Hostname: page-component-cd9895bd7-hc48f Total loading time: 0 Render date: 2024-12-28T22:44:57.571Z Has data issue: false hasContentIssue false
  • English
  • Français

Effects of OH− activity and temperature on the dissolution rate of compacted montmorillonite under highly alkaline conditions

Published online by Cambridge University Press:  02 January 2018

Takuma Sawaguchi ,
Manabu Tsukada ,
Tetsuji Yamaguchi  and
Masayuki Mukai
Takuma Sawaguchi*
Affiliation:
Waste Safety Research Group, Nuclear Safety Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan
Manabu Tsukada
Affiliation:
Waste Safety Research Group, Nuclear Safety Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan
Tetsuji Yamaguchi
Affiliation:
Waste Safety Research Group, Nuclear Safety Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan
Masayuki Mukai
Affiliation:
Waste Safety Research Group, Nuclear Safety Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan
*
*E-mail: [email protected]
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

The highly alkaline environment induced by cementitious materials in a deep geological disposal system of high-level radioactive waste is likely to alter montmorillonite, the main constituent of bentonite buffer materials. Over long time periods, the alteration may cause the physical and/or chemical barrier functions of the buffer materials to deteriorate. In order to evaluate the long-term alteration behaviour, the dissolution rate, RA (kgm−3 s−1), of compacted pure montmorillonite (Kunipia-F) was investigated experimentally under conditions of hydroxide ion concentration of 0.10—1.0 mol dm−3 at temperatures of 50—90°C. The dissolution rate data, including those from a previous study at 130°C, were formulated as a function of the activity of hydroxide ions, aOH− (mol dm−3), and temperature, T (K), and expressed as RA = 104.5·(aOH−)1.3·e−55000/RT by multiple regression analysis, where R is the gas constant. The dissolution rate of montmorillonite was greater in the compacted montmorillonite than in the compacted sand-bentonite mixtures. The difference can be explained by considering the decrease in aOH− in the mixtures accompanied by dissolution of accessory minerals such as quartz and chalcedony. The dissolution rate model developed for pure montmorillonite is expected to be applied to bentonite mixtures if quantification of the decrease in aOH− is achieved somehow.

Keywords

compacted montmorillonitehighly alkaline conditionsdissolution rateactivity of hydroxide ionstemperatureaccessory minerals
Type
Research Article
Information
Clay Minerals , Volume 51 , Issue 2 , May 2016 , pp. 267 - 278
Creative Commons
Creative Common License - CCCreative Common License - BY
Copyright © The Mineralogical Society of Great Britain and Ireland 2016 This is an Open Access article, distributed under the terms of the Creative Commons Attribution license. (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited.
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2016

