No CrossRef data available.
Article contents
Analcime reactions at 25–90°C in hyperalkaline fluids
Published online by Cambridge University Press: 05 July 2018
Abstract
Extensive use of cement and concrete is envisaged in the construction of geological disposal facilities for radioactive wastes. The hyperalkaline porefluids typical of groundwaters that have reacted with these materials have the potential to react chemically with other engineered barrier components such as bentonite, potentially degrading their performance. Analcime, NaAlSi2O6.H2O, has been identified from previous modelling and experimental studies as a potential alteration product of bentonite.
Laboratory experiments to investigate the stability of analcime under hyperalkaline porefluid conditions have been performed. Experiments used both batch and fluidized bed equipment at 25, 50, 70 and 90°C in K-based pH buffer solutions, both under- and over-saturated with respect to analcime. Results from dissolution experiments demonstrate that release of Na was greatly enhanced (by up to a factor of thirty) over that for Si and Al, particularly at pH 10 and 11. However, enhanced release of both Na and Al occurred in the batch experiments at pH 12–13. Near stoichiometric dissolution was observed in fluidized bed experiments under steady-state conditions at 70°C. Sodium was removed from the analcime structure by ion exchange for K, without involving dissolution and re-precipitation of the analcime framework. Scanning electron microscopy of reacted analcime grains showed that some grains had pronounced cracks parallel to original cleavage traces. These cracks were a result of volume decrease due to the substitution of K for Na ions and water molecules in the analcime structure to form leucite, KAlSi2O6.
Synthesis of the dissolution data shows that the rate of dissolution increased with increasing temperature in the range 25–70°C and with pH at each temperature. Absolute rates of dissolution ranged from 10−10 mol m−2 s−1 at pH 9.5 at 25°C to 10−7 mol m−2 s−1 a pH 12 at 70 and 90°C. The rate of dissolution at any temperature was pH-dependent, such that the rate could be described by k (aH+)n, where k is the rate constant and n is −0.3 at 25°C, −0.4 at 50°C, −0.6 at 70°C and −0.7 at 90°C. Attempts to measure the growth rate of analcime in supersaturated solutions at 70 and 90°C were unsuccessful, although a limiting rate at 70°C, pH 10 was calculated to be 4 × 10−11 mol m−2 s−1, roughly 100× less than the rate of dissolution under the same conditions.
These results imply that any trace amounts of analcime in bentonite will be converted to leucite by reaction with cement fluids with a high K/Na ratio. In some instances, leucite may thus incorporate K+ in preference to other phases (e.g. illite, K-feldspar) during alteration of bentonite by cement porefluids.
- Type
- Research Article
- Information
- Copyright
- Copyright © The Mineralogical Society of Great Britain and Ireland 2001
References
Atkinson, A. (1985) The time dependence of pH within a repository for radioactive waste disposal. United Kingdom Atomic Energy Authority Report, AERE-R11777.Google Scholar
Atkinson, A., Everitt, N.M. and Guppy, R. (1987) Evolution of pH in a radwaste repository. Experimental simulation of cement leaching. United Kingdom Atomic Energy Authority Report, AERE-R12594.Google Scholar
Barrer, R.M. (1950) Ion-exchange and ion-sieve processes in crystalline zeolites. J. Chem. Soc., 2342–50.CrossRefGoogle Scholar
Barrer, R.M. and Hinds, L. (1953) Ion-exchange in crystals of analcite and leucite. J. Chem. Soc., 1879–88.CrossRefGoogle Scholar
Barrer, R.M., Hinds, J.W. and McCallum, N. (1953
a) Hydrothermal chemistry of silicates. Part V. Compounds structurally related to analcite. J. Chem. Soc., 4035–41.CrossRefGoogle Scholar
Barrer, R.M., Baynham, L. and White, E.A. (1953
b) The hydrotherma l chemistry of silicates. Part III. Reactions of analcite and leucite. J. Chem. Soc., 1466– 75.CrossRefGoogle Scholar
Barth-Wirsching, U., Klammer, D. and Kovic-Kralj, P. (1994) The formation of analcime from laumontite in the Smrekovec volcanics, Northwest Slovenia – an experimental approach. Pp. 299–305 in: Zeolites and Related Microporous Materials: State of the Art 1994, Studies in Surface Science and Catalysis, 4 299-305.Google Scholar
Beattie, I.R. (1954
a) The structure of analcite and ion-exchanged forms of analcite. Acta Crystallogr., 7, 357–8.CrossRefGoogle Scholar
Beattie, I.R. (1954
b) The electrical conductivity of analcite and ion-exchanged forms of analcite and chabazite. Trans. Faraday Soc., 50, 581–7.CrossRefGoogle Scholar
Beattie, I.R. (1955) The electrical conductivity of partially ion-exchanged forms of analcite. Trans. Faraday Soc., 51, 712–8.CrossRefGoogle Scholar
Beattie, I.R. and Dyer, A. (1957) The diffusion of sodium ions in analcite as a function of water content. Trans. Faraday Soc., 53, 61–6.CrossRefGoogle Scholar
Berner, U.R. (1992) Evolution of pore water chemistry during degradation of cement in a radioactive waste repository environment. Waste Management, 2, 201–19.CrossRefGoogle Scholar
Blum, J. and Lasaga, A.C. (1988) Role of surface speciation in the low-temperature dissolution of minerals. Nature, 31, 431–3.CrossRefGoogle Scholar
Brady, P.V. and Walther, J.V. (1989) Controls on silicate dissolution rates in neutral and basic pH solutions at 25°C. Geochim. Cosmochim. Acta, 53, 2823–30.CrossRefGoogle Scholar
Carroll-Webb, S.A. and Walther, J.V. (1988) A surface complex reaction model for the pH-dependence of corundum and kaolinite dissolution rates. Geochim. Cosmochim. Acta, 52, 2609–23.CrossRefGoogle Scholar
Chermak, J.A. (1992) Low temperature experimental investigation of the effect of high pH NaOH solutions on the Opalinus Shale, Switzerland. Clays Clay Miner., 40, 650–8.CrossRefGoogle Scholar
Deer, W.A., Howie, R.A. and Zussman, J. (1992) An Introduction to the Rock-Forming Minerals.
