Copper Electrowinning At Duisburger Kupferhuette

CIM Bulletin, Vol. 70, No. 785, 1977

H. Kudelka, R. Dobbener and N. L. Piret, Duisburger Kupferhuette, West Germany

Copper electrowinning at Duisburger Kupferhuette was introduced in March 1975. The electrowinning plant has a capacity of 10,000 mT of copper cathodes a year. The cuprous oxide feed material is an intermediate product of the treatment of the leach solutions, originating from chloridizing roasting of pyrite cinders. This material is characterized not only by a wide spectrum of accompanying impurities, but also by an unusually high level of precious metals. As the priority set was the production of high-purity cathodes, there was a need for developing a process which would be suited to treat complex leach liquors. The process adopted consists of an oxidizing leach in spent electrolyte, followed by two-stage purification. By this means, a low-acid pregnant copper electrolyte is obtained free of elements detrimental to copper quality. Electrowinning is carried out at a current density of 200 A/m2 in the presence of 10 g/l zinc. The electro-won copper has a conductivity of at least 101.4% I ACS and a softening temperature not exceeding 200° C, which makes it a suitable product for continuous casting and dip-forming.
Keywords: Hydrometallurgy, Electrowinning, Copper electrowinning, Leaching, Purification, Iron Precipitation, Chloride precipitation, Starting sheets, Cathodes, Duisburger Kupferhuette.