Infrared Spectroscopy Study of Tetrahedral and Octahedral Substitutions in an Interstratified Illite-Smectite Clay

E. Srasra1, F. Bergaya2 and J. J. Fripiat3
1 Unité de chimie appliquée, I.N.R.S.T. B.P.: 95-2050 Hammam-Lif, Tunisie
2 CRMD CNRS, 1 B, Rue de la férollerie 45075 Orléans Cedex 2, France
3 Department of Chemistry and Laboratory for Surface Studies, P.O. Box 413 University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53201

Abstract: Infrared spectroscopy is used to distinguish between octahedral and tetrahedral substitutions in an interstratified illite-smectite clay. The Hofmann-Klemen (Li) test suggests that the AlMg□ and FeMg□ octahedral vacancies are preferentially occupied by Li after thermal treatment at 250°C. The ammonium (Chourabi-Fripiat) test reveals the beidellitic character by the formation of two OH stretching modes upon deammonation. The illitic layers are not affected since K is not exchangeable.

Key Words: Chourabi-Fripiat test • Hofmann-Klemen effect • Illite • Infrared spectroscopy • Interstratified • Smectite • Tetrahedral substitution

Clays and Clay Minerals; June 1994 v. 42; no. 3; p. 237-241; DOI: 10.1346/CCMN.1994.0420301
© 1994, The Clay Minerals Society
Clay Minerals Society (www.clays.org)