NOUFERROUS METALLURGICAL EQUIPMENT

Cyanide leaching process is a mature gold extraction method which has been widely practiced in the gold metallurgy industry. The large quantities of extremely toxic cyanide-bearing effluent from the cyanide leaching process, is the main source of effluent for goldrefineries. This experiment tried to catalyze the oxidation of the cyanide-bearing effluent with ozone as the oxidant and γ-Al₂O₃ as the catalyst. It explored the effects of various parameters upon the decomposition of cyanides, including the duration and temperature of γ-Al₂O₃ roasting, the dosage of the catalyst and ozone, and solution pH value. According to the experiment result, the optimal process parameters for decomposing the cyanides are: roasting γ-Al₂O₃ at 450℃ for 3h, feeding γ-Al₂O₃ at 20g·L^-1 and ozone addition at 75mg·min^-1, and solution pH kept within 7~9.