Hostname: page-component-586b7cd67f-t7czq Total loading time: 0 Render date: 2024-11-28T04:03:39.077Z Has data issue: false hasContentIssue false

Redox Chemistry in Two Iron-Bentonite Field Experiments at Äspö Hard Rock Laboratory, Sweden: An XRD and Fe K-Edge Xanes Study

Published online by Cambridge University Press:  01 January 2024

Per Daniel Svensson*
Affiliation:
Swedish Nuclear Fuel and Waste Management Co, Oskarshamn, Sweden
Staffan Hansen
Affiliation:
Centre for Analysis and Synthesis, Department of Chemistry, Lund University, Sweden
*
*E-mail address of corresponding author: [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.

Excavated bentonite from two large iron-bentonite field experiments at Äspö Hard Rock Laboratory in Sweden was investigated with respect to iron redox chemistry and mineralogy. The iron redox chemistry was studied by Fe K-edge X-ray absorption near edge structure spectroscopy and the mineral phases were studied using X-ray diffraction. Bentonite is to be used as a buffer material in high-level radioactive waste repositories to protect the waste containers from their surroundings. Montmorillonite, which is responsible for the sealing properties in the bentonite, is susceptible to redox reactions. A change in the montmorillonite iron redox chemistry may affect its layer charge and hence its properties. The experiments included are the first Alternative Buffer Material test (ABM1) and the Temperature Buffer Test (TBT). The clays were heated to a maximum of ~130°C (ABM1) or ~150°C (TBT) for 2.5 and 7 y, respectively. In the central part of the compacted clay blocks was placed an iron heater and the distance from the heater to the rock was ~10 cm (ABM1) and ~50 cm (TBT), respectively. Eleven different clay materials were included in the ABM1 experiment and five were analyzed here. In the ABM1 experiment, the Fe(II)/Fe(III) ratio was increased in several samples from the vicinity of the heater. Kinetic data were collected and showed that most of the Fe(II)-rich samples oxidized rapidly when exposed to atmospheric oxygen. In the TBT experiment the corrosion products were dominated by Fe(III) and no significant increase in Fe(II) was seen. In ABM1, reducing conditions were achieved, at least in parts of the experiment; in TBT, reducing conditions were not achieved. The difference was attributed to the larger scale of the TBT experiment, providing more oxygen after the installation, and to the longer time taken for water saturation; oxidation of the samples during excavation cannot be ruled out. Minor changes in the bentonite mineral phases were found in some cases where direct contact was made with the iron heater but no significant impact on the bentonite performance in high-level radioactive waste applications was expected as a result.

Type
Research Article
Copyright
Copyright © European Higher Education Society 2013

