The effect of polysaccharide depressant xanthan gum on the flotation of arsenopyrite from chlorite

Abstract The efficient separation of sulphide from low hardness minerals, especially hydrophobic gangue minerals, remains a practical challenge. The effect of the polysaccharide depressant xanthan gum on the depression of chlorite in arsenopyrite flotation was studied using potassium amyl xanthate (PAX) as the collector. In micro-flotation, xanthan gum showed a better depression performance on chlorite flotation than on arsenopyrite flotation. The selective depression mechanism of xanthan gum on arsenopyrite and chlorite surfaces was studied by adsorption tests, and Fourier transform infrared spectra (FT-IR) and molecular dynamics simulation (MDS) analyses. The results indicated that xanthan gum could selectively adsorb on chlorite surfaces involving chemisorption, while it exhibited weak physical adsorption to arsenopyrite. The chemisorption of xanthan gum on the chlorite surface was based on the interaction between –COOH groups and metal (Mg) ions.