Activation mechanism of lead ions in cassiterite flotation with salicylhydroxamic acid as collector

The effect of lead ions on cassiterite flotation with salicylhydroxamic acid as collector was assessed by a combination of microflotation tests, adsorption experiments, zeta-potential determinations, and X-ray photoelectron spectroscopy (XPS) analysis in this work. Microflotation tests confirmed the contribution of lead ions to cassiterite flotation at an increased floatability of 12.12% compared with that in the absence of lead ions. The adsorption experiments demonstrated that the adsorbed amount of SHA onto cassiterite surfaces was greatly increased after treatment with lead ions. The results of zeta-potential determinations indicated that the cassiterite surface was activated by the adsorption of lead species in the form of Pb(OH)(+), and the higher adsorption capacity of SHA onto the mineral surface was obtained after modifying with lead ions. XPS analysis revealed that lead ions adsorbed onto the mineral surface through the interaction between lead species and oxygen sites of cassiterite surfaces. This occurrence increased the number of active sites on the mineral surface and improved the collector attachment. These results consistently indicated that the activity of the cassiterite surface increased after pretreatment with lead ions and enhanced the flotation behavior. (C) 2017 Elsevier B.V. All rights reserved.