STRUCTURAL IMPURITIES IN QUARTZ OF TITANIUM ORE DRESSING TAILINGS OF THE PIZHEMSKY DEPOSIT
The results of the EPR study of structural elements-impurities in quartz concentrates obtained from the dressing tailings of the Pizhemsky titanium ores in the Middle Timan are presented. The silica content in concentrates ranges from 95-98 wt%. The main impurity elements, such as Al2O3 (14000- 29000 ppm), TiO2 (2000-15000 ppm), and Fe2O3 (2000-5000 ppm), are almost completely localized in the impurity mineral phases. The concentrations of structural impurities Al, Ti, and Ge in the quartz lattice are 10-16 and 0.5-2, 0.1-0.3 ppm, respectively. High-temperature calcination of concentrates, accompanied by cristobalitization, somewhat reduces the content of Al and Ti impurities. Quartz of the concentrates from the Pizhemsky titanium-bearing layers are significantly inferior in structural purity to the quartz of granulated veins in the Middle Urals developing deposits and do not differ from typical varieties of glassy quartz from Jurassic deposits in the south of the Komi Republic.