Mining Institute of Kola Science Center of Russian Academy of Sciences:

Rakaev A. I., Head of Laboratory, Doctor of Engineering Sciences, e-mail: rakaev@goi.kolasc.net.ru
Alekseeva S. A., Researcher
Chernousenko E. V., Researcher

«Karelmet» JSC:
Rudakov S. N., Deputy Chief Executive Officer

Geological Institute of Kola Science Center of Russian Academy of Sciences:
Neradovskiy Yu. N., Leading Researcher, Candidate of Geological and Mineralogical Sciences

Aganozerskoe chromium ores deposit is situated in Pudozhsky District (Republic of Karelia). According to industrial classification, ore belongs to rarely-inclined type with fine-grained chromospinelide. 11,9–33,2 % of Cr₂O₃ is included in ore. Ore includes two types of chromospinelide with equal chemical composition, but different morphological peculiarities and size of releases: fine grains of octahedral habitus with coarseness from 0.01 to 0.2-0.3 mm and significantly coarser grains with size from 0.2 to 2-2.5 mm. Research of ore grinding kinetics in rod and grinding barrel mill has shown the advantages of application of rod mill in the I stage. Rod mill provides the big yield of productive grade with minimal amount of slimes. Coarseness of -0.63 mm is optimal for this stage. It is shown that large-grain chromite is extracted rather completely with this coarseness. Grinding of material in ball mill to the coarseness of -0.2 mm, corresponding to average weighted size of chromite grains, is recommended in the II stage for opening of fine-grained variety of chromite. Concentration of chromite ores was carried out by gravitation method on spiral separators and concentration tables and magnetic method with application of high-gradient separators. Concentrate (yield is near 34%, content of Cr₂O₃ is 45.5%, extraction is near 76%) was obtained by developed two-stage gravitation-magnetic scheme of concentration from ore, containing near 20% of Cr₂O₃. Content of Cr₂O₃ in tails is 7.2%.

1. Available at: http://www.karelnedra.karelia.ru.
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3. Lavrov M. M., Trofimov N. N. Doklady Akademii Nauk SSSR — Reports of USSR Academy of Sciences, 1986, Vol. 286, No. 2, pp. 449–452.
4. Metodicheskie rekomendatsii po primeneniyu klassifikatsii zapasov k mestorozhdeniyam khromovykh rud (Methodical recommendations on application of classification of reserves to chromium ores' deposits). Moscow : Ministry of Natural Resources of Russian Federation, 2005, 41 p.
5. Rakaev A. I. Optimizatsiya rudopodgotovki pri gravitatsionnom obogashchenii (Optimization of ore preparation during gravitation processing). Leningrad : Nauka, 1989, 184 p.