Quartz Ore Beneficiation by Reverse Flotation for Silicon Production

International audienceIn this work the reverse flotation as beneficiation process for high-purity silica valorization from Draissa quartz deposits (Algeria) is studied as a potential raw material for photovoltaic silicon production and starting charge for crystal growth material for a large wide of applications such laser and scintillation. The samples are investigated by optical microscopy, secondary ion mass spectroscopy, X-ray fluorescence and Raman spectroscopy. The microscopic investigations detect solid impurities such as alkaline and plagioclase feldspars, micas and iron oxides. The analyzed silica shows well-developed crystals areas, delimited by microcrystalline regions. Impurities are predominantly located in low quartz granulometry (50-100 μm). The XRF results highlight 93.63 wt% SiO2, 0.16 wt%, Fe2O3, 0.171 wt% Cl, 0.15 wt% CaO, 5.74 wt% Al2O3, 0.074 wt% K2O, 0.001 wt% CdO, 0.006 wt% SnO2. However, these results remain insufficient for predestined use of this raw material. A preliminary enrichment using reverse flotation process improves the silica purity up to 99.6% and removes the major impurities, which is suitable intermediate technological product able for silicon production and optical application