Residual Hydroxyl Groups in the Metakaolin Range1

V. Stubičan
Institute for Silicate Chemistry, Zagreb, Yugoslavia.
1Extracted from a thesis submitted to the University of Zagreb for a title of Assistant Professor.

Summary: Infra-red absorption spectroscopy has been used to study the retention of hydroxyl groups by kaolinite and halloysite after heat treatment in the range 600° C. to 850° C. Structurally disordered specimens initially lose water more rapidly than do ordered specimens, but retain hydroxyl groups at higher temperatures. Work on the phases obtained above 1100° C. is incomplete, but results for the lower temperatures indicate that the ordered structures tend to retain their atomic arrangement and form metakaolin, whereas disordered structures readily rearrange to yield γ-alumina, to the formation of which water is probably essential.

Mineralogical Magazine; March 1959 v. 32; no. 244; p. 38-52; DOI: 10.1180/minmag.1959.032.244.06
© 1959, The Mineralogical Society
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