HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Weed, S. B. Articles by Leonard, R. A. Search for Related Content PubMed Articles by Weed, S. B. Articles by Leonard, R. A. Agricola Articles by Weed, S. B. Articles by Leonard, R. A.

A Comparison of Mg²⁺, Ca²⁺, and Sr²⁺ as Exchange Ions for Mineralogical Studies of Clays¹

ABSTRACT

Strontium-, Ca²⁺-, and Mg²⁺-saturated clay minerals were studied with respect to X-ray diffraction, differential thermal analysis, cation exchange capacity, and glycerol adsorption. In general, 3-layer clay minerals saturated with Sr²⁺ lost interlayer water at lower temperatures and at higher vapor pressures than did Mg²⁺-clays; Ca²⁺-clays were intermediate. A clay mineral-ion-saturation interaction was apparent. Calcium- and Sr²⁺-saturation of clays yielded similar values for cation exchange capacity. Strontium-saturated 3-layer clays retained more glycerol than did clays saturated with Ca²⁺. Expansion of vermiculite with glycerol and ethylene glycol was dependent on cation saturation and lattice charge. Strontium-saturated vermiculites expanded to near 16Å. more readily than did Mg²⁺-clays, and Ca²⁺-clays were intermediate. Vermiculites with high lattice charge expanded less readily than did vermiculites with relatively low lattice charge.

Strontium can satisfactorily substitute for Ca²⁺ and Mg²⁺ in routine mineralogical studies of clays though special care may be needed to control relative humidity. Additional information regarding lattice charge of 3-layer clays may be obtained by using several divalent ion saturations.

¹ Contribution from the Department of Soil Science, North Carolina Agr. Exp. Sta., North Carolina State College, Raleigh. Published with the approval of the Director as Paper No. 1602 of the Journal Series. Presented before Div. II, Soil Science Society of America, Aug. 21, 1962, at Ithaca, New York.

² Associate Professor of Soils and Instructor in Soils, respectively.

Received for publication April 15, 1963. Accepted for publication September 4, 1963.