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  • 1 Department of Materials Science, IVIC Apartado 21827, 1020A Caracas, Venezuela
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Abstract

Controlled heating (in air) of clay minerals leads to transformations into disordered structures and recrystallization into new phases at high temperatures. These phase transformations are of topotactic nature. On the other hand, prolonged dry-grinding treatments of the same silicates causes structural amorphization with no recrystallization into new phases. The mechanical energy relaxation mechanism, invoked to explain these differences, accounts for the particle size changes and the large growth of dislocations. The latters affect sensibly the reactivity of the materials submitted to such solid-state treatments.

These processes are monitored mostly by XRD, DTA and IR spectroscopy. The latter method allows to study in some silicates submitted to progressive grinding the location and nature of OH groups and water molecules.

  • 1 Mendelovici, E. 1989 Thermochim. Acta 148 205205 .

  • 2 Mendelovici, E., ICTAC News, in press.

  • 3 Mackenzie, R. C. 1957 The Differential Thermal Investigation of Clays Mineralogical Soc. London.

  • 4 Dent, L. S. Glasser, F. P. Taylor, H. E. W. 1962 Quart. Rev. 16 343343 .

  • 5 Brett, N. H. Mackenzie, K. J. P. Sharp, J. H. 1970 Quart. Rev. 24 185185. .

  • 6 Brindley, G. W. Lemaitre, J. 1987 Chemistry of Clays and Clay Minerals Mineralogical Soc. London.

  • 7 Grim, R. E. 1968 Clay Mineralogy Willey USA.

  • 8 Fripiat, J. J. Toussaint, F. 1960 Nature, London 186 627627. .

  • 9 Mendelovici, E. Villalba, R. Sagarzazu, A. Carias, O. 1995 Clay Minerals 30 307307. .

  • 10 Mendelovici, E. Sagarzazu, A. 1994 Int. J. Mechanochemistry Mechanical Alloying 3 176176.

  • 11 Papirer, E. Roland, P. 1981 Clays Clay Miner. 29 161161. .

  • 12 Perez-Rodriguez, J. L. Madrid Sanchez del Villar, L. Sanchez-Soto, P. J. 1988 Clay Miner. 23 399399 .

  • 13 Perez-Rodriguez, J. L. Sanchez-Soto, P. J. 1991 J. Thermal Anal. 37 14011401. .

  • 14 Rouxhet, P. G. 1970 Am. Miner. 55 841841.

  • 15 Mackenzie, R. C. Milne, A. A. 1953 Min. Mag. 30 178178.

  • 16 Brown, I. W. M. Mackenzie, K. J. D. Meinhold, R. H. 1987 J. Mater. Sci. 22 32653265. .

  • 17 Cicel, B. Kranz, G. 1981 Clay Minerals 16 151151. .

  • 18 Mendelovici, E., Sagarzazu, A. and Villalba, R., Proc. Int. Semin. Mechanochemistry and Mechanoactivation, St. Petersburg, Russia 1995, p. 123.

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  • 19 Yariv, S. 1975 Powder Technology 12 131131. .

  • 20 Mendelovici, E. 1973 Clays Clay Miner. 21 115115. .

  • 21 Stoch, L. 1992 J. Thermal Anal. 38 131131. .

  • 22 Nagata, H. Shimoda, S. Siudo, T. 1974 Clays Clay Min. 22 285285. .

  • 23 Mendelovici, E. Nadiv, S. Lin, I. 1983 J. Mater. Sci. 19 15561556 .

  • 24 Senna, M. 1985 Crystal Res. Technol. 20 209209. .

  • 25 Boldyrev, V. V. Pavlov, S. V. Goldberg, E. L. 1996 Int. J. Miner. Process. 44 181181 .

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