An electrochemical model for the leaching kinetics of gold ore in cyanide solutions

• Main Author: Conradie, Petrus Jacobus
• Format: Others
• Language: en
• Published: 2015
• Online Access: http://hdl.handle.net/10539/16962

This project consisted of a literature and a laboratory study to investigate the applicability of an electrochemical model, to the leaching kinetics of gold ore. The procedure was to get an approximate measurement of the gold surface potential and then, to use only this potential and an area term in a two parameter rate expression. The potential measurements in a pulp, with a gold and gold-silver electrode, were attempted but, the electrodes became passive. The results showed that the rate controlling mechanism was a combination of the rate of both oxygen and cyanide diffusion and it was concluded that the applicability of an electrochemical model to the leaching kinetics of gold ore, could not be ruled out. It was found that the leaching kinetics could be modelled very accurately by using the solution redox potential, however, no theoretical basis could be found to explain this observation.