METODOLOGY FOR LATERITICS CU-BEARING CLAY MINERALS CHARACTERIZATION

Lateritic material lies over nearly 75% of the Brazilian surface area; but not more than 30% of this material is exploited. The expressive volume of clay minerals associated to the ores is the main reason of this low figure, especially because clay minerals are very complex, most of the time, impossible to concentrate. Under this circumstance, a proper mineral identification and the knowledge of the clay mineral structure are essential for the best mineral processing route choice. This study describes an optimized methodology to characterize a Cu-lateritic ore, mainly composed of Cu-bearing clay minerals. Cations saturations and particle sizes separation, combined with X-ray diffraction, mid infrared spectroscopy and scanning electron microscopy allow concluding that this Cu-lateritic ore is mainly composed of smectites, micas and kaolinite; furthermore, the copper is especially associated to mica and secondarily to smectite.