Effect of an additive TEA on thiosulfate leaching of low sulfur gold concentrate

Abstract

The environmentally friendly and non-cyanide thiosulfate gold leaching technology was used to extract gold from a low-sulfur gold concentrate. The effect of TEA on leaching of pure gold under the condition of adding quartz indicated that TEA could significant increase the dissolution rates of gold and the mixed solution potentials and decrease the consumption of thiosulfate. Quartz has little effect on the gold leaching process. Moreover, the effect of additive Triethanolamine (TEA) on the gold extraction was further studied. The chemical analysis and process mineralogy analysis of the concentrate indicated that the concentrate contained 59 g/t Au, 64.49% SiO2, 19.55% Al and 5.76% Fe. The concentrate was composed of quartz, muscovite and chlorite as major minerals. Quartz was the main gold-bearing mineral in concentrate. The gold particles of less than 20 μm in the concentrate reached 50.56%. Traditional thiosulfate leaching technology was used to extract gold from the concentrate, and the gold leaching rate was only 44.49% after 48 hours. When 0.024 M (MTEA:Mcopper=2:1) TEA was added in the thiosulfate leaching gold system, the thiosulfate consumption significantly reduced by about 32% and the leaching rate of gold increased to 73.40%.