Direct Cupric Chloride Leaching of Gold from Refractory Sulfide Ore: Process Simulation and Life Cycle Assessment

Abstract

A simulation-based life cycle assessment was conducted to compare the impacts of different cyanide-free chloride processing routes for refractory ores to determine whether one-stage leaching of gold from the ores could be advantageous over chloride leaching after conventional pressure oxidation from an environmental perspective. It was shown that both leaching conditions and the refractoriness of the ore strongly affect the environmental impacts of the process. The global warming potential in the direct leaching route was determined to vary between 7.7–17.0 t CO2-eq for 1 kg gold/Au. Prerequisites for the sustainable application of the direct leaching process are suggested.