A$M 1,786 74 169 196 209 192 186 176 192 199 192
Net Gold Revenue A$M 241 17 23 - 28 125 48 - - - -
Govt. Royalties A$M (66) (3) (6) (6) (8) (11) (8) (6) (6) (6) (6)
Net Revenue A$M 1,961 88 186 189 229 306 226 170 186 193 186
Wonawinta Mining A$M (274) (11) (35) (36) (27) (29) (35) (36) (33) (23) (11)
Mt Boppy Mining A$M (84) (4) (7) (18) (35) (19) (2) - - - -
Processing A$M (266) (17) (31) (27) (29) (32) (28) (26) (26) (26) (24)
G&A + Logistics A$M (71) (5) (7) (7) (7) (7) (7) (7) (7) (7) (7)
EBITDA A$M 1,265 52 106 101 131 220 153 101 120 136 145
Pre Revenue Capex A$M - - - - - - - - - - -
Sustaining Capex A$M (70) (29) (5) (6) (6) (1) (7) (2) (5) (8) (0)
Net Project Cashflow A$M 1,196 23 101 95 125 219 147 99 114 129 144
Cumulative Cashflow A$M
23 124 219 344 563 710 808 923 1,051 1,196
NPV
8
A$M
805.3
IRR
%
1,092%
Average EBITDA p.a.
A$M
126.5
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Financial Assumptions
• A silver price of US$95/oz (~25% below spot of US$118/oz) and a gold price of
US$4,800/oz (~15% below spot of US$5,525/oz) have been used for the base
case financial evaluation.
• An AUD/USD exchange rate of 0.7000 has been adopted reflecting the spot
price.
• A refining charge of A$0.25 per recovered ounce has been applied to both silver
and gold based on typical commercial terms.
• A 4% Government Royalty net of allowable deductions including refining costs,
processing costs and depreciation has been applied.
• The model has been prepared on a real, pre-tax, pre-finance basis. It is noted
however that the Company has an accumulated tax loss position of
approximately A$70 million available to offset against future profits.
• A discount rate of 8% has been applied to calculate NPV.
Project Costs
Operating Costs (Table 4) and Capital costs (Table 5) have been built up from first
principles using a combination of supplier/contractor quotes, recent operating
experience and previous actual costs incurred at Wonawinta and Mt Boppy by Manuka.
Table 4: Operating Cost Summary
Item
LOM Total
(A$M)
A$/oz Ag Unit Rate Unit
Open Pit Mining - Wonawinta 273.8 20.7 5.2 $/t Mined
Open Pit Mining - Mt Boppy 63.0 4.8 8.6 $/t Mined
Stockpile Reclamation - Mt Boppy 2.6 0.2 10.2 $/t Mined
Ore Haulage to Wonawinta 18.7 1.4 38.0 $/t Ore Hauled
Processing Costs 266.0 20.1 34.2 $ Ore Milled
G & A & Logistics 71.1 5.4 9.1 $ Ore Milled
Total Opex 695.2 52.6 89.4 $ Ore Milled
Net Gold Credits (241.0) (18.2) (6.8) $ Ore Milled
Net Opex (C1 incl Gold Credits) 454.3 34.4 82.6 $ Ore Milled
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Table 5: Capital Cost Summary (A$M)
Item
Pre-
Production
During
Production
Total
Crushing/Screening/Deslime Plant 11.1 0.3 11.4
Ads Tk 1
Repairs/Pumpcell/Platforms/Gantry Crane
0.5 0.0 0.5
Control System Upgrade 0.2 0.2 0.4
Product Room (Filter/Retort) 0.4 - 0.4
Restore Site Services 0.5 - 0.5
Elution (Burners/Regen Kiln/Column) 1.1 0.0 1.2
Dewatering Thickener and Detox Upgrade 0.7 1.7 2.3
Plant Repairs/Restoration 0.5 0.4 0.9
Lab Equipment and Restock 0.3 - 0.3
Camp Repairs, Upgrade and Restock 1.1 - 1.1
Offices/Site Ablutions/Laundry 1.2 - 1.2
Replenish Inventory 0.1 - 0.1
Geo Sample Storage/Technical Hardware
and Software
0.7 - 0.7
Safety, Pre-Employment Medicals and
Uniforms
0.3 0.0 0.3
First Fill Reagents 0.5 0.4 0.9
Tailings Dam Lifts 2.3 33.3 36
Mt Boppy Camp Upgrade
- 1.4 1.4
Mt Boppy Technical Services
- 0.6 0.6
TSF3 Bunding
- 3.1 3.1
Sustaining Capex Provision - 3.9 3.9
Contingency 2.2 0.6 2.8
Sub-Total 23.9 45.9 69.7
Processing Staff Ramp Up 1.4 - 1.4
Admin and Management Staff Ramp Up 1.4 - 1.4
Total Capex 26.6 45.9 72.5
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Project Sensitivities
Table 7: Project Sensitivity Matrix: NPV (A$M) vs Silver (US$/oz) vs Gold (US$/oz) at 10%
price increments and AUD/USD 0.7000
A$M
Silver Price change (US$/oz)
48 57 67 76 86 95 105 114 124 133 143
-50% -40% -30% -20% -10% 0% 10% 20% 30% 40% 50%
Gold Price Change (US$/oz
)
7,200 50% 303 421 539 656 774 892 1,009 1,127 1,245 1,362 1,480
6,720 40% 286 404 521 639 757 874 992 1,110 1,227 1,345 1,463
6,240 30% 269 386 504 622 739 857 975 1,092 1,210 1,328 1,445
5,760 20% 251 369 487 604 722 840 957 1,075 1,193 1,310 1,428
5,280 10% 234 352 470 587 705 823 940 1,058 1,176 1,293 1,411
4,800 0% 217 335 452 570 688 805 923 1,041 1,158 1,276 1,394
4,320 -10% 200 317 435 553 670 788 906 1,023 1,141 1,259 1,376
3,840 -20% 182 300 418 535 653 771 888 1,006 1,124 1,242 1,359
3,360 -30% 165 283 401 518 636 754 871 989 1,107 1,224 1,342
2,880 -40% 148 266 383 501 619 736 854 972 1,089 1,207 1,325
2,400 -50% 131 248 366 484 601 719 837 954 1,072 1,190 1,307
Base Case Spot Case
Figure 7: Project Sensitivity Chart (NPV vs Project inputs)
400
500
600
700
800
900
1000
1100
1200
-25%-20%-15%-10%-5%0%5%10%15%20%25%
Project NPV
RecoveryWTA Mining CostsCapexGold
SilverMtB Mining CostsProcessing Costs
Page 13
Implementation Schedule
The Company is targeting financial close on the debt facility and a Final Investment
Decision in Q1 2026. The Company aims to be in production by late Q2 2026 (Table 8).
Table 8: Indicative Implementation Schedule
Workstream
2026
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
De
c
Debt Funding / Final Investment Decision
Re-establish Camp
Re-establish Offices, Stores & Workshop
Refurbish, Modify & Processing Plant
Commission Process Plant
Steady State Production
Construct TSF Lift 3
First Shipment of Silver Concentrate
Mobilise Mining
Mining Commencement
Value Enhancement Opportunities
• Early Production from Mt Boppy Stockpiles: Mt Boppy ore does not require
processing through the proposed new deslime circuit and therefore can be fed
directly into the existing mill. There is an opportunity, given the current gold price,
to commence hauling ore from Mt Boppy Stockpiles to Wonawinta in Q1 2026
and feeding it to the existing plant to generate immediate gold credits.
• Strategic Opportunities in the Cobar Basin: Operating a processing facility
within the Cobar Basin positions Manuka to unlock strategic value. The plant’s
capacity to treat precious metal ores presents opportunities to monetise and
potentially support nearby stranded assets that lack sufficient scale to justify
standalone processing infrastructure.
• Gold Credit from Wonawinta Silver Ore: As previously noted, Manuka has
been generating a modest but meaningful gold credit while processing stockpiles
of Wonawinta silver ore. If gold continues to be recovered consistently throughout
the life of mine, it could deliver a materially positive impact on both project
cashflows and overall valuation.
• Continued Haulage of Mt Boppy Gold Ore: The current Mine Plan incorporates
0.2Mt of gold ore stockpiles from Mt Boppy—a small fraction of the broader 2.2Mt
Resource of mineralised rock dumps, tailings, and stockpiles at the site. Ongoing
identification of high-grade zones within these materials offers the potential to
further increase gold ore feed and enhance cashflow generation.
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• Further Resource-to-Reserve Conversion: The current Mine Plan utilises
10.4Mt of ore—approximately 25% of the total defined in-ground and stockpiled
Resources at Wonawinta. Additional drilling and sampling could enable the
conversion of further Resources into Reserves, thereby extending mine life and
strengthening project economics.
• Exploration Drilling at Mt Boppy and Pipeline Ridge: Manuka is currently
undertaking a gold exploration drilling program at Mt Boppy and Pipeline Ridge.