References

Ardizzone, S. and Formaro, L., 1982 Temperature induced phase transformation of metastable Fe(OH)3 in the presence of ferrous ions. Materials Chemistry and Physics 8 125133.CrossRefGoogle Scholar
Akesson, M. Olsson, S. Dueck, A. Nilsson, U. and Karnland, O., 2012.TBT — Hydro-mechanical and chemical/miner-alogical characterizationsGoogle Scholar
Bath, A. and Hermansson, H.-P., 2009.Biogeochemistry of redox at repository depth and implications for the canisterGoogle Scholar
Carlson, L. Karnland, O. Oversby, V.M. Rance, A.P. Smart, N.R. Snellman, M. Vähänen, M. and Werme, L.O., 2007 Experimental studies of the interactions between anaerobi-cally corroding iron and bentonite. Physics and Chemistry of the Earth 32 334345.CrossRefGoogle Scholar
Carlson, S. Clausén, M. Gridneva, L. Sommarin, B. and Svensson, C., 2006 XAFS experiments at beamline 1811, MAX-lab synchrotron source, Sweden. Journal of Synchrotron Radiation 13 359364.CrossRefGoogle Scholar
Cerenius, Y. Stahl, K. Svensson, L.A. Ursby, T. Oskarsson, A. Albertsson, J. and Liljas, A., 2000 The crystallography beamline 1711 at MAX II. Journal of Synchrotron Radiation 7 203.CrossRefGoogle Scholar
Charpentiera, D. Devineau, K. Mosser-Ruck, R. Cathelineau, M. and Villiéras, F., 2006 Bentonite-iron interactions under alkaline condition: An experimental approach. Applied Clay Science 32 113.CrossRefGoogle Scholar
Crank, J., 1980 The Mathematics of Diffusion 2nd edition Oxford Clarendon Press.Google Scholar
Dohrmann, R. Olsson, S. Kaufhold, S. and Sellin, P., 2013 Mineralogical investigations of the first package of the alternative buffer material test II. Exchangeable cation population rearrangement. Clay Minerals 48 215233.CrossRefGoogle Scholar
Galoisy, L. Calas, G. and Arrio, M.A., 2001 High-resolution XANES spectra of iron in minerals and glasses: structural information from the pre-edge region. Chemical Geology 174 307319.CrossRefGoogle Scholar
Gaucher, E.C. Tournassat, C. Pearson, F.J. Blanc, P. Crouzet, C. Lerouge, C. and Altmann, S., 2009 A robust model for pore-water chemistry of clayrock. Geochimica et Cosmochimica Acta 73 64706487.CrossRefGoogle Scholar
Grandia, F. Domènech, C. Arcos, D. and Duro, L., 2006.Assessment of the oxygen consumption in the backfill. Geochemical modelling in a saturated backfillGoogle Scholar
Grenthe, L. Stumm, W. Laaksuharju, M. Nilsson, A.-C. and Wikberg, P., 1992 Redox potentials and redox reactions in deep groundwater systems. Chemical Geology 98 131150.CrossRefGoogle Scholar
Guillaume, D. Neaman, A. Cathelineau, M. Mosser-Ruck, R. Peiffert, C. Abdelmoula, M. Dubessy, J. Villiéras, F. and Michau, N., 2004 Experimental study of the transformation of smectite at 80 and 300°C in the presence of Fe oxides. Clay Minerals 39 1734.CrossRefGoogle Scholar
Jodin-Caumon, M.C. Mosser-Ruck, R. Rousset, D. Randi, A. Cathelineau, M. and Michau, N., 2010 Effect of a thermal gradient of iron-clay interactions. Clays and Clay Minerals 58 667681.CrossRefGoogle Scholar
Kaufhold, S. Dohrmann, R. Sandén, T. Sellin, P. and Svensson, D., 2013 Mineralogical investigations of the alternative buffer material test — I. Alteration of bentonites. Clay Minerals 48 199213.CrossRefGoogle Scholar
Kumpulainen, S. Kiviranta, L. Carlsson, T. Muurinen, A. Svensson, D. Sasamoto, H. and Wersin, P., 2010.Long-term alteration of bentonite in the presence of metallic ironGoogle Scholar
Kwiatek, W.M. Galka, M. Hanson, A.L. Paluszkiewicz, C. and Cichocki, T., 2001 XANES as a tool for iron oxidation state determination in tissues. Journal of Alloys and Compounds 328 276282.CrossRefGoogle Scholar
Lantenois, S. Lanson, B. Muller, F. Bauer, A. Jullien, M. and Plançon, A., 2005 Experimental study of smectite interaction with metal Fe at low temperature: 1. Smectite destabilization. Clays and Clay Minerals 53 597612.CrossRefGoogle Scholar
Martin, F.A. Bataillon, C. and Schlegel, M.L., 2008 Corrosion of iron and low alloyed steel within a water saturated brick of clay under anaerobic deep geological disposal conditions: An integrated experiment. Journal of Nuclear Materials 379 8090.CrossRefGoogle Scholar
