Influence of mechanical activation on selectivity of acid leaching of arsenopyrite

Mineral arsenopyrite (FeAsS) was exposed to leaching in H2SO4 solution. Surface changes of mechanically activated sulphide were investigated before and after leaching using infrared spectroscopy and scanning electron microscopy. Mechanical activation of the mineral resulted in mechanochemical surface oxidation and in the formation of sulphates. Furthermore, the specific surface area and the disordering of mineral crystal structure increased. These aspects influence the kinetics and selectivity of acid leaching of arsenopyrite.