Behavior of S2O32− and SO32− in sulfur-bearing aqueous solution
system for gold leaching
(1. School of Metallurgical Engineering, Xi’an University of Architecture and Technology, Xi’an 710055, China;
2. Research Center of Metallurgical Engineering and Technology of Shaanxi Province,
Xi’an University of Architecture and Technology, Xi’an 710055, China)
2. Research Center of Metallurgical Engineering and Technology of Shaanxi Province,
Xi’an University of Architecture and Technology, Xi’an 710055, China)
Abstract: The concentrations of S2O32− and SO32− were measured in gold leaching systems, including thiosulfate system, polysulfide system and the modified lime sulfur synthetic solution (ML) system in the process of chemical reaction. The interactions among S2O32−, SO32− and S2− were discussed. The behavior mechanism of sulfur-bearing reagents was proposed to describe the process reactions and their Gibbs free energy. The proper quantity oxygen and SO32− reduce decomposition of S2O32− and react with sulfur derived from the decomposition of SX2−. So, SO32− ions have action to stabilize sulfur-bearing system and are favorable to leach gold.
Key words: sulfur-bearing system; gold leaching; thermodynamics