Thermodynamic analysis of the sulphation roasting of enargite concentrates

Abstract

The mining industry is under increasing pressure to assess the extraction of value from complex copper ores, such as those containing enargite (Cu3AsS4 ), due to the rising demand for copper and gold. A sulphation roast, weak acid leach, and electrowinning process flowsheet has been studied to address the treatment of copper concentrates containing significant amounts of enargite. Copper is recovered from the calcine by acid leaching, with most of the arsenic being fixed in the leach residue after gold extraction by cyanidation. The relative simplicity of roasting combined with proven hydrometallurgical technologies has the potential to be economically advantageous and readily scaled for commercial operation. Based on a proposed reaction mechanism, a thermodynamic analysis has been performed using HSC Chemistry ® 6.1 in order to establish an operating window and assess the overall potential feasibility of the proposed flowsheet.