An investigation on grinding behavior of pyritic copper ores

The particle size distribution of a ground ore is summation of the particle size distribution of the minerals present in the ore and has an important effect on the performance of the flotation process. Therefore, the specific rate of breakage, Si, and the particle size distributions of the minerals were determined using samples of pyritic copper ores with high pyrite content (HPy) and low pyrite content (LPy). Then, these data were comparatively evaluated in terms of the grinding behavior of the minerals. It was found that chalcopyrite and pyrite are ground slightly faster (16.9% and 20.47%) than the non-sulfide gangue (NSG) minerals in the HPY ore. Conversely, these minerals in the LPy ore have higher Si than that of the NSG minerals for almost all size fractions. On average, chalcopyrite and pyrite in the LPy ore are ground faster 71.47% and 22.48% than the NSG minerals, respectively, indicating that selective breakage occurred during the grinding of this ore. Furthermore, an empirical model was built to estimate the Si of each mineral without performing the size-by-mineral analysis. The results imply that the presented approach can be used as a simple and inexpensive tool to design and improve the grinding circuits