The Role of Hydrogen Peroxide in Arsenopyrite Depression and Its Response Mechanism

The oxidation depression of arsenopyrite has been widely used in the sulfide ore flotation process to improve the quality of the final product. Hydrogen peroxide (H₂O₂) has been successfully applied in the oxidation inhibition of arsenopyrite, although its mechanism requires further refinement. This paper investigated the surface characterization of arsenopyrite depressed with hydrogen peroxide and its response to flotation performance to further clarify the composition of oxidized products on the arsenopyrite surface. The flotation experiment results suggested that the addition of H₂O₂ significantly reduced the flotation recovery of arsenopyrite, and the average recovery dropped by nearly 20%. The adsorption experiments showed that the adsorption capacity of butyl xanthate on the arsenopyrite surface was reduced from 1.4 × 10^-6 mol/L to 0.33 × 10^-6 mol/L when the dosage of H₂O₂ was 1 × 10^-4 mol/L at pH 7. XPS analysis results displayed that a large number of oxides, such as As-(V)-O, As-(III)-O, Fe-(III)-O, sulfates, and sulfites species, were produced on the arsenopyrite surface after H₂O₂ treatment, which effectively prevented butyl xanthate from adsorbing on the arsenopyrite surface. Furthermore, the solution component analysis results in the multiphase system further elucidated the existence forms of oxide products on the arsenopyrite surface. This study further improved the depression mechanism of the oxidation depressant on arsenopyrite.