Positive results at the high-grade Mt Boppy gold mine or at the shallow Pipeline
Ridge deposit may lead to an increase in Resource tonnes that could be
incorporated into the mine plan at a later point
• Mining Fleet Optimisation: As procurement discussions with mining contractors
advance, there is scope to reassess and refine equipment requirements and
associated costs. These negotiations offer the potential to reduce unit mining
costs and improve operating margins.
• Re-optimisation of Open Pit Design: The Wonawinta and Mt Boppy Open Pit
designs were based on pit shells optimised for a silver price of A$50/oz and a
gold price of A$4,000/oz respectively. Given the significant change in precious
metal pricing since the optimisations were complete, there exist an opportunity
to update pit optimisations to determine whether additional lower grade or deeper
ore can be brought into the mine plan and therefore extend mine life.
This announcement has been approved for release by the Board of Manuka Resources
Limited.
For further information contact:
Dennis Karp
Executive Chairman
Manuka Resources Limited
Tel. +61 412 268 114
About Manuka Resources Limited
Manuka Resources Limited (ASX: MKR) is an Australian mining and exploration
company with key gold and silver assets located in the Cobar Basin (NSW), and offshore
vanadium and titanium bearing iron sands in the South Taranaki Bight of New Zealand.
Page 15
Compliance Statements
Information relating to in-ground Mineral Resources Estimate for the Wonawinta Silver
Mine is extracted from the announcement titled “43% Increase in Measured & Indicated
Resources at Wonawinta Silver Project” dated 1 April 2021 and available to view on the
Company’s website. The Company is not aware of any new information or data that
materially affects the information used to compile the Mineral Resource and all material
assumptions and technical parameters underpinning the estimates in the relevant
market announcements continue to apply and have not materially changed.
Information relating to Mineral Resources Estimate for the Wonawinta Stockpiles, Mt
Boppy Rock Dump, Tailings and Stockpiles, and Ore Reserves relating to the in-ground
Wonawinta deposit, the Wonawinta Stockpiles and the Mt Boppy Rock Dump, Tailings
and Stockpiles is extracted from the announcement titled “Updated Cobar Basin
Production Plan” dated 30 May 2025 and available to view on the Company’s website.
The Company is not aware of any new information or data that materially affects the
information used to compile the Mineral Resource and all material assumptions and
technical parameters underpinning the estimates in the relevant market announcements
continue to apply and have not materially changed.
Information relating to the Mineral Resource Estimate and Ore Reserves relating to the
in-ground Mt Boppy Deposit, is extracted from the announcement titled “29 July 2025
Announcement Clarification” dated 5 August 2025 and available to view on the
Company’s website. The Company is not aware of any new information or data that
materially affects the information used to compile the Mineral Resource and all material
assumptions and technical parameters underpinning the estimates in the relevant
market announcements continue to apply and have not materially changed.
Page 16
Appendix A: Project Implementation Plan
Location and Access
Wonawinta and Mt Boppy are located 100km south and 50km east respectively of Cobar
in central New South Wales (Figure A1).
Access to Cobar from the major regional centre of Dubbo is via 300km of State
highways. Access to Wonawinta from Cobar is via 70km of sealed highway and 30km
of shire and private unsealed roads. Access to Mt Boppy is via sealed highway and local
sealed road. The distance by road between Mt Boppy and Wonawinta is approximately
150km via Cobar.
Figure A1: Location of and access to Wonawinta and Mt Boppy relative to Cobar.
Page 17
Project Tenure
The granted tenements held by Manuka Resources Ltd and its wholly owned subsidiary
Mt Boppy Resources Pty Ltd that comprise the Project Implementation Plan and Mine
Plan are listed in Table A1.
Table A1: Mining Leases comprising the Mine Plan
ID Holder Area Grant Date Expiry Date
ML1659 Manuka Resources Limited 923.8 Ha 23-11-2011 23-11-2032
EL7345 Manuka Resources Limited 59 Units 25-05-2009 25-05-2028
MPL240 Mt Boppy Resources Pty Ltd 17.8 Ha 17-01-1986 12-12-2033
ML1681 Mt Boppy Resources Pty Ltd 188.1 Ha 12-12-2012 12-12-2033
ML311 Mt Boppy Resources Pty Ltd 10.12 Ha 08-12-1976 12-12-2033
GL5848 Mt Boppy Resources Pty Ltd 8.63 Ha 15-02-1968 15-06-2033
GL5898 Mt Boppy Resources Pty Ltd 7.51 Ha 21-06-1972 12-12-2033
GL3255 Mt Boppy Resources Pty Ltd 8.28 Ha 20-05-1926 20-05-2033
GL5836 Mt Boppy Resources Pty Ltd 6.05 Ha 15-06-1965 15-06-2033
Wonawinta
Manuka is the 100% owner of the Western Lands Lease (pastoral lease) on which the
Project Mining lease and Mineral Resource is situated.
To date, there are no option agreements or joint venture terms in place for the Project
nor are there commercial obligations on ground covered by tenure comprising
Wonawinta. No compensation agreements are in place for the Project.
Mt Boppy
The property on which the Mount Boppy mine situated is Crown Land. A Native Title
Agreement is in place with the traditional owners over a mining lease on the western
edge (ML1681, not within the current project area). The Company notes that no land
within the licence area may be classified as sensitive land and the site has been subject
to over 100 years of intermittent mining activity. No further approvals other than those
required under the Mining Act 1992 are required for current operations.
Site Layout
Recent aerial images of the Wonawinta and Mt Boppy Project areas labelled with key
features are shown in Figure A2 and A3.
Page 18
Figure A2: Existing layout of Wonawinta
Page 19
Figure A3: Existing layout of Mt Boppy
Page 20
Mineral Resource Estimates & Ore Reserves
Wonawinta
The Wonawinta Mineral Resource Estimate comprises:
• 38.3Mt of in-ground Mineral Resource with a grade of 41.3g/t Ag and 0.54% Pb;
• a Stockpile Mineral Resource of 0.2Mt with a grade of 60g/t Ag and 0.07g/t Au.
The Mineral Resource Estimate for Wonawinta was previously released to the ASX on
1 April 2021 and remains unchanged. The Wonawinta Stockpile Mineral Resource
Estimate was previously released to the ASX on 30 May 2025 and remains unchanged.
The Wonawinta Ore Reserve comprises:
• a 6.2Mt of in-ground Reserve with a grade of 56.4g/t Ag;
• a stockpile Reserve of 0.2Mt with a grade of 60g/t Ag and 0.07g/t Au.
The in-ground Ore Reserve and stockpile Ore Reserve for Wonawinta was previously
released to the ASX on 30 May 2025 and remain unchanged.
Mt Boppy
The Mt Boppy Mineral Resource Estimate comprises:
• 0.3Mt in-ground Mineral Resources grading 4.12g/t Au; and
• A Rock Dump, Tailings and Stockpile Resource of 2.2Mt at 0.84g/t Au.
The Mt Boppy Mineral Resource Estimate was previously released to the ASX on 5
August 2025 and remains unchanged. The Rock Dump, Tailings and Stockpile
Resource Estimate was previously released to the ASX on 30 May 2025 and remains
unchanged.
The Mt Boppy Ore Reserve comprises:
• A Rock Dump, Tailings and Stockpiles comprising 0.2Mt at 1.1g/t Au.
• An Open Pit in-ground Reserve comprising 0.3Mt at 4.2g/t Au
The Rock Dump, Tailings and Stockpile Ore Reserve for Mt Boppy was previously
released to the ASX on 30 May 2025 and remain unchanged. The Open Pit Ore Reserve
was previously released to the ASX on 5 August 2025 and remains unchanged.
A breakdown of the Ore Reserves and Mineral Resources underpinning the Cobar
Basin Mine Plan are shown in Tables A2 – A6.
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Table A2: Mine Plan Ore Reserves
Reserve Category
Tonnes
(Mt)
Ag
(g/t)
Ag
(Moz)
Au
(g/t)
Au
(koz)
Probable – Wonawinta In-Ground 6.2 56.4 11.2 - -
Probable – Wonawinta Stockpiles 0.2 60 0.4 0.07 0.5
Probable – Mt Boppy In-Ground 0.3 - - 4.2 39.0
Probable – Mt Boppy Stockpiles 0.2 - - 1.1 7.3
Total 6.9 52.4 11.6 0.22 46.8
Table A3: Wonawinta In-Ground Mineral Resource Estimate
Resource Category Tonnes (Mt) Ag (g/t) Ag (Moz) Pb (%) Pb (kt)
Measured 1.1 47.3 1.65 0.69 7.5
Indicated 12.3 45.5 18.04 0.83 102.8
Inferred 24.9 39.0 31.25 0.39 96.9
Total 38.3 41.3 50.94 0.54 207.2
Table A4: Wonawinta Stockpiles Mineral Resource Estimate
Resource Category Tonnes (Mt) Ag (g/t) Ag (Moz) Au (g/t) Au (koz)
Measured 0.1 61 0.3 0.03 0.1
Indicated 0.1 58 0.1 0.16 0.4
Total 0.2 60 0.4 0.07 0.5
Table A5: Mt Boppy In-Ground Mineral Resource Estimate
Resource Category Tonnes (Mt) Au (g/t) Au (koz)
Measured 0.2 4.01 21.8
Indicated 0.2 4.24 22.4
Inferred - - -
Total 0.3 4.12 44.2
Table A6: Mt Boppy Mineral Resource Estimate – Rock Dumps, Stockpiles & Tailings
Resource Category Tonnes (Mt) Au (g/t) Au (koz)
Indicated 1.4 0.69 30.0
Inferred 0.9 1.09 30.2
Total 2.2 0.84 60.2
Note: Tonnes and Grade are rounded. Discrepancies in calculated values are due to rounding.
