ESTONIAN ACADEMY
PUBLISHERS
eesti teaduste
akadeemia kirjastus
PUBLISHED
SINCE 1952
 
Proceeding cover
proceedings
of the estonian academy of sciences
ISSN 1736-7530 (Electronic)
ISSN 1736-6046 (Print)
Impact Factor (2022): 0.9
Reduction of tantalum pentoxide with aluminium and calcium: thermodynamic modelling and scale skilled tests; pp. 243–252
PDF | doi: 10.3176/proc.2010.3.07

Authors
Rein Munter, Anatoli Parshin, Leonid Yamshchikov, Vladimir Plotnikov, Valeri Gorkunov, Viktor Kober
Abstract

High reactivity of powdered aluminium together with its relatively low price are the main reasons for the application of this metal as a reducing agent for the reduction of oxides and fluorides of rare and rare earth metals by the aluminothermal method. This technology is widely used in the production of master alloys for ferrous metallurgy. The “out-of-furnace” process (i.e. without external heat access) is the prevailing technology for metallic niobium production worldwide. However, aluminothermal reduction for industrial production of metallic tantalum has been limited because of the high required temperature, over 2800 °C.

In this paper the results of simultaneous reduction of tantalum(V) and iron(III) oxides by calcium–aluminothermal “out-of-furnace” process are presented. Powdered aluminium and metallic calcium were used as reductants. The pickup of tantalum at smeltings with the mass of raw materials over 1 kg reached 94%. The metal was obtained in the form of compact ingot; separation of metallic and slag phases was excellent. Crushed melt underwent refining remelting in an electron beam furnace.

For thermodynamic studies and optimization of the aluminothermal reduction processes of Ta2O5 and Fe2O3 in the temperature range of 1000–3000 °C a licensed computer simulation program “HSC Chemistry 6.1, 2007”, elaborated by the company Outotec Oy, was applied.
References

  1. Bose, D. K. and Gupta, C. K. Extractive metallurgy of tantalum. Mineral Processing and Extractive Metallurgy Review, 2001, 22(4–6), 389–412.
doi:10.1080/08827509808962508

  2. Zelikman, A., Korshunov, B., and Elyutin, A. Niobium and Tantalum. Меtallurgiya, Мoscow, 1990 (in Russian).

  3. Gorkunov, V. and Munter, R. Calcium–aluminothermal production of niobium and mineral composition of the slag. Proc. Estonian Acad. Sci. Chem., 2007, 56, 142–156.

  4. Tsegel¢nik, É. Tantalum. Journal of Atomic Strategy, 2006, 20. ProAtom, St. Petersburg (in Russian). http://www.proatom.ru/modules.php?name=onas

  5. Linnupõld, L. Complex environmental impact of techno­logical processes of Silmet JSC and estimation of correspondence of applied technology to the requirements of BAT. Report No. E1131. Tallinn, 2009 (in Russian). www.sillamae.ee/public/files/ S%2013.03.07%20rus.doc

  6. Parshin, A. and Plotnikov, V. Elaboration and introduction of aluminothermal technology for the production of tantalum ingots and powders with application of electronbeam refining. Joint Report. VNIIHT, Мoscow, 1984, (in Russian). Аrchives AS Sillmet-Chemical Factory, Sillamäe (Estonia), No. А-115с (in Russian).

  7. Orlov, V. M., Kryzhanov, M. V., and Sukhorukov, V. V. Magnesiothermic reduction of tantalum pentoxide. In Abstracts of the International Conference “Chemistry of solids, monocrystals, nanomaterials, nano­technology”, 11.–16.10. 2009. Kislovodsk, Russia, 65–68.

  8. Lyakishev, N. (ed.). Phase Diagrams of Twin Metallic Systems. Handbook. Mechanical Engineering, Moscow, Vol. 1, 1996; Vol. 2, 1997 (in Russian).

  9. Phase diagram of the system CaO-Al2O3. In Schlackatlas. Stahleisen Verlag GmbH, Düsseldorf, 1981.

10. Zelikman, A., Korshunov, B., and Elyutin, A. Metallurgy of Refractory Rare Metals. Меtallurgiya, Мoscow, 1986 (in Russian).

11. Nair, K. U., Mukherjee, T. K., and Gupta, C. K. Pro­duction of Tantalum Metal by the Aluminothermic Reduction of Tantalum Pentoxide. Metallurgy Division, Bhabha Atomic Research Centre, Trombay, Bombay, India, 1975.

12. Polak, L. (ed.). Kinetics and Thermodynamics of Chemical Reactions in Low-temperature Plasma. Collection of papers. Institute of Oil-Shale Synthesis, USSR Academy of Sciences, 1965 (in Russian).

13. Маlkin, О. А. Relaxation Processes in Gas. Atomizdat, Moscow, 1971 (in Russian).

14. Pupyshev, А. А. Application of thermodynamics for description, analysis, studies and control of thermo­chemical processes in sources of atomization and excitement of spectrums. Doctoral Thesis. Ural State University, Yekaterinburg, 1994.

15. Lyakishev, N. P. Aluminothermal Processes. Меtallurgiya, Мoscow, 1978.

16. Pliner, J. and Ignatenko, G. Reduction of Oxides with Aluminium. Меtallurgiya, Мoscow, 1967 (in Russian).

17. Belov, G. V. Thermodynamic Modelling: Methods, Algorithms, Programs. Nauchnyj mir, Мoscow, 2002 (in Russian).

18. Obabkov, N., Gorkunov, V., Munter, R., and Beketov, A. Computation of the temperature field in the furnace of aluminothermal reduction. Sci. Proc. Riga Technical University “Material Science and Applied Chemistry”, Ser. 1. Riga, 2007, 100–110.

19. Obabkov, N. High-temperature composite anticorrosion and antierosion protective coatings for construction materials. Doctoral Thesis. Ural State University, Yekaterinburg, 2001 (in Russian).

20. Gorkunov, V. and Munter, R. Production of silicon free master alloys in Estonia. Sci. Proc. Riga Technical University “Material Science and Applied Chemistry”, Ser. 1. Riga, 2007, 111–120.

21. Beketov, A., Obabkov, N., Gorkunov, V., and Munter, R. Protective coatings for the graphite facing in calcium–aluminothermal processes. Proc. Estonian Acad. Sci. Chem., 2008, 57, 54–60.
doi:10.3176/proc.2008.1.06

22. http://www.outotec.com/templates/Search_9173.aspx?epslanguage=EN&find=HSC+Chemistry++6.1

23. Sokolov, I. and Ponomarev, N. Introduction to the Metallo­thermal Processes. Меtallurgiya, Мoscow, 1990 (in Russian).

24. Miroshnikova, L. D. Tantalum oxides. J. Inorganic Chem., 1989, 34(1), 184–187.

25. Shunk, F. A. Constitution of Binary Alloys. Меtallurgiya, Мoscow, 1973 (in Russian).

26. Bennett, L. Phase Diagrams of Alloys. Mir, Moscow, 1986 (in Russian).

27. Bakish, R. The substance of a technology: electron-beam melting and refining. J. Min. Met. Mat. Soc., 1998, 50(11), 28–30. Springer, Boston.
doi:10.1007/s11837-998-0283-9

28. Hunt Coy, R. and Raman, A. Alloy chemistry of β(σU)-related phases. I. Extension and occurrence of μ¢-phases in ternary systems Nb(Ta)–X–Al. Z. Metallknd., 1968, 59(9), 701–707.
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