Longman Scientific & Technical, Harlow, Essex, UK.Google Scholar
Diakonov, I., Pokrovskii, G., Schott, J., Castet, S. and Gout, R. (1996) An experimental and computational study of sodium-aluminium complexing in crustal fluids. Geochim. Cosmochim. Acta, 8, 2011–24.Google Scholar
Dyer, A. (2000) Thallium cations in the analcime framework. Mineral. Mag., 64, 9–10.CrossRefGoogle Scholar
Dyer, A. and Yusof, A.M. (1987) Diffusion in heteroionic analcimes: Part 1. Sodium-potassiumwater system. Zeolites, 7, 191–6.CrossRefGoogle Scholar
Dyer, A. and Yusof, A.M. (1989) Diffusion in heteroionic analcimes: Part 2. Diffusion of water in sodium/thallium, sodium/lithium, and sodium/ammonium analcimes. Zeolites, 9, 129–35.CrossRefGoogle Scholar
Flerov, G.B., Koloskov, A.V. and Moskaleva, S.V. (1998) Leucite and analcime in the Upper Cretaceous-Paleogene potassium basaltoids, Central Kamchatka. Dokl. Earth Sci., 62, 912–4.Google Scholar
Francis, A.J., Cather, R. and Crossland, I.G. (1997) Development of the Nirex Reference Vault Backfill; report on current status in 1994.
UK Nirex Ltd. Science Report, S/97/014. UK Nirex Ltd., Harwell, UK.Google Scholar
Fulignati, P.
Marianelli, P. and Sbrana, A. (2000) Glass-bearing felsic nodules from the crystallizing sidewalls of the Vesuvius magma chamber. Mineral. Mag., 64, 481–96.CrossRefGoogle Scholar
Glasser, F.P. (2001) Mineralogical aspects of cement in radioactive waste disposal. Mineral. Mag., 65, 621–33.CrossRefGoogle Scholar
Gupta, A.K. and Fyfe, W.S. (1975) Leucite survival: the alteration to analcime. Canad. Mineral., 3, 361–3.Google Scholar
Helgeson, H.C., Kirkham, D.H. and Flowers, G.C. (1981) Theoretical prediction of the thermodynamic behavior of aqueous electrolytes at high pressures and temperatures: IV. Calculation of activity coefficients, and apparent molal standard and relative partial molal properties to 600°C and 5 kbar. Amer. J. Sci., 281, 1249–1516.CrossRefGoogle Scholar
JNC (2000) Progress report on disposal concept for TRU waste in Japan. Japan Nuclear Cycle Development Institute Report JNC TY1400 2000-02. Japan Nuclear Cycle Development Institute, Tokyo, Japan.Google Scholar
Johnson, G.K., Flotow, H.E., O’Hare, P.A.G. and Wise, W.S. (1982) Thermodynamic studies of zeolites: analcime and dehydrated analcime. Amer. Mineral., 7, 736–48.Google Scholar
Johnson, G.K., Tasker, I.R., Flotow, H.E., O’Hare, P.A.G. and Wise, W.S. (1992
a) Thermodynamic studies of mordenite, dehydrated mordenite, and gibbsite. Amer. Mineral., 7, 85–93.Google Scholar
Johnson, J.W., Oelkers, E.H. and Helgeson, H.C. (1992
b) SUPCRT92. A software package for calculating the standard molal thermodynamic properties of minerals, gases, aqueous species, and reactions from 1 to 5000 bar and 0 to 1000°C. Comp. Geosci., 8, 899–947.CrossRefGoogle Scholar
Leggo, P.J., Cochemé, J.-J., Demant, A. and Lee, W.T. (2001) The role of argillic alteration in the zeolitization of volcanic glass. Mineral. Mag., 65, 653–63.CrossRefGoogle Scholar
Line, C.M.B., Putnis, A., Putnis, C. and Giampaolo, C. (1995) The dehydration kinetics and microtexture of analcime from two parageneses. Amer. Mineral., 80, 268–79.CrossRefGoogle Scholar
Mimura, H., Tezuka, T. and Akiba, K. (1996) Preparation of analcime film from hydrogels. J. Nucl. Sci. Technol., 33, 892–4.CrossRefGoogle Scholar
Murphy, W.M., Pabalan, R.T., Prikryl, J.D. and Goulet, C.J. (1996) Reaction kinetics and thermodynamics of aqueous dissolution and growth of analcime and Naclinoptilolite at 25°C. Amer. J. Sci., 96, 128–86.CrossRefGoogle Scholar
Parks, G.A. (1967) Aqueous surface chemistry of oxides and complex oxide minerals: isoelectric point and zero point of charge. Pp. 121–60 in: Equilibrium Concepts in Natural Water Systems. ACS, 67. American Chemical Society, Washington, D.C.
