Plasmochemical process for the production of niobium and tantalum nanopowders; pp. 137–145Full article in PDF format | doi: 10.3176/proc.2012.2.06
Niobium and tantalum powders used in modern manufacturing are materials with nanostructure. The authors have studied and optimized the process of the production of niobium and tantalum nanopowders (adjusted in the range of the particle size of 20–150 nm) at pilot scale. The process is based on the reduction reaction of pentachlorides of tantalum and niobium with hydrogen in a plasma generator at about 3500 K. To stabilize the structure and adjust the granulometric composition of the produced nanopowders thermal treatment at 1373 K under vacuum was applied. The powders are characterized by very high purity with regard to oxygen and metallic admixtures and by low bulk density (0.1–0.3 g/cm3). The specimens had a high specific surface area (10–30 m2/g). The process of compacting and sintering of powders was tested at temperatures from 1173 to 1373 K. The porosity of the specimens was 0.55–0.75 from the theoretical. The pore diameter was adjusted to 0.5–0.05 μm.
1. Mining-tehnology.com. The website for the mining, tunnelling and quarrying industries. http://translate. google.ru/translate?hl=ru&sl=en&tl=ru&u=http%3A%2F%2Fwww.mining-technology.com%2Ffeatures% 2Ffeature74139%2F&anno=2/ (visited 14.01.2010). The Future of Tantalum and Niobium. Simon Walker looks at the market forces facing tantalum and niobium. 14.01.2010.
2. Levine, B. Niobium vs. tantalum caps: industry debates the pros and cons – Components. Electronic News. Find Articles.com. 27 Jun. 2011. http://findarticles.com/ p/articles/mi_m0EKF/is_15_48/ai_84649705/ (visited 10.08.2011).
3. Tekna Plasma Systems Inc., Sherbrooke, Québec, J1L 2T9. Canada. http://www.tekna.com/ (visited 10.08.2011).
4. Grabis, J. Preparation of nanosized powders of refractory compounds and their composites by plasma techniques. Int. J. MPT, Special Issue Progress in Powders Materials and Technologies, 2007, 252–269.
5. Neomat Co. Salaspils, Latvia. http://www.neomat.lv/ company.html/ (visited 10.08.2011).
6. Gorkunov, V., Nosikov, A. et al. A method for niobium and tantalum production. Author’s Certificate SU 158467. Registr. 08.04.81. Priority since 29.05.1980. Sillamäe, Estonia (in Russian).
7. Rare metals. Tantalum. Niobium. Alloys. By-products. http://www.silmet.ee/ (visited 10.08.2011).
8. HSC CHEMISTRY® 6.0. Outotec Oy, Finland. http:// www.outotec.com/templates/Search_9173.aspx?epslanguage=EN&find=HSC/ (visited 15.01.2011).
9. Munter, R., Parshin, A., Yamshchikov, L., Plotnikov, V., Gorkunov, V., and Kober, V. Reduction of tantalum pentoxide with aluminium and calcium: thermodynamic modelling and scale skilled tests. Proc. Estonian Acad. Sci., 2010, 59, 243–252.
10. Blagoveshchenskiy, Y. and Panfilov, S. Jet-plasma process for powder metallurgy. Elektrometallurgiya, 1999, 3, 28–34 (in Russian).
11. Blagoveshchenskiy, Y., Isaeva, N., Melnik, I., and Blagoveshchenskaya, N. Tantalum and niobium nanopowders for nanoporous material creation. Redkie metally, Special Issue, 2009, 28, 646–650 (in Russian).
12. Blagoveshchenskiy, Y., Levinski, Y., and Voldman, G. Coagulation of ultradispersed powders by annealing under vacuum. Меtally, 2002, 2, 35–41 (in Russian).
13. Kobyakov, V. and Kalandarishvili, A. Efficacy of application of oxygen-containing niobium in thermoemission transformers of energy. Zh. tekhn. fiz., 1998, 68(8), 131–138 (in Russian).14. Kyun Young Park, Ho Jung Kim, and Yong Jae Suh. Preparation of tantalum nanopowders through hydrogen reduction of TaCl5 vapor. Powder Technology, 2007, 172(3), 144–148.
Back to Issue