Electrochemistry and Leaching Kinetics of Gold-Silver Alloys in Cyanide Solutions

  • Guan, Y.Charles (Department of Metallurgical Engineering South Dakota School of Mines and Technology Rapid City) ;
  • Sun, Xiaowei (Department of Metallurgical Engineering South Dakota School of Mines and Technology Rapid City) ;
  • Han, Kenneth N. (Department of Metallurgical Engineering South Dakota School of Mines and Technology Rapid City)
  • Published : 2001.02.01

Abstract

The dissolution behavior of gold and silver from gold-silver alloys in aerated cyanide solutions has been investigated by an electrochemical means as well as a direct measurement of gold and silver ions reported in the bulk solution as a function of time using rotating disc electrodes. The variables studied included oxygen partial pressure, rotating speed of the disc, concentration of cyanide, temperature and composition of the allyos. The dissolution potential and the rate of dissolution were obtained in view of the anodic and cathodic current-potential relationships. The results were discussed in terms of the mixed potential theory. The results showed that the dissolution rate of gold and silver from the alloys was controlled partially by chemical reaction. but largely by transport of either oxygen or cyanide, depending on their relative concentration under the experimental conditions employed in this study.

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