World Intellectual Property Organization (2000) Treating Niobium and/or Tantalum Containing Raw Materials, (WO/2000/024943). http://www.wipo.int/pctdb/en/wo.jsp?WO=2000024943&IA=SE1999001888&DISPLAY=C LAIMS, retrieved on 12/10/2009.

has been cited by the following article:

• TITLE: A Review of Niobium-Tantalum Separation in Hydrometallurgy

  AUTHORS: Olushola S. Ayanda, Folahan A. Adekola

  KEYWORDS: Niobium, Tantalum, Columbite, Tantalite, Solvent extractant and Solvent extraction.

  JOURNAL NAME: Journal of Minerals and Materials Characterization and Engineering, Vol.10 No.3, March 5, 2011

  ABSTRACT: Niobium and tantalum are chemically similar and are associated with each other in nature which makes it very difficult to separate. For many years, the separation of tantalum from niobium involved the fractional crystallization of potassium heptafluorotantalate away from potassium oxypentafluoroniobate monohydrate, this method has been supplanted by solvent extraction from fluoride-containing solutions by the use of solvent extractants such as Octanol, bis(2-ethylhexyl)phosphoric acid (DEHPA), Alamine 336, methyl isobutyl ketone (MIBK), tri-nbutyl phosphate (TBP) or cyclohexanone. A detailed review of the various processes involved in the breakdown treatment of niobium and tantalum primary sources, extraction and separation and newer processes of extraction as well as the various technique involved were discussed.