I. V. Tananaev Institute of Chemistry and Technology of Rare Elements and Mineral Raw Materials, Kola Science Center of the Russian Academy of Sciences, Apatity, Russia:

E. A. Shchelokova, Junior Researcher, e-mail: shchelokova@chemy.kolasc.net.ru
P. B. Gromov, Deputy Director for Science, e-mail: gromov@chemy.kolasc.net.ru
E. K. Kopkova, Senior Researcher, e-mail: kopkova@chemy.kolasc.net.ru

According to the explored reserves of titanium ores, Russia holds the second place in the world (China holds the first place). Titanium ores are strategic raw materials: 20 deposits were explored and evaluated, and balance reserves were accounted in 13 of them. The Gremyakha-Vyrmes deposit, located at the Kola Peninsula, is one of the most prospective and largest native deposits of highquality titanium-magnetite-ilmenite ores. Ilmenite is the main mineral for production of metallic titanium, dioxide, carbide and other titanium-based compounds. Ilmenite belongs to hardly-opened minerals: either pyrometallurgical or hightemperature hydrometallurgical methods are applied for its decomposition. Preliminary mechanical activation is one of the methods for intensification of raw material processing. It leads to deformation and change of surface characteristics of minerals and improves their reaction ability. We investigated the influence of mechanical activation duration of the specific surface, structure of particles and morphology of ilmenite’s surface layer. We also considered the possibility of decomposition of activated ilmenite concentrate of the Gremyakha-Vyrmes deposit in sulphuric acid solutions with concentration of 750 g/l and the temperature range from 80 to 120 ^oC. We also investigated the influence of main technological parameters (duration of mechanical activation, concentration and consumption of acid, temperature) on efficiency of sulphuric acid process of ilmenite decomposition. Preliminary mechanical activation considerably intensifies the dissolution of iron and titanium in sulphuric acid as a result of decrease of activation energy in this process. We defined the duration of mechanical activation and conditions of sulphuric acid leaching, providing a high level of decomposition of ilmenite (>92%) and extraction of titanium (>94%) in solution.

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