Thermodynamic analysis of gold leaching by copper-glycine-thiosulfate solutions using Eh-pH and species distribution diagrams

•A novel copper-catalytic glycine thiosulfate collaborative system of gold leaching is proposed.•Eh-pH and species distribution diagrams for gold/copper-glycine-thiosulfate system under various conditions are constructed.•Electrochemical models for the copper-catalytic mechanism of gold leaching with glycine-thiosulfate are proposed.•Thermodynamic diagrams provide a theoretical basis for the optimization of gold leaching with copper-catalytic glycine thiosulfate system.