CrossRefGoogle Scholar
Pokrovskii, V.A. and Helgeson, H.C. (1994) Calculation of the effect of KAl(OH)4
0 formation on the solubility of corundum at high pressures and temperatures. Mineral. Mag., 58A, 736–7.CrossRefGoogle Scholar
Robie, R.A., Hemingway, B.S. and Fisher, J.R. (1978) Thermodynamic properties of minerals and related substances at 298.15 K and 1 bar (105 Pascals) pressure and at higher temperatures. U.S. Geol. Surv. Bull., 1452.Google Scholar
Savage, D. (editor) (1995) The Scientific and Regulatory Basis for the Geological Disposal of Radioactive Wastes.
John Wiley, London.Google Scholar
Savage, D. (1997) Review of the potential effects of alkaline plume migration from a cementitious repository for radioactive waste. Implications for performance assessment. UK Environment Agency Technical Report. P. 60.Google Scholar
Savage, D., Noy, D.J. and Mihara, M. (in press) Modelling the interaction of bentonite with hyperalkaline fluids. Appl. Geochem.
Google Scholar
Savage, D. and Rochelle, C.A. (1993) Modelling reactions between cement pore fluids and rock: implications for porosity change. J. Contam. Hydrol., 13, 365–78.CrossRefGoogle Scholar
Smyth, J. (1989) Electrostatic characterization of oxygen sites in minerals. Geochim. Cosmochim. Acta, 53, 1101–10.CrossRefGoogle Scholar
Steefel, C.I. and Lichtner, P.C. (1994) Diffusion and reaction in rock matrix bordering a hyperalkaline fluid-filled fracture. Geochim. Cosmochim. Acta, 58, 3595–612.CrossRefGoogle Scholar
Stumm, W., Furrer, F. and Kunz, B. (1983) The role of surface coordination in precipitation (heterogeneous nucleation) and dissolution of mineral phases. Croatica Chemica Acta, 42, 223–45.Google Scholar
Todorovic, M., Gal, I.J. and Brucher, H. (1987) The exchange of tritiated water between natural zeolite analcime and surrounding water. Waste Manag. Nucl. Fuel Cycle, 8, 339–46.Google Scholar
Walther, J.V. (1996) Relation between rates of aluminosilicate mineral dissolution, pH, temperature, and surface charge. Amer. J. Sci., 296, 693–728.CrossRefGoogle Scholar
Wiersema, G.S. and Thompson, R.W. (1996) Nucleation and crystal growth of analcime from clear aluminosilicate solutions. J. Mat. Chem., 6, 1693–9.CrossRefGoogle Scholar
Wilkin, R.T. and Barnes, H.L. (1997) Temperature- and free energy-dependence of zeolite precipitation and dissolution rates. Proceedings of the 7th Annual Goldschmidt Conference, 219.Google Scholar
Wilkin, R.T. and Barnes, H.L. (1998). Solubility and stability of zeolites in aqueous solution: I. Analcime, Na-, and K-clinoptilolite. Amer. Mineral., 83, 746–61.CrossRefGoogle Scholar
Wolery, T.J. (1992) EQ3NR, a computer program for geochemical aqueous speciation-solubility calculations: Theoretical manual, users guide, and related documentation (version 7.0). Lawrence Livermore National Laboratory Report UCRL-MA-110662 PT IV.CrossRefGoogle Scholar
Zhao, D., Szostak, R. and Kevan, L. (1998) Role of alkali-metal cations and seeds in the synthesis of silica-rich heulandite-type zeolites. J. Mat. Chem., 8, 233–9.CrossRefGoogle Scholar