Removal of mechanical additives from the surface of cast niobium; pp. 241–246Full article in PDF format | doi: 10.3176/proc.2008.4.06
A combined method of the utilization of deposits from the shaft furnace of niobium production consisting of the stages of thermomechanical treatment, hydrogenation, grinding, and separation was elaborated in industrial conditions. This method enables to clean the surface of metallic niobium from slag (3CaO·5Al2O3) and from graphite additives. Altogether more than 20 tonnes of Nb–Al (5%) powder meeting the requirements presented to commercial technical niobium was produced. Application of the proposed utilization technology increases the profitability of pure niobium production by 0.2–0.3%. The results obtained can be used for cleaning other refractory metals from slag and other surface additives.
1. 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.
2. Obabkov, N., Gorkunov, V., Munter, R., and Beketov, A. Computation of the temperature field in the furnace of aluminothermal reduction. Mat. Sci. Appl. Chem. (Riga), 2007, Ser. 1, 15, 100–110.
3. Plotnikov, V., Paršin, A., and Gorkunov, V. Elaboration of Technology for Utilization of Niobium Wastes. Joint Report. Part I. VNIIHT, Мoscow, Sillamäe Chemical Factory, Sillamäe, 1984 (in Russian).
doc?PHPSESSID=dc9c7bf3546f9dc7531848f6ff83ff9a. AS Silmet, 2007 (in Estonian).
5. Gorkunov, V., Paršin, A., and Kogtev, M. Method of production of metallic niobium from wastes formed in the process of reduction of niobium pentoxide. Author’s Certificate SU 233207, 1986 (in Russian).
6. Askeland, D. R. The Science and Engineering of Materials. PWS Publishing Company, Boston, 1994.
7. Rjabuhhin, A. Linear coefficient of thermal expansion of metals. In Physical Chemistry and Technology of Inorganic Materials. Proc. Cheljabinsk Scientific Center, 1999, 3 (in Russian).
9. Samsonov, S. (ed.) Properties of Elements. Handbook. Мetallurgy, Мoscow, 1976 (in Russian).
10. Ubbelode, А. and Lewis, F. Graphite and Its Crystallic Compounds. Mir, Мoscow, 1965 (in Russian).
13. Orlov, V. and Novichkov, V. Character of niobium break-down in the reaction with hydrogen. Fiz.-Khim. Mekh. Mater., 1989, 3, 21–23 (in Russian).
16. Smirnova, T., Chibisov, A., Kopylov, N., and Cheremnych, G. Fire and explosion prevention during niobium hydride production. (shp.by.ru/sci/fullerene/ forums/ichms/2003/lit/down/0040-0043.pdf.
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