Summary

Deposit type

• Sediment-hosted
• Breccia pipe / Stockwork
• Stratabound

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.

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.

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. The stratigraphic sequence consists of a basal rift related bimodal volcanic suite named the Kgwebe Formation and consists of predominately rhyolites, andesites and gabbros. The Kgwebe volcanic is unconformably overlain by the Ghanzi Group metasediments. This Group, from oldest to youngest, consists of the Kuke Formation, NPF, D’Kar Formation and Mamuno Formation.

Mineralisation is both stratigraphically and structurally controlled with copper-silver mineralisation occurring at the redox front near the contact between the oxidised Ngwako Pan and the reduced D’Kar Formations. Increased copper-silver 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.

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

Zone 5 and the adjacent deposits are characterised as structurally controlled, sediment hosted strata-bound copper-silver deposits.

Zone 5 has a deposit strike length of 4.2km with mineralisation dipping at 56 degrees to the south-east over an average thickness of 10 m. Mineralisation is situated in the hanging wall sequence, 30m above the contact between the D'Kar Formation and Ngwako Pan Formation. Mineralisation is sub-parallel to lithology and typically cross-cuts host units from the lower D’Kar limestone unit in the south-west to the carbon rich siltstone unit and interbedded alternating siltstone and sandstone unit toward the north-east. The host rock assemblage is sandwiched between two competent sandstone units; the footwall Ngwako Pan quartzite sandstone and the hanging wall Marker sandstone. The down dip extension of mineralisation has been drilled to a maximum depth of 1,200m vertically below surface. The deposit remains open at depth (down dip) and partially along strike.

Mineral boundaries were interpreted to distinguish areas that comprised overburden, oxide plus sulphide minerals and sulphide-only assemblages. The near surface mineralised zone was identified as a transitional sulphide zone that contained both oxide and sulphide minerals. The boundary between this zone and the sulphide only undulates parallel to topography between 60 and 80m depth below the surface. This boundary was defined by acid soluble copper and total copper ratios, logged drill core and recorded specific gravity values. Common minerals found in this zone, in order of abundance, include malachite, bornite, chalcopyrite, native copper and minor chrysocolla. A small zone of deeper oxidation, with mineralisation consisting dominantly of native copper, is located in the centre portion of the deposit. This area shows strong brecciation and extends to depths of 400m below the surface.

Economic mineralisation consists of massive bornite and chalcocite with accompanying chalcopyrite and silver. Locally, secondary massive chalcocite has replaced bornite in the Central portion of the deposit at the forereef slope. These minerals are largely vein hosted and make up the greater than 1.0% Cu grade domain. The mineralisation is hosted within an extensive system of quartz and quartz carbonate veins, shears and cleavages. Parallel and sub-parallel shearing continues for hundreds of metres and are likely influenced by subtle changes in lithology and structure. Within the more competent units, shearing is replaced by brittle deformation, generally in the form of brecciation.

Localised parasitic folds, thrusts and shears have thickened the mineralisation and repeated the stratigraphy resulting in enhanced copper and silver grades over very wide intervals. Structural data in the NE portion of the deposit suggests a gently plunging fold toward the south-west. The fold is overprinted in the centre portion of the deposit by a vertically plunging facies change. These two areas have the highest grades and thickest intervals.

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.

The Zone 5 mine is a bulk mechanised mine, designed for a total production rate of 3.65Mtpa through three (3) mining corridors, with a single mining corridor production rate between 1.0Mtpa to 2.0Mtpa. The ore is transported to surface via a truck haulage system.

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). The first section of the mine incorporates pillars and no pastefill, and then as depth increases pastefill will be used to improve overall resource recovery. Paste fill is planned at depths greater than 445m below surface for North Corridor and 475m below surface for Central Corridor and South Corridor.

In the mining areas, in specially designed truck loops, the loaders transfer the ore from the ore passes to the trucks. Given the current depth of the known mineral resource, trucking was deemed the most practical and the least capital-intensive option. From the loading points, the trucks travel up the decline(s) to the surface for dumping of the ore at the Run Of Mine (ROM) pads.

Given that the orebody has a strike length of more than 4km, it necessitated dividing it up into mining corridors due to the mining method selected, with twin decline systems dedicated to servicing each corridor. (the North Corridor starts as single decline.) The twin decline layout allows for more than 1,000m coverage of strike extent of the orebody, while offering multiple orezone attack points, highly productive layouts, and significant redundancy.

Surface access, through unconsolidated surface sands, to each of the 3 corridor decline systems is achieved through 3 boxcuts, which have dimensions 850 to 900m long, 400 to 450m wide and 52m deep, requiring excavation of 1.3million m³ of material per boxcut.

The decline profile has been designed at 6m x 6m to permit the passage of the largest fleet item, the haulage trucks, as well as for ventilation requirements, while maintaining required and statutory stand-off distances to the excavation walls and associated intermittent construction services (air, water, pumping, power, communications, and secondary ventilation) prior to being repositioned to the independent permanent infrastructure positions. An ergonomic style decline configuration with a minimum radius of 25m has been designed to provide optimal access to levels spaced 25 vertical metres apart, while also allowing trucks to operate at a safe productive speed when travelling up and down the decline. The downward gradient has been designed at 1:7 to maximize the capability of the haulage fleet whilst minimizing decline length per vertical metre.

The level intervals for the LHOS area have been designed at 25m vertical floor to floor based on a maximum accurate production drill hole lengths of approximately 30m. The flat level access is a horizontal drive that marks the beginning of a mine level, linking the decline access to the ore drive. Level accesses have been designed at 50m vertical intervals, however, this increases to 60m when passing the sill pillar locations. From the flat level access, access drives are inclined and declined to intersect the orebody on the 25m vertical level spacing where ore drives will be developed and utilized for stoping. The declines and associated orebody accesses have been positioned on the centroid of the corridors to maximise the corridor’s productivity.

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 between 0.8Mtpa and 1.1Mtpa of ore mining.

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.

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.

Commodity Production

Operational metrics

Personnel

Job Title	Name	Profile	Ref. Date
Exploration Manager	Oarabile Disang		May 20, 2025
Mining Contracts Manager	Brent Alting		May 20, 2025
Mining Manager	Logic Sebopeng		May 20, 2025
Sr. Mine Planner	Boago Maphane		May 20, 2025
Technical Services Manager	Bava Reddy		May 20, 2025