References

Bauer, A. & Berger, G. (1998) Kaolinite and smectite dissolution in high molar KOH solutions at 35°C and 80°C. Applied Geochemistry, 13, 905–916.10.1016/S0883-2927(98)00018-3CrossRefGoogle Scholar
Brindley, G.W. & Thompson, T.D. (1970) Methylene blue absorption by montmorillonites. Determinations of surface areas and exchange capacities with different initial cation saturations (clay-organic studies XIX). IsraelJournal of Chemistry, 8, 409–415.10.1002/ijch.197000047CrossRefGoogle Scholar
Hang, P.T. & Brindley, G.W. (1970) Methylene blue absorption by clay minerals. Determination of surface areas and cation exchange capacities (clay—organic studies XVIII). Clays and Clay Minerals, 18, 203–212.10.1346/CCMN.1970.0180404CrossRefGoogle Scholar
Ito, M., Okamoto, M., Shibata, M., Sasaki, Y., Danhara, T., Suzuki, K. & Watanabe, T. (1993) Mineral Composition Analysis of Bentonite. PNC TN 8430 93-003, Power Reactor and Nuclear Fuel Development, Corporation, Tokyo (in Japanese).Google Scholar
Japan Bentonite Manufacturers Association (1991) JBAS-107-91 Measuring Method of Methylene Blue Adsorption Value of Bentonite. pp. 1-5 (in Japanese).Google Scholar
Japanese Standard Association (2004) 44 Silica (SiO2), JIS K 0101 Testing method for industrial water. pp. 468-73 in: JIS Handbook 53, Environmental Technology II (Water Contamination), 2004, Japanese Standard Association, Tokyo (in Japanese).Google Scholar
Kubo, H., Kuroki, Y. & Mihara, M. (1998) Experimental investigation on alteration of bentonite by concrete pore fluids. Tsuchi-to-Kiso, The Japanese Geotechnical Society, 46, 31–34.(in Japanese).Google Scholar
Lemire, R.J., Fuger, J., Nitsche, H., Potter, P., Rand, M.H., Rydberg, J., Spahiu, K., Sullivan, J.C., Ullman, W., Vitorge, P. & Wanner, H. (2001) Chemical Thermodynamics of Neptunium and Plutonium, pp. 800–810, Elsevier, Amsterdam.Google Scholar
Miyoshi, Y., Horiuchi, Y. & Takagi, T. (2015) Present state of methylene-blue adsorption-test for bentonite in Japan. Journal of the Clay Science Society of Japan, 53, 26–36.(in Japanese).Google Scholar
Nakayama, S., Sakamoto, Y., Yamaguchi, T., Akai, M., Tanaka, T., Sato, T. & Iida, Y. (2004) Dissolution of montmorillonite in compacted bentonite by highly alkaline aqueous solutions and diffusivity of hydroxide ions. Applied Clay Science, 27, 53–65.10.1016/j.clay.2003.12.023CrossRefGoogle Scholar
Rand, M.C., Greenberg, A.E., Taras, M.J. & Franson, M.A. (1976) Standard Methods for the Examination of Water and Wastewater. American Public Health Association, Washington, D.C., pp. 484–492.Google Scholar
Rozalén , M.L., Huertas, F.J., Brady, P.V., Cama, J., Garcia-Palma, S. & Linares, J. (2008) Experimental study of the effect of pH on the kinetics of montmorillonite dissolution at 25°C. Geochimica et Cosmochimica Acta, 72, 4224–253.10.1016/j.gca.2008.05.065CrossRefGoogle Scholar
Rozalén, M., Huertas, F.J. & Brady, P.V. (2009) Experimental study of the effect of pH and temperature on the kinetics of montmorillonite dissolution. Geochimica et Cosmochimica Acta, 73, 3752–3766.10.1016/j.gca.2009.03.026CrossRefGoogle Scholar
Sato, T., Kuroda, M., Yokoyama, S., Tsutsui, M., Fukushi, K., Tanaka, T. & Nakayama, S. (2004) Dissolution mechanism and kinetics of smectite under alkaline conditions. In: Proceedings of the International Workshop on Bentonite-Cement Interaction in Repository Environment, 14-16 April 2004, Tokyo, NUMO-TR-04-05, pp. A3-38-A3-41.Google Scholar
Savage, D. & Liu, J. (2015) Water/clay ratio, clay porosity models and impacts upon clay transformations. Applied Clay Science, 116–117, 16-22.Google Scholar
Savage, D., Bateman, K., Hill, P., Hughes, C., Milodowski, A., Pearce, J., Rae, E. & Rochelle, C. (1992) Rate and mechanism of the reaction of silicates with cement pore fluids. Applied Clay Science, 7, 33–45.10.1016/0169-1317(92)90026-JCrossRefGoogle Scholar
Sawaguchi, T., Kadowaki, M., Yamaguchi, T., Mukai, M. & Tanaka, T. (2013) Alkaline dissolution behaviour of montmorillonite under compacted conditions. Journalof Nuclear Fuel Cycle and Environment, 20, 71–78.(in Japanese).10.3327/jnuce.20.71CrossRefGoogle Scholar
The Japan Society for Analytical Chemistry Hokkaido (1994) Analysis of Water, 4th edition. Kagaku-Dojin Publishing Company, Inc., Kyoto, Japan, pp. 181-184 (in Japanese).Google Scholar
Yamaguchi, T., Sakamoto, Y., Akai, M., Takazawa, M., Iida, Y., Tanaka, T. & Nakayama, S. (2007) Experimental and modeling study on long-term alteration of compacted bentonite with alkaline groundwater. Physics and Chemistry of the Earth, 32, 298–310.10.1016/j.pce.2005.10.003CrossRefGoogle Scholar
Yamaguchi, T., Sawaguchi, T., Tsukada, M., Kadowaki, M. & Tanaka, T. (2013) Changes in hydraulic conductivity of sand-bentonite mixtures accompanied by alkaline alteration. Clay Minerals, 48, 403–410.10.1180/claymin.2013.048.2.18CrossRefGoogle Scholar