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The dehydration of brucite

Published online by Cambridge University Press:  14 March 2018

M. C. Ball
Affiliation:
Department of Chemistry, University of Aberdeen, Scotland
H. F. W. Taylor
Affiliation:
Department of Chemistry, University of Aberdeen, Scotland

Summary

This process has been reinvestigated, mainly with X-rays, using an FeO-containing, fibrous variety (nemalite), and also a nearly pure specimen. The results confirm that the transformation is oriented, the c- and a-directions of the brucite becoming the normals to (111) and (11̄0) in the periclase. There is an intermediate, spinel-like stage; the spinel a-axis is parallel to, and twice as long as, that of the periclase. This stage is especially prominent when nemalite is heated in air or nitrogen, but is shown also by the nearly pure material. The nemalite shows also a further intermediate stage under certain conditions. A new hypothesis is proposed for the dehydration mechanism, in which the number of oxygen atoms per unit volume is ahnost unchanged in those parts of the crystal that are converted into periclase. The process is essentially one of cation migration, and the occurrence of the spinel-like phase is readily explained. Similar mechanisms possibly apply to the dehydration of other lamellar hydroxides and oxy-hydroxides (e.g. gibbsite, kaolinite) and of certain carbonates and other oxy-salts.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1961

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References

Berman, (H.), 1932. Amer. Min., vol. 17, p. 313.Google Scholar
Bernal, (J. D.), Dasgupta, (D. R.), and Mackay, (A. L.), 1959. Clay Minerals Bull., vol. 4, p. 15.Google Scholar
Brindley, (G. W.) and Ogilvie, (G. J.), 1952. Acta Cryst., vol. 5, p. 412.Google Scholar
Büsssem, (W.) and Köberich, (F.), 1932. Zeits. physikal. Chem., ser. B, vol. 17, p. 310.Google Scholar
Donnay, (J. D. H.), 1945. Univ. Toronto Studies, Geol. Ser., No. 49, p. 5.Google Scholar
Garrido, (J.), 1936a. Compt. Rend. Acad. Sci. Paris, vol. 203, p. 94.Google Scholar
Garrido, (J.) 1936b. An. Soc. Españ. Fís. Quím., vol. 34, p. 853.Google Scholar
Garrido, (J.) 1951. Ion. Rev. Españ. Quím. Aplic., vol. ll, pp. 206, 220, 453.Google Scholar
Goodman, (J. F.), 1958. Proc. Roy. Soc., ser. A, vol. 247, p. 346.Google Scholar
Gregg, (S. J.) and Razouk, (R. I.), 1949. Journ. Chem. Soc., Suppl. vol., p. S 36.Google Scholar
Kelly, (A.) and Williamson, (G. K.), 1960. 5th Internat. Congr. Cryst., Abstracts of Communications, p. 33.Google Scholar
Kennedy, (G. C.), 1956. Amer. Journ. Sci., vol. 254, p. 567.Google Scholar
[Kurnakov, (N. S.) and Chernykh, (V. V.)] KyphaKob, (H. C.) , 1926. [. (Mém. Soc. Russe Min.), vol. 55, p. 74.(English with Russian summary)] ; abstr, in Neues Jahrb. Min., 1927, Abt. A, vol. 1, p. 313.Google Scholar
May, (J. E.) and Kronberg, (M. L.), 1960. Journ. Amer. Ceram. Soc., vol. 43, p. 525.Google Scholar
Mügge, (O.), 1919. Nachr. Gesell. Wiss. Göttingen, Math.-Phys. Kl., p. 47.Google Scholar
Posnjak, (E.), 1930. Amer. Journ. Sci., ser. 5, vol. 19, p. 67.Google Scholar
RazouK, (R. I.) and Mikhail, (R. Sh.), 1959. Egypt. Journ. Chem., vol. 2, p. 207.Google Scholar
Rinne, (F.), 1891. Zeits. deutsch, geol. Ges., vol. 43, p. 231.Google Scholar
RoY, (D. M.) and RoY, (R.), 1957. Amer. Journ. Sci., vol. 255, p. 573.CrossRefGoogle Scholar
Smith, (J. V.), 1953. Amer. Min., vol. 38, p. 643.Google Scholar
Warren, (B. E.), 1930. Zeits. Krist., vol. 74, p. 131.Google Scholar
West, (C. D.), 1932. Amer. Min., vol. 17, p. 316.Google Scholar
West, (C. D.) 1934. Ibid., vol. 19, p. 281.Google Scholar