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Formation of Mica During Experimental Alteration of K-Feldspar

Published online by Cambridge University Press:  28 February 2024

Motoharu Kawano  and
Katsutoshi Tomita
Motoharu Kawano
Affiliation:
Department of Environmental Sciences and Technology, Faculty of Agriculture Kagoshima University, 1-21-24 Korimoto, Kagoshima 890, Japan
Katsutoshi Tomita
Affiliation:
Institute of Earth Sciences, Faculty of Science, Kagoshima University 1-21-35 Korimoto, Kagoshima 890, Japan
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Abstract

Experimental alterations of K-feldspar in distilled-deionized water at 150°, 175°, 200°, and 225°C were performed. The alteration products and dissolution mechanism of K-feldspar were examined by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDX), and X-ray photoelectron spectroscopy (XPS). SEM, TEM, and EDX clearly showed formation of fibrous boehmite less than 1.0 μm in length at the early alteration stages. The boehmite fibers decreased in abundance and rounded platy 1 M mica was produced as alteration proceeded. The mica exhibited initially angular shaped small flakes of 0.69 μm in average size, which developed to rounded platy particles of 1.97 μm. The main chemical reactions occurring in this experimental system can be expressed by: $$\begin{array}{l} \mathop {KAlS{i_3}{O_3}}\limits_{\left[ {K - feldspar} \right]} + 6{H_2}O + {H^ + } \to \mathop {AlO\left( {OH} \right)}\limits_{\left[ {boehmite} \right]} + 3{H_4}Si{O_4} + {K^ + }, \\ \mathop {3KAlS{i_3}{O_8}}\limits_{\left[ {K - feldspar} \right]} + 12{H_2}O \to \mathop {KA{l_3}S{i_3}{O_{10}}{{\left( {OH} \right)}_2}}\limits_{\left[ {mica} \right]} + 2{K^ + } + 6{H_4}Si{O_4} + 22{H^ + }. \\ \end{array}$$ XPS showed no significant changes in intensities of photoelectron lines excited from K, Si, and Al in the K-feldspar surface before and after alteration, however the K/Si molar ratios in the solutions were considerably smaller than that of the original K-feldspar. The results of XPS strongly indicate that no dealkalized layer was produced on the surface, and that dissolution of K-feldspar in aqueous solution proceeded congruently by a surface-reaction mechanism. The discrepancy of mass balance in the solutions may be mainly caused by adsorption of K on the surface of boehmite.

Keywords

Dissolution mechanismExperimental alterationFibrous boehmiteK-feldsparMica
Type
Research Article
Information
Clays and Clay Minerals , Volume 43 , Issue 4 , August 1995 , pp. 397 - 405
Copyright
Copyright © 1995, The Clay Minerals Society

