The combined inhibitory effect of potassium permanganate and modified polyacrylamide on the flotation behavior of antimonite and arsenopyrite

Abstract

The selective separation of antimonite and arsenopyrite minerals is both a critical and challenging task. This study investigated the combined inhibitory effects of two new reagents on the flotation behaviour of these minerals under low-alkalinity conditions. The inhibitory effects and adsorption mechanisms of these reagents were systematically studied through microflotation and mixed ore flotation experiments, X-ray photoelectron spectroscopy (XPS) energy spectrum analysis, contact angle testing, scanning electron microscopy-energy dispersive X-ray (SEM–EDS) analysis, phase diagram analysis, and first-principles calculations. The flotation results showed that the combined use of potassium permanganate and modified polyacrylamide produced a stronger inhibitory effect on arsenopyrite compared to their individual effects. Using potassium permanganate and modified polyacrylamide as the inhibitor system and butylamine black as the collector at pH 9, the recovery rates of antimony ore and arsenopyrite differed by more than 80 %. XPS measurements indicated that potassium permanganate caused severe oxidation of arsenopyrite surfaces, forming iron oxide/hydroxide, which facilitated the adsorption of modified polyacrylamide. Contact angle measurements showed that potassium permanganate rendered arsenopyrite surfaces more hydrophilic, whereas modified polyacrylamide increased the difference between the surfaces of antimonite and arsenopyrite. SEM–EDS testing analysed the oxidation degree and identified oxidation products on arsenopyrite surfaces, which were validated through phase diagram analysis. First-principles calculations revealed the adsorption inhibition mechanism of the reagents on the arsenopyrite surface.