EFFECT OF COBALT IONS ON THE PERFORMANCE OF LEAD ANODES USED FOR THE ELECTROWINNING OF COPPER - A LITERATURE REVIEW.

The effect of cobalt ions in the electrolyte on the performance of lead alloy anodes used for oxygen evolution during electrolysis of copper/sulfuric acid solutions has been studied extensively over the past 90 years. A review of the literature has confirmed that cobalt both as constituent of the anode material and present as ions in the electrolyte reduces the rate of corrosion of the anodes, lowers the overpotential for the evolution of oxygen, and reduces lead contamination of the copper cathodes. Despite the fact that these effects have been developed into widespread applications in the electrowinning industry, a fundamental understanding of the mechanism of the action of cobalt ions remains a point of debate. A selection of the most relevant literature on this phenomenon has been reviewed and the data and proposed mechanisms critically evaluated. [ABSTRACT FROM AUTHOR]