Effects of Mechanical Activation on the Bioleaching of Sphalerite and Marmatite for Zn Extraction

Even though mechanical activation is a significant pretreatment technology for the efficient extraction of metals from mineral resources, its effects on the bioleaching of sphalerite and marmatite are rarely discussed. In this study, mechanical activation pretreatment using various grinding media and grinding times was conducted, and particle size distribution, morphology, X-ray diffraction (XRD) and energy dispersive spectrometry (EDS) analyses, as well as batch bioleaching experiments, were carried out. The results suggest that #C conditions (corundum jar with zirconia balls) were more efficient than #S conditions (stainless steel jar with stainless steel balls) for the grinding of both sphalerite and marmatite. Mechanical activation significantly improved the bioleaching of sphalerite; however, it inhibited that of marmatite, possibly due to the formation of reactive oxygen species (ROS). The optimum grinding conditions for the bioleaching of sphalerite and marmatite are proposed.