Page 22
Metallurgy - Wonawinta Silver Deposit
Eleven different ore lithologies observed within the Wonawinta Resource have been
grouped into five categories - Oxidised Clays, Fresh Clays, Oxidised Limestone, Fresh
Limestone and Fresh Granite. The proportion of each of these categories within the
Mine Plan is shown in Table A7. These groups have been further assigned a
metallurgical classification of either Clay, Semi-Competent and Competent (Table A8).
The metallurgical characteristics of the Wonawinta ore are intrinsically linked to the
mineralogy of the deposit (Table A8). Analysis of drill cores from the Wonawinta deposit,
were investigated by the CSIRO (2022) utilising a hyperspectral core scanner
(HyLogger3) and X-ray computed tomography to determine mineralogy and 3D
structure. Samples of this core with high Ag content and variable Zn and Pb contents
(from assays provided) were further analysed using the Maia Mapper micro-X-ray
fluorescence scanner to examine the Ag mineralogy and distribution. Characterisation
of the supergene mineralisation and transition zone containing clays and dolostones
indicates Ag occurs along planar features within the cores,and shows that Ag is
transported along cracks within the clay matrix. Pb accumulations are not spatially
correlated with the Ag but, XRF imaging shows they are associated with Mn-oxide and
goethite development in largely clay-rich host rocks. Ag occurs as Ag-halide minerals,
iodargyrite and embolite (a mixture of chlorargyrite and bromargyrite). In some samples
it also occurs with Hg in a phase that preliminary data suggest contains S and Cl but
more work is required to define what this mineral is.
At the top of the underlying dolostone sequence, Ag occurs in clays and goethite
developed in micritic layers and filling vugs in the dolostone. Thermodynamic modelling
shows that Ag mineralogy is controlled by oxidation state within the groundwater, and
that halides can be sourced from the groundwater. Clay mineralogy is controlled by
weathering extent and acidity, while the other economic elements (Zn and Pb) are
deposited in secondary oxide phases and as carbonates respectively.
From a mining perspective the Ag mineralisation is classified into clay, variably oxidised
limestone and dolomite, and fresh limestone and dolomite.
Table A7: Proportion of each Lithology included in the Mine Plan
Lithology Met Class
Tonnes
(Mt)
Oxidised Clays
Clay
5.6
Fresh Clays 2.0
Oxidised Limestone Semi Comp. 1.6
Fresh Limestone
Competent
1.1
Fresh Granite 0.3
Total
10.8
Page 23
Table A8: Stratigraphy and Lithology descriptions for Wonawinta
Ox.
State
Lithology
Met.
Class
Description
Oxidised
Sandstone SST
Clay
S rich (sulphates?) Fe rich fine grained brown sandstone only found in one hole in Bimble in middle of iron rich
clay
Dolomitic and
Limestone
Clays
DOL-CLY +
LST-CLY
High Ca, brown to dk grey clay, well weathered occurring just above, or occasionally within dolomite or
limestone
Light Coloured
Clays
CLY-L
Occurs at the top of drill holes, below soil and silcrete, white, cream, light pink, light grey, light brow, light yellow
etc., low in Fe, Ca and S, except for odd gypsum layer which usually has no silver
Iron Rich Clays CLY-FE
Red, brown, orange with high Fe, low Ca, variable S. Can contain significant proportion of harder material
(manganiferrous ironstone and ferruginous siltstone) occurring usually between light coloured clays and
limestone.
Ferricrete FECR
Found below or within Fe rich clays, and adjoining limestone. Hard, shades of red or brown with highest Fe on
site and low Ca. Can be high Mn (pyrolusite).
Granite OX-GRT Low Ca, S and Fe, medium sized quartz grains occurring at base of drill hole in one hole in Belah
Oxidised
Dolomite and
Limestone
OX DOL +
LST
Semi-
Competent
Highly variable in colour with varying amounts of weathering, Fe, S and quartz-carbonate alteration. Found at
base of drill holes with high Ca. Also known as saprolite (totally oxidised) or saprock (partially oxidised).
Fresh
Dark Clays CLY-C Clay
Grey to black occurring usually below light-coloured clays, sometimes in deeper sections above dolomite and
limestone. Highly variable S sometimes highly elevated.
Fresh Dolomite
and Limestone
FRSH DOL
+ LST
Competent
Grey to dark grey showing no signs of oxidation occurring at base of observed sequences with high Ca and
variable S, sometimes elevated.
Mudstone MDST
Occurring either within or below dark clays often contain visible pyrite and generally dark grey to black but can
occur as shades of olive and pale yellow to brown. Higher S than dark clays and more Fe than iron rich clays.
Low Ca.
Granite FR-GRT Occurring below base of oxidation and assumed to contain sphalerite, galena, silver sulphides and sulphosalts.
Page 24
Deslime mass and silver metal recovery to slimes derived from the -38μm size fraction
of 6 samples collected from crushing/screening trials conducted on the Wonawinta
stockpiles is shown in Figure A4.
Figure A4: Silver/Mass Deportment for -38μm fraction of Wonawinta ore.
Average Leachwell leach recoveries achieved on test work undertaken on more than
600 samples from four pits for various ore lithologies (Table A9).
Table A9: Distribution of Leachwell testwork samples versus lithologies and pits
Met Class Clay
Semi
-
Competent
Competent
LITHO
CODE
SST
DOL
-
CLY +
LST
-
CLY
CLY
-
L
CLY
-
FE
CLY
-
C
FECR
OX
-
GRT
OX DOL + LST
FRSH DOL + LST
MDST
FR
-
GRT
Total
Belah - 5 18 21 25 12 3 5 - - - 89
Bimble 3 5 5 56 46 3 - 9 1 - - 128
Boundary - 6 9 51 61 5 - 30 1 27 - 190
Manuka - 7 16 30 4 4 - 144 19 4 - 228
Total 3 23 48 158 136 24 3 188 21 31 - 635
Avg Rec. 96% 84% 67% 93% 74% 46% 57%
Page 25
Metallurgy – Mt Boppy Gold Deposit
The ore from Mt Boppy is to be sourced from a combination of screened surface dump
and stockpile material by previous mining operations, and open pit ore from planned
dewatering and pushback from the existing open pit. The gold mineralisation at Mt
Boppy is hosted in quartz and quartz-carbonate veins, stockworks and breccias with
pyrite (FeS) the dominant sulphide with subordinate sphalerite (ZnS). The gold
deportment is mostly as very fine grains (~25 μm or finer) hosted within pyrite.
Gold CIL leach recovery for Mt Boppy Stockpile and Open Pit Ore is based on previous
operating experience from when gold ores from Mt Boppy were processed at
Wonawinta by Manuka Resources (Figure A5).
Figure A6 below shows the relationship between feed grade and tail grade for Mt Boppy
ore processed at Wonawinta. It shows that tails below 0.38 g/t gold were never achieved
and a reasonable trend can be shown for tailings grade based on feed grade for feed
grades > 1.3g/t gold. Expected tailings grade is 0.38 g/t for feed grades <1.3g/t gold
and =0.1855*(feed grade g/t gold) + 0.168. Expected gold recovery can then be
calculated from the planned feed grade and predicted tail grade.
Figure A5: Recoveries achieved during the prior processing of Mt Boppy Ore via the
Wonawinta processing plant by Manuka.
Figure A6: the relationship between feed grade and tail grade for Mt Boppy ore processed
at Wonawinta.
0%
20%
40%
60%
80%
100%
0.0
1.0
2.0
3.0
4.0
5.0
Apr-20
May-20
Jun-20
Jul-20
Aug-20
Sep-20
Oct-20
Nov-20
Dec-20
Jan-21
Feb-21
Mar-21
Apr-21
May-21
Jun-21
Jul-21
Aug-21
Sep-21
Oct-21
Nov-21
Dec-21
Jan-22
Feb-22
Jun-23
Jul-23
Aug-23
Sep-23
Oct-23
Nov-23
Dec-23
Recovery
Grade (g/t Au)
Feed (g/t)Tail (g/t)Rec’y (%)
y = 0.1855x + 0.168
R² = 0.8024
-
0.20
0.40
0.60
0.80
1.00
1.20
- 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 5.00
Tailings Grade Au (g/t)
Feed Grade Au (g/t)
Page 26
CIL Gold recoveries for the Mt Boppy Stockpiles through the Wonawinta Processing Plant are
based on bottle roll test results summarised in Table A10.
