Overview

Mine Type	Underground
Status	Active
Commodities	Copper Silver
Mining Method	Longhole open stoping
Production Start	...
Mine Life	...
Snapshot	Khoemacau is one of the largest underground copper mines in the world. Newly built, modern underground mine with large stable stopes. PFS complete for ~130ktpa expansion project, with further expansion potential.

Deposit type

• Sediment-hosted
• Breccia pipe / Stockwork
• Stratabound

Summary:

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 10m. 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.

Please also refer to the exploration section that provides more detail on the regional geology.

Mining Methods

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Comminution

Crushers and Mills

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Processing

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Production

Commodity	Units	2024
Copper	t	....

Operational metrics

Metrics	2022
Annual mining capacity	....
Annual milling capacity	....

Personnel

Job Title	Name	Profile	Ref. Date
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