Summary

Deposit type

• Sediment-hosted
• Breccia pipe / Stockwork
• Stratabound

Summary:

The Khoemacau Project consists of a current operating underground copper mine (Zone 5), and a total of 14 other deposits which have defined Mineral Resources, and several are planned to be in production in the near future.

Copper and silver mineralisation is hosted within the Ghanzi-Chobe Fold and Thrust Belt that forms the southern portion of the much larger Pan-African Mobile Belt. In Botswana, the Ghanzi-Chobe Belt is also known as the Kalahari Copper Belt, and it consists of a deformed package of metasedimentary and metavolcanic host rocks that contains several significant stratabound sediment-hosted copper deposits.

Mineralisation is characterised as sediment-hosted copper with multi-stage mineralisation history that includes both diagenetic (sediment hosted) and epigenetic (structurally hosted) events.

The Kalahari Copper Belt consists of a deformed package of meta-sedimentary and metavolcanic rocks that were deposited during the late Mesoproterozoic to early Neoproterozoic eras along the rifted northwest margin of the Kalahari Craton. The late Neoproterozoic collision of the Kalahari and Congo Cratons resulted in the formation of the Pan-African Damara Orogeny forming the present-day structural configuration of the Kalahari Copper Belt.

In Botswana, the Kalahari Copper Belt is host to several well-known stratabound sediment-hosted copper deposits and mining operations.

Deposits generally occur at the margins of basement structures where the stratigraphic redox boundary is controlled by sediment deposition and structural geometry. Flexural slip along bedding on the limbs of parasitic folding were important primary fluid pathways. Brittle fractures, and tectonic breccia at local and deposit scale are the dominant secondary structural mechanisms.

Mineralisation is both stratigraphically and structurally controlled with coppersilver mineralisation occurring at the redox front near the contact between the oxidised Ngwako Pan and the reduced D’Kar Formations. Increased coppersilver grades are principally related to shearing and flexural slip hosted within the less competent ductile units of the D’Kar Formation; shale, siltstone, and sandstone.

The dominant structural trends are northeast-southwest related to the Pan African Damaran–Lufilian Orogen.

Economic copper mineralisation is predominantly chalcocite, bornite and chalcopyrite.

Dimensions
The whole of the Project area is covered by an unmineralised overburden sequence of 2 - 60m depth.

The mineralisation starts immediately below the cover sequence, though the upper 50-60m is variably oxidised, with reduced metallurgical recovery.

The mineralisation at Zone 5 extends over a strike length of 4.2km and dips between 55° and 65° towards the southeast. The resource model extends from the base of oxidation (approximately 60–80m below surface) to a maximum depth of approximately 1,200m vertically below surface with an average thickness of 20 m. Drilling has intersected deeper mineralisation below the bottom of the model and the deposit remains open at depth and along strike.

The Mango NE deposit has defined mineralisation over a total strike length of 5 km dipping at 65° to the southeast. The central portion of the deposit is host to economic mineralisation over a strike length of 1.5 km. The deposit has only been drilled to 700 m below surface and remains open both along strike and at depth. Two copper domains were identified using a high-grade (>1%) copper cut-off. The domains are separated by 5–6 m of low to moderate grade (<0.4%) copper mineralisation. The high-grade wireframes average 6 m width in both the hangingwall and the footwall zones. Both the hanging wall and footwall zone are continuous across the strike of the central portion of the deposit.

The Zeta NE deposit has been drilled over a total strike length of 5 km with mineralisation dipping at 80° toward the northwest. The central portion of the deposit is host to economic mineralisation over a strike length of 1.2 km. Two high-grade (>1%) copper domains are present and are separated by 5–10 m of barren to low-grade (0.2%) copper mineralisation. The high-grade wireframes average 4m width in both the hangingwall and footwall zones. The footwall zone is continuous across the strike of the deposit. Higher-grade mineralisation is not always present in the upper hangingwall zone but is continuous over the Central portion of the deposit. Where both the hangingwall and footwall are intersected, both zones plus dilution average 13 m.

The Zone 5N deposit has been drilled over a strike length of 4.6 km with mineralisation striking at 235° and dipping at 65° to the northwest. The central portion of the deposit is host to economic mineralisation over a strike length of 1.4 km. The deposit has been drilled to 1,000 m below surface and remains open both along strike and at depth. Economic mineralisation has an average thickness of 5 m.

The wireframed mineralisation at Banana Zone covers a strike length of approximately 32 km along each limb and has both a southeast dipping and northwest dipping component. The mineralisation starts immediately below the cover sequence, though the upper 50-60m is variably oxidised, with reduced metallurgical recovery. Away from the well drilled model areas (listed separately below), the classification generally extends to 800 m RL which is approximately 250 m below the topography.

