Abstract:Vitriol and ammonium hydrogen fluoride pre-treatment process of copper leaching residue of complex gold concentrate was studied. Effects of molar concentration ratio of sulfuric acid and ammonium hydrogen fluoride (RS/A), molar concentration, L/S, reaction time, reaction temperature, and stirring speed on extraction rate of gold and silver were investigated. The results show that RS/A and molar concentration of sulfuric acid and ammonium hydrogen fluoride are the key factors impacting extraction rate of gold and silver. When RS/A=1/1, extraction rate of gold and silver can be improved significantly with increase of molar concentration of sulfuric acid and ammonium hydrogen fluoride. Inclusions of copper leaching residue are destructed and honeycomb ?pores appear, and silicon content drops from 33.28% to 5.49% in pre-treatment process. The optimum pretreatment conditions include RS/A=1/1, molar concentration of sulfuric acid and ammonium hydrogen fluoride of 1.5 mol/L, L/S=5/1, reaction time of 2 h, reaction temperature of 298 K, and stirring speed of 250 r/min. Cyanidation conditions include L/S=4/1, pH value of 10.5, sodium cyanide concentration of 4‰, stirring speed of 300 r/min, reaction time of 72 h, and reaction temperature of 298 K. Extraction rate of gold and silver is 98.20% and 95.77% respectively under the above-mentioned conditions, and content of gold and silver in cyanide residue is less than 1.3 g/t and 50 g/t respectively.