Table A10: Gold Recoveries of Mt Boppy Stockpiles
Source
Observed
Recovery
Testwork
Basis
Predicted
Recovery
ROM Stockpiles (+22mm) 59% WWTA Bottle Roll 75%
Oxide Area 1B 0-2 & 2-6m 85% WWTA Bottle Roll 75%
Old tailings ROM Pad 50% WWTA Bottle Roll 50%
Fresh Main Dump A4 56% Gekko Bottle Roll 60%
Fresh Main Dump A6 60% Gekko Bottle Roll 60%
Total 64% 68%
The geometallurgical model developed for the Mine Plan is outlined in Table A11.
Table A11: Geometallurgical Model for the Project
Lithology
Deslime CIL
% slimes rec. % rec. %
Clay (Silver) 36% 84% 90%
Semi Competent (Silver) 23% 86% 75%
Competent (Silver) 6% 94% 50%
Mt Boppy Open Pit (Gold) 0% 100% 69-79%
Mt Boppy Stockpiles (Gold) 0% 100% 68%
Wonawinta Stockpiles (Gold) 0.23% gold oz recovered per Ag oz recovered
A negligible Mt Boppy ore slimes content is based on previous operating experience.
A 90% CIL recovery for clay ore is based on the Leachwell data with some modifications.
Laboratory leach tests with carbon showed improved recoveries with early leach tests
indicating “pre-robbing” behaviour with silver re-adsorbing onto clays and other “preg-
robbing” material. Removal of slimes will improve adsorption.
Assaying and metallurgical testwork on the Wonawinta ROM stockpiles have confirmed
a low tenor recoverable gold credit. It has therefore been deemed reasonable to model
gold being produced from the Wonawinta ROM Stockpiles at a ratio of 0.23% ounces
of gold per silver ounce as it had for the 287kt previously processed by the Company.
Page 27
Mining - Wonawinta
Independent consultants Mining Associates were engaged to undertake pit
optimisation, pit design and mine schedule for the in-ground Wonawinta deposits. This
work was carried out utilising the Deswik CAD package and the SPRY scheduling
package. Source, destination and haulage scheduling were undertaken in SPRY.
Deswik’s optimisation module uses the Pseudoflow optimiser algorithm.
The Life Of Mine Plan prepared by Mining Associates was optimised, designed and
scheduled using Measured, Indicated and Inferred Mineral Resource categories and
used as the basis for financial forecasts presented in this announcement; and
Pit Optimisation
A mining block model was created by regularising the Wonawinta Resource Block
model to a standard minimum unit size of 5m x 10m x 2.5m (xyz) to generate a block
model suitable for pit optimisation purposes. Ore losses and mining dilution were
incorporated into the regularisation process and resulted in a reduction of 2.5% silver
ounces versus the Resource block model.
For the Manuka and Boundary pits that have been previously mined, pit slopes were
set as follows:
• the first 3 benches to have 10m bench heights, 65-degree batter angles and 5m
berm widths.
• lower benches (assuming in rock) to have 10-20m bench heights, 70-degree
batter angles and 5m berm widths
A conservative design approach was adopted to pit slope in Belah, Bimble and Pothole
pits (which are yet to be mined) based on previous geotechnical studies (Table A12).
Table A12: Geotechnical parameters adopted for the Belah, Bimble and Pothole pits.
Pit Depth (m)
Batter Height
(m)
Bench Face
Angle (°)
Berm Width
(m)
Overall Slope
Angle – Toe to
Crest (°)
20 10 65 7 48
30
10 65 11 40
15 55 14 40
40
10 65 13 35
15 55 14 35
50
10 65 14 32
15 55 15 32
60
10 65 14 31
15 55 19 31
Page 28
The marginal cut-off grades used for pit optimisation were estimated on an individual
block by block basis using the processing costs, processing recoveries (based on the
assigned geometallurgical classification of the block), G&A costs and royalty costs.
Marginal cut-off grades used to initially determine ore and waste blocks in the pit
optimisation process are outlined in Table A13.
Table A13: Indicative Marginal Cut-Off Grades for Pit Optimisation
Ore Type
Oxidised
Clay
Fresh
Clay
Oxidised
Limestone
Fresh Limestone/
Granite
Mining Cost (A$/t) 3.50 3.50 3.50 3.50
Process/ G&A (A$/t) 27.39 29.17 27.39 36.26
Recovery (%) 75.6% 79.2% 64.5% 51.7%
Marginal Cut-Off 23.3 g/t Ag 23.7 g/t Ag 31.1 g/t Ag 45.1g/t Ag
*Based on a Silver price of A$50/oz, payability of 99.7%, refining charge of A$0.25/oz and Royalty of 2.4%
The mining block model was subsequently coded with the revenue and cost parameters
shown in Table A14 and an iterative process in Pseudoflow to identify the optimal pit
size for mine design. A pit specific mining cost was applied to account for Manuka’s plan
to initially mine on a dry hire basis (Manuka and Belah Pits) before transitioning to an
owner-operator model (Bimble, Pothole and Boundary Pits).
Table A14: Revenue and Cost assumptions used for pit optimisation and design
Revenue Factors Value Units
Silver Price 32.5 US$/oz
Exchange Rate 0.65 A$:US$
Silver Price 50 A$/oz
Royalty 2.4% Ad Valorem
Refining Charge 0.25 A$/ounce
Ag Payability 99.7% Recovered Ounces
Operating Cost Assumptions
Drill & Blast 1.79 $/t blasted
Grade Control 1.63 $/t ore
Mining – Dry Hire 10.15 $/BCM moved
Mining – Owner Operator 3.23 $/BCM moved
Fixed Processing Costs 10.34 $ per annum
Variable Processing Costs 2.17 $/t crushed
plus
13.45 $/t milled
Page 29
Mine Schedule and Pit Designs
The Life of Mine Plan comprises mining of two existing open pits (Manuka and
Boundary) and 3 new open pits (Belah, Bimble and Pothole) located at Wonawinta. Life
of Mine Plan mine scheduling was undertaken in the Micromine SPRY software
package. Source, destination and haulage scheduling was completed on the Life of
Mine Plan pit design.
The Life of Mine Plan (Figure A7) comprises 59% Measured and Indicated Resources
with 41% being sourced from Inferred Resources. Given the larger portion of Inferred
Resources sourced from the Boundary pit, it was scheduled at the end of the Life of
Mine Plan. Manuka plans to undertake Grade Control drilling that will also upgrade the
Inferred Resources to Indicated Resources well in advance of mining taking place.
Figure A7: Life of Mine Plan Mining Schedule and Resource classification
It is noted that a portion of the Boundary pit included in the Life of Mine Plan extends
beyond the current mining lease. The Company is scheduling the required regulatory
approval process to expand the Mining Lease ahead of entering this portion of the pit
before it is scheduled to be mined in the final years of the Life of Mine Plan.
Mining Operations
Mining at Wonawinta (including Load & Haul and Drill & Blast) will be undertaken by an
experienced mining contractor under technical guidance and supervision by Manuka
staff. It will be completed on a day and night shift roster (~8Mtpa) except for periods in
Production Years 1, 4,5,8, 9 and 10 where only a dayshift will be employed.
Page 30
Figure A8: Life of Mine Pit Designs
Page 31
Open Pit Mining – Mt Boppy
The Resource model was regularised to a standard selective mining unit of 2.5m x 5.0m
x 2.5m. Mining dilution and ore losses were accounted for during the standardisation
process, resulting in a 7.8% reduction in gold ounces. A marginal cut-off grade of 1.0g/t
based on a A$4,000/oz gold price was used for pit optimisation. Optimisations were run
at different gold prices to determine the production target sensitivity to changes in the
gold price. There were only minor changes to the production target for gold prices down
to A$3,500/oz.
The proposed design is a cutback that focusses on the southern and central portions of
the existing pit (Figure A9). Overall pit depth increases by 80m, the equivalent of four
benches. The pit design has a single 10m access ramp with four passing bays of 16.5m
width. Geotechnical parameters including slope angles were adopted assuming that
ground conditions that will be experienced are similar to those in the exposed current
pit. A number of geotechnical risks have been identified that will need to be either further
investigated prior to mining or managed throughout the mining process.
There is currently ~500ML of water at the bottom of the current pit from the previous
flooding event. This water will need to be pumped out before mining in the cutback can
take place. At 83 litres per second there is approximately 2.5 months of pumping
required to dewater the pit.
Mining will initially target a rate of 4.5Mt per annum whilst mining predominately waste
material before tapering off as high-grade ore is exposed (Figure A10). Mt Boppy
operations first operate two shifts per day for 17 months, with a forecast 90% availability
and 80% utilisation. When working room reduces towards the base of the pit, there is
eight months of mining on single shifts and utilisation is reduced to 40% and then to
20%, to allow the drill-blast-load-haul cycle to take place in a confined area.