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References

Aagaard, P., and Helgeson, H. C. 1982. Thermodynamic and kinetic constraints on reaction rates among minerals and aqueous solutions. I. Theoretical considerations. Am. J. Sci. 282: 237–285.Google Scholar
Abrajano, T. A., Bates, J. K., and Woodland, A. B. Analytical electron microscopy of leached nuclear waste glasses. In Ceramic Transactions, Vol. 9, Nuclear Waste Management III. Mellinger, G., 1989 ed. Westerville, Ohio: American Ceramic Society, 211–228.Google Scholar
Abrajano, T. A., Bates, J. K., and Woodland, A. B. 1990. Secondary phase formation during nuclear waste-glass dissolution. Clays & Clay Miner. 38: 537–548.CrossRefGoogle Scholar
Armstrong, L. C., 1940. Decomposition and alteration of feldspar and spodumene by water. Amer. Miner. 25: 810–820.Google Scholar
Banba, T., Murakami, T., and Isobe, H. Growth rate of alteration layer and elemental mass losses during leaching of borosilicate nuclear waste glass. In Scientific Basis for Nuclear Waste Management XIII. Oversby, V. M., and Brown, P. W., 1990 eds. Pittsburgh: Materials Research Society, 363–370.Google Scholar
Baronnet, A., 1982. Ostwald ripening in solution. The case of calcite and mica. Estudios Geologicos 38: 185–198.Google Scholar
Berner, R. A., 1978. Rate control of mineral dissolution under Earth surface conditions. Am. J. Sci. 278: 1235–1252.Google Scholar
Berner, R. A., 1981. Kinetics of weathering and diagenesis. In Reviews in Mineralogy, Vol. 8, Kinetics of Geochemical Processes. Lasaga, A. C., and Kirkpatrick, R. J., eds. Washington, D. C.: The Mineralogical Society of America, 111–134.Google Scholar
Berner, R. A., and Holdren, G. R. Jr. 1979. Mechanism of feldspar weathering: Some observational evidence. Geology 5: 369–372.Google Scholar
Berner, R. A., Holdren, G. R. Jr., and Schott, J. 1985. Surface layer on dissolving silicates (Comments on “Study of the weathering of albite at room temperature and pressure with a fluidized bed reactor” by L. Chou and R. Wollast). Geochim. Cosmochim. Acta 49: 1657–1658.Google Scholar
Busenberg, E., 1978. The products of the interaction of feldspars with aqueous solutions at 25°C. Geochim. Cosmochim. Acta 42: 1679–1686.CrossRefGoogle Scholar
Busenberg, E., and Clemency, C. V., 1976. The dissolution kinetics of feldspars at 25°C and 1 atm CO2 partial pressure. Geochim. Cosmochim. Acta 40: 41–49.CrossRefGoogle Scholar
Chou, L., and Wollast, R. 1984. Study of the weathering of albite at room temperature and pressure with a fluidized bed reactor. Geochim. Cosmochim. Acta 48: 2205–2217.CrossRefGoogle Scholar
Chou, L., and Wollast, R. 1985. Steady-state kinetics and dissolution mechanisms of albite. Am. J. Sci. 285: 963–993.Google Scholar
Correns, C. W., and Englehardt, W. von. 1938. Neue Untersuchungen uber die Verwitterung des Kalifeldspats. Chemie Erde 12: 1–22.Google Scholar
Dibble, W. E. Jr., and Tiller, W. A. 1981. Non-equilibrium water/rock interactions. I. Model for interface-controlled reactions. Geochim. Cosmochim. Acta 45: 79–92.Google Scholar
Doremus, R. H., 1975. Interdiflusion of hydrogen and alkali ions in a glass surface. J. Non-Cryst. Solids 19: 137–144.Google Scholar
Fung, P. C., Bird, G. W., Mcintyre, N. S., Sanipelli, G. G., and Lopata, V. J. 1980. Aspects of feldspar dissolution. Nuclear Tech. 51: 188–196.Google Scholar
Gardner, L. R., 1983. Mechanics and kinetics of incongruent feldspar dissolution. Geology 11: 418–421.2.0.CO;2>CrossRefGoogle Scholar
Gruner, J. W., 1944. Hydrothermal alteration of feldspars in acid solutions between 300° and 400°C. Econ. Geology 39: 578–589.CrossRefGoogle Scholar
Helgeson, H. C., 1971. Kinetics of mass transfer among silicates and aqueous solutions. Geochim. Cosmochim. Acta 35: 421–469.Google Scholar
Helgeson, H. C., 1972. Kinetics of mass transfer among silicates and aqueous solutions: Correction and clarification. Geochim. Cosmochim. Acta 36: 1067–1070.Google Scholar
Helgeson, H. C., Garrels, R. M., and Mackenzie, F. T. 1969. Evaluation of irreversible reactions in geochemical processes involving minerals and aqueous solutions—II. Applications. Geochim. Cosmochim. Acta 32: 455–482.Google Scholar
Helgeson, H. C., Murphy, W. M., and Aagaard, P. 1984. Thermodynamic and kinetic constrains on reaction rates among minerals and aqueous solutions. II. Rate constants, effective surface area, and the hydrolysis of feldspar. Geochim. Cosmochim. Acta 48: 2405–2432.Google Scholar
