Abstract:Arsenic is one of paragenetic and associated elements in non-ferrous minerals, which is enriched in “the three wastes” containing arsenic during the smelting of nonferrous metal processes. The safety disposal of wastewater containing arsenic has troubled nonferrous metals smelting enterprises due to the strong carcinogenicity and toxicity of arsenic. This paper firstly introduced the sources and harm of wastewater arsenic-containing. And then the stabilization technologies including chemical stabilization and mineral stabilization were reviewed. By comparing the advantages and disadvantages of stabilization technologies for treating wastewater containing arsenic, and referring to the mineralization rule of arsenic in geochemistry, a sulfidization-hydrothermal reduction mineralization process of arsenic was proposed. The results show that, firstly, 99.65% arsenic in wastewater containing arsenic was precipitated in the form of amorphous As₂S₃ by using Na₂S. Then the leachate concentration of arsenic of amorphous As₂S₃ in TCLP test is 212.97 mg/L. Next, the hydrothermal reduction mineralization process in As-S unary system and hydrothermal reduction mineralization process in As-Fe-S binary system are adopted to transform amorphous As₂S₃ to orpiment and orpiment and iron-sulfur system (pyrite, ferrous sulfide) mixture separately. And the As leachate concentration of these corresponding hydrothermal slags in the TCLP test is reduced to 3.86 mg/L, 2.65 mg/L separately. A satisfied result of removal and stabilization of arsenic from wastewater are achieved by the novel processes, which provides a promising way to remove and stabilize arsenic from high arsenic containing wastewater.

Key words: arsenic; arsenic trisulfide; stabilization; hydrothermal; mineralization