Skip to main content Accessibility help
×
Home

Re-examination of the kinetics of the thermal dehydroxylation of kaolinite

  • J. M. Criado (a1), A. Ortega (a1), C. Real (a1) and E. Torres De Torres (a1)

Abstract

The results obtained from this study of kaolinite dehydroxylation explain why different investigators have ascribed both first-order kinetics and a diffusion mechanism to this reaction. The fact that activation energies reported by these workers agree well, in spite of the different kinetics assumed when performing the calculations, is also explained. From a comparison of the results obtained by isothermal and non-isothermal methods it is concluded that, for reacted fractions, α, <0·6, kaolinite dehydroxylation is controlled by a diffusion process. A reaction mechanism explaining this behaviour is proposed.

Copyright

References

Hide All
Allison, E.B. (1954) Determination of specific heats and heats of reaction of clay minerals by thermal analysis. Silicates Ind. 19, 363373.
Achar, B.N.N., Brindley, G.W. & Sharp, J.H. (1966) Kinetics and mechanism of dehydroxylation processes, III, applications and limitations of dynamic methods. Proe. Int. Clay Conf. Jerusalem, I, 6773.
Brindley, G.W., Sharp, J.H., Patterson, J.H. & Narahari, B.N. (1967) Kinetics and mechanism of dehydroxylation processesses. I. Temperature and vapor pressure dependence of dehydroxylation of kaolinite. Am. Miner. 52, 201211.
Coats, A.W. & Redfern, J.P. (1964) Kinetic parameters from thermogravimetric data. Nature 201, 6669.
Criado, J.M., Morales, J., Ortega, A. & Rives-Arnau, V. (1980) Estudio del mecanismo de descomposición térmica de la caolinita. XVIII Reunión Bienal Burgos Libro H, 13-42.
Delmon, B. (1969) Introduction à la Cinétique Hétérogene. Ed. Technip, Paris.
Gallagher, K.J. (1965) The effect of particle size distribution on the kinetics of diffusion reactions in powders. Pp. 192203 in: Reactivity of Solids (Schwab, M., editor). American Elsevier Publishing Co. Inc., New York.
Holt, J.B., Culter, I.B. & Wadsworth, M.E. (1962) Rate of thermal dehydration of kaolinite in vacuum. J. Am. Ceram. Soc. 45, 133136.
Hancock, J.D. & Sharp, J.H. (1972) Method of comparing solid-state kinetic data and its application to the decomposition of kaolinite, brucite and BaCO3 . J. Am. Ceram. Soc. 55, 7477.
Johnson, H.B. & Kessler, F. (1969) Kaolinite dehydroxylation kinetics. J. Am. Ceram. Soc. 52, 199204.
Kromer, H. (1972) Mineral composition and properties of two North Spanish kaolins from the region of Vivero (Galicia). Interceram 4, 259264.
Lahiri, A.K. (1980) The effect of particle size distribution on TG. Thermochim. Acta 40, 289295.
Murray, P. & White, J. (1955) Kinetics of thermal dehydration characteristics of the clay minerals. Trans. Brit. Ceram. Soc. 54, 137150.
Otero-Arean, C., Letellier, M., Gerstein, B.C. & Fripiat, J.J. (1982) Protonic structure of kaolinite during dehydroxylation studied by proton nuclear magnetic resonance. Proc. 7th Int. Clay Conf. Bologna & Pavia, 7385.
Sharp, J.H., Brindley, G.W, & Achar, B.N.N. (1966) Numerical data for some commonly used solid state reaction equations. J. Am. Ceram. Soc. 49, 379382.
Toussaint, F., Fripiat, J.J. & Gastuche, M.C. (1963) Dehydroxylation of kaolinite: I. J. Phys. Chem. 67, 2630.

Re-examination of the kinetics of the thermal dehydroxylation of kaolinite

  • J. M. Criado (a1), A. Ortega (a1), C. Real (a1) and E. Torres De Torres (a1)

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed