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Study of the dehydration process of vermiculites by applying a vacuum pressure: formation of interstratified phases

Published online by Cambridge University Press:  05 July 2018

C. Marcos*
Affiliation:
Departamento de Geología e Instituto de Organometálica Enrique Moles, Universidad de Oviedo, C/. Jesús Arias de Velasco s/n, 33005, Oviedo, Spain
A. Argüelles
Affiliation:
Departamento de Geología e Instituto de Organometálica Enrique Moles, Universidad de Oviedo, C/. Jesús Arias de Velasco s/n, 33005, Oviedo, Spain Departamento de Física, Universidad de Oviedo, C/. Jesús Arias de Velasco s/n, 33005, Oviedo, Spain
A. Ruíz-Conde
Affiliation:
Instituto de Ciencia de Materiales de Sevilla, Instituto Mixto Consejo Superior de Investigaciones Científicas (C.S.I.C.)-Universidad de Sevilla, c/ Américo Vespucio s/n, Isla de la Cartuja, 41092-Sevilla, Spain
P. J. Sánchez-Soto
Affiliation:
Instituto de Ciencia de Materiales de Sevilla, Instituto Mixto Consejo Superior de Investigaciones Científicas (C.S.I.C.)-Universidad de Sevilla, c/ Américo Vespucio s/n, Isla de la Cartuja, 41092-Sevilla, Spain
J. A. Blanco
Affiliation:
Departamento de Física, Universidad de Oviedo, C/. Jesús Arias de Velasco s/n, 33005, Oviedo, Spain
*

Abstract

Structural transformations between the different hydration states of three vermiculite samples from Sta. Olalla (Huelva, Spain), Paulistana (Piaui, Brasil) and West China, have been observed by X-ray diffraction at atmospheric pressure, P = 1.4 x 10–2 mbar and P = 2.4 x 10–4 mbar. The samples were studied in flake and powder forms. The effect of vacuum has been proven to be the same as that of temperature, i.e. it causes dehydration of vermiculite, but with a different evolution through the different hydration states. In fact, under vacuum, the process seems to be inhibited at a one-water layer hydration state (1-WLHS), without a further dehydration of samples to a zero-water layer hydration state (0-WLHS).

Furthermore, the dehydration process has been shown to occur through different interstratified states in each vermiculite. This result has been related to the interlayer Mg-cation content, due to its affinity to water molecules. The interstratified states have been analysed by the direct Fourier-transform method. The vermiculite from Sta. Olalla exhibits the most complex process, with formation of three different interstratified phases: two phases characterized by an interstratification of interplanar distances, d = 11.5 –13.8 Å and d = 9.6 –11.5 Å , respectively, and a practically segregated phase characterized by d = 13.8 Å . For the vermiculite from China, an interstratified phase not previously reported has been found, with an interplanar distance of 12.10 Å.

The inhibition of dehydration at 1-WLHS, as observed, could be used in applications such as adsorption and separation technology of gases and liquids, or in heterogeneous catalysis processes.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2003

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References

Brindley, G.W. and Brown, G. (1980) Crystal Structures of Clay Minerals and their X-ray Identification. Monograph 5, Mineralogical Society, London, 495 pp.Google Scholar
Collins, D.R., Fitch, A.N. and Catlow, R.A. (1992) Dehydration of vermiculites and montmorillonites: a time-resolved powder neutron diffraction study. Journal of Material Chemistry, 8, 865873.CrossRefGoogle Scholar
de la Calle, C. and Suquet, H. (1988) Vermiculites. Pp. 455495 in: Hydrous Phyllosilicates (Bailey, S.W., editor). Reviews in Mineralogy, 19. Mineralogical Society of America, Washington D.C..CrossRefGoogle Scholar
de la Calle, C, Suquet, H. and Pons, C.H. (1988) Stacking Order in A14.30 — A Mg-Vermiculite. Clays and Clay Minerals, 36, 481490.CrossRefGoogle Scholar
Foster, M.D. (1963) Interpretation of the composition of vermiculites and hydrobiotites.. Clays and Clay Minerals, 10, 7089.CrossRefGoogle Scholar
Gonzalez Garcia, F. and Garcia Ramos, G. (1960) On the genesis and transformations of vermiculite. Transactions 7* International Congress of Soil Science, Madison, Wisconsin, 4, pp. 482491.Google Scholar
Grim, R.E. (1968) Clay Mineralogy. McGraw Hill, New York, pp. 330332.Google Scholar
Hennies, W.T. and Stellin, A. (1978) A jazida de vermiculita de Paulistana, Estado do Piaui. Annais do XXX Congreso Brasileiro de Geologia, Recife, 4, 17961804.Google Scholar
Justo, A., Maqueda, C. and Perez Rodriguez, J.L. (1986) Estudio Qufmico de Vermiculitas de Andalucia y Badajoz. Boletin Sociedad Espanola de Mineralogta, 9, 123129.Google Scholar
Laird, J. and Albee, A.L. (1981) High pressure metamorphism in mafic sheet from northern vermont. American Journal of Science, 281, 127177.CrossRefGoogle Scholar
Luque, F.J., Rodas, M. and Dovla, M. (1985) Mineralog fa y Genesis de los yacimientos de vermiculita de Ojen. Boletin de la Sociedad Espanola de Mineralogta, 8, 229238.Google Scholar
MacEwan, D.M.C., Ruiz-Amil, A. and Brown, G. (1961) In The X-ray Identification and Crystal Structure of Clay Minerals (Brown, G., editor). Mineralogical Society, London, 393 pp.Google Scholar
Mathieson, A.M. and Walker, G.F. (1954) Crystal structure of magnesium-vermiculite. American Mineralogist, 39, 231255.Google Scholar
Reichenbach, H.G. and Beyer, J. (1994) Dehydration and rehydration of vermiculites: IV. Arrangements of interlayer components in the 1.43 nm and 1.38 nm hydrates of Mg-vermiculit. Clay Minerals, 29, 327340.Google Scholar
Rietveld, H.M. (1969) A profile refinement method for nuclear and magnetic structures. Journal of Applied Crystallography, 2, 65.CrossRefGoogle Scholar
Rodriguez Carvajal, J. (1990) Satellite Meeting on Powder Diffraction of the XV Congress of the International Union of Crystallography, Abstract. Toulouse, p. 127.Google Scholar
Ruiz-Amil, A., Ramirez-Garcia, A. and MacEwan, D.M.C. (1967) X-ray Diffraction Curves for the Analysis of Interstratified Structures, Volturna Press, Edinburgh, UK, p. 11Google Scholar
Ruiz-Conde, A., Ruiz-Amil, A., Perez-Rodriguez, J.L. and Sanchez-Soto, PJ. (1996) Dehydration-rehydra-tion in magnesium vermiculite: conversion from two-one and one-two water hydration states through the formation of interstratified phases.. Journal of Material Chemistry, 6, 15571566.CrossRefGoogle Scholar
Shirozu, H. and Bailey, S.W. (1966) Crystal structure of a two-layer Mg-vermiculite. American Mineralogist, 51, 11241143.Google Scholar
Strand, P.R. and Stewart, E. (1983) Vermiculites. Pp. 13751381 in: Industrial Minerals and Rocks (Lefond, SJ., editor). The Society of Mining Engineers of the American Institute of Mining, Metallurgical and Petroleum Engineers, Inc., New York.Google Scholar
Vali, H. and Hesse, R. (1992) Identification of vermiculite by transmission electron microscopy and X-ray diffraction. Clay Minerals, 27, 185192.CrossRefGoogle Scholar
Velasco, F., Casquet, C., Ortega Huertas, M. and Rodriguez Gordillo, J. (1981) Indicio de vermiculita en el skarn magnetico (aposkarn flogopitico) de La Garrenchosa (Sta. Olalla, Huelva). Sociedad Espanola de Mineralogta, 2, 135149.Google Scholar
Velde, B. (1978) High temperature or metamorphic vermiculites. Contributions to Mineralogy and Petrology, 66, 319323.CrossRefGoogle Scholar
Vila, E. and Ruiz-Amil, A. (1988) Computer Program for Analysing Interstratified Structures by Fourier Transform Methods. Powder Diffraction, 3, 7.CrossRefGoogle Scholar
Walker, G.F. (1956) Mechanism of dehydration of Mg-vermiculite. Clays and Clay Minerals, 4, 101.CrossRefGoogle Scholar
Warshaw, CM., Rosenberg, P.E. and Roy, R. (1960) Changes effected in layer silicates by heating below 550°C. Clay Minerals Bulletin, 4, 113126.CrossRefGoogle Scholar