High-alumina rocks from the Panimba and Mayakon areas (Yenisei Ridge): Composition and industrial perspectives

Abstract

Research subject. Аndalusite- and kyanite-bearing (13–19 wt % Al2SiO5) rocks of the Teya metamorphic complex (Mayakon and Panimba areas), Yenisei Ridge.Aim. To study the composition and mineral content of high-alumina rocks from the Panimba and Mayakon areas.Materials and methods. Laboratory mineral processing was employed to estimate the mineral content of metamorphic rocks of the Teya complex using a magnetic and gravity separation at the Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences (Novosibirsk). The concentrates were obtained from typical samples of andalusite, kyanite, and andalusite-kyanite metapilites. After crushing and grinding, the rock samples were separated into size fractions <0.06, 0.06 ≤ x < 0.1 and 0.1 ≤ x < 0.25 mm. The concentrates were recovered from size fractions ≥0.06 mm. Phase, bulk rock, and trace element composition of the rock samples, mineral concentrates, and other fractions were analyzed using XRD, XRF, ICP-MS, and SEM.Results. The magnetic product obtained at the first stage of mineral processing using magnetic separation accumalated staurolite, biotite, chlorite, ilmenite, pyrrhotite, and pyrite. At the second stage, light products containing quartz, feldspars, and muscovite were separated from non-magnetic products with CHBr3 using a centrifugal concentrator. At the last stage, using a double-knife separator, the heavy product from the previous beneficiation stage was separated into a “magnetic” raw concentrate (52–92 wt % Al2SiO5) and a “non-magnetic” final (70–97 wt % Al2SiO5) concentrate. The andalusite-kyanite concentrates (up to 97 wt % Al2SiO5) were obtained by the combination of cheapest and simplest methods of magnetic and gravity separation. The concentrates containing andalusite and kyanite with low recovery (0.7–6%) are comparable to the grade of kyanite-bearing ores of Karelia, the Kola Peninsula, and Gansu Province, China.Conclusions. The study shows that high-quality andalusite and/or kyanite concentrates can be recovered from high-alumina metapelites of the Teya metamorphic complex.