Sustainable Mining and Metallurgy

In the process of gold refining, high concentration of chlorine-containing wastewater will be produced by solution chlorination. Usually, the concentration of chloride ion can reach about 100g/L, which needs to be dechlorinated. In this paper, the copper salt precipitation method was used to reduce the chlorine content in wastewater, and the optimum process conditions for the treatment of chlorine-containing wastewater by copper salt method were investigated. The experimental results show that the optimal control parameters of wastewater dechlorination production are as follows: initial sulfuric acid acidity 42g/L, reaction temperature 20℃, reaction time 1h, copper powder dosage 1.5 times of the theoretical value, and copper salt dosage 1.2 times of the theoretical value. Under these conditions, the chloride ion precipitation rate is more than 90%. In the multiple dechlorination cycle test, the dechlorination rate remained above 90%, indicating that the copper slag was used to remove chlorine from multiple circulating wastewater, which had strong stability and high efficiency. This technology can provide reference for the industrial treatment of high concentration chlorine-containing wastewater.