Improving separation of sphalerite and galena by surface oxidation behavior regulation using calcium lentisulfonate as depressant

Abstract

BackgroundSphalerite and galena often exist in mixed form and are difficult to separate effectively. The effect of surface oxidation behavior regulation on the depression of calcium lentisulfonate (CLS) was studied in galena and sphalerite. MethodsFlotation experiment, contact angle experiment, X-ray photoelectron spectroscopy (XPS) analysis and microcalorimetric experiment were used to study the effect and mechanism of modulation of surface oxidation behaviour on CLS on the depression of galena flotation. Significant findingsThe results show that CLS can depress both galena and sphalerite. The oxidizing agent H2O2 oxidizes galena significantly faster than sphalerite. The treatment with H2O2 induces the formation of more oxidation products, such as PbSO4, on the surface of galena, enhances the adsorption of CLS and makes the surface of galena hydrophilic, thus reducing the recovery of galena in the flotation process. On the other hand, the treatment of the activator ethylenediaminetetraacetic acid (EDTA) reduces the amount of oxidation products ZnSO4 on the sphalerite surface, and CLS loses the active site that can be adsorbed on the galena surface, making the galena surface hydrophilic. In view of the huge hydrophobicity difference between sphalerite and galena, flotation separation is achieved.