An innovative thiourea gold leaching process

The aim of this experimental work was devoted to the preliminary evaluation of the feasibility of thiourea leaching for the extraction of gold from a domestic gold-bearing ore 4 g/t Au, at laboratory scale. The study has permitted identification of the influence of temperature, leaching agent concentration, pulp density and leaching time on the gold dissolution. Gold has been recovered from the leach liquors by adsorption onto activated carbon and subsequent electrodeposition. After the optimisation of the experimental conditions of the process, about 80% of gold recovery was obtained, for the complete cycle of treatment; the consumption of reagents has been low (5 g/kg of thiourea, 5 g/kg of sulphuric acid and 0.5 g/kg of ferric sulphate). (C) 1998 Elsevier Science B.V.