The effect of pressure on order/disorder in kaolinite under wet and dry conditions
Galán, Emilio (Universidad de Sevilla. Departamento de Cristalografía, Mineralogía y Química Agrícola)
Aparicio, Patricia (Universidad de Sevilla. Departamento de Cristalografía, Mineralogía y Química Agrícola)
La Iglesia, Angel (Universidad Complutense de Madrid. Instituto de Geología Económica)
González, Isabel (Universidad de Sevilla. Departamento de Cristalografía, Mineralogía y Química Agrícola)

Date:	2006
Abstract:	Well ordered kaolinite was isostatically and uniaxially pressurized up to 13,200 kg/cm for 10 min in dry conditions and the effects of pressure on kaolinite order were determined by analyzing the shapes of two-dimensional diffraction bands on X-ray powder diffraction patterns. Increased pressure decreased the percentage of low-defect kaolinite phase, and isostatic pressure proved to be more effective than uniaxial pressure in increasing disorder, e. g. the degree of disorder resulting from 2000 kg/cm isostatic pressure was equivalent to that caused by a 3200 kg/cm uniaxial pressure. Also, the effect of high pressure was similar to that obtained with lower pressures applied several times (e. g. the effect of applying 8500 kg/cm pressure for 10 min was comparable to using 3200 kg/cm pressure five times). In addition, six kaolinites of different structural order were isostatically pressurized up to 4000 kg/cm for 10 min, both in dry and wet (water) conditions. Under dry conditions, changes in structurally ordered kaolinite were comparable to those cited above whereas kaolinite pressurized in wet conditions showed a moderate improvement in structural order. These results may contribute to our understanding of kaolinite behavior during burial diagenesis and low-grade metamorphism. In addition, these results can also be used in industry to improve kaolin technological properties that depend on kaolinite structural order by application of appropriate industrial pressure processes.
Grants:	Ministerio de Educación y Ciencia BTE 2001-2415
Rights:	Tots els drets reservats.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Subject:	Experimental Pressure Behavior ; Kaolinite Order Disorder
Published in:	Clays and Clay Minerals, Vol. 54, Núm. 2 (2006) , p. 230-239, ISSN 1552-8367

DOI: 10.1346/CCMN.2006.0540208

10 p, 1.1 MB  UAB restricted access

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