Hostname: page-component-586b7cd67f-gb8f7 Total loading time: 0 Render date: 2024-11-27T04:29:02.719Z Has data issue: false hasContentIssue false

Structural transformation of a kaolinite and calcite mixture to gehlenite and anorthite

Published online by Cambridge University Press:  31 January 2011

Karfa Traoré
Affiliation:
Laboratoire de physico-chimie et de Technologie des Matériaux, UFR-SEA, Université de Ouagadougou, B.P. 7021 Ouagadougou 03, Burkina Faso
Philippe Blanchart
Affiliation:
GEMH, ENSCI, 87065 Limoges cedex, France
Get access

Abstract

Kaolinite mixed with calcite was sintered at low temperature (1100 °C; 5 °C/min). The successive phase transformations are metakaolinite to gehlenite and then anorthite, although the available phase diagram indicates a direct anorthite recrystallization. Transmission electron microscopy and electron diffraction studies of nanocrystallites revealed that the transformation path is favored by the structural similarities of phases. In particular, the pseudolayers of gehlenite have a major orientation relationship with the initial metakaolinite layers. The gehlenite axis, [001]G, is parallel to the metakaolinite axis, [001]A. This direct transition is favored by the existence of Si tetrahedral units and 4–fold–coordinated Al in both structures. Ca atoms, initially in the interlayer spacing of metakaolinite, remain in the interlayers of gehlenite. During the second transformation step, anorthite recrystallizes from gehlenite with axis [020]A parallel to [210]G. It is proposed that this orientation relationship is favored by the orientation and shape of Ca-atom channels through both structures, along [001]G and [100]A axes.

Type
Articles
Copyright
Copyright © Materials Research Society 2003

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Eze, E.O. and Onabanjo, S.A., Appl. Clay Sci. 9, 397 (1995).CrossRefGoogle Scholar
Bell, F.G. and Maud, R.R., Int. J. Rock Mech. Min. Sci. 33, 121A (1996).Google Scholar
Lagzdina, S., Bidermanis, L., Liepins, J., and Sedmalis, U., J. Eur. Ceram. Soc. 18, 1717 (1998).CrossRefGoogle Scholar
Carretero, M.I., Dondi, M., Fabbri, B., and Raimondo, M., Appl. Clay Sci. 20, 301 (2002).CrossRefGoogle Scholar
White, G.N., Dixon, J.B., Weaver, R.M., and Kunkle, A.C., Clays Clay Miner. 40, 555 (1992).CrossRefGoogle Scholar
Traoré, K., Kabré, T.S., and Blanchart, P., Appl. Clay Sci. 17, 279 (2000).CrossRefGoogle Scholar
Traoré, K., Kabré, T.S., and Blanchart, P., Ceram. Int. 27, 875 (2001).CrossRefGoogle Scholar
Singh, B., Mackinnon, I.D.R., Intercalation of Kaolins by Alkaline Earth Metal Salts (International Clay Conference, Ottawa, Canada, 1997) pp. 489495.Google Scholar
Sanchez-Soto, P.J., Haro, M.C. Jimenez de, Perez-Maqueda, L.A., Varona, I., and Perez-Rodriguez, J.L., J. Am. Ceram. Soc. 83, 1649 (2000).CrossRefGoogle Scholar
Osborn, E.F. and Muan, A., System SiO2-CaO-Al2O3, Phase Equilibrium Diagrams of Oxide Systems, Fig. 630 (American Ceramic Society, Columbus, OH, 1960).Google Scholar
Roisnel, T. and Rodríguez-Carvajal, J., WinPLOTR: a Windows Tool for Powder Diffraction Patterns Analysis, in Materials Science Forum, Proceedings of the Seventh European Powder Diffraction Conference (EPDIC 7), edited by Delhez, R., Mittenmeijer, E.J. (Trans. Tech. Publications, Uetikon A.S., Switzerland, 2000), pp. 118123.Google Scholar
Galtieri, A., Belloto, M., Phys. Chem. Miner. 25, 442 (1998).CrossRefGoogle Scholar
Bergaya, F., Dion, P., Alcover, J.F., Clinard, C., Tchoubar, D., J. Mater. Sci. 31, 5069 (1996).CrossRefGoogle Scholar
Swaison, I.P., Dove, M.T., Scmahl, W.W., and Putnis, A., Phys. Chem. Miner. 19, 185 (1992).Google Scholar
Thayaparam, S., Dove, M.T., and Heine, V., Phys. Chem. Miner. 21, 110 (1994).CrossRefGoogle Scholar
Bragg, L.S., Claringbull, G.F., and Taylor, W.H., in The Crystalline State, edited by Bragg, L., Bell, G. (1965), Vol. IV, pp. 304339.Google Scholar
Wainwright, J.E. and Starkey, J., Acta Crystallogr. 23, 1005 (1967).Google Scholar