The Company's Usoke processing facility is located in Lubumbashi, approximately 10km from the Etoile mine. The Usoke plant is the Company's primary processing facility, with existing installed capacity to produce 31,500 tonnes of copper cathodes and 2,400 tonnes of cobalt salt per annum.
A series of improvements have been worked on in the last few years to improve throughput/plant capacity, recoveries and reduce operating costs. These include:
Improvements done during 2010
- A wet screening system to handle fine ore and improve productivity.
- New leach reactors to increase residence time for efficient leaching.
Improvements done during 2011
- Pre-Leach concentration system was commissioned in August 2011 to increase throughput (by increasing raffinate recycling), reduce limestone consumption and improve the plant's water balance.
- Additional CCD's for post leach solid liquid separation and copper SX split circuit is under construction. This will increase soluble metal recovery, plant throughput, plant efficiency and capacity to produce 31,500 tpa of copper cathodes.
Improvements during 2012 and Ongoing
- Installation of two additional counter-current decentaters, to assist in improving throughput even when feeding poor settling material.
- Effluent treatment plant to treat tailings to meet environmental requirements is under design stage.
- Conversion of solvent extraction plans to a 'split SX' configuration with separate high-grade and low-grade circuits, to improve copper recovery while reducing acid consumption.
- Reconfiguration of HMS plants to run in series, to improve copper recovery.
To date, the Company has invested over $400 million into the Usoke processing plant.