Leaching of Copper, Cobalt, and Nickel from Complex Ore

The paper focuses on leaching of complex copper–cobalt–nickel ore from Mwinilunga district in Zambia, containing 0.6% Cu, 0.21% Co, 2.6% Fe, and 0.13% Ni. Mineralogical examination of the ore using scanning electron microscope (SEM) showed that copper, cobalt, and nickel exist in fine particles of heterogenite and limonite mineral phases. The effects of leaching temperature, pH, and sodium meta-bisulphate (SMBS) addition were studied. The optimal conditions were found as follows: leaching temperature of 65–75 °C, leaching time of 1 h, and SMBS addition at 0.6 wt%. Copper, cobalt, and nickel were recovered from the leach solution via precipitation with sodium sulphide and magnesium oxide. Sodium sulphide was more selective than magnesium oxide.