The Reversible Dehydroxylization of Clay Minerals*

Edward C. Jonas
* Published with permission of the Chief, Illinois State Geological Survey, Urbana, Illinois,
Present address, The University of Texas, Austin, Texas.

Abstract: Rehydroxylization of the anhydrous modification of dioctahedral montmorillonites can be carried out under DTA conditions with controlled atmosphere techniques. The structural character of the rehydrate prepared in this way is determined from X-ray and DTA data. The mechanism of the reactions by which the rehydrate can be formed is also considered. Thermal analysis curves of the rehydrate form of several pure montmorillonite samples failed to show any large variation such as is shown by the curves of the original clays themselves. The possibility is considered that such large variations in the dehydroxylization curves of montmorillonites are related to structural instead of compositional variations within the sample. It is suggested that montmorillonites showing two reactions attributable to dehydroxylization may be mixtures of the rehydrate form and montmorillonite.

Clays and Clay Minerals; 1954 v. 3; no. 1; p. 66-72; DOI: 10.1346/CCMN.1954.0030106
© 1954, The Clay Minerals Society
Clay Minerals Society (www.clays.org)