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Dehydration and rehydration of vermiculites: III. Phlogopitic Sr- and Ba-vermiculite

Published online by Cambridge University Press:  09 July 2018

H. Graf v. Reichenbach
Affiliation:
Institute of Soil Science and SFB 173, University of Hannover, 30419 Hannover, Germany
J. Beyer
Affiliation:
Institute of Soil Science and SFB 173, University of Hannover, 30419 Hannover, Germany

Abstract

Dehydration and rehydration of a phlogopitic vermiculite saturated with either Sr2+ or Ba2+ were studied by thermoanalysis (TG, DSC, DTA) and by in situ X-ray powder diffractometry. A detailed analysis of the relationship between temperature and state of hydration of the vermiculites close to equilibrium at atmospheric pressure was rendered possible by use of low heating rates in combination with a fast recording position-sensitive detector. For Sr-vermiculite, the results reveal the existence of a number of distinct states of hydration characterized by basal spacings of 1.54, 1.51, 1.49, 1.23, 1.21 and 0.96 nm. The Ba-vermiculite failed to develop a two-layer hydrate even in contact with water. Its one-layer hydrate (1.24 nm) was reversibly transformed into an incompletely dehydrated ordered ‘mica-structure’ (1.00-0.99 urn), before an irreversibly dehydrated structure was attained at temperatures exceeding 700°C The formation of regular 1:1 interstratification was confirmed for all transformations characterized by a change in the number of water layers. The concluding compilation summarizes basal spacings, stacking orders, layer translations and specific water contents for all discrete states of hydration observed in our experiments at saturation of vermiculite with different alkaline earth cations.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1997

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References

Barshad, I. (1948) Vermiculite and its relation to biotite as revealed by base exchange reactions, X-ray analyses, differential thermal curves and water content. Am. Miner. 33, 655678.Google Scholar
Beyer, J. (1995) Die Variation von Wassergehalten und Stapelordnungen in Yermiculiten unterschiedlicher Kationenbelegung. PhD thesis, University of Harmover, Germany.Google Scholar
Calle, C. de la, Suquet, H., Dubernat, J. & Pezerat, H. (1978) Mode d'empilement des feuillets dans les vermiculites hydratées à ‘deux couches'. Clay Miner. 13, 275297.Google Scholar
Calle, C. de la, Suquet, H. & Pezerat, H. (1985) Vermiculites hydrat6es h une couche. Clay Miner. 20, 221230.Google Scholar
Gorny, A. (1991) Einflub der Oxidation des oktaedrisch koordinierten Eisens aufdas Dehydratations verhalten yon Vermiculiten. PhD thesis, University of Hannover, Germany.Google Scholar
Keay, J. & Wild, A. (1961) Hydration properties of vermiculite. Clay Miner. Bull. 4, 221228.Google Scholar
Rausell-Colom, J.A., Fernandez, M., Serratosa, J.M., Alcover, J.F. & Gatineau, L. (1980) Organisation de l'espace interlamellaire dans les vermiculites monocouches et anhydres. Clay Miner. 15, 37–57.Google Scholar
Reichenbach, H. Graf, v. & Beyer, J. (1994) Dehydration and rehydration of vermiculites : I. Phlogopitic Mgvermiculite. Clay Miner. 29, 327340.Google Scholar
Reichenbach, H. Graf, v. & Beyer, J. (1995a) Dehydration and rehydration of vermiculites : II. Phlogopitic Cavermiculite. Clay Miner. 30, 273286.Google Scholar
Reichenbach, H. Graf, v. & Beyer, J. (1995b) Dehydration and rehydration of vermiculites as studied by X-ray diffraction at a highly resolved time scale. Proc. 10th Int. Clay Conf., Adelaide, 240-242.Google Scholar
Schütte, R. (1993) pH2O-T Stabilitätsdiagramme von Vermiculiten unterschiedlicher Kationenbelegung: Thermoanalytische Untersuchung. PhD thesis, University of Harmover, Germany.Google Scholar
Suquet, H. & Pezerat, H. (1987) Parameters influencing layer stacking types in saponites and vermiculites. Clays Clay Miner. 35, 353362.Google Scholar
Walker, G.F. (1961) Vermiculite minerals. Pp. 297-324 in: The X-ray Identification and Crystal Structures of Clay Minerals. (Brown, G., editor) Mineralogical Society, London.Google Scholar
Walker, G.F. & Milne, A. (1950) Hydration of vermiculites saturated with various cations. Trans. Int. Congr. Soil Sci. 2, 6267.Google Scholar