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Compaction and Swelling of Ca-Smectite in Water and in CaCl2 Solutions: Water Activity Measurements and Matrix Resistance to Compaction

Published online by Cambridge University Press:  02 April 2024

Jérôme H. Denis*
Affiliation:
Schlumberger Cambridge Research, PO Box 153, Cambridge CB3 OHG, United Kingdom
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Abstract

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Direct water-activity measurements were made for calcium-smectite-CaCl2 mixtures. The samples used were prepared by high-pressure filtration and had water contents <0.60% by weight of clay. For deionized water, the water activity (aw) ranged between 1 and 0.4 and was independent of the pressure history of the clay cake. Good agreement was found with the results of an adsorption isotherm. Samples were also prepared in 1,3, and 5 M CaCl2 solutions. The final concentration of chloride present in the cakes was measured: substantial anion exclusion was observed. The water activity of the clay-salt mixtures depended on both the water content and the concentration of CaCl2. The data can be well represented by the expression aw = min(aw0, aw*c × aw*s), where aw0 is the water activity of the brine used to prepare the cake, and aw*c and aw*s are water activities calculated for clay (in absence of salt) and salt (in absence of clay), respectively. The compaction and swelling behavior of a core of the same Ca-smectite was also investigated for pressures (P) between 0.5 and 800 bar. In two compaction-swelling cycles total recovery of the void ratio (e) was observed with, however, large hysteresis in the relationship between e and P. The osmotic pressure developed in the core at equilibrium, evaluated using the water-activity data, was intermediate between the compaction and swelling pressures. Apparently, another force, Pm, linked to irreversible changes in the structure of the matrix was contributing to the resistance to compaction. Pm values agreed with literature results for Ca-smectite suspensions.

Type
Research Article
Copyright
Copyright © 1991, The Clay Minerals Society

References

Attard, P., Mitchell, J. D. and Ninham, B. W., 1988 Beyond Poisson-Boltzmann: Images and correlations in the electric double layer II J. Chem. Phys. 89 43584367.CrossRefGoogle Scholar
von Engelhardt, W. and Gaida, K. H., 1963 Concentration changes of pore solutions during the compaction of clay sediments J. Sed. Pet. 33 919930.CrossRefGoogle Scholar
Glaeser, R., 1968 J. Homogeneous hydration domains of the smectites Compt. Rend. Acad. Sci. (Paris) 267 436466.Google Scholar
Glueckauf, E., 1952 A theoretical treatment of cation exchangers. I Proc. Roy. Soc. London A214 207225.Google Scholar
Gregg, S. G. and Sing, K. S. W., 1982 Adsorption, Surface Area and Porosity London Academic Press 126132.Google Scholar
Gueuze, E C W A Rebull, P. M. and Bailey, S. W., 1966 Mechanical force fields in a clay mineral particle system Clays and Clay Minerals, Proc. 14th Natl. Conf., Berkeley, California, 1965 New York Pergamon Press 103116.Google Scholar
Hunter, R. J. (1987) Foundations of Colloid Science, Vol. 1: Oxford University Press, Oxford, United Kingdom.Google Scholar
Israelachvili, J. N. and Adams, G. E., 1978 Measurements of forces between two mica surfaces in aqueous electrolyte solutions in the range 0–100 nm J. Chem. Soc. Faraday Tans. 1 74 9751001.CrossRefGoogle Scholar
Keren, R. and Shainberg, I., 1979 Water adsorption isotherms and heat of immersion of Na/Ca montmorillonites systems—II: mixed systems Clays & Clay Minerals 27 145151.CrossRefGoogle Scholar
Kjellander, R. and Marčelja, S., 1988 Attractive double-layer interactions between calcium clay particles J. Colloid Interface Sci. 126 194211.CrossRefGoogle Scholar
Kjellander, R., Marčelja, S., Pashley, R. M. and Quirk, J. P., 1988 Double-layer correlation forces restrict calcium-clay swelling J. Phys. Chem. 92 64896492.CrossRefGoogle Scholar
Lubetkin, S. D., Middleton, S. R. and Ottewill, R. H., 1984 Some properties of clay-water dispersions Phil. Trans. R. Soc. Lond. A 311 353368.Google Scholar
Mesri, G. and Olson, R. E., 1971 Consolidation characteristics of montmorillonite Géotechnique 21 341352.CrossRefGoogle Scholar
Norrish, K., 1954 The swelling of montmorillonite Disc. Faraday Soc. 18 120134.CrossRefGoogle Scholar
van Olphen, H., Swineford, A. and Plummer, N., 1954 Interlayer forces in bentonite Clays and Clay Minerals, Proc. 2nd Natl. Conf., Columbia, Missouri, 1953 418438.CrossRefGoogle Scholar
van Olphen, H., 1977 An Introduction to Clay Colloid Chemistry New-York Wiley 2942.Google Scholar
Olson, R. E. and Mesri, G., 1970 Mechanism controlling compressibility of clays J. Soil. Mech. Found. Div. 96 18631878.CrossRefGoogle Scholar
Pashley, R. M., 1981 Hydration forces between mica surfaces in Li, Na, K, and Cs electrolyte solutions J. Colloid Interface Sci. 80 153162.CrossRefGoogle Scholar
Pashley, R. M. and Israelachvili, J. N., 1984 Molecular layering of water in thin films between mica surfaces and its relation to hydration forces J. Colloid Interface Sci. 101 511523.CrossRefGoogle Scholar
Rard, J. A., Habenschuss, A. and Spedding, F. H., 1977 A review of the osmotic coefficients of aqueous CaCl2 at 25°C J. Chem. Eng. Data 22 180186.CrossRefGoogle Scholar
Robinson, R. A. and Stokes, R. M., 1970 Electrolyte Solutions London Butterworth 510.Google Scholar
Söhnel, O. and Novotný, P., 1985 Densities of Aqueous Solutions of Inorganic Substances Amsterdam Elsevier D225.Google Scholar
Soldano, B. and Larson, Q. V., 1954 Osmotic behavior of anion and cation exchangers J. Phys. Chem. 77 13311334.Google Scholar
Young, J. F., 1967 Humidity control in the laboratory using salt solutions—a review J. Appl. Chem. 17 241245.CrossRefGoogle Scholar
Warkentin, B. P., Bolt, G.H. and Miller, R.D., 1957 Swelling pressure of montmorillonite Soil Sci. Soc. Amer. Proc. 21 495497.CrossRefGoogle Scholar