SIMS and XPS study of the adsorption of sulfide collectors on pyroxene: a case for inadvert metal in activation

SIMS and XPS measurements were used to study the interaction between pyroxene, a magnesium silicate mineral, and sulfide collectors xanthate and thionocarbamate at pH 9. No collector adsorption could be detected on as-is pyroxene. Collector adsorption was observed only after pyroxene had been treated first with Cu2+ ions, washed and then treated with collector. XPS measurements show that Cu on pyroxene was reduced from cupric to cuprous upon collector adsorption suggesting the formation of a cuprous complex of the collector. SIMS imaging suggests that the collector adsorption occurs at copper sites on the surface.