NOUFERROUS METALLURGICAL EQUIPMENT

The process of sulfurizing the H3AsO₃ dissolved in sulphuric acid （55%） with H₂S used as sulfidization agent was investigated. It was revealed by the results that H₂S could precipitate the arsenious acid in the sulphuric acid successfully and generate amorphous sulfoarsenide. After the sulfidization process， the As content in the sulphuric acid was decreased from 2481.43 ppm to 0.81 ppm which was lower than the As-concentration obtained from theoretical calculation by 2 orders of magnitude. The reason might be that As（III） is reduced into As（II） under excessive H₂S which greatly improve the sulphurizing-precipitation of As. It could be concluded that even under the present high H⁺ concentration， H₂S is still an effective sulfidization agent to treat and purify the sulphuric acid. This made it possible to clean the As-polluted sulphuric acid and recover it as a resource.