Abstract:The sulfurization method is currently the most widely used method for removing arsenic from smelting waste acid. The conventional sulfurization method adopts stepped sulfurization, multistage sulfurization, and high-efficiency sulfurization reactor, which may produces a large amount of hazardous waste residue and the effluent cannot be reused and can only be discharged, or the cost is high, the process is long, or the treatment effect of high arsenic content waste acid is not ideal. The impurity removal process of high arsenic content waste acid containing 16 060 mg/L arsenic, 28.04 mg/L copper, and 9.80 mg/L lead was studied. The effects of the addition amount and method of Na2S?9H2O, reaction time and temperature on impurity removal effect were investigated. The process of "vulcanization + flocculation" was determined. By optimizing the method of adding agents to reduce the amount of adding agents, the optimal process conditions were explored to achieve the purpose of "short process, precise dosing and small pollution". The results show that arsenic in the waste acid can be reduced to 0.23 mg/L or even <0.1 mg/L, while lead and copper can be reduced to <0.1mg/L respectively, far below the limit of industrial sulfuric acid Grade 1.