Copper extraction from copper ore by electro-reduction in molten CaCl2–NaCl

Sintered solid porous pellets of copper sulfide (Cu2S) and Cu2S/FeS were electrolysed at a cell voltage of 2.2–2.8 V to elemental Cu, S and Cu, Fe, S, respectively in molten CaCl2–NaCl at 800 °C under the protection of argon gas. The process parameters for optimal electrolysis are presented. The electrolysis products are characterized by microscopic techniques and XRD. The product characteristics are linked to the process parameters. The direct electrolysis of the sulfide to copper with the emission of elemental sulphur offers an attractive green process route for the treatment of copper ore.