Process mineralogy of gold: Gold from telluride-bearing ores

Abstract

Petrographic and microanalytical studies of gold in gold-silver telluride deposits show that it occurs as "visible gold" extracted by cyanidation, and as visible gold and "invisible gold" that are unamenable to cyanidation. Two gold-bearing tellurides, calaverite and buckhornite, are considerably less amenable to cyanidation in comparison to Au-Ag tellurides. Secondary ion mass spectroscopy and recent developments in dynamic analysis of proton-induced x-ray emission demonstrate that Au occurs as nanoparticles and is structurally bound in As-, Ag-, and Te-rich pyrite and that an antithetic relationship can also exist between Au and As in pyrite.