Comparison of different pretreatment on the recovery of gold and silver from Sarcheshmeh copper anode slime

The anode slime produced in the refining of copper by electrolysis contains that part of the anode which is insoluble in electrolyte and contains varying quantities of copper,nickel,silver,gold,selenium,tellurium,arsenic,lead,etc.depending on the anode. The main object in treating anode slimes has been to separate the valuable metals with high recovery[1]. In the treatment of anode slime selenium is usually removed . In this paper we compare influence of different methods to removal of selenium on the recovery of gold and silver. Sulfating roasting, soda roasting and oxidative leaching were tested then cyanidation of gold and silver was carried out[2]. results showed Se removal by oxidative leaching pretreatment, remarkably improved the extraction of silver from levels of less than 87% to 99% and gold from less than 90% to 99.2% during subsequent cyanidation. On the other the consumption of cyanide and the time of reaction decreased significantly