An influence of mechanical activation on the selectivity of tetrahedrite acid leaching

Sulphidic mineral - tetrahedrite Cu12Sb4S13 was subjected to leaching in a H2SO4 medium. Physico-chemical changes of a mechanically activated mineral were investigated before and after leaching using the infrared spectroscopy and the scanning electron microscopy. The mechanical activation of the mineral resulted in the mechanochemical surface oxidation and the formation of sulphates and iron carbonate. Further, the specific surface area and the crystal structure disordering of the mineral increased. These aspects influence the kinetics and the selectivity of acid leaching of tetrahedrite. The effect of the reaction surface decreases due to the agglomeration during the milling and the formation of iron hydroxyoxides or iron hydroxysulphates from admixed pyrite and adversely affects the extraction rate of metals from tetrahedrite.