The Chibuluma deposits are SSC deposits located in the Zambian portion of the Central African Copperbelt. The Copperbelt forms one of the world’s largest metallogenic provinces containing over a third of the world’s cobalt mineral reserves and a tenth of the world’s copper mineral reserves.

The copper-cobalt deposits of the Central African Copperbelt are hosted within a strongly deformed, arcuate belt of rocks that extends from north eastern Angola through southern DRC and into Zambia, referred to as the Lufilian Arc.

Mineralisation in both Zambia and the DRC is largely restricted to the Lower Roan or Mines Group, although vein style mineralisation is locally important higher in the succession (e.g. Kansanshi, Kipushi, Dikulushi). Mineralisation in the Zambian deposits is dominantly sulphide, comprising chalcopyrite, bornite and chalcocite, variably accompanied by pyrite and pyrrhotite, carollite, covellite and diginite. Ore grades are commonly around 3% to 4% Cu and 0.1% to 0.2% Co.

Copperbelt, oxidation and leaching of copper minerals is common to about 45 m to 60 m from surface, although it may be observed to depths of several hundred metres. The leached zone close to surface is commonly barren or very poorly mineralised. Supergene enrichment below the zone of leaching is highly variable with the main supergene minerals including malachite, chalcocite, cuprite, chysocolla and vermiculite.

The Chibuluma South Mine is an underground mine and access to the mine for miners, materials and utilities is through the decline ramp positioned from the bottom of the open pit. Fresh air is downcast through the ramp and is directed to all underground workings. A cut and fill mining method is applied to extract the majority of the orebody and long hole stoping method is often used where the orebody is narrow or to mine the remaining 7.5 m cut where cut and fill mining approaches a mined out level above.

Ore from the Chibuluma South Mine is treated at the on-site Chibuluma concentrator. Ore is first crushed and milled into a fine powder before
being fed into the floatation plant for concentration. At the concentration stage, the ore is mixed with chemicals and introduced to a water bath. Copper sulphides form as a froth at the surface and are skimmed off. The froth is dried and forms a copper concentrate with a grade of 46.0% copper. Trucks then haul the concentrate to CCS, where it is purchased.

The ore from the South section is stockpiled on a ramp with a capacity of 20 kt. The ore with a size grading of - 700 mm is fed by front-end loader directly into a jaw crusher. The product from the jaw crusher is –100 mm and is further crushed by the Hazemac impact crusher to a size of 60% -13.5 mm. This product is then deposited on a 6 kt tonne capacity stockpile. This crusher increased the concentrator capacity from 42 ktpm to 48 ktpm. The crusher can be operated in or out of circuit.

A series of conveyors feed a secondary cone crusher (which acts as a standby unit for the Hazemac impact crusher) via a vibrating scalping screen. The scalping screen undersize and the secondary crusher products are fed to a sizing screen which is in closed circuit with a tertiary cone crusher.

The product from the sizing screen is 85% –13.5 mm and is deposited on a 3 kt capacity stockpile. A conveyor fitted with a weightometer feeds a 20 t mill feed bin and two mill feeder conveyor belts fitted with weightometers feed the two ball mills at a similar rate. A cyclone is in closed circuit with each mill.

The concentrated is de-watered in a thickener and pumped to a filter press. The overflow from the thickener is recycled to the process water tank. Water from the tailings dam is also returned to the process water tank. The fresh water make-up comes from a local stream located 3 km from the processing facility. The concentrate with a moisture content of 10% is deposited on a stockpile.