Mining at Mt Boppy (including Load & Haul and Drill & Blast) will be undertaken by an
experienced mining contractor under technical guidance and supervision by Manuka
staff. Mined ore will be stockpiled on site at Mt Boppy and then hauled 150km to
Wonawinta for processing at a rate of ~13kt per month (Figure 12). A contractor has
supplied
Page 32
Figure A9: Cross-Section looking west (Top) and north (Bottom) showing through the
Mt Boppy Orebody showing orebody shape and grade versus the existing, optimised
and designed pit outlines.
Page 33
Figure A10: Mt Boppy Open Pit Cutback Production Target
Figure A11: Resource Classification of the Production Target
Figure A12: Stockpile and Ore Haulage Schedule
-
1.00
2.00
3.00
4.00
5.00
6.00
7.00
-
50,000
100,000
150,000
200,000
250,000
300,000
350,000
400,000
450,000
147101316192225283134
Gold Grade g/t
Ore tonnes
Ore Mined tWaste Mined tGold Grade g/t
0%
20%
40%
60%
80%
100%
147101316192225283134
% Ore Tonnes Mined
Measured TonnesIndicated Tonnes
-
25,000
50,000
75,000
100,000
125,000
150,000
-
15,000
30,000
45,000
1357911131517192123252729313335
Mined Ore Stockpile
Ore Hauled to Wonawinta
(t)
Closing ROM StockpileOre Hauled to WON
Page 34
Stockpile Reclamation – Mt Boppy
Selected material (Table A15) from the Mt Boppy Stockpile and Rock Dump Resource
has been initially identified for haulage to and processing at Wonawinta as a supplement
to the silver ore from Wonawinta ROM Stockpile and open pit material. Approximately
157kt of material is suitable for direct haulage to Wonawinta. A further 102kt of material
will be screened and upgraded prior to haulage to Wonawinta.
Mt Boppy gold ore has previously been hauled to and processed at Wonawinta by
Manuka at rates up to 125 t/hr with gold recovery typically 75-77% via either
electrowinning cell or by zinc precipitation when silver levels in the feed were high.
Table A15: Selected Mt Boppy material included in the Mine Plan (in order of processing)
Source Tonnes fraction Mass Product Grade Au oz
ROM Stockpiles (+22mm) 84,895 >22mm 100% 84,895 1.11 3,030
Oxide Area 1B 0-2 & 2-6m 60,317 Total 100% 60,317 0.85 1,640
Old tailings ROM Pad 12,112 <2mm 100% 12,112 2.42 942
Fresh Main Dump A4 76,086 <22mm 47% 35,677 0.99 1,130
Fresh Main Dump A6 25,990 <22mm 57% 14,749 1.10 520
Total 259,400
207,750 1.09 7,264
Indicated 247,161 195,510 1.10 6,929
Inferred 12,239 12,239 0.85 334
Stockpile reclamation and screening will be performed by contractors with Manuka
providing on-site supervision and auxiliary vehicles.
Haulage to Wonawinta
Ore mined from the Open Pit and reclaimed from the stockpiles and rock dumps will be
hauled ~150km to Wonawinta for processing. Haulage trucks are typically a B-Double
configuration capable of a 55t payload. The trailers will be covered and self-tipping. Ore
haulage rates are based on four trucks operating 6 days per week. Two and a half trips
per day are planned for each truck with breaks during the day to ensure the task is
performed safely and within current national vehicle (fatigue management) guidelines.
Ore haulage drivers would be accommodated either at the Wonawinta or Mt Boppy
camp at Manuka’s cost.
Page 35
Previous Production via Wonawinta Process Plant
The Wonawinta Plant (Figure A13) was originally built by Cobar Consolidated
Resources (CCR) in 2012. Black Oak (BOK) acquired the Wonawinta operation in
September 2014. Manuka Resources Limited (MKR) acquired Wonawinta in June 2016.
Figure A13: Layout of the existing Wonawinta Processing Plant
Since its construction in 2012, approximately 1.7Mt of Silver Ore has reported to have
been milled at an average grade of 95g/t Ag for the recovery of approximately 3.2Moz
of silver for an average recovery of 63.3% (Table A16).
The original plant by CCR was designed to dry attrition ore via log washer before
screening to separate a -2mm fines fraction for downstream processing. Log-washer
undersize, typically containing >100g/t Ag, was pumped over a 1mm trash screen
before cyanide leaching and adsorption of soluble silver onto carbon, followed by
elution, zinc precipitation and filtration to produce a concentrate which was retorted for
mercury removal and smelted to produce silver bars.
It was quickly established that trash screen oversize comprising 15-20% of total feed
routinely assayed >100g/t Ag and at times >200g/t Ag indicating higher grade
mineralisation in the coarser size fractions. Screened +10mm log washer oversize was
also found to contain ~100g/t Ag and this was stockpiled for future processing.
A mobile jaw crusher was subsequently commissioned to improve silver deportment to
the finer -2mm fraction which was estimated at 70%. Leach feed grades were frequently
below those of trash screen oversize grades confirming extensive silver mineralisation
in the coarser particles. Larger 3mm lower deck log washer screens were subsequently
employed reducing log-washer oversize but increasing trash screen oversize which
Page 36
resulted in more frequent downtime due to frequent bogging of slurry transfer lines and
blinding of intertank screens.
BOK installed an 1800kW ball mill to further liberate silver from harder dolomitic
limestone. Silver recoveries of around 70% were reported against a target of 85%. Low
silver production was attributed to ‘unexpected’ ore types and ‘sub-optimal’ plant
practices and procedures. Silver ore was processed from March to September 2015
before a brief period of processing Mt Boppy gold ore in November 2015. MKR
processed open pit gold ore from Mt Boppy over the period April 2020-March 2022
(560kt @ 3.03 g/t Au for 41Koz Au recovered).
MKR processed silver ore stockpiles through the Wonawinta plant from April 2022
through to January 2023, During the period, the Company completed a series of trial
modifications and innovations to the Wonawinta processing facility including the
introduction of a temporary deslime circuit to remove deleterious fine clays from the ore
and increase feed grade into the CIL circuit. Metallurgical test work, confirmed by
production data, saw an uplift in silver feed grades to the leach circuit by up to 100%.
Higher grades and lower clays increased silver loadings onto carbon.
The Company received a rebate of A$1.07M in relation to the trial production program
under the Government’s R&D tax incentive scheme
Table A16: Historic production of Silver ore at Wonawinta
Period Units
CCR
(Mar 2013 to
Mar 2014)
BOK
(Mar 2015 to
Sep 2015)
MKR
(Apr 2022 to
Jan 2023)
TOTAL
Ore Milled tonnes 885,707 483,671 287,000 1,656,378
Milled Grade Ag (g/t) 100.5 95.8 75.9 94.9
Recovery % 61.3% 71.2% 56.3% 63.3%
Silver
Recovered
oz 1,755,019 1,044,963 381,873 3,181,855
Historical Gold Production from Wonawinta ore
During Manuka processing of Wonawinta silver stockpiles, it was observed that there
were gold credits in silver doré and silver concentrate shipments despite only low levels
of gold being identified in previous drilling and assaying of the orebody. Approximately
1,077oz of gold was recovered along with 381,873oz of silver whilst processing 287,000
tonnes of Wonawinta stockpiled silver ore.
Figure A8 plots the ratio of contained gold to contained silver for each delivery to the
refinery as assayed by the refinery. The cumulative average ratio over the period was
calculated to be 0.23%.
Page 37
Historical Gold Production – Mt Boppy
At Mt Boppy Underground mining from 1897 to 1923 extracted in the order of 1 million
tonnes grading on average 16 g/t Au ore to a maximum depth of about 230m (McQueen
2005). Open pit mining first occurred between 2002-2005 when Polymetals mined to a
maximum depth of 80m extracting ~500kt at 5g/t.
Under Manuka’s ownership, open pit mining at Mt Boppy recommenced between April
2020-February 2022. Over 560kt of ore at approximately 3g/t was mined from the pit
and hauled to Wonawinta for processing before a severe weather event caused flooding
in the pit, instability in the pit wall and the subsequent cessation of mining activities.
During the period June-Dec 2023 Manuka processed screened ROM pad and rock
dump material totaling 151kt which was hauled to Wonawinta for processing.
Production results under Manuka is summarised in Table A17.
Table A17: Production of Mt Boppy ore through the Wonawinta plant by Manuka.
Period Units Apr 20 - Feb 22 Jun 23 - Dec 23 Total
Ore Mined / Milled tonnes 560,429 150,760 711,189
Head Grade Au (g/t) 3.03 1.45 2.697862
Recovery % 75% 70% 75%
Recovered Ounces oz 41,219 4,944 46,164
Processing Plant Upgrade Design Basis
The basis for designing the updated flowsheet for processing of Wonawinta silver ore
is to apply the learnings from the previous attempts at silver recovery by continuing the
successful practices and modifying those which proved detrimental or unsuccessful.
The key learning is that the clays or slimes, which are typically of lower silver grade than
the coarser fractions, contribute to numerous operational issues which adversely impact
overall silver recovery and reliable production, and they should be removed from the
processing stream.
