Extraction of Gold and Copper from Flotation Tailings Using Glycine-Ammonia Solutions in the Presence of Permanganate

This study presents the novel idea of a cyanide-free leaching method, i.e., glycine-ammonia in presence permanganate, to treat low-grade and copper-bearing gold tailing. Ammonia played key role as pH modifier, lixiviant potential catalyst (as cupric ammine) this study. Replacing ammonia with other modifiers (i.e., sodium hydroxide or lime) made extractions infeasibly low (<30%). The increased additions glycine (23–93 kg/t), (30–157 kg/t) permanganate (5–20 enhanced copper considerably. Increasing solids content from 20 40% did not make any obvious changes extraction. However, kinetics was slightly better at lower content. It indicated that staged addition unnecessary under conditions. Recovery by CIL shown be feasible, it improved extraction 15%, but no effect observed for Percentages 76.5% 64.5% were extracted 48 h g/L glycine, 10 kg/t carbon, 10.5 30% solids. Higher could potentially achieved further optimization, such increasing addition, extending time ultra-fine grinding.