An electrochemical study on the dissolution of gold and copper from gold/copper alloys

Abstract

The dissolution behavior of gold and copper from their elemental states and from gold/copper alloys in cyanide solutions has been investigated using a rotating-disc electrode. The anodic and cathodic reactions were studied separately, and the resulting polarization curves were combined to examine the overall dissolution reactions. The dissolution rate of pure gold in the aerated cyanide solutions was inhibited by the anodic passivation on the gold surface, whereas the dissolution rate of pure copper was found to be mass-transfer controlled. On the other hand, the dissolution of gold and copper from the alloys was partially controlled by electrochemical reaction and largely by mass transfer.