Viscous slurries created from slimes prevented effective classification and contributed
to poor slurry flow through the adsorption tank inter-tank screens resulting in blocked
screens and inability to maintain required carbon levels in the adsorption tanks. Screen
blockages cause the adsorption tanks to overflow losing carbon to the bund below, and
cleaning of the screens allowed any carbon to escape the tank and flow into the
subsequent tank, thereby mixing the carbon resulting in a flatter carbon loading profile
which does not assist adsorption or recovery.
In addition, the fine slimes contributed to poor loading capacity of the activated carbon,
presumably by physically blocking access to adsorption sites within the carbon resulting
in soluble silver losses. High loadings of lead were observed on the carbon, however
leach solutions contained little or no lead in solution suggesting that the lead in the
carbon was physically attached and not chemically adsorbed. No chemical treatment
tested resulted in improvements in activity by removing these foulants.
Page 38
Removing the clays also removes some of the original feed mass but with only a small
proportion of the contained silver. Silver mineralisation is more abundant in the +45μm
to 700μm fractions with lower grades reporting to the finer fractions. No other changes
to the flowsheet are required as the removal of fines should alleviate any previous
operational issues that impaired reliability or recovery.
Flowsheet
The proposed flowsheet is a combination of some of the original CCR plant used in the
previous three attempts at silver ore processing at Wonawinta and new equipment to
be installed based on learnings gained from those previous attempts (Figure A14).
Crushing, Screening and Desliming
Crushing comminution data was initially determined to have an average Impact
Crushing Work Index of 5.4kWhr/t for (Friable) and 4.7kWhr/t for (Limestone) for the
twenty samples tested for each composite. This work was conducted on <10mm
material and cannot be compared to a traditional Bond Crushing Work Index. The
maximum work index recorded on single samples was up to 12.8kWhr/t. A design
crushing work index of 10kWhr/t has been used.
ROM stockpile reclaim ore is loaded by a 980 Loader or similar, at a rate of up to 180t/hr
onto a fixed 600mm grizzly located above a crusher feed hopper. Grizzly oversize will
be cast aside and broken with a rock breaker as required.
Figure A14: Schematic of the Wonawinta Flow Sheet showing elements of the existing
plant and the proposed upgrades
Page 39
Figure A15: Example of the proposed modular Jaw Crusher
Grizzly undersize is fed over a grizzly feeder with +65mm oversize feeding a 110kW jaw
crusher (Figure A15). The Jaw crusher discharge and -65mm undersize feed a 200t/hr
capacity log washer. Coarse, deslimed +6mm product from the log washer is fed to a
220kW cone crusher before further screening along with jaw crusher product at 15mm
prior to milling. The 15mm screen oversize is returned to the cone crusher which is
protected by a fixed magnet. Cone crusher operation is assisted by a feed hopper and
variable speed controller.
The -6mm fine fraction containing the clays from the log washer is sent to a deslime
circuit where the aim is to remove the -38μm slimes. The -6mm stream is fed to the first
of two desliming units where the -75μm fraction is removed and the +75μm/-6mm
dewatered fraction sent to the mill feed conveyor. The -75μm fraction is sent to the
second desliming unit where the -38μm fraction is removed and pumped to the tailings
feed hopper with a new pumping arrangement. The +38μm/-75μm fraction is also
dewatered and sent the mill feed hopper.
Milling
The combined +38μm/-75μm, +75μm/-6mm and -15mm screen undersize are conveyed
to the 1800kW ball mill feed chute. Collectively the mill feed will be ground to p80 =
75μm or finer at a rate of approximately 120 t/hr depending on the slimes/coarse ratio
and amount of deslimed material rejected (Figure A16). The 400kW secondary ball mill
will be run in parallel with the primary ball mill, fed from a fraction of hydrocyclone
underflow, to maintain the throughput and achieve as fine a grind as possible.
Page 40
Mill discharge is classified in a hydrocyclone cluster. Classified slurry is fed over a trash
screen to remove wood, plastic and other contaminants before pumping to the existing
leaching and adsorption circuit.
Hydrated lime is dosed onto the mill feed conveyor from a storage silo to a set pH level
to provide protective alkalinity and ensure most of the cyanide added is kept in solution
and does not evolve as cyanide gas. Liquid oxygen is dosed into the discharge of the
leach feed pump to oxidise any cyanide consuming mineralisation and provide adequate
oxygen for the leach reaction.
Leaching and Adsorption
Ground slurry from the grinding circuit is pumped to the first of two leach tanks where
cyanide is added to a set concentration for optimal leaching. Leached slurry then
gravitates to the first of five carbon adsorption tanks where leached silver is adsorbed
onto the carbon in five stages (Figure A17). The flow of carbon is counter-current to the
slurry and is pumped daily from tank to tank.
Each day a twelve-tonne batch of loaded carbon from the first adsorption tank is
pumped over a screen to wash the slurry from the carbon and dewatered carbon is
added to the loaded carbon hopper to commence the elution cycle. A similar amount
of carbon is then pumped from tank to tank to restore the inventory in each tank and the
barren carbon from the previous elution is then added to the last adsorption tank.
Figure A16: Existing 1800kW Ball Mill
Page 41
Figure A17: Existing CIL and Adsorption Tanks and Elution Column
Leached slurry exits the last adsorption tank and is fed over the carbon safety screen
to catch any carbon that may have escaped from the last tank. Slurry passes through
the screen to the final tailings hopper where ferric chloride is added to detoxify residual
cyanide as it is pumped to the tailings dam.
Elution, Zinc Precipitation, Concentrate Filtering and Retorting
The final part of the process is where loaded carbon is stripped of contained silver, and
a silver concentrate produced after zinc precipitation, filtering and retorting to remove
mercury.
The loaded carbon is first washed in dilute hydrochloric acid to remove acid soluble
contaminants on the carbon and then it is washed in potable water before transferring
to the elution column. A caustic and cyanide solution is heated to approximately 110°C
and then pumped through the elution column removing adsorbed silver into a
concentrated solution which is then mixed with zinc to precipitate a silver concentrate
prior to filtering in existing pressure filters. Filtered concentrate is then heated in a retort
furnace to volatilise and collect any contained mercury before the concentrate is packed
in drums and transported to the refinery.
Future Flotation Optionality
Implementation of a flotation circuit to treat sulphidic base metals ore at Wonawinta is
relatively simple with plenty of space to accommodate the flotation and dewatering
circuits required to produce a flotation concentrate. The fine mineralisation would benefit
from Jameson Cells with their very fine bubble size and their footprint is quite small. A
regrind mill already exists on site. Concentrate logistics are provided by nearby rail
loading facilities at Cobar and Hermidale.
Page 42
Commissioning
Process Plant Commissioning will be managed by the Project Manager with assistance
from the MKR Owners Team and mechanical and electrical installers, process control
contractors and OEM support. Commissioning will occur in 5 stages:
• Equipment Installation Verification Confirm that all mechanical equipment is
correctly installed—alignment, fasteners, guards—and that electrical
installations (cabling, terminations, earthing) meet specification.
• Energisation Apply and verify power to all motors, drives, and control panels,
conduct insulation and safety tests, and ensure all electrical systems operate
reliably under no‐load conditions.
• Wet Commissioning Introduce and circulate water through every process
circuit. Inspect for leaks, confirm pump flow rates, and validate screens,
cyclones, and other water‐handling equipment for proper operation.
• Slurry Commissioning Feed a slurry of solids and water at near‐design
concentrations and flow rates. Calibrate and test sensors, valves, and
throughput controls, and verify mass‐balance and performance across each
unit operation.
• Performance Assessment & Handover Execute acceptance tests to confirm
that throughput, recovery, power consumption, and other key performance
metrics meet contractual guarantees. Resolve any remaining punch‐list items,
compile “as‐run” documentation, and formally hand over the plant to operations.
It is planned to commission the plant using ore from existing ROM stockpiles. A Mineral
Resource Estimate and Reserve of 0.2Mt at 60g/t Ag and 0.07g/t Au has been assigned
to the existing ROM stockpiles at Wonawinta. Further details of the ROM Stockpile
Resource are discussed in Appendix C.
The first stockpiles to be processed will be the remnant Mt Boppy -22mm gold ore
stockpiles located closest to the ball mill feed hopper. This ore can be fed directly into
the ball mill via the feed hopper as it is already crushed and screened.
A blend of stockpiles will be used for initial crushing, screening and deslime circuit
commissioning. The blend would start on more competent material to test the crushing
and screening capability first before introducing more fines to then test the deslime
circuit capability.
It is anticipated to take between 3 and 4 months to complete process plant ramp up and
deplete the existing ROM stockpile and in doing so prepare the ROM Pad for the
commencement of Mining at Wonawinta and receipt of hauled Ore from Mt Boppy
Mt Boppy gold ore would be processed in conjunction with the Wonawinta silver ore
mine from open pits located at Wonawinta as an incremental part of the feed blend using
the upgraded process plant design described above.
