Influence of electrolysis variables on the passivation time of copper anodes in copper electrorefining

Abstract In the present work it is assumed that passivation of copper anodes is due, in sulphate solutions, to the precipitation of a copper sulphate layer on the surface. An equation describing dependence of the passivation time on the current density has been established under some simplifying assumptions. The influence of the current density, solution composition, temperature and the solution flow rate on the passivation time has been investigated. Experimental data are consistent, to a large extent, with the semi-empirical equation for passivation time suggested by the authors.