Recovery of Copper Metal through Reprocessing of Residues from a Hydrometallurgical Plant

The Chemical of Africa (CHEMAF) is a hydrometallurgical plant operated in Katanga since 2001, producing copper metal through sulphuric acid leaching of copper-cobalt oxide ores under reducing conditions, followed by leach liquor purification and electrowinning. With the increase in the sulphide minerals content of run of mine ores and the environmental impact of storing process residues, reprocessing these residues has become critical. This research aims to recover copper metal from residues containing 2.01% Cu and 0.32% Co via sulphuric acid leaching followed by cementation with iron shavings. The experiments demonstrated that leaching achieved a copper extraction efficiency of approximately 90% and cobalt 86% when conducted for 90 minutes at 75°C with a specific concentration of sulphuric acid and reducing agent. Furthermore, successful copper recovery (2.5 g of solids with 93% Cu) was observed through the treatment of leachate with iron shavings, achieving satisfactory results at room temperature under controlled conditions. This study confirms the feasibility of copper recovery from hydrometallurgical plant residues, addressing both metal recovery and environmental concerns.