Page 43
The nameplate design capacity of the proposed new crushing and screening circuit is
180t/hr and can accommodate the expected maximum feed rate of up to 170t/hr.
The planned 12,698 t/month of gold ore equates to an incremental milling rate of 19t/hr
(assuming 100% mass recovery of Mt Boppy ore through the deslime circuit). With
100t/hr of Wonawinta silver ore this would total 119 t/hr of mill feed. The nameplate
capacity of the grinding circuit is 135 t/hr and has previously been run up to 125 t/hr on
Mt Boppy gold ore screened to <22mm.
Stockpile Management and Ore Blending
The ROM stockpile covers an approximate area of 70,000m
2
of which 300m x 200m or
60,000 m
2
is available for ROM ore stockpiling and blending, close enough to the
proposed jaw crusher feed bin to comfortably feed the circuit with a single CAT 980
loader or similar.
Ore will be stockpiled based on ore lithology, namely clay, pyritic clay, semi-competent
and competent ore. Pyritic clays will be stockpiled close to the ROM until a suitable
processing strategy is identified. Two fingers for each ore lithology will be required, one
finger for dumping whilst the other finger is reclaimed. The stockpile height needs to be
limited to 5m to allow the CAT 980 Loader safe access to the ore for reclaiming with
minimal risk of engulfment.
The available area has space for at least 8 x 20m wide stockpiles which could be up to
300m long if aligned parallel to the mill feed conveyor. Using a bulk density of 1.6t/m3
means that up to 160,000t of ore can be easily stored in this manner. Additional areas
are available for ROM storage if required. Expected crushing rates of up to 180t/hr can
be safely maintained with tramming distances up to 250m.
Tailings Storage Facility
Background
The existing Wonawinta Tailing Storage Facility (TSF) is a “turkey’s nest” type
impoundment situated north of the processing plant with embankments constructed
from mining waste. The northwest and east embankments are keyed into in-situ
sequences in the northeast corner where elevations are higher and form the northern
boundary of the storage.
Tailings deposition on the TSF is with perimeter piping and spigoting feeding towards
the central decant for water recovery maintaining a minimum 0.5m freeboard between
the height of the surrounding crest and the highest level of tailings deposition.
The TSF has a central concrete decant structure accessed by a causeway extending
from the east embankment. Favourable topography and location of the TSF relative to
the process plant enabled installation of a gravity decant system to remove decant water
from the TSF rather than a pumped decant system. The gravity decant drainage pipe
discharges decant water through a conduit passing beneath initial embankment and is
Page 44
embedded into the natural foundation. The reclaimed water is returned to the HDPE
lined Process Water Pond for reuse.
The original TSF design planned for seven upstream lifts to be constructed in nine
stages. An initial 10m starter embankment (Stage 1A) and a downstream 3m
embankment (Stage 1B) were to be followed by seven 2.5m lifts to a final crest height
of RL 279.5. To date Lift 1 (Stage 1A and Stage 1B) and Lift 2 have been completed.
Future Lifts
Noting that the practice of upstream lifts on old tailings is no longer the favoured/default
construction technique and either a centreline or downstream lift construction
methodology is encouraged where possible, Life of Mine tailings storage capacity has
been estimated using the existing starting footprint, centre-line construction
methodology with 8 x 2.5m lifts on top of Lift 1 Stage B and a consolidated tailings bulk
density of 1.6t/m
3
acquired from recent drilling data resulting in a notional capacity of
1.7Mt tails for each lift providing a total 10.8Mt tailings storage capacity
Calculated tailings capacity versus the 10-year mine plan conceptual lift construction
methodology and are shown in Table A18 and Figure A18. The next lift on the TSF will
be required to be completed mid-2026 assuming a H1 2026 start of production. It is
therefore planned to commence construction of Lift 3 in Q2 2026 with completion of
design / alternative solutions, approvals and construction documentation expected in
Q1 2026. Construction methodology has not been finalised but would be completed by
a specialised earthmoving and civil-construction contractor using their own fleet and
personnel, working under the instructions and supervision of a Project Manager and
TSF Designer.
Table A18: Calculation Tailings Capacity versus the Life of Mine Plan
CY 25 26 27 28 29 30 31 32 33 34 35 Total
Tonnes - 1.19 1.06 1.14 1.13 1.10 1.12 1.04 1.17 1.17 0.66 10.79
Cum. - 1.19 2.25 3.39 4.52 5.62 6.74 7.78 8.95 10.13 10.79 -
Lift 3 - 1.19 0.66 - - - - - - - - 1.85
Lift 4 - - 0.40 0.97 - - - - - - - 1.38
Lift 5 - - - 0.17 1.13 0.08 - - - - - 1.38
Lift 6 - - - - - 1.02 0.35 - - - - 1.38
Lift 7 - - - - - - 0.76 0.61 - - - 1.38
Lift 8 - - - - - - - 0.43 0.95 - - 1.38
Lift 9 - - - - - - - - 0.23 1.15 - 1.38
Lift 10 - - - - - - - - - 0.02 0.66 0.69
Capacity - 1.19 1.06 1.14 1.13 1.10 1.12 1.04 1.17 1.17 0.66 10.79
Page 45
Figure A18: Conceptual design of TSF centre-line lifts vs the existing TSF embankment.
Power
Power to the process plant will be provided by four hired 1250KVA diesel gensets on
an N+1 basis. A single 1,675KVA genset (owned by Manuka) will be used to supply
power during process plant shutdowns and through process plant start-up to support
peak draw requirements. Power for the water bores and camp is supplied by separate
smaller 220KVA diesel generators.
Site Offices and Ablutions
An overhead view of existing site offices, buildings and associated infrastructure is in
Figure A19. The administration office block has eight office rooms that can each
accommodate two desks and two larger rooms that can accommodate at least four
desks each, a large manager’s office and meeting area, and a crib room that can seat
approximately 12-15 people. A large training room for 20-30 people is in a separate
building which also contains three female toilets and showers and changing area, the
site laundry and storeroom and a small office. Three male toilets, six showers and
change facilities are in a separate building. The First Aid building also has an office and
storeroom. A small spare office is also available.
Planned upgrades for when mining personnel are mobilised to site include the following:
• New ablution buildings for the mining personnel. Two buildings, one each for
males and females are planned, located in the area allocated for mining
equipment parking, maintenance, workshop and office. A new crib room with
office will also be required.
• A new sewerage system, or upgrade to the existing system may be required.
Page 46
Figure A19: Layout of the existing administration and ablution facilities
Water
Site make up water is provided from a borefield located approximately 4km south of the
processing plant. The borefield was developed in September 2012 based on the original
plant design and has an estimated 25L/s production capacity.
Bore water is received at the plant in the Raw Water Pond and it can also be directed
into the Process Water Pond. Both ponds are lined with HDPE liner to prevent leakage.
Raw water is distributed to the processing plant through a duty/standby pumping
arrangement and is available for dust suppression at a dedicated standpipe fed by a
diesel-powered pump. Raw water also feeds the Reverse Osmosis (RO) plant to
produce potable water.
The introduction of the deslime circuit will result in a negative overall site water balance
as significant water used in the process is lost with the slimes to the tailings dam. To
avoid this imbalance a dewatering thicker will be included in the deslime circuit to reduce
the slimes moisture content from 90% to between 45-55% and recover between 93 –
98L/s of water for reuse in the processing circuit (Table A19).
Page 47
Table A19: Site wide water balance
Base Case (30% to slimes) t/hr wt% solids wt% moist. L/s
ROM Feed 143 92 8 4
Deslime to Tailings 43 10 90 (107)
Leach Tailings 100 48 52 (30)
Decant Return
21
Site Dust Suppression
(2)
Total Losses
(115)
Bore water
25
Surface Water Harvesting
2
Total Inputs
27
Balance (pre-dewatering)
(88)
Dewatering Thickener
92.7 - 97.5
Balance (post-dewatering) 4.3 - 9.1
Camp Accommodation
The Wonawinta mine camp (Figure A20) lies just over 2 km east of the process plant
and administration buildings. The existing facility comprises eighteen industry-standard
accommodation units, housing up to 70 residents in single-bed, ensuite rooms equipped
with air conditioning, a wardrobe, small refrigerator, networked TV, desk and chair.
Manuka personnel will clean and maintain all rooms.
Central amenities include a fully segregated kitchen and food-storage area, a large
dining hall with seating for 30, and a recreation building with gym facilities. Camp
operations and support services will be staffed by Manuka employees.
To accommodate the anticipated increase in headcount, two additional four-room
blocks (each room with an ensuite) will be installed, boosting capacity to 78. Suitable
units are available at MKR’s Mt Boppy camp and can be relocated if required;
alternatively, new units have been budgeted for in the capex estimate.
Page 48
Figure A20: Layout of the existing accommodation camp
Infrastructure – Mt Boppy
Available infrastructure at Mt Boppy includes grid power, potable water from Cobar, tar
road access, and a ~40 person camp with kitchen and ablutions (Figure A21), a 70kL
diesel storage facility, an undercover heavy mining equipment workshop area (Figure
A22), and mine offices. A capital provision has been made to upgrade the
accommodation facilities and an engineered bund to manage the interaction between
cutback and the dry tailings impoundment (TSF3) located at the southern end of the Mt
Boppy Open Pit.
