Hostname: page-component-848d4c4894-wzw2p Total loading time: 0 Render date: 2024-05-17T17:06:20.347Z Has data issue: false hasContentIssue false

The Effect of Thermal Treatment on Some of the Physicochemical Properties of a Bentonite

Published online by Cambridge University Press:  28 February 2024

Yüksel Sarikaya*
Affiliation:
University of Ankara, Faculty of Science, Department of Chemistry, 06100, Besevler, Ankara, Turkey
Müşerref Önal
Affiliation:
University of Ankara, Faculty of Science, Department of Chemistry, 06100, Besevler, Ankara, Turkey
Bülent Baran
Affiliation:
University of Ankara, Faculty of Science, Department of Chemistry, 06100, Besevler, Ankara, Turkey
Tülay Alemdaroğlu
Affiliation:
University of Ankara, Faculty of Science, Department of Chemistry, 06100, Besevler, Ankara, Turkey
*
E-mail of corresponding author: sakaya@science.ankara.edu.tr

Abstract

A white calcium bentonite (CaB) from the Kütahya region, Turkey, contains 35 wt. % opal-CT and 65 wt. 9c Ca-rich montmorillonite (CaM). Samples were heated at various temperatures between 100–1300°C for 2 h. Thermal gravimetric (TG), derivative thermal gravimetric (DTG), and differential thermal analysis (DTA) curves were determined. Adsorption and desorption of N2 at liquid N2 temperature for each heat-treated sample was determined. X-ray diffraction (XRD) and cation-exchange capacity (CEC) data were obtained. The change in the <d(001) value and the deformation of the crystal structure of CaM depend on temperature. Deformation is defined here as changes of the clay by dehydration, dehydroxylation, recrystallization, shrinkage, fracture, etc. The activation energies related to the dehydration and dehydroxylation of CaB calculated from the thermogravimetric data are 33 and 59 kJ mol−1, respectively. The average deformation enthalpies, in the respective temperature intervals between 200–700°C and 700–900°C, were estimated to be 25 and 205 kJ mol−1 using CEC data and an approach developed in this study. The specific surface area (S) and the specific micropore-mesopore volume (V) calculated from the adsorption and desorption data, respectively, show a “zig zag” variation with increasing temperature to 700°C, but decrease rapidly above this temperature. The S and V values were 43 m2 g−1 and 0.107 cm3 g−1, respectively, for untreated bentonite. They reach a maximum at 500°C and are 89 m2 g−1 and 0.149 cm3 g−1 respectively. The XRD data clearly show that, at 500°C, where the irreversible dehydration is completed without any change in the crystal structure, the porosity of CaM reaches its maximum.

Type
Research Article
Copyright
Copyright © 2000, The Clay Minerals Society

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

Bradley, W.F. and Grim, R.E., (1951) High temperature thermal effects of clay and related materials American Mineralogist 36 182201.Google Scholar
Brindley, G.W., (1978) Thermal reactions of clay and clay minerals Ceramica 24 217224.Google Scholar
Ceylan, H. Yildiz, A. and Sankaya, Y., (1993) Investigation of adsorption of fatty acids on two different clays using IR, DTA and TGA techniques Turkish Journal of Chemistry 17 267272.Google Scholar
Coats, A.W. and Redfern, J.R., (1964) Kinetic parameters from thermogravimetric data Nature 201 6869 10.1038/201068a0.CrossRefGoogle Scholar
Elzea, J.M. Odom, I.E. and Miles, W.J., (1994) Distinguishing well-ordered opal-CT and opal-C from high temperature cristobalite by X-ray diffraction Analytica Chimica Acta 286 107116 10.1016/0003-2670(94)80182-7.CrossRefGoogle Scholar
Gregg, S. and Sing, K.S.W., (1982) Adsorption Surface Area and Porosity London Academic Press 111 19.Google Scholar
Grim, R.E. and Güven, N., (1978) Bentonites, Geology, Mineralogy, Properties and Uses, Developments in Sedimen-tology, Volume 24 Amsterdam Elsevier 512.Google Scholar
Güler, and Saner, N., (1990) Kinetics of the thermal dehydration of acid activated montmorillonite by the rising temperature technique Thermochimica Acta 159 2933 10.1016/0040-6031(90)80090-L.CrossRefGoogle Scholar
Hang, P.T. and Brindley, G.W., (1970) Methylene blue adsorption by clay minerals. Determination of surface areas and cation exchange capacities (Clay-organic studies XVIII) Clays and Clay Minerals 18 203312 10.1346/CCMN.1970.0180404.CrossRefGoogle Scholar
Joshi, R.C. Achari, G. Horfield, D. and Nagaraj, T.S., (1994) Effect of heat treatment on strength of clays Journal of Geotechnical Engineering 120 10801088 10.1061/(ASCE)0733-9410(1994)120:6(1080).CrossRefGoogle Scholar
Miles, W.J., (1994) Crystalline silica analysis of Wyoming bentonite by X-ray diffraction after phosphoric acid digestion Analytica Chimica Acta 286 97105 10.1016/0003-2670(94)80181-9.CrossRefGoogle Scholar
Mozas, T. Bruque, S. and Rodriguez, A., (1980) Effect of thermal treatment on lanthanide montmorillonites: Dehydration Clay Minerals 15 421428 10.1180/claymin.1980.015.4.09.CrossRefGoogle Scholar
Murray, H.H., (1991) Overview-clay mineral applications Applied Clay Science 5 379395 10.1016/0169-1317(91)90014-Z.CrossRefGoogle Scholar
Reicle, W.T., (1985) Catalytic reactions by thermally activated, synthetic, anionic clay minerals Journal of Catalysis 94 547557 10.1016/0021-9517(85)90219-2.CrossRefGoogle Scholar
Rytwo, G S C Nir, S. and Margulies, L., (1991) Use of methylene blue and crystal violet for determination of exchangeable cations in montmorillonite Clays and Clay Minerals 39 551555 10.1346/CCMN.1991.0390510.CrossRefGoogle Scholar
Sankaya, Y. and Aybar, S., (1978) The adsorption of NH3, N2O and CO, gases on the 5A molecular sieve Communications (Faculty of Science, University of Ankara) 24 3339.Google Scholar
Sankaya, Y. Ceylan, H. Bozdogan, L. and Akinç, M., (1993) Determination of pore size distributions from thermal analysis data: Thermoporometry Turkish Journal of Chemistry 17 119124.Google Scholar
Sevinç, I. Sankaya, Y. and Akinç, M., (1991) Adsorption characteristics of alumina powders produced by emulsion evaporation Ceramics International 17 14 10.1016/0272-8842(91)90002-H.CrossRefGoogle Scholar
Talvitie, N.A., (1951) Determination of quartz in presence of silicates using phosphoric acid Analytical Chemistry 23 523626 10.1021/ac60052a021.CrossRefGoogle Scholar
Wang, M.C. Benway, J.M. Arayssi, A.M., Hoodinott, K.B. Lamb, R.O. and Lutenegger, A.J., (1990) The effect of heating on engineering properties of clays Physicochemical Aspects of Soil and Related Materials Philadelphia ASTM STP 1095 11391158.Google Scholar
Yildiz, N. Sarikaya, Y. and Çalimli, A., (1999) The effect of the electrolyte concentration and pH on the Theological properties of the original and Na2CO3-activated Kiitahya bentonite Applied Clay Science 14 319327 10.1016/S0169-1317(99)00006-X.CrossRefGoogle Scholar