Mehra, O.P. and Jackson, M.L., 1958 Iron oxide removal from soils and clays by a dithionite citrate system buffered with sodium bicarbonate. Clays and Clay Minerals 7 317327.CrossRefGoogle Scholar
Meier, L.P. and Kahr, G., 1999 Determination of the cation exchange capacity (CEC) of clay minerals using complexes of copper(II) ion with triethylenetetramine and tetraethylenepentamine. Clays and Clay Minerals 47 386388.CrossRefGoogle Scholar
Mosser-Ruck, R. Cathelineau, M. Guillaume, D. Charpentiera, D. Rousset, D. Barres, O. and Michaue, N., 2010 Effects of temperature, pH, and iron/clay and liquid/ clay ratios on experimental conversion of dioctahedral smectite to berthierine, chlorite, vermiculite, or saponite. Clays and Clay Minerals 58 280291.CrossRefGoogle Scholar
O’Day, P.A. Rivera, N Jr. Root, R. and Carroll, S.A., 2004 X-ray absorption spectroscopic study of Fe reference compounds for the analysis of natural sediments. American Mineralogist 89 572585.CrossRefGoogle Scholar
Ogawa, M. Sato, T. Takahashi, N. and Tanaka, M., 1991.Synthetic stevensite and process for preparation thereofGoogle Scholar
Paris, E. Mottana, A. and Mattias, P., 1991 Iron environment in a montmorillonite from Gola del Furlo (Marche, Italy). A synchrotron radiation XANES and a Mössbauer study. Mineralogy and Petrology 45 105117.CrossRefGoogle Scholar
Pentráková, L. Su, K. Pentrák, M. and Stucki, J. W., 2013 A review of microbial redox interactions with structural Fe in clay minerals Clay Minerals 48 543560.CrossRefGoogle Scholar
Perronnet, M. Jullien, M. Villiéras, F. Raynal, J. Bonnin, D. and Bruno, G., 2008 Evidence of a critical content in Fe(0) on FoCa7 bentonite reactivity at 80°C. Applied Clay Science 38 187202.CrossRefGoogle Scholar
Quartieri, S. Riccardi, M.P. Messiga, B. and Boscherini, F., 2005 The ancient glass production of the medieval Val Gargassa glasshouse: Fe and Mn XANES study. Journal of Non-Crystalline Solids 351 30133022.CrossRefGoogle Scholar
Ronov, A.B. and Yaroshevsky, A.A., 1969 Chemical composition of the Earth’s crust The Earth’s Crust and Upper Mantle 13 3757.Google Scholar
Sandén, T. Goudarzi, R. Combarieu, M. Åkesson, M. and Hökmark, H., 2007 Temperature buffer test — design, instrumentation and measurements. Physics and Chemistry of the Earth 32 7792.CrossRefGoogle Scholar
SKB, 2001 O2 depletion in granitic media .Google Scholar
SKB, 2007 RD & D Programme .Google Scholar
Stucki, J.W. Lee, K. Zhang, L. and Larson, R.A., 2002 Effects of iron oxidation state on the surface and structural properties of smectites. Pure and Applied Chemistry 74 20812094.CrossRefGoogle Scholar
Svensson, D., 2013 Early observations in a large scale 61/2 year iron-bentonite field experiment (ABM2) at Äspö hard rock laboratory, Sweden Illinois, USA Urbana-Champaign.Google Scholar
Svensson, D. Eng, A. and Sellin, P., 2007.Alternative buffer material experimentGoogle Scholar
Svensson, D. Sandén, T. Kaufhold, S. and Sellin, P., 2010.Alternative buffer material experiment — experimental concept and progressGoogle Scholar
Svensson, D. Dueck, A. Nilsson, U. Olsson, S. Sandén, T. Eriksson, S. Jägervall, S. and Hansen, S., 2011.Alternative Buffer Material. Status of the ongoing laboratory investigation of reference materials and test package 1Google Scholar
Wersin, P. Spahiu, K. and Bruno, J., 1994.Time evolution of dissolved oxygen and redox conditions in a HLW repositoryGoogle Scholar
Wersin, P. Birgersson, M. Olsson, S. Karnland, O. and Snellman, M., 2008.Impact of corrosion-derived iron on the bentonite buffer within the KBS-3H disposal conceptGoogle Scholar
White, A.F. and Yee, A., 1985 Aqueous oxidation-reduction kinetics associated with coupled electron-cation transfer from iron-containing silicates at 25°C. Geochimica et Cosmochimica Acta 49 12631275.CrossRefGoogle Scholar
Wilke, M. Farges, F. Petit, P.-E. Brown, G.E. Jr. and Martin, F., 2001 Oxidation state and coordination of Fe in minerals: An Fe K-XANES spectroscopic study. American Mineralogist 86 714730.CrossRefGoogle Scholar
Wilke, M. Partzsch, G.M. Bernhardt, R. and Lattard, D., 2005 Determination of the iron oxidation state in basaltic glasses using XANES at the K-edge. Chemical Geology 220 143161.CrossRefGoogle Scholar