The salt extraction process – a novel route for metal extraction Part 2 – Cu/Fe extraction from copper oxide and sulphides

Abstract

The present work is Part 2 of a novel salt extraction process towards the extraction of metal values from slag, low grade ores, etc. The authors describe the extraction of copper/iron from CuO, Cu₂S and CuFeS₂, which provides a green process route to treat the copper ore including both oxides and sulphides. The dissolution properties were investigated with respect to process parameters such as weight ratio of flux/copper ore and temperature. The highest extraction ratio is found at 92% in dissolution of Cu₂S, and residue of salt melt was confirmed to be mainly Al₂O₃. A cell voltage between 1·6 and 2·2 V is introduced for electrolysis, and the cathode products are proved to be pure Cu for electrolysis of CuO/Cu₂S, and Cu/Fe mixture for CuFeS₂ by X-ray diffraction and scanning electron microscopy/energy dispersive spectroscopy analysis. Some sulphur and iron chloride were found to volatilise and were deposited in the low temperature zone. Yield of copper has been estimated to be 52·3% during electrolysis of Cu₂S.

Keywords:

• MOLTEN SALTS
• ELECTROLYSIS
• COPPER OXIDE
• COPPER SULPHIDES