Abstract
A series of hydrothermal experiments was performed to determine the effect of layer charge of starting materials on the smectite to illite reaction rate that might be applied to nuclear-waste repository design. The experiments were conducted on K-saturated <2μm fractions of Wyoming smectite (SWy-1) and Tsukinuno smectite (SKu-F, commercially, Kunipia-F) in a closed system at temperatures of 95, 150, 200, 250, 300°C for run durations of up to 477 days with a 1:20 mass ratio of solid to deionized water. The mean layer charge and tetrahedral charge of SKu-F are larger than those of SWy-1. The proportion of smectite layers in illite/smectite interstratified minerals rapidly decreases, and then slowly decreases with increase in reaction time; a plot of In (100/% smectite) vs. time produces two distinct straight lines in all experiments. These lines are suggestive of two first-order kinetic processes with different rates for this reaction; the first process has a greater rate than the second one. An Arrhenius plot of the reaction rates for each process produces a folding and straight lines for the first and second processes, respectively, suggesting that there are at least two parallel processes in the first process, and a dominant process is different between high- and low-temperature reactions. The activation energies of the first and second processes determined from the plots are the same for the two starting materials, meaning that the reaction mechanisms for the two starting materials are the same. However, the rate of the first process is different between the two starting materials, although that of the second process is similar. The difference in the rate of the first process results possibly from the difference in the amount of layer charge between the two starting smectites.
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References
J. F. Burst, Amer. Assoc. Petrol. Geol. Bull. 53, 73 (1969).
C. H. Bruce, AAPG Bulletin 68, 637 (1984).
J. R. Boles and S. G. Franks, J.Sed. Petrology 49, 55 (1979).
A. Inoue, M. Utada and K. Wakita, Applied Clay Science 7, 131 (1992).
D. D. Eberl and J. Hower, Geol. Soc. Amer. Bull. 87, 1326 (1976).
H. E. Roberson and R. W. Lahann, Clays and Clay Miner. 29, 129 (1981).
J. J. Howard and D. M. Roy, Clays and Clay Miner. 33, 81 (1985).
W. L. Huang, J. M. Longo and D. R. Pevear, Clays Clay Miner. 41, 162 (1993).
C. M. Bethke and S. P. Altaner, Clays and Clay Miner. 34, 136 (1986).
A. M. Pytte and R. C. Reynolds, in The thermal transformation of smectite to