Elucidação da ação do silicato de sódio como depressor na flotação de calcita e quartzo
Silva, João Paulo Pereira da
Baltar, Carlos Adolpho Magalhães
Leite, José Yvan Pereira
Peres, Antônio Eduardo Clark
MetadadosMostrar registro completo
This work aimed to elucidate the sodium silicate action mechanism as a depressor in the flotation of the minerals quartz and calcite. The experiments were done with high-purity mineral samples (quartz and calcite) in the particle size range below 147μm. The samples were characterized in size distribution (diffraction laser), chemical composition (X-ray fluorescence) and mineralogical composition (X-ray diffraction). The study of flotation in Hallimond tube showed that, in all systems tested, the efficiency of sodium silicate increased with the concentration. At concentrations above 1.500g/t, it was obtained almost total depression (96% for calcite and 97% for quartz). The most efficient depression pH range was observed between 5 and 8. Starting from 11 pH, the sodium silicate did not work as a depressor. The infrared spectra obtained at 7 pH, after contact of sodium silicate, showed the presence of the groups OH and Si-OH, both suggesting that the adsorption of the species Si(OH)4, as well as siloxane groups (Si-O-Si) attributed the adsorption of polymeric species.