A study of the influence of copper on the gold electrowinning process

Electrowinning is an attractive method for the recovery of gold from concentrated aurodicyanide solutions produced during the elution of loaded carbon. This study investigates the influence of base metals, particularly copper, on the electrowinning process. Given that gold typically exists in the form of aurodicyanide (Au(CN)2-), it is crucial to understand how the presence of base metals can affect gold deposition efficiency. The theoretical background includes relevant electrochemical reactions that illustrate the competitive nature of deposits formed during the electrowinning process. Methodologies employed include electrochemical analysis at various copper concentrations and examination of cathodic reactions at different potentials. Results indicate that higher concentrations of copper can adversely impact the current efficiencies, resulting in inferior bullion quality and potential passivation of the cathode. The study concludes that while electrowinning remains a viable option for gold recovery, careful management of base metal concentrations is essential to maintain optimal processing conditions and yield high-purity gold deposits.