Selective depression of marmatite by sodium alginate in flotation separation of galena and marmatite

Abstract

In this study, sodium alginate (SA) is proposed as a flotation depressant for the selective separation of galena and marmatite. The effect of SA on the flotation performance of galena and marmatite was investigated using sodium butyl xanthate (SBX) as the collector. The adsorption behavior of SA on the mineral surface was theoretically analyzed. The micro-flotation results demonstrated that the flotation of marmatite could be selectively depressed through the addition of SA before SBX at pH = 11. The contact angle, FTIR, XPS, and zeta potential results demonstrated that SA could be selectively adsorbed on the marmatite surface, thereby hindering the subsequent adsorption of the collector and affecting its flotation. A coordination theory analysis further confirmed that Fe2+ was the active site on the marmatite surface. SA can form π-backbonding with Fe2+ on the surface of the marmatite, resulting in strong adsorption but weaker interactions with Zn2+ and Pb2+. Overall, the high selectivity and environmental compatibility of SA make it an effective green depressant for the flotation separation of marmatite.