Enhancement of salicylhydroxamic acid adsorption by Pb(II) modified hemimorphite surfaces and its effect on floatability

Hemimorphite is an important zinc oxide mineral, but only a few studies have been conducted on the enhanced flotation recovery of hemimorphite with salicylhydroxamic acid (SHA) as the collector. In this study, the effect of Pb(II) on SHA adsorption on the hemimorphite surface with regard to its floatability was systematically studied. X-ray photoelectron spectroscopy (XPS) analysis showed that the Pb species could interact with O sites on the hemimorphite surface, thus forming -Zn-O-Pb and -Si-O-Pb complexes on the mineral surface and exhibiting strong reactivity toward SHA. Zeta potential measurements indicated that Pb2+ and Pb(OH)(+) adsorbed onto the hemimorphite surfaces via physical and chemical adsorption within a pH range that was suitable for the flotation, further enhancing SHA adsorption on the activated mineral surface. Adsorption tests showed that more SHA adsorbed on the Pb-treated hemimorphite surface than on the untreated hemimorphite, and Pb-SHA complexes that were generated in the pulp solution could also adsorb on the surface of hemimorphite. Microflotation tests confirmed that the floatability of hemimorphite significantly increased after treatment with Pb(II) ions when SHA was used as the collector. Thus, this paper proposes a promising method of improving the flotation recovery of hemimorphite through via surface modification with Pb(II) ions.