Conference Proceedings

Towards an understanding of copper(I) speciation and reactivity in the copper-ammonia-thiosulfate lixiviant system

J Black, L Spiccia, DC McPhail, C Young (ed.), A Alfantazi (ed.), C Anderson (ed.), A James (ed.), D Dreisinger (ed.), B Harris (ed.)

HYDROMETALLURGY 2003 PROCEEDINGS, VOLS 1 AND 2 | MINERALOGICAL SOC AMER & GEOCHEMICAL SOC | Published : 2003

Abstract

In the thiosulfate gold leaching process gold is oxidized to Au + by a copper(II) ammine catalyst and complexed by thiosulfate. Copper(I) complexes, formed during gold oxidation, are reoxidised to Cu(II) complexes by oxygen. In this study, we present the results of a spectrophotometric study of the Cu(I)-NH3-Cl system, which follows on from our recent investigations of speciation in the Cu(I)-Cl and Cu(I)-S 2O3-Cl systems and is part of a detailed study of copper(I) speciation associated with the gold leaching process. Formation constants for Cu(I)-NH3-Cl complexes have been determined by modeling the systematic changes in the UV spectra that occur as the concentration of the components is v..

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