Abstract
Thiosulfate offers a nontoxic alternative to cyanide for processing gold ores. The mechanism of leaching gold using ammoniacal thiosulfate solution is driven by the Cu(II)-Cu(I) redox couple and is complicated by competing ligands such as NH3 and S2O32−. It is shown that an understanding of the copper speciation and sulfur speciation is required to optimize this system. This paper presents Eh-pH and speciation diagrams for varying concentrations of Cu(II), S2O32− and NH3 and discusses the conditions under which various copper and sulfur species are stable.
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Aylmore, M.G., Muir, D.M. Thermodynamic analysis of gold leaching by ammoniacal thiosulfate using Eh/pH and speciation diagrams. Mining, Metallurgy & Exploration 18, 221–227 (2001). https://doi.org/10.1007/BF03403254
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DOI: https://doi.org/10.1007/BF03403254