The mineralisation at Zone 6 extends over a strike length of 2km and dips between 47o and 50o towards the southeast. The deposit has a thickness ranging from 2 to 10 m. The resource model extends from the base of oxidation (approximately 80 to 100m below surface) to a maximum depth of approximately 650m vertically below surface. Drilling has intersected deeper mineralisation below the bottom of the model and the deposit remains open in all directions.

At Ophion, the mineralisation wireframes cover a strike distance of approximately 5.5 km and extends to 230 m below surface. Each of the four main mineralisation zones is approximately 2–6 m thick and generally dipping 80° to the northwest. Drilling intersected mineralisation at depths between 23 m and 190 m below surface and always below the base of complete oxidation. On average, the highgrade zones are 8 m in width.

The Selene deposit has been drilled over a total strike length of 7 km and dips approximately 70° to the southeast. Mineralisation has been intersected at depths between 25 m to 200 m from surface, and the deposit remains open at depth. On average, the high-grade zones are 3 m in width.

The Plutus mineralisation extends over a strike length of approximately 3 km and dips between 55° and 65° towards the northwest. The deposit has been drilled to a reasonable density to within 200 m of surface. A limited amount of drilling has taken place down to 500 m from surface in the central portion of the deposit, and the deposit remains open at depth. On average, the zone of copper mineralisation is some 5.5 m wide.

The Zeta deposit has been drilled over a total strike length of 6.5 km with mineralisation dipping at 75° toward the northwest. The mineralisation at Zeta has been identified by drilling over a strike length of approximately 6.5 km. Wireframe interpretations have been extended along this entire length. In the centre of the deposit, mineralisation has been identified to a depth of >600 m below surface and is open at depth. On average the high-grade mineralisation is approximately 5.5 m wide.

Mining Methods

• Longhole open stoping

Summary:

Khoemacau consists of a current operating underground copper mine (Zone 5), and a total of 14 other deposits which have defined Mineral Resources, and several are planned to be in production in the near future.

Commissioning of the Zone 5 mine was completed in 2023 to support an Expansion Project focused on the development and mining of three additional areas (Mango, Zeta North East (Zeta NE) and Zone 5 North (Zone 5N)) that will replace Zone 5 production from the Boseto plant. Current plans propose the expansion of production from Zone 5 from 3.65 Mtpa to 4.50 Mtpa that would be processed through a new processing plant co-located in the immediate vicinity of the existing Zone 5 underground mines.

Zone 5
Ore production at Zone 5 is conducted through Long Hole Open Stoping (LHOS) methods (planned 25m high, 50m long and a minimum width of 3m).

Paste fill is planned at depths greater than 445m below surface for North Corridor and 475m below surface for Central Corridor and South Corridor.

There were five mining methods considered for the Zone 5 development that resulted in 48 primary variations in concept which considered crown pillars, stope orientation, contained metal, mine fill and production profiles.

Engineering studies completed in 2018 confirmed that up-hole, continuous retreat longhole open stoping was the preferred mining method for use with Khoemacau-style deposits exhibiting a tabular geometry and narrow to medium width mineralised zones. The inclusion of paste backfill into the mining system from ~400 m below surface was also shown to add significant value to the project economics by increasing the ultimate extraction of each deposit.

The exercise resulted in an inclined three corridor mining system at Zone 5, with corridor strikes ranging from 0.9 km to 1.1 km in length and where a bulk mechanised mining method was considered most appropriate and utilised uphole longitudinal longhole open stoping and transitioning to paste fill with increasing depth. multiple boxcuts were developed through the Kalahari sand to establish portal faces.

Individual geotechnical design values for each underground mine can vary depending on depth, the following have been included in the design:
– Crown, rib and sill pillars.
– 2.5 m long 25 mm diameter full column resin bolt support at various densities and dependent on the excavation dimensions.
– Cable bolt support for large excavations or areas of poor ground conditions as specified.
– Shotcrete at 50 mm to 60 mm in thickness.
– Backfill from ~400 m below surface in order to increase percentage extraction with the exception of Mango where backfill will not be used.

Mineable Stope Optimiser (MSO) was used to create the stope shapes above the NSR cut-off. Parameters included in the MSO runs were:
– Level spacing 25 m.
– Stope length including rib pillar 50 m.
– Minimum mining width 3.0 m (true width).
– Minimum waste pillar (Zone 5, Zone 5N and Mango 10 m, Zeta NE 5 m).
– Hangingwall dilution skin 0.5 m built into stope shape (Zone 5N, Mango, and Zeta NE).
– Footwall dilution skin 0.5 m built into stope shape (Zone 5N, Mango, and Zeta NE).

The development and drilling rates used at Zone 5 have been based on historical performance for activities estimated. The historical performance to date at Zone 5 has been below what is considered industry standard for some development activities and the development rates assumed/used for the Expansion Deposits are in line with industry standards. These estimates will eventually align as Zone 5 reaches planned performance.

