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Early Reaction Determination in Two Hydroxide-Kaolinite Systems by Electron Microscopy and Diffraction

Published online by Cambridge University Press:  01 January 2024

Richard L. Sloane*
Affiliation:
University of Arizona, Tucson, Arizona, USA

Abstract

Results of the study of the kaolinite-sodium hydroxide interaction showed extensive dissolution of the kaolinite structure at particle edges, with some production of “silicate relicts” as a secondary effect. The method of specimen preparation for electron micro-scopy precluded electron-diffraction study of soluble reaction products. The study of the kaolinite-calcium hydroxide interaction revealed a similar attack on particle edges and formation of “silicate relics” and, in addition, formation of an insoluble reaction product that was tentatively identified by electron diffraction as prehnite, Ca2Al2Si3O10(OH)2. Both studies showed an ephemeral phase that, by selected area elec- tron diffraction, appeared to be a layer lattice silicate in (001) orientation. In the calcium hydroxide-treated kaolinite, formation of the reaction product was followed from nucleation along particle edges, after 24 hr, to growth of particles about 0.5 to 1 μ in size after 15 days. The combination of electron microscopy of surface replicas to detect changes in morphology with selected area electron diffraction of parallel pseudoreplicas for identification shows promise as a tool for study of the early stages in mineral- chemical interaction.

Type
General Session
Copyright
Copyright © Clay Minerals Society 1964

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References

ASTM X-ray Card File and Index (1962) American Society for Testing and Materials, Philadelphia, Pa.Google Scholar
Bradley, D. E. (1954) Evaporated carbon films for use in electron microscopy, J. Appl. Phys. 5, 65; 96.Google Scholar
Bradley, D. E. (1958) Simultaneous evaporation of platinum and carbon for possible use in high-resolution shadow-casting for the electron microscope, Nature 181, 875.CrossRefGoogle ScholarPubMed
Brindley, G. W., and DeKimpe, C. (1961) Identification of clay minerals by single crystal electron diffraction, Am. Mineralogist 46, 1005–16.Google Scholar
Eades, J. L., and Grim, R. E. (1960) Reaction of hydrated lime with pure clay minerals in soil stabilization, Highway Research Board, Bull. 262.Google Scholar
Langston, R. V., and Jenne, E. A. (1964) NaOH dissolution of some oxide impurities from kaolins, Clays and Clay Minerals, 12th Conf. [1963], pp. 633–47, Pergamon Press, New York.Google Scholar
Oberlin, A., and Mering, J. (1962) Observations en microscopie et micro-diffraction électroniques sur la montmorillonite Na, J. Microscopie 1, 107.Google Scholar
Ross, S., and Kerr, P. F. (1934) Halloysite and allophane, U.S. Geol. Surv. Profess. Papers 185-G.CrossRefGoogle Scholar
Williams, R. C., and Wyckoff, R. W. G. (1946) Applications of metallic shadow-casting to microscopy, J. Appl. Phys. 17, 23.CrossRefGoogle Scholar