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Fluorination of Thorium Oxide by Ammonium Bifluoride and Its Reduction to Metal

  • Abhishek MukherjeeEmail author
  • Alok Awasthi
Conference paper

Abstract

The fluorination of thoria (ThO2) with ammonium bifluoride NH4HF2 to obtain oxygen-free thorium fluoride is reported. It is interesting to note that the fluorination starts right from room temperature to form ammonium thorium fluoride intermediate. On heating, the intermediate decomposes to form pure ThF4. It was also seen that any unreacted ThO2 reacts with the ThF4 to form ThOF2. The oxygen-free ThF4 produced was then reduced by calcium to form metallic thorium. The advantage in the process is that it can make thorium in bulk form which greatly reduces the issue of handling powders. However, as the process involves the melting of thorium, selection of suitable crucible becomes a key to its success. Yttria crucible appears to be a good choice.

Keywords

Thorium Yttria crucible Fluorination Ammonium thorium fluoride 

Notes

Acknowledgements

The authors gratefully acknowledge Dr. N. Krishnamurthy, on whose guidance the new route of thorium making could be attempted. Densified yttria crucible was custom-made by Dr Abhijit Ghosh for this work. We also thank Dr. R. K. Singhal for helping us in the XRF analysis of the thorium sample.

References

  1. 1.
    R.K. Sinha, A. Kakodkar, Nucl. Eng. Des. 236, 683–700 (2006)CrossRefGoogle Scholar
  2. 2.
    S.C. Chetal, V. Balasubramaniyan, P. Chellapandi, P. Mohanakrishnan, P. Puthiyavinayagam, C.P. Pillai, S. Raghupathy, T.K. Shanmugham, C.S. Pillai, Nucl. Eng. Des. 236, 852–860 (2006)CrossRefGoogle Scholar
  3. 3.
    Y.-I. Chang, Nucl. Eng. Technol. 39, 161–170 (2007)CrossRefGoogle Scholar
  4. 4.
    Interim report on metallurgy of thorium and thorium alloys (ORNL 1090. eng 26.), contract no.w740 s, ORNL, 1949–1951Google Scholar
  5. 5.
    B.G. William, Fabrication of metallic thorium, Google Patents, 1928Google Scholar
  6. 6.
    J.M. Dukert, Thorium and the third fuel, U.S. Atomic Energy Commission, Division of Technical Information, [Washington, D.C.], 1970Google Scholar
  7. 7.
    D.T. Peterson, W.E. Krupp, F.A. Schmidt, J. Less Common Met. 7, 288–295 (1964)CrossRefGoogle Scholar
  8. 8.
    P.L. Vijay, J.C. Sehra, C.V. Sundaram, K.R. Gurumurthy, R.V. Raghavan, BARC report 969, 1–24 (1978)Google Scholar
  9. 9.
    A. Mukherjee, A. Awasthi, N. Krishnamurthy, Mineral Process. Extr. Metall. 125, 26–31 (2016)CrossRefGoogle Scholar
  10. 10.
    M. Binnewies, E. Milke, Thermochemical data of elements and compounds, 2nd edn. (Wiley-Vch Verlag Gmbh, Weinheim, 2002)CrossRefGoogle Scholar
  11. 11.
    C.K. Gupta, N. Krishnamurthy, Extractive metallurgy of rare earths (CRC Press, Boca Raton, 2004)CrossRefGoogle Scholar
  12. 12.
    A. Mukherjee, A. Awasthi, S. Mishra, N. Krishnamurthy, Thermochim. Acta 520, 145–152 (2011)CrossRefGoogle Scholar
  13. 13.
    G.W.C. Silva, C.B. Yeamans, G.S. Cerefice, A.P. Sattelberger, K.R. Czerwinski, Inorg. Chem. 48, 5736–5746 (2009)CrossRefGoogle Scholar
  14. 14.
    B.N. Wani, S.J. Patwe, U.R.K. Rao, K.S. Venkateswarlu, J. Fluor. Chem. 44, 177–185 (1989)CrossRefGoogle Scholar

Copyright information

© Springer Nature Singapore Pte Ltd. 2019

Authors and Affiliations

  1. 1.Materials Processing and Corrosion Engineering DivisionBhabha Atomic Research CentreMumbaiIndia

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