Siberian Federal University (Krasnoyarsk, Russia)

Gilmanshina T. R., Associate Professor, Candidate of Engineering Sciences, Associate Professor, gtr1977@mail.ru
Dubinin P. S., Head of Laboratory, Candidate of Engineering Sciences, Associate Professor, Dubinin-2005@yandex.ru
Samoilo A. S., Research Engineer, x_lab@rambler.ru

JSC «Krasnoyarskgrafit» (Krasnoyarsk, Russia)

Bashmakov A. A., Lab Engineer, sahsa01ba@gmail.com

Separation of graphite particles from impurities while preserving the graphite’s flaky structure during processing is an essential challenge in graphite beneficiation. Thermal grinding of cryptocrystalline graphite, as proposed by A. D. Dmitriev, is a promising approach to address this challenge. This research was aimed to identify the optimal thermal grinding parameters for graphite that maximize the separation of cryptocrystalline graphite particles from impurity minerals without compromising the graphite’s flaky morphology. Graphite ore samples from the Kureiskoye deposit with a particle size fraction of –20+15 mm were used for this research. The optimal thermal grinding conditions selected for the work included maintaining the graphite temperature at 800–850 °C for 20 minutes, with an initial graphite moisture content of 5 %. Thermally ground graphite with a particle size of –0.2+0.16 mm, exhibiting a carbon content of 91–95 % and a crystallinity degree of 39.5 %, has been identified as the most promising fraction for new products. The isolated fraction of thermally ground graphite meets the specifications for graphite grade GT-2 under GOST 17022–81, with an ash content not exceeding 8.2 %, moisture content of 0.58 %, sulfur content of 0.06 %, iron content of 0.78 %, and no detectable volatile substances. The yield of the –0.2+0.16 mm fraction is approximately 10 %, with 20–30 % consisting of barren ore that can be effectively utilized as a filler in concrete mixes, while the remaining graphite can be used in metallurgical applications. Successful separation of the flaky component from cryptocrystalline graphite through thermal grinding significantly broadens the range of thermally ground graphite-based products, including the production of crucibles for melting metals and alloys.

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