Aktas quartz in Central Kazakhstan is important raw for the production of hi-tech products

This study presents the investigation of the Aktas quartz deposit in the central part of Kazakhstan as a potential source of high-purity quartz (HPQ) for use as raw materials for special applications in high-technical industries especially solar energy industry. Geochemical studies revealed that the Aktas quartz deposit can be classified as pure quartz one due to its high silica content 99.21- 99.29 %. Also it is characterized by low contents of Al2O3, Fe2O3, CaO, MgO, Na2O3, K2O and P2O5. Therefore, the quartz of this deposit without preliminary treatment matches well the requirements of the Aluminum and Ferrosilicon alloy industries. The beneficiation processes that applied on the studied quartz samples of Aktas to remove the excess and undesirable high contents of mineral inclusions (hematite, pyrite and magnetite) and impurities (Fe2O3, TiO2, Al2O3, CaO... etc) are related to froth flotation in three stages. These stages were carried out at a fixed pH condition (5.5-6) but with changing the time of grinding (20, 40, 60 min, respectively). The beneficiation of Aktas quartz with froth flotation in the 1st stage (20 min time of grinding) displayed a marked increase of the SiO2 content and decrease of the Al2O3, Fe2O3 and CaO contents to a noticeable percent, while the 2nd and 3rd stages of flotation had a negative effect on the quartz and this is reflected by the decrease of SiO2 content (98.71 % in the 2nd stage and 98.83% in the 3rd stage of flotation) and increase of Fe2O3 content (0.58 % in the 2nd stage and 0.79% in the 3rd stage of flotation), therefore the 1st stage of flotation is recommended (grinding time 20 min and the pH 5.5-6), because it gives better results. The beneficiation processes with froth flotation at a fixed condition (pH 5,5-6 and 20 min time of grinding) allowed the use of the quartz of Aktas for the production of silicon carbide.