Metallurgical Transactions

, Volume 2, Issue 10, pp 2817–2823 | Cite as

Open aluminothermic reduction of columbium (Nb) pentoxide and purification of the reduced metal

  • G. R. Kamat
  • C. K. Gupta
Process Metallurgy


This investigation is concerned with the extraction of columbium metal by aluminothermic reduction of its pentoxide in a refractory-lined open reactor. Reduction with 15 pct of aluminum in excess of stoichiometric and priming at the center are found to be optimum parameters. Trials with 3 kg batches of columbium oxide have resulted in high yields of consolidate columbium. Aluminum-reduced columbium has been further processed by electron-beam melting-after prior pyro-vacuum treatment for removal of aluminum, and also directly—and in either case it has been possible to produce pure and ductile columbium. The investigation proceeds to evaluate fused salt electrorefining of the reduced columbium employing NaCl-KCl-K2CbF7 bath. Conditions for operating the cell at 90 pct or more current efficiency have been established. Electrorefining has been found to be effective in lowering of most of the impurities in the anode feed. Electrolytic columbium on consolidation by electron-beam melting is found to have a hardness value of 50 Dph.


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Copyright information

© The Metallurgical Society of American Institute of Mining, Mitallurgical and Petroleum Engineers, Inc., and American Society for Metals 1971

Authors and Affiliations

  • G. R. Kamat
    • 1
  • C. K. Gupta
    • 1
  1. 1.Extractive Metallurgy Section of Metallurgy DivisionBhabna Atomic Research CentreBombayIndia

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