Wonawinta - Workforce
The Project will employ up to 140 personnel (Figure A23) operating on a mix of roster
patterns—5/24/3, 8/6 day-shift, 7/7 day-shift, 7/7 night-shift, and 7/7 continuous-shift.
Peak camp accommodation must support approximately 75 beds, including a 15%
percent contingency for contractors and visitors. Staffing forecasts and corresponding
camp requirements over time are illustrated in Figure A23.
The organisational structure is led by an Operations Manager with direct reports
including the Senior Metallurgist and Managers for Processing, Maintenance,
Administration, and HSE. During the construction and commissioning phase, an
experienced Construction Manager will be engaged to oversee project delivery. A Mine
Manager—holding the requisite statutory quarry ticket—will also report to the
Operations Manager. An organisational chart is provided in Figure A24.
Page 49
Figure A21: Existing camp facilities located at Mt Boppy.
Figure A22: Existing mining and diesel power infrastructure at Mt Boppy.
Page 50
Figure A23: Employee Count.
Figure A24: Project Organisation Chart.
Page 51
Environment and Approvals
Wonawinta
Wonawinta is situated on an existing mining lease, with approvals in place from prior
operations. These approvals are still in place for four pits. In essence nothing material
needs to be done to modify any current approval to recommence mining as the original
conditions which considered four pits have not varied. Regularising of existing approvals
will be undertaken to allow for additional open pits within the existing disturbance
footprint or to allow for greater footprints of waste dumps etc.
Manuka in April 2025 engaged Irwin Environmental Management Pty Ltd to undertake
an environmental compliance audit. The audit conclusions were that the Company is
maintaining the Wonawinta Mine Site under care and maintenance in a manner which
satisfactorily reduces the risk of harm to the environment. Some non-compliances have
been noted, with the majority of these representing matters which are administrative in
nature or have low risk of adverse environmental impact.
The following approvals are current for the Wonawinta Mine.
• Development Consent 2010/LD00074: issued by Cobar Shire Council (Council)
and modified three times (most recently 15 September 2015).
• Environment Protection Licence (EPL) 20020: issued by the NSW Environment
Protection Authority (EPA).
• Mining Lease (ML) 1659: Issued by the Minister for Resources and Energy on 23
November 2011.
• Water Supply Works Approval 85WA752614: issued by the Department of
Climate Change, Energy, Environment and Water (DCCEEW) for eight
groundwater bores.
• Water Access Licence (WAL) 30322: issued by WaterNSW for take of up to 750
units from the Kanmantoo Fold Belt MDB Groundwater Source.
The Life of Mine Plan proposes some new waste dump locations, capacities and
designs. These updated designs will be modified or regularised to existing approvals in
due course and will not impede development timelines.
A Material Characterisation Report was undertaken by Landloch Pty Ltd the conclusions
included:
• The main chemical constraints of the Clay and Waste rock material were salinity,
sodicity and alkalinity. Gypsum will ameliorate the sodicity and PH constraints.
Screening for PH and salinity needs to take place before the addition of gypsum.
• Plant species used in rehabilitation need to have a high salt tolerance.
Planning for the Tailings dam lifts and tailings disposal is still ongoing. This work is
well progressed by the Company’s TSF engineer but is not yet completed at the date
of publication of this Mine Plan.
Page 52
Mt Boppy
Existing Development Approvals with Cobar Shire Council (CSC), and related licences
and consents are summarised in Table A20 and A21:
Table A20: Cobar Shire Council Development Approvals
Development
Approvals
Date
Granted
Expiry Details / Comments
Development
Consent
2012/LD-00034
22 Nov 2012 N/A Granted by Cobar Shire Council (CSC) for the
expansion of the off-lease mining camp.
Development
Consent
2011/LD-00070
27 Sep 2012 N/A Granted for the continuation of mining and
processing of ore at an upgraded processing
plant on the Mine Site, including construction
of new TSF
Development
Consent
2011/LD-00070-
Rev01
27 Jul 2015 N/A Modification of DC granted by CSC to add five
new conditions and to alter specific conditions
within original DC.
Condition 1 altered to include the 2015
Statement of Environmental Effects ([SEE]
Reference No. 569/05) as legal
supplementary document.
Condition 23 altered to modify stated
timeframe to “the determination date of the
first modification approval of the consent.”
New Conditions (i) to (v) were added for
approval of, and supplementary conditions for:
•Submission of required plans.
•Obtaining site specific licences.
•Granting the extension and operation of the
mine including mining of approximately
630,000t of ore.
•Management of potentially acid forming
waste rock.
•Transportation of ore to the Manuka Mine
(Wonawinta).
•Construction of temporary mine water storage
dams, roadways and road drainage.
•24-hour 7-days per week operations.
•Additional rehab requirements.
Page 53
Table A21: Development Consent Licences
License Date
Issu
ed
Expi
ry
Details
Environment
Protection
Licence No.
20192
10
Jan
2013
N/A Issued by NSW EPA under the Protection of the
Environment Operations Act 1997 (‘POEO Act’).
Current licence version is Notice No: 1566717.
Groundwater
Licence
85BL256088
24
May
2011
N/A Issued by the (then) NSW Office of Water (NOW) for
monitoring bores PBP001, PBP003, PBP004, PBP018,
PBP019 and PBP020.
Groundwater
Licence
85WA752612
16
Jan
2012
16
Mar
2033
Issued by the NOW for water supply works associated
with three historic water supply bores within Lot 7301
DP 1170536.
Groundwater
Licence
85WA753524
10
Jun
2013
6
Jun
2033
Issued by NOW for water supply works associated with
excavation of the open cut pit and production water.
Licence
WAL30045
14
Jun
2012
N/A Issued by NOW providing entitlement to 250Ml from the
Lachlan Fold Belt MDB Groundwater Source.
Three mining leases (ML 240, 311 and 1681) issued under the Mining Act 1992 and
four Gold Leases (GL 3255, 5836, 5848 and 5898) issued under the Mining Act 1906,
are held by Mt Boppy Resources Pty Ltd (a wholly owned subsidiary of Manuka). All
permits are current and in good standing.
The property on which the Mount Boppy mine is situated is on Crown Land. A Native
Title Agreement is in place with the traditional owners over ML1681 however no current
production is anticipated from this lease. The Company notes that no land within the
licence area is classified as sensitive land. No further approvals other than those
required under the Mining Act 1992 are required.
Mt Boppy operates under Development Consents 2006/LD00015 and 2011/LD-00070-
Rev1, inclusive of an amended Mining Operations Plan (2020). A compliance review
was completed in Dec 2024 on the Mt Boppy Mine. The following approvals are
current for the Mt Boppy Gold Mine.
• Development Consent 2006/lD00015: issued by Cobar Shire Council (Council).
• Development Consent 2011/lD0070: issued by Council and modified in 2015.
• Environment Protection Licence (EPL) 20192: issued by the NSW Environment
Protection Authority (EPA).
• Water Supply Works Approval 85WA752611: issued by the Department of Climate
Change, Energy, Environment and Water (DCCEW) for two groundwater bores.
• Water Supply Works Approval 85WA753524: issued by DCCEW for groundwater
extraction from an open excavation (open cut).
Page 54
• Water Supply Works Approval 85WA753525: issued by DCCEW for watercourse
diversion.
• Water Access Licence (WAL) 30045: issued by WaterNSW for take of up to 250
units from the Lachlan Fold Belt MDB Groundwater Source.
Water quality of the Open Pit water is suitable for stock (based on prior and current
analysis), and approvals are in hand for pumping out using existing return water storage
dams, evaporation or else the mostly dry creek bed adjacent to the Open Pit.
Waste rock geochemical characterisation has been undertaken through ICP analyses
at ALS Orange of evaluation drilling sampling of the Mt Boppy orebody. The Mineral
Resource block model incorporates these analyses. Waste characterisation testing
completed to date confirms that a proportion of the waste rock is classified as Potentially
Acid Forming (PAF). PAF material has been encountered once mining reached depths
of approximately 50m to 60m below ground level. PAF waste rock material with total
sulphur content greater than 1% (~242,148bcm) will be placed either within the existing
TSF3 structure or a new separate area demarcated within the Main Waste Dump prior
to capping. The remaining PAF material with total sulphur content between 0.3% and
1% (~720,259bcm) will be placed within specially designed sections of the Waste Rock
Emplacement. The remaining ~2,500,000bcm of waste rock is considered non-acid
forming (NAF). It should be noted that no stockpiled PAF material exhibits any signs of
acid formation with generally clean water forming around those piles – this is exhibited
across the entire site.
Data sourced from publicly available NZX filings. Our datasets may not be complete. Automated analysis can produce errors. If you believe any data on this page is incorrect, please contact us at hello@nzxplorer.co.nz. For informational purposes only. Not investment advice.