Abstract:The pressure oxidation pretreatment process of a refractory gold concentrate containing 21.2% sulfur and 40.3 g/t gold was studied. The effects of grinding fineness, reaction pressure, reaction temperature, reaction time, stirring speed and pulp concentration on cyanidation were studied by single factor test. A pressure oxidized slag is obtained which is easy to cyanide. Then, the influence of pulp concentration, sodium cyanide dosage, pH value and leaching time on gold leaching rate in the process of cyanidation gold extraction was studied. The results show that the gold average cyanidation leaching rate is 97.3% under the optimum conditions including grinding fineness of -0.045 mm content of 95%, reaction pressure of 1.6 MPa, slurry concentration of 20%, reaction temperature of 160 ℃, reaction time of 240 min, and stirring speed of 350 r/min.