K. V. Simeiko1, 2, O. P. Kozhan2, M. A. Sydorenko1, V. S. Ryabchuk2, K. V. Lobach3, O. M. Skoblyk1, V. S. Havrylenko1, P. A. Sabienin1
1 Institute for Safety Problems of Nuclear Power Plants, NAS of Ukraine, 36a, Kirova st., Chornobyl, 07270, Ukraine
2 Gas Institute of the NAS of Ukraine, 39, Dehtiarivska st., Kyiv, 03113, Ukraine
3 National Science Center “Kharkiv Institute of Physics and Technology”, 1, Akademichna st., Kharkiv, 61108, Ukraine
DOI: doi.org/10.31717/2311-8253.24.2.7
Abstract
The general increase in electricity consumption and the development of nuclear energy, including next generation nuclear reactors where graphite-based materials are used, definitely leads to an increase in the need for its production. Therefore, the development and improvement of technologies for the production of high-purity graphite (including nuclear), namely the understanding of the thermodynamic and hydrodynamic processes of graphite purification, is of great practical importance. Thermodynamic calculations of the main chemical reactions of the high-temperature graphite purification process were carried out in the paper. For conducting thermodynamic calculations, a sample of natural graphite with a purity of up to 94.33% mass was taken. With the following composition of impurities: SiO2 –3.05 % mass; Al2 O3 –1.05% mass; Fe2 O3 –1.01% mass; CaO — 0.2% mass; MgO — 0.31% mass; S — 0.048% mass. The thermochemical parameters of the process were determined by the thermodynamic method (“TERRA” program). During the calculation, 0.9433 mol of C, 0.0305 mol of SiO2 , 0.0105 mol of Al2 O3 , 0.0101 mol of Fe2 O3 , 0.0002 mol of CaO, 0.0031 mol of MgO, 0.00048 mol of S, and 1 mol of N2 were taken, temperature range is 300…3278 K, and pressure is 0.1 MPa. Obtained results show that at a temperature above 1600 K, part of the initial carbon is oxidized to CO, and nitrogen actually does not affect the process. And also taking into account that part of the substances CO; Si; SiC2 ; SiS; Al; Fe; Mg; Ca; SiO at temperatures of 2800…3200 K are in a gas state and are carried to the purifier, from which we can conclude that the reaction temperature must be higher than 2800 K to carry out this process. The study of the hydrodynamic characteristics of graphite in a fluidized bed was carried out on the designed model installation with a fluidized bed. The working zone of the device is made in the form of a graphite cone with an opening angle of 25°, which provided the creation of a “spouted bed”. Besides, part of the fluidizing agent (nitrogen) was supplied in a pulsating mode. For the research, 6 samples of graphite with different physical properties and chemical composition were chosen, the filling volume was 0.5 l. Based on thermodynamic calculations of the basic thermochemical reactions and cold hydrodynamic tests, a laboratory installation was created to monitor the process of high-temperature purification of graphite
Keywords: nuclear-purity graphite, electrothermal fluidized bed, hot filtration, thermodynamics, hydrodynamics
References
1. Part of the substances (Si; SiC2; SiS; Al; Fe; Mg; Ca; SiO) that should be formed during the process of high-temperature purification of graphite at temperatures above 2800 K are in a gaseous state. Therefore, to carry out this process, the reaction temperature must be above 2800 K.
2. On the basis of thermodynamic calculations of the main thermochemical reactions, a laboratory installation for researching the process of high-temperature graphite purification was developed and cold hydrodynamic tests were created. References 1. Toniolo B. (2016). European Carbon and Graphite Association ECGA. Annual Report 2014–2015. Bruxelles, Belgium: EGGA, 19 p. Available at: http://www.ecga.net/sites/default/files/pdf/ecga_ar_2014–15_draft-final.pdf. 2. Jewell S., Kimball S. M. (2017). Mineral commodity summaries 2017. U. S. Geological Survey, Reston, U.S., 202 p., doi.org/10.3133/70180197.
3. Olson D. W. (2014). Graphite. U. S. Geological Survey Min‑erals Yearbook — 2014 Graphite [Advance release]. U. S. Department of the Interior, U. S. Geological Survey, 15 p.
