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Stability of Magadiite Between 20 and 100°C

Published online by Cambridge University Press:  01 January 2024

Martin Dietzel  and
Ilse Letofsky-Papst
Martin Dietzel*
Affiliation:
Institute of Engineering Geology and Applied Mineralogy, University of Technology, A-8010 Graz, Austria
Ilse Letofsky-Papst
Affiliation:
Research Institute for Electron Microscopy, Steyrergasse 17, A-8010 Graz, Austria
*
*E-mail address of corresponding author: dietzel@egam.tu-graz.ac.at
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Abstract

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New experimental data with respect to the solubility of natural and synthesized magadiite at elevated temperatures and in alkaline solutions are presented. The results show that the solubility of magadiite increases according to the expression ln(Kmag) = −8146·T(K)−1 − 5.71 from 20 to 100°C ((ΔGR0(Kmag)=19.6±0.3 and ΔHR0(Kmag)=16.2±0.4kcalmol−1). The experimental results and the related data from the literature suggest that the formation of magadiite may be favored by a decrease of temperature and pH (pH >9) as well by large amounts of Na+ ions and low ionic strength. These effects are related to the value of ΔHR0(Kmag), the distribution of dissolved silica species, the stoichiometry of magadiite, and the occurrence of negatively-charged species, respectively.

Keywords

Alkaline SolutionsAmorphous SilicaMagadiiteMonosilicic AcidPolysilicic AcidsSolubility
Type
Research Article
Information
Clays and Clay Minerals , Volume 50 , Issue 5 , October 2002 , pp. 657 - 666
Copyright
Copyright © 2002, The Clay Minerals Society

