Accession Number : ADA190824

Title :   Underlying Basis for the Effects of Iron Oxidation State on Clay Swelling.

Descriptive Note : Final rept. Sep 84-Sep 87,

Corporate Author : ILLINOIS UNIV AT URBANA

Personal Author(s) : Stucki, Joseph W

PDF Url : ADA190824

Report Date : 12 Jan 1988

Pagination or Media Count : 38

Abstract : The effect of iron(II) in the crystal structure of the clay mineral nontronite on the fraction of clay layers that become completely collapsed was measured directly using a 2-ethoxyethanol surface area technique. Measurements showed that up to 28% of the clay layers became completely collapsed as a result of Fe reduction. X-ray diffraction results also showed that may layers become partially collapsed. Since the combined fraction of these types of layers increased with increasing Fe(II) content in the clay and neither of these types of layers participates in the swelling process, one necessarily concludes that Fe(II) alters swelling by decreasing the number of layers that are capable of full expansion in the presence of water.

Descriptors :   *CLAY, *IRON, CRYSTAL STRUCTURE, EXPANSION, OXIDATION, WATER, X RAY DIFFRACTION, REDUCTION, INTERFACES, REPRINTS

Subject Categories : Inorganic Chemistry
      Geology, Geochemistry and Mineralogy

Distribution Statement : APPROVED FOR PUBLIC RELEASE