The decline development restarts only once each main level development is completed. This approach has the effect of delaying the decline advance by some 2.5–3 months for each main level development and results in an estimated overall decline system advance rate less than the scheduled instantaneous rate. This approach is also applied to the ore drive development which is stopped when ancillary excavations need to be developed, resulting in an effective ore drive advance rate lower than the instantaneous schedule rate.

Mango NE, Zone 5N, Zeta NE (Expansion Project)
MSO shapes generated for Mango NE, Zeta NE and Zone 5N use the same methodology as used for Zone 5 (planned 25m high, 50m long and a minimum width of 3m).

The current mine designs for the Expansion deposits are based on the Zone 5 single corridor assumptions of a twin decline layout, LHOS and 25 m level spacing.

Banana Zone
Underground mining scenarios were assessed for development of the New Discovery and South Limb Definition deposits and on the deeper portions of the North East Fold deposit. The proposed mining method entails fully mechanised long hole open stope mining with access development and support infrastructure developed in the footwall of the deposit. This arrangement has been demonstrated to be the best approach for the long strike, but in some cases relatively narrow, deposits encountered in the Kalahari. In each case the production rate from the deposit was sized for local conditions and varied between0.8Mtpa and 1.1Mtpa of ore mining.

At North East Fold, the stacked but relatively narrow ore zones were considered better suited to conventional truck and shovel, open pit mining. Mine planning defined the maximum economic depth of the open pit. An analysis of underground mining potential was undertaken on the remaining ore zones below the North East Fold open pit, particularly on the steeply dipping NW limb. The 2022 analysis of the potential for underground mining at NEF concluded that the grade and/or width was not sufficient to support development at the prices in use for that study (USD7600 versus the current MMG corporate Ore Reserve copper price of USD8995/t.

As the Banana Zone (other) areas are in the early stages of project development, as further engineering studies are completed, the individual model areas could change from potentially mineable by open pit methods to a combination of open pit and underground methods. Work completed in 2014 by RPM Global indicated that CC and NEF were the only areas that should be considered open pit targets.

Zeta
Underground mining plans developed for Zeta by RPM Global in 2014 proposed sub-level cave stoping as the mining method. Stope recovery of 90% with 15% dilution was applied, with a minimum mining width of 4 m.

Comminution

Crushers and Mills

Processing

• Jameson Cell Flotation
• Crush & Screen plant
• Flotation
• Dewatering

Summary:

The Boseto sulphide concentrator was upgraded from its original 3.0 million tonnes per annum nameplate capacity, to 3.65 million tonnes per annum to treat the Zone 5 ores. The ores respond well to conventional sulphide flotation, producing approximately 155,000 tonnes of high-grade copper concentrate at 40% Cu and 375g/t Ag. Since commissioning in mid 2021 the process plant has been successfully operated at design capacity and is achieving design performance parameters. The concentrate will be road hauled to port, for shipping and sale on the international market.

Ores mined from the Expansion Project deposits (Zone 5N, Mango and Zeta NE) will be processed through the existing Boseto Plant, a new plant will be constructed for the expanded Zone 5 production using the Boseto Plant being as the basis of design.

Metallurgical processing involves conventional bulk sulphide treatment and recovery including:
- 3-stage crushing and single-stage ball milling;
- Flash flotation, followed by conventional rougher flotation;
- Cleaner flotation with Jameson cells;
- Concentrate Regrind using Glencore HIG mill;
- The process is widely used in the base metals industry.

Growth strategy aiming for 130kt/a Cu at Khoemacau
• Phase 1 (2026-2027): Increase production to 60kt/a utilizing the current plant.
• Phase 2 (2028): Establish a new 4.5Mtpa plant, expand Zone 5, and incorporate additional deposits. Aim for a capacity of 130kt/a with better C1 costs.

A feasibility study is underway for an expansion to 130,000-tonne annual capacity. Construction for this project is expected to commence in 2026, with first concentrate production anticipated in 2028, pending a comprehensive assessment of the timeline in the feasibility study.

Water Supply

Summary:

Water is sourced from Khoemacau owned Boseto and Haka wellfields and supplemented by mine dewatering.

Haka water system licensed for 2Ml/day: pumped through high-density polyethylene pipeline from 5 boreholes to the reservoir and then pumped onto Zone 5 via 40km of buried pipeline.

Studies have identified sources to meet the Expansion’s needs from expansion of the Haka wellfield, and a number of new wellfields.

Commodity Production

Operational metrics

Personnel

Job Title	Name	Profile	Ref. Date
Exploration Manager	Oarabile Disang		May 20, 2025
Maintenance Planner	Onkgolotse Sepako		May 27, 2025
Mining Contracts Manager	Brent Alting		May 20, 2025
Mining Manager	Logic Sebopeng		May 20, 2025
Technical Services Manager	Bava Reddy		May 20, 2025