Leaching a complex copper–cobalt oxide ore from Zebesha Mine in Zambia, a novel method.

The article investigates the selective leaching of complex copper–cobalt oxide ore from Zebesha Mine in Zambia using iron-containing sulphate salts—specifically ferrous sulphate (FeSO₄·7H₂O), ammonium ferrous sulphate ((NH₄)₂Fe(SO₄)₂·6H₂O), and ferric sulphate (Fe₂(SO₄)₃)—as lixiviants instead of conventional sulphuric acid and reductants like sodium metabisulphite (SMBS). The study found that ferric sulphate effectively and selectively leaches copper (over 80% recovery) at room temperature, while ferrous sulphate requires elevated temperatures (around 70 °C) to achieve high recoveries of cobalt (about 85%) and manganese (about 93%), but yields lower copper extraction due to higher solution pH. Mineralogical analysis showed copper mainly in malachite and cobalt in heterogenite, with gangue minerals including quartz, biotite, and talc. The research suggests that iron sulphate salts, often available as industrial by-products, offer a more environmentally friendly and cost-effective alternative to traditional acid-reductive leaching methods for copper–cobalt oxide ores in the Zambian Copperbelt.