Sustainable Mining and Metallurgy

The effluent of a gold mine in Shandong has high COD and cyanide content. To remove/reduce these substances, a pilot test was carried out to compare the oxidation effect of hydrogen peroxide, sodium hypochlorite, and ozone, and the potency of ozone was verified. Then the effect of pH, ozone dosage, reaction temperature and duration upon the oxidation process were studied and optimization was conducted. The study showed that when ozone is injected at 1.5L/min, with pH=11, reaction temperature at 45℃ and reaction lasting 90min, the removal efficiency of COD and CN^- can reach 95.7% and 96.2% respectively, which satisfied the effluent reuse requirements.