Reactions between Clay Volatiles and Calcite Reinvestigated
Calcite crystals exposed to clay volatiles react with some components of these volatiles, giving rise to a variety of surface morphologies. F, Cl, and S in different proportions were detected by electron microprobe analysis of the calcite surfaces. Under identical experimental conditions, volatiles from every clay mineral examined caused a specific morphology and chemical composition of the calcite surfaces, but these varied with temperature of the calcite. Changes in pH values and mass spectra of the volatiles after passage through calcite demonstrate that even on rapid heating some clay volatile-calcite reactions occur at temperatures as low as 150°C. Species other than those detectable by electron microprobe analysis also participate in the reactions in which CO2 is liberated.
Key WordsCalcite Clay volatiles Mass spectra pH measurements Surface morphology
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- Gmelin’s Handbuch der Anorganischen Chemie (1961) Calcium: 28, VCH, Weinheim, 921–922.Google Scholar
- Heller-Kallai, L., Miloslavski, I., and Grayevski, A. (1989a) Evolution of hydrogen on dehydroxylation of clay minerals: Amer. Mineral. 74, 818–820.Google Scholar
- Heller-Kallai, L., Miloslavski, I., Aizenshtat, Z., and Halicz, L. (1988) Chemical and mass spectrometric analysis of volatiles derived from clay: Amer. Mineral. 73, 376–382.Google Scholar
- Keller, W.D. (1986) Composition of condensates from heated clay minerals and shales: Amer. Mineral. 71, 1420–1425.Google Scholar
- Tokuyama, A., Kitano, Y., and Kanamori, N. (1973) Crystal forms of calcium carbonate formed from calcium bicarbonate solution containing heavy metal ions: Bull. Sciences and Engineering Division, Univ. of the Ryukyus 16, 90–108.Google Scholar
- Wicks, F. J. and Ramik, R. A. (1990) Vacuum thermographic analysis and evolved gas analysis by mass spectroscopy: in Thermal Analysis in Clay Science, J. W. Stucki, D. L. Bish, and F. A. Mumpton, eds., The Clay Minerals Society, Boulder, Colorado, 160–189.Google Scholar