Copper dissolution from cupric ferrite in conventional cyanidation

This paper presents the principal results of the residue cyanidation from the lixiviation of a white metal oxidized calcine with high content of copper (10,6%) as cupric ferrite. The gold and silver grades of this residue are 38,5 and 1085 g/ton respectively. The copper extraction is lower than those reported on the literature. Under complete gold extraction conditions, the copper extraction is only 0,36% in contrast with 5% obtained from an extraction of 60% of silver. It is possible that the high refractority of copper, as a cupric ferrite, is the cause of the low dissolution of this metal in cyanide.