Recovery of gold, silver and copper from complex gold concentrate by roasting-acidic leaching-cyanidation process

Gold, silver and copper were extracted from complex gold concentrate by roasting-acidic leachingcyanidation process. The experimental results show that the roasting temperature, time, additive and its dosagehave great influence on the leaching of gold, silver and copper. The optimal conditions were furtherdetermined as follows: NaOH dosage of 6 %(ω), roasting temperature of 630 °C, roasting time of 3 h, sulfuricacid concentration of 1 mol/L, liquid to solid ratio of 5:1 in acidic leach, leaching temperature of 50 °C, leachingtime of 4 h, sodium cyanide concentration of 3 ‰, liquid to solid ratio of 5:1 in cyanidation, room temperatureand cyanidation time of 72 h. Under above-mentioned conditions, the leaching rate of gold, silver and copperachieved at 93.53 %, 75.37 % and 94.23 % respectively.