Hostname: page-component-cd9895bd7-jn8rn Total loading time: 0 Render date: 2024-12-26T08:06:14.489Z Has data issue: false hasContentIssue false

Intracrystalline Swelling of Mixed-Layer Illite-Smectite in K-Bentonites

Published online by Cambridge University Press:  09 July 2018

M. Müller-Vonmoos
Affiliation:
Division of Geotechnical Engineering, Laboratory for Clay Mineralogy, Federal Institute of Technology, CH-8092 Zürich, Switzerland
G. Kahr
Affiliation:
Division of Geotechnical Engineering, Laboratory for Clay Mineralogy, Federal Institute of Technology, CH-8092 Zürich, Switzerland
F.T. Madsen
Affiliation:
Division of Geotechnical Engineering, Laboratory for Clay Mineralogy, Federal Institute of Technology, CH-8092 Zürich, Switzerland

Abstract

To investigate the long-term stability of bentonite under final disposal conditions of highly radioactive waste, K-bentonites from Kinnekulle (Sweden) and from the Marias River Formation in the Montana disturbed belt (USA) were studied. After separating the mixed-layer illite-smectite (I-S) from the K-bentonite samples, the interlayer charge was calculated from the cation exchange capacity (CEC) and the amount of fixed interlayer K+ ions (Kfix). The interlayer charge was also determined by the alkylammonium method. According to both methods the interlayer charge was in the range for smectite. The results show that the amount of exchangeable cations increased linearly with decreasing Kfix. A small increase in the interlayer charge with increasing Kfix was observed as was a linear correlation between the intracrystalline swelling up to the second water layer, the CEC and the content of Kfix. Divalent exchangeable cations were then found to be surrounded by approximately 24 water molecules per cation. Fixed interlayer K+ ions were unhydrated. Forming the third and fourth water layer, swelling was presumably limited by free silica formed by the vitrification of the volcanic ash.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1994