References

Arnorsson, S. Sigurdsson, S. and Svavarsson, H., (1982) The chemistry of geothermal waters in Iceland. I. Calculation of aqueous speciation from 0° to 370°C Geochimica et Cosmochimica Acta 46 1513–1532 10.1016/0016-7037(82)90311-8.Google Scholar
Baes, C.F. and Mesmer, R.E. (1976) The Hydrolysis of Cations. Wiley-Interscience, New York, 489 pp.Google Scholar
Barth-Wirsching, U. and Höller, H., (1989) Experimental studies on zeolite formation conditions European Journal of Mineralogy 1 489–506 10.1127/ejm/1/4/0489.Google Scholar
Bricker, O.P., (1969) Stability constants and free energies of formation of magadiite and kenyaite American Mineralogist 5 1026 1033.Google Scholar
Brindley, G.W., (1969) Unit cell of Magadiit in air, vacuo and under other conditions American Mineralogist 54 1583 1591.Google Scholar
Busey, R.H. and Mesmer, R.E., (1977) Ionization equilibria of silicic acid and polysilicate formation in aqueous sodium chloride solutions to 300°C Inorganic Chemistry 16 2444–2450 10.1021/ic50176a004.Google Scholar
Dietzel, M. and Usdowski, E., (1995) Depolymerization of soluble silicate in dilute aqueous solutions Colloid and Polymer Science 273 590–597 10.1007/BF00658690.Google Scholar
Eikenberg, J. (1990) On the problem of silica solubility at high pH. Nationale Genossenschaft für die Lagerung radioaktiver Abfalle, Baden (Switzerland). Technical Report 90–36, 54 pp.Google Scholar
Eugster, H.P., (1967) Hydrous sodium silicates from Lake Magadi, Kenya; Precursors of bedded chert Science 157 1177–1180 10.1126/science.157.3793.1177.Google Scholar
Eugster, H.P., (1970) Chemistry and origin of the brines of Lake Magadi, Kenya Mineralogical Society of America Special Paper 3 213 235.Google Scholar
Eugster, H.P. and Maglione, G., (1979) Brines and evaporites of the Lake Chad basin Geochimica et Cosmochimica Acta 43 973–981 10.1016/0016-7037(79)90087-5.Google Scholar
Fritz, B. Zins-Pawlas, M.-P. and Gueddari, M., (1987) Geochemistry of silica-rich brines from Lake Natron (Tanzania) Science Géologiques Bulletin 40 97–110 10.3406/sgeol.1987.1753.Google Scholar
Grenthe, I. Fuger, J. Konings, R.J.M. Lemire, R.J. Muller, A.B. Nguyen-Trung Cregu, C. and Wanner, H., (1992) Chemical Thermodynamics of Uranium Chemical Thermodynamics 1 North-Holland Elsevier Nuclear Energy Agency 750 pp.Google Scholar
Hay, R.L., Murakami, Y. Iijima, A. and Ward, J.W., (1986) Geological occurrences of zeolites and some associated minerals New Developments in Zeolite Science and Technology Amsterdam, Oxford Elsevier 35–40 10.1016/S0167-2991(09)60853-3.Google Scholar
Helgeson, H.C., (1967) Thermodynamics of complex dissociation in aqueous solution at elevated temperatures Journal of Physical Chemistry 71 3121–3136 10.1021/j100869a002.Google Scholar
Hem, J.D. (1970) Study and interpretation of the chemical characteristics of natural waters. Geological Survey Water-Supply Paper, 1473, 363 pp.Google Scholar
Houser, B.B., (1982) Chert derived from magadiite in the middle Eocene McBean Formation, South Carolina Abstracts, 17th Annual Meeting of the Northeastern Section and 31st Annual Meeting Southeastern Section, Geological Soiety of America 14 27.Google Scholar
Iler, R.K., (1979) The Chemistry of Silica — Solubility, Polymerization, Colloid and Surface Properties and Biochemistry New York Wiley-Interscience 866 pp.Google Scholar
Jones, B.F. Eugster, H.P. and Rettig, S.F., (1977) Hydrochemistry of the Lake Magadi basin, Kenya Geochimica et Cosmochimica Acta 41 53–72 10.1016/0016-7037(77)90186-7.Google Scholar
Kwon, O.-Y. Jeong, S.-Y. Suh, J.-K. and Lee, J.-M., (1995) Hydrothermal syntheses of Na-magadiite and Na-kenyaite in the presence of carbonate Bulletin of the Korean Chemical Society 16 737 741.Google Scholar
Lagaly, G. Beneke, K. and Weiss, A., (1975) Magadiit and H-Magdiit. I-Sodium Magadiit and some of its derivatives American Mineralogist 60 642 649.Google Scholar
Lide, D.R., (1996) CRC Handbook of Chemistry and Physics Boca Raton, Florida CRC Press.Google Scholar
Maglione, G., (1970) Magadiite, an authentic sodic silicate of the evaporite facies in Kanem, northeast shore of Lake Chad Alsace-Lorraine Service Carte Géologiques Bulletin 23 177–189 10.3406/sgeol.1970.1376.Google Scholar
Manega, P. and Bieda, S., (1987) Modern sediments of Lake Natron, Tanzania Science Géologiques Bulletin 40 83–95 10.3406/sgeol.1987.1752.Google Scholar
McAtee, J.L. House, R. and Eugster, H.P., (1968) Magadiite from Trinity Country, California American Mineralogist 53 2061 2069.Google Scholar
Rimstidt, J.D., (1997) Quartz solubility at low temperature Geochimica et Cosmochimica Acta 61 2553–2558 10.1016/S0016-7037(97)00103-8.Google Scholar
Rimstidt, J.D. and Barnes, H.L., (1980) The kinetics of silica-water reactions Geochimica et Cosmochimica Acta 44 1683–1699 10.1016/0016-7037(80)90220-3.Google Scholar
Rooney, T.P. Jones, B.F. and Neal, J.T., (1969) Magadiite from Alkali Lake, Oregon American Mineralogist 54 1035 1043.Google Scholar
Schecher, W.D. and McAvoy, D.C., (1998) MINEQL+: A chemical equilibrium modeling system, Version 4.0 for Windows, User’s manual Hallowell, Maine Environmental Research Software 318 pp.Google Scholar
Scholzen, G. Beneke, K. and Lagaly, G., (1991) Diversity of magadiite Zeitschrift für Anorganische und Allgemeine Chemie 597 183–196 10.1002/zaac.19915970121.Google Scholar
Seward, T.M., (1974) Determination of the first ionization constant of silicic acid from quartz solubility in borate buffer solutions to 350°C Geochimica et Cosmochimica Acta 38 1651–1664 10.1016/0016-7037(74)90183-5.Google Scholar
Sjöberg, S. Nordin, A. and Ingri, N., (1981) Equilibrium and structural studies of silicon(IV) and aluminium(III) in aqueous solution. II. Formation constants for the monosilicate ions SiO(OH)3 − and SiO2OH)2 2∞ Marine Chemistry 10 521–532 10.1016/0304-4203(81)90005-0.Google Scholar
Sjöberg, S. Hägglund, Y. Nordin, A. and Ingri, N., (1983) Equilibrium and structural studies of silicon(IV) and aluminium(III) in aqueous solutions: V. Acidity constants of silicic acid and the ionic product of water in the medium range 0.05–2.0 M Na(Cl) at 25°C Marine Chemistry 13 35–44 10.1016/0304-4203(83)90047-6.Google Scholar
Sjöberg, S. Öhman, L.O. and Ingri, N., (1985) Equilibrium and structural studies of silicon(IV) and aluminium(III) in aqueous solution. 11. Polysilicate formation in alkaline aqueous solution. A combined potentiometric and 29Si NMR study Acta Chemica Scandinavica 39 93–107 10.3891/acta.chem.scand.39a-0093.Google Scholar
Surdam, R.C. Eugster, H.P. and Mariner, R.H., (1972) Magadi-Type Chert in Jurassic and Eocene to Pleistocene Rocks, Wyoming Geological Society of America Bulletin 83 2261–2262 10.1130/0016-7606(1972)83[2261:MCIJAE]2.0.CO;2.Google Scholar
Wolery, T.J. (1992) EQ3NR, a computer program for geochemical aqueous speciation-solubility calculations: theoretical manual, user’s guide and related documentation (version 7.0). Lawrence Livermore National Laboratory Report UCRL-MA-110662 (3).Google Scholar