Hemley, J. J., 1959. Some mineralogical equilibria in the system K2O-Al2O3-SiO2-H2O. Am. J. Sci. 257: 241–270.Google Scholar
Holdren, G. H. Jr., and Berner, R. A. 1979. Mechanism of feldspar weathering—I. Experimental studies. Geochim. Cosmochim. Acta 43: 1161–1171.CrossRefGoogle Scholar
Houser, C. A., Herman, J. S., Tsong, I. S. T., White, W. B., and Lanford, W. A. 1980. Sodium-hydrogen interdiffusion in sodium silicate glasses. J. Non-Cryst. Solids 41: 89–98.CrossRefGoogle Scholar
Kawano, M., and Tomita, K. 1994. Growth of smectite from leached layer during experimental alteration of albite. Clays & Clay Miner. 42: 7–17.Google Scholar
Kawano, M., Tomita, K., and Kamino, Y. 1993. Formation of clay minerals during low temperature experimental alteration of obsidian. Clays & Clay Miner. 41: 431–441.Google Scholar
Lagache, M., 1965. Contribution à l'étude de l'altération des feldspaths, dans l'eau, entre 100 et 200°C, sous diverses pressions de CO2, et application à la synthèse des minéraux angileux. Bulletin de la Société Framçaise de Minéralogie et de Cristallographie 88: 223–253.Google Scholar
Lagache, M., Wyart, J., and Sabatier, G. 1961a. Dissolution des feldspaths alcalins l'eau pure ou chargée de CO2 à 200°C. Comptes Rendus Hebdomabaires des Séances de l'académie des Sciences 253: 2019–2022.Google Scholar
Lagache, M., Wyart, J., and Sabatier, G. 1961b. Mécanisme de la dissolution des feldspaths alcalins dans l'eau pure ou chargée de CO2 à 200°C. Comptes Rendus Hebdomabaires des Séances de l'académie des Sciences 253: 2296–2299.Google Scholar
Lanford, W. A., Davis, K., Lamarche, P., Laursen, T., and Groleau, R. 1979. Hydration of soda-lime glass. J. Non-Cryst. Solids 33: 249–266.Google Scholar
Murakami, T., Banba, T., Jercinovic, M., and Ewing, R. Formation and evolution of alteration layers on borosilicate and basalt glass: Initial stage. In Scientific Basis for Nuclear Waste Management XII. Lutze, W., and Ewing, R., 1989 eds. Pittsburgh: Materials Research Society, 65–72.Google Scholar
Nixon, R. A., 1979. Differences in incongruent weathering of plagioclase and microcline—Cation leaching versus precipitates. Geology 7: 221–224.Google Scholar
Norton, F. G., 1939. Hydrothermal formation of clay minerals in the laboratory. Amer. Miner. 24: 1–17.Google Scholar
Pačes, T., 1972. Chemical characteristics and equilibrium in natural water-felsic rock-CO2 system. Geochim. Cosmochim. Acta 36: 217–240.Google Scholar
Pačes, T., 1973. Steady-state kinetics and equilibrium between ground water and granitic rock. Geochim. Cosmochim. Acta 37: 2641–2663.Google Scholar
Petrovic, R., 1976. Rate control in feldspar dissolution. II. The protective effect of precipitates. Geochim. Cosmochim. Acta 40: 1509–1521.CrossRefGoogle Scholar
Petrović, R., Berner, R. A., and Goldhaber, M. B. 1976. Rate control in dissolution of alkali feldspar. I. Studies of residual feldspar grains by X-ray photoelectron spectroscopy. Geochim. Cosmochim. Acta 40: 537–548.Google Scholar
Smets, B. M., and Lommen, T. P. A. 1982. The leaching of sodium aluminosilicate glasses studied by secondary ion mass spectrometry. Phys. Chem. Glasses 23: 83–87.Google Scholar
van der Gaast, S. J., Wada, K., Wada, S.-I., and Kakuto, Y. 1985. Small-angle X-ray diffraction, morphology, and structure of allophane and imogolite. Clays & Clay Miner. 33: 237–243.CrossRefGoogle Scholar
Velbel, M. A., 1986. Influence of surface area, surface characteristics, and solution composition on feldspar weathering rates. In Geochemical Processes at Mineral Surfaces. Davis, J. A., and Hayes, K. F., eds. Washington, DC: American Chemical Society, 615–634.Google Scholar
Velde, B., 1965. Experimental determination of muscovite polymorph stabilities. Amer. Miner. 50: 436–449.Google Scholar
Wollast, R., 1967. Kinetics of the alteration of K-feldspar in buffered solutions at low temperature. Geochim. Cosmochim. Acta 31: 635–648.Google Scholar
Wollast, R., and Chou, L. Kinetic study of the dissolution of albite with a continuous flow-through fluidized reactor. In The Chemistry of Weathering. Drever, J. I., 1985 ed. Dordrecht, The Netherlands: Reidel, 75–96.Google Scholar
Yoder, H. S., and Eugster, H. P. 1955. Synthetic and natural muscovites. Geochim. Cosmochim. Acta 8: 225–280.Google Scholar