Study On Novel Thiosulfate For Extraction Process Of Gold Ore

Thiosulfate leaching is an effective way to replace cyanidation.In our work,a new leaching system is developed by adding complex reagent M.The study of leaching gold from ore and recovering gold from leachate have been investigated.The parameters including copper concentration,thiosulfate concentration,M concentration,temperature,pH and time have been optimized.Gold extraction can achieve 92.56%under the optimized experimental conditions:0.05mol/L CuSO4,0.2 mol/L M,0.5mol/L thiosulfate,pH 10.5,temperature 70 ?,leaching time of 9.0h.The absorption parameters such as copper concentration,thiosulfate concentration,M concentration,temperature,pH and time have been carried out.The X ray photoelectron spectroscopy and infrared spectra analysis show that the optimized gold adsorption of 16.2mg/L is achieved for D201 resin under the optimum absorption condition of 0.001 mol/L copper concentration,0.2mol/L M concentration,0.1 mol/L thiosulfate concentration,absorption time 180minutes,pH 10.5 and absorption temperature 40?.The FT-IR and XPS studies show that the resin adsorption belongs to a chemical reaction.After adsorption,Sodium,Copper,Gold and Sulfur exist in form of Na+,Cu+;Au+,SO42-and S2O32-,respectively on the resin surface.The experiments of gold recovery has been studied by the precipitation replacement method.The results show that the 99.46%and 87.47%gold recovery is respectively achieved by zinc powder and copper powder replacement reaction.The optimum zinc replacement conditions are reaction temperature 40?,pH 9.5 and zinc powder dosage 3.2g/L.Moreover,The best conditions for copper powder replacement are reaction temperature 55?,pH 10.5-11.5 and copper powder dosage 5.0g/L.