Activation mechanisms of Cu2+ and Pb2+ in stibnite flotation

The activation differences and mechanisms of Cu2+and Pb2+in antimony ore flotation were studied through micro flotation tests, adsorption capacity tests, and density functional theory (DFT) calculations. The micro flotation test showed that the recovery rate of antimony ore after Pb2+activation using butyl xanthate (BX) increased by 7.82% compared to Cu2+activation. The adsorption capacity test shows that after Pb2+acts on the surface of stibnite, its surface can adsorb more BX. The DFT calculation results indicate that the S1 double bond atom of BX activated by Cu2+forms a Cu-S bond with Cu and belongs to the electron withdrawing system, while the single bond S1 and double bond S2 atoms of BX activated by Pb2+form a stable chelating structure with Pb and belong to the electron withdrawing system. The interaction between xanthate and oxygen provides conditions for the formation of double xanthate on the mineral surface, significantly improving the floatability of antimony trioxide.