Uncovering the roles of C-S-C group in improving the flotation performance of benzohydroxamic acid toward galena

• BTHA was first introduced as a collector for the flotation of galena. • The incorporation of C-S-C group improved the molecular properties of BHA. • BTHA exhibited better collecting ability toward galena in comparison with BHA. • BTHA chemically adsorbed on the galena surface through its -C(=O)-NHOH and C-S-C groups. In this contribution, the roles of the thioether (C-S-C) group in improving the flotation performance of benzohydroxamic acid (BHA) toward galena were studied by density functional theory (DFT) calculation, adsorption experiments, zeta potential, surface energy measurements and X-ray photoelectron spectroscopy (XPS). It was found that the incorporation of C-S-C group was observed to increase the functional groups, chelating ability and hydrophobicity of BHA, thus enhance its flotation performance to galena. The adsorption mechanism analyses demonstrated that 2-(benzythio)-eacetohydroxamic acid (BTHA) molecule anchored on the galena surface mainly by the reactions of the two O atoms originated from -C(=O)-NH-OH group and lead species with the formation of a five-membered rings. Additionally, the C-S-C group in BTHA molecule could donate its electrons to lead species on galena surface, which was also helpful to the adsorption of BTHA on galena surface.