4. Keeling J. (2017). Graphite: properties, uses and South Australian resources. MESA Journal, vol. 84 (3), pp. 28–41.
5. Siow K. S. (2017). Graphite Exfoliation to Commercialize Graphene Technology. Sains Malaysiana, vol. 46 (7), pp. 1047–1059. doi.org/10.17576/jsm-2017–4607–06.
6. Kalyoncu R. S. (2000). Graphite. U. S. Geological Survey Minerals Yearbook. Reston, US: U. S. Geological Survey, pp. 76–77.
7. Crossley P. (2000). Graphite: high-tech supply sharpens up. Industrial Minerals, vol. 398, pp. 31–47.
8. Vasilenko I. Ya., Osipov V. A., Rublevskij V. P. (1992). Radioaktivnyj uglerod [Radioactive carbon]. Priroda, no. 12, pp. 59–65. (in Rus.)
9. Vlasova K. P. (1964). Grafit kak vysokotemperaturnyj material [Graphite as a high temperature material.]. Collection of articles. Moscow: Mir, 420 p. (in Rus.)
10. Zhmurikov Ye. I., Bubnenkov I. A., Dremov V. V., Samarin S. I., Pokrovskiy A. S., Kharkov D. V. (2013). Grafit v nauke i yadernoj tekhnike [Graphite in science and nuclear engineering]. Novosibirsk, 193 p. (in Rus.)
11. Dollezhal N. A., Yemelyanov I. Ya. (1980). Kanalnyj yadernyj energeticheskij reaktor [Channel nuclear power reactor], Moscow: Atomizdat, 208 p. (in Rus.)
12. Komir A. I., Odeychuk N. P., Nikolaenko A. A., Tkachenko V. I., Derevyanko V. A., Krivchenko O. V., SheTable 6. The value of the operating parameters of the laboratory installation for the research of the process of natural graphite high-temperature purification Parameter Unit of measurement A measurement value or range The volume of the reaction zone m3 0.0015 Type of gas distribution device cone The type of electric current between the electrodes Removable Amperage А 0…400 High-voltage В 20…60 Material processing temperature °C 1500…3000 Duration of material processing h 0.5…1.5 Thermodynamic calculations and hydrodynamic studies of the process pelev A. G. (2016). [Graphite as a Structural Material for Generation IV Nuclear Energy Systems]. Voprosy Atomnoj Nauki i Tehniki [Issues of Atomic Science and Technology], vol. 1 (101), pp. 51–55. (in Rus.)
13. Barsukov V. Z., Khomenko V. G., Senik I. V., Chernyy O. Sh. (2013). [Lithium batteries for transport applications: modern problems and prospects]. Voprosy Khimii i Khimicheskoj Tehnologii [Issues of Chemistry and Chemical technology], no. 4, pp. 127–131. (in Rus.)
14. Moradi B., Botte G. G. (2016). Recycling of graphite anodes for the next generation of lithium ion batteries. Journal of Applied Electrochemistry, vol. 46 (2), pp. 123–148. doi.org/10.1007/s10800-015-0914-0.
15. Li J., Henry F., Feng Y. (2017). How to develop best carbon/graphite products for lead-carbon battery applications (Superior Graphite). Poster session presented at the 10th In‑
ternational conference on leadacid batteries LABAT’2017, (Golden Sands, Bulgaria 13–16 June 2017), p. 23.
16. Elementenergy. Cost and performance of EV batteries (Final report for The Committee on Climate Change). Retrieved from Elementenergy, 2012, 91 p.
17. Simeiko K. V., Kupriianchuk S. V., Syniahovskyi A. O. (2023). Technologies and Promising Developments of Graphite Production (Overview). Nuclear Power and the Environment, vol. 4 (26), pp. 9–23. doi.org/10.31717/2311-8253.23.1.2. (in Ukr.)
If the article is accepted for publication in the journal «Industrial Heat Engineering» the author must sign an agreement on transfer of copyright. The agreement is sent to the postal (original) or e-mail address (scanned copy) of the journal editions.
Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License International CC-BY that allows others to share the work with an acknowledgement of the work’s authorship and initial publication in this journal.