Abstract:
The research presents an upgrading of low quality silica sand from Thung Tako Deposit in Thailand. This research mainly focuses on the mineral processing of silica sand with the following objectives; (1) to reduce the iron impurities from silica sand by physical and chemical methods, (2) to analyze the iron content with spectrophotometer, to identify the heavy minerals by frantz isodynamic magnetic sepatator and to characterize the silica sand with X-Ray diffraction. The laboratory shaking table has been used for upgrading this type of the low grade silica sand deposits and 92.3 % SiO2 and 0.08% Fe2O3 were achieved under 100 inclination of the table as the best result. The non-magnetic final concentrate (silica sand) obtained by wet high-intensity magnetic separator was 98.6% which can respond the standard of the glass- grade silica sand and Fe2O3 0.08% was achieved with an environmental friendly manner. Flotation method can be reduced the iron impurities from 0.13% (raw) to 0.07% and 0.05% Fe2O3. Silica sand grade exceed up to 99% and the grade 0.05% of Fe2O3 were achieved by using 100 ml collectors (AOA and Nanza). The best conditions of the iron-impurities from the silica sand by using the strong industrial acid (H2SO4, HCl and HF) was 0.03 and 0.04% (from 0.13% Fe2O3 (raw)). As leaching time (0.5, 1, 2, 3, 4, 5 hours) increased, the iron constituent level decreased. The lowest values of the iron contents are obtained after 5 hour’s leaching time. Leaching of the silica sand sample seemed to be the most effective for the glass industry. This method is very expensive and the ensuing effluents are environmentally unacceptable. Even though all the techniques exhibited a successful removing the unwanted minerals, the financial and environmental aspects were considered. Therefore, Wet High Intensity Magnetic Separator technique is highly recommended.
