A new leach SX/EW plant at the Etoile mine site is expected to be commissioned by Q2 2016. SENET Pty Ltd is awarded EP contract and ACE LTD FZE is awarded Construction contract for the project. Site preparation and Civil work is currently in progress. This plant will primarily treat both stockpiles and current HMS rejects.
It is designed to produce 19,000 tonnes per year of copper cathodes and up to 3,800 tonnes of cobalt in form of Cobalt Hydroxide, with a front-end feed capacity of 3,100 tonnes per day. The process uses a modern design comprising conventional ball milling, leaching, two-stage copper solvent extraction and electrowinning. Sulphur dioxide is sparged into the leach vessels, and the leach is operated at an elevated temperature, to ensure high cobalt extractions. The raffinate bleed stream is routed to a cobalt recovery circuit where iron and manganese, together with aluminium, are first precipitated under oxidising conditions, following which cobalt is precipitated as a hydroxide using magnesia as precipitants.