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

Altaner, S.P., Hower, R., Whitney, G. & Aronson, J.L. (1984) Model for K-bentonite formation: Evidence from zoned K-bentonites in the disturbed belt Montana. Geology, 12, 412–115.2.0.CO;2>CrossRefGoogle Scholar
Ayranci, B. (1977) The major, minor and trace element analysis of silicate rocks and minerals from a single sample solution. Schweiz. Mineral. Petrogr. Mitt, 57, 299312.Google Scholar
Brusewitz, A.M. (1986) Chemical and physical properties of Palaeozoic potassium bentonites from Kinnekulle, Sweden. Clays Clay Miner, 34, 442454.Google Scholar
Eslinger, E., Highsmith, P., Albers, D. & Demayo, B. (1979) Role of iron reduction in the conversion of smectite to illite in bentonites in the disturbed belt, Montana. Clays Clay Miner, 27, 327338.CrossRefGoogle Scholar
Gabis, V. (1963) Etude mineralogique et geochimique de la série sédimentaire oligocéne du Velay. Bull. Soc. frang. Miner. Crist, 86, 315354.Google Scholar
Gregg, S.J. & Sing, K.S.W. (1982) Adsorption, Surface Area and Porosity. 2nd ed. Academic Press, London.Google Scholar
Grim, R.E. & Guven, N. (1978) Bentonites. Elsevier, N.Y. Google Scholar
Hower, J. & Mowatt, T.C. (1966) The mineralogy of illites and mixed-layer illite/montmorillonites. Am. Miner, 51, 825854.Google Scholar
Kahr, G., Kraehenbuehl, F., Muller-Vonmoos, M. & Stoeckli, H.F. (1986) Wasseraufnahme und Wasserbe- wegung in hochverdichtetem Bentonit. NAGRA, Tech- nischer Bericht,86-14, NAGRA, Baden, Switzerland.Google Scholar
Kahr, G., Kraehenbuehl, F., Stoeckli, H.F. & Muller- Vonmoos, M. (1990) Study of the water-bentonite system by vapour adsorption, immersion calorimetry and X-ray techniques: II. Heats of immersion, swelling pressures and thermodynamic properties. Clay. Miner, 25, 499506.Google Scholar
Roster, H.M. (1977) Die Berechnung kristallchemischer Strukturformeln von 2:1-Schichtsilikaten unter Beriick- sichtigung der gemessenen Zwischenschichtladungen und Kationenaustauschkapazitaten, sowie die Darstel- lung der Ladungsverteilung in der Struktur mittels Dreieckskoordinaten. Clay Miner, 12, 4554.Google Scholar
Kraehenbuehl, F., Sauvain, J.J. & Stoeckli, H.F. (1987a) Thermodynamique du gonflement de systemes eau- bentonite, eau-métabentonite, eau-illite. NAGRA Rapport Technique. 87-01, NAGRA, Baden, Switzerland.Google Scholar
Kraehenbuehl, F., Stoeckli, H.F., Brunner, F., Kahr, G. & Muller-Vonmoos, M. (1987b) Study of the water- bentonite system by vapour adsorption, immersion calorimetry and X-ray techniques: I. Micropore volumes and internal surface areas, following Dubinin's theory. Clay Miner, 22, 19.CrossRefGoogle Scholar
Lagaly, G. (1981) Characterization of clays by organic compounds. Clay Miner, 16, 121.Google Scholar
Lagaly, G. & Weiss, A. (1971) Schichteinlagerungsverbin- dungen als Modelle fiir Struktur und Strukturumwand- lungen von monomolekularen und bimolekularen Schichten langkettiger Verbindungen. Teil I: n-Alkylam- monium-Schichtsilikate mit primāren n-Alkanolen. Kol-loid-Z.Z.Polymer, 248, 968978.Google Scholar
Low, P.F. & Anderson, D.M. (1958) Osmotic pressure equations for determining thermodynamic properties of soil water. Soil Sci, 86, 251253.Google Scholar
Mackenzie, R.C. (1951) A micromethod for determination of cation-exchange capacity of clay. J. Coll. Sci, 6, 219222.Google Scholar
Meike, A. (1989) Transmission electron microscope study of illite/smectite mixed layers. NAGRA Technical Repor. 89-03, NAGRA, Baden, Switzerland.Google Scholar
Mūller-Vonmoos, M. (1971) Zur Korngrossenfraktionie- rung tonreicher Sedimente. Schweiz. Mineral. Petrogr. Mitt, 51, 245257.Google Scholar
Mūller-Vonmoos, M. & Kahr, G. (1983) Mineralogische Untersuchungen von Wyoming Bentonit MX-80 und Montigel. NAGRA Technischer Bericht. 83-12, NAGRA, Baden, Switzerland.Google Scholar
Muller-Vonmoos, M., Kahr, G., Bucher, F. & Madsen, F. (1990) Investigation of Kinnekulle K-bentonite aimed at assessing the long-term stability of bentonites under repository conditions. Engin. Geol, 28, 269280.Google Scholar
NAGRA (1985) Projekt ‘Gewahr 1985’. Endlager fiir hochaktive Abfālle: das System der Sicherheitsbarrieren. NGB 85-04, NAGRA, Baden, Switzerland.Google Scholar
Oliphant, J.L. & Low, P.F. (1982) The relative partial specific enthalpy of water in water-montmorillonite systems and its relation to the swelling of these systems. J. Coll. Interf. Sci, 89, 366373.Google Scholar
Pusch, R. (1983) Stability of deep-sited smectite minerals in crystalline rock—chemical aspects. KBS 83-16, Swedish Nuclear Fuel and Waste Management Company, Stockholm, Sweden.Google Scholar
Van Olphen, H. (1977) An Introduction to Clay Colloid Chemistry,2nd ed. Wiley, Chichester.Google Scholar
Waern, B., Thorslund, P. & Henningsmoen, G. (1948) Deep boring through Ordovician and Silurian strata at Kinnekulle, Vestergotland. Bull. Geol. Univ. Uppsal, 32, 337474.Google Scholar
Weaver, C.E. & Beck, K.C. (1971) Clay-water diagenesis during burial; how mud becomes gneiss. Geol. Soc. Amer. Spec. Pap. 134, 96 pp.Google Scholar
Weiss, A. (1958) Kationenaustausch der Tonminerale. I. Vergleich der Untersuchungsmethoden. Z. anorg. allgem. Chem, 297, 232256.Google Scholar
Weiss, A. (1958) Ūberdas Kationenaustauschvermogen der Tonminerale. III. Der Kationenaustausch bei Kaolinit. Z. anorg. allgem. Chem, 299, 92120.Google Scholar