LAMINATION INTERFACE OF THE WAXLESS PERMANENT CATHODE PROCESS IN COPPER REFINERY

摘要

The lamination interface generated by a power outage during the electrorefining of copper using a waxless permanent-cathode was investigated to elucidate the formation mechanism of the interface. X-ray diffraction and X-ray photoelectron spectroscopic measurements revealed that the interface is composed mostly of CuCl(s). Based on the thermodynamics of aqueous solution containing copper ions and chloride anions, it is considered that Cu~+ ions are spontaneously generated through the reaction Cu + Cu~(2+)→2Cu~+ at the surface of the copper cathode, resulting in the deposition of insoluble CuCl(s). Circulation of electrolyte during the power outage could suppress the accumulation of Cu~+ ions in the vicinity of the cathode and minimize the formation of CuCl(s) layer, which makes the lamination interface after recovery from the power outage.