Fundamental studies of copper anode passivation during electrorefining: Part I. Development of techniques

Anode passivation is an extremely important phenomenon in commercial copper electrorefining operations. Due to the electrochemical nature of the refining process, various electrochemical techniques have been applied to examine anode passivation behavior. In this investigation, cyclic voltammetry, linear potential sweep, and chronopotentiometry measurements were carried out on several commercial copper anodes, as well as on pure electrowon (EW) copper cathode, in synthetic electrolytes simulating the primary constituents for industrial operations. The important parameters associated with anode passivation were identified and compared for the three electrochemical techniques. Chronopotentiometry is an extremely sensitive technique and proved to be the most suitable for analyzing and characterizing copper anode passivation.