Browsing Research Output by Subject "Solvent extraction"

Now showing items 1-7 of 7

    • Comparison of extractants for the separation of TaF5 and NbF5 in different acidic media 

      Ungerer, M.J.; Van der Westhuizen, D.J.; Lachmann, G.; Krieg, H.M. (Elsevier, 2014)
      To optimise the solvent extraction (SX) of Ta and Nb, eight different extractants were investigated, including the cation exchangers di-iso-octyl-phosphinic acid (PA) and di-(2-ethylhexyl)-phosphoric acid (D2EHPA), the ...

    • Extraction of uranium from synthetic nuclear conversion plant waste 

      Potgieter, M.; Van der Westhuizen, D.J.; Krieg, H.M.; Barry, J.C. (Taylor & Francis, 2019)
      The nuclear conversion plant operated at Necsa in the past resulted in the formation of a large amount of waste material containing ~ 50% U, which has reuse potential if the recovery thereof can be achieved. The waste ...

    • The hafnium-selective extraction from a zirconium(hafnium) heptafluoride ammonium solution using organophosphorus-based extractants 

      Conradie, Elizabeth Wilhelmina; Van der Westhuizen, Derik Jacobus; Krieg, Henning Manfred; Nel, Johann Theodorus (Taylor & Francis, 2018)
      The suitability of the organophosphorus-based extractants, DiOPA, Ionquest 801 and D2EHPA was evaluated for the selective extraction of Zr and Hf from an (NH4)3Zr(Hf)F7 acidic solution using both dispersive and pertraction ...

    • Mechanistic study of hafnium and zirconium extraction with organophosphorus extractants 

      Vermaak, V.; Krieg, H.M.; De Beer, L.; Van der Westhuizen, D. (Taylor & Francis, 2018)
      Research on the purification of Zr has increased in the last few decades and although effective processes have been developed, little is known about the mechanism of Hf and Zr extraction; particularly, at low acid ...

    • Molecular modelling of tantalum in an aqueous phase 

      Ungerer, M.J.; Van Sittert, C.G.C.E.; Van der Westhuizen, D.J.; Krieg, H.M. (SAIMM, 2017)
      The transition metals tantalum (Ta) and niobium (Nb) are of significant importance, for example in the nuclear energy sector where they are used as cladding materials, as well as in capacitors and specialized materials. For ...

    • Solvent extraction and separation of hafnium from zirconium using Ionquest 801 

      De Beer, L.; Van der Westhuizen, D.J.; Krieg, H.M. (SAIMM, 2016)
      The solvent extraction (SX) characteristics of Ionquest 801 were investigated to determine if the selective extraction of hafnium (Hf) over zirconium (Zr) is possible. Firstly, Ionquest 801 was screened for its suitability ...

    • The time dependent solvent extraction of Ta and Nb 

      Van der Westhuizen, Derik J.; De Beer, Leon; Ungerer, Marietjie J.; Krieg, Henning M. (Trans Tech Publications, 2014)
      The suitability of Liquid-liquid extraction (LLE) for the selective extraction of chemically similar tantalum (Ta) and niobium (Nb) mixtures was investigated by determining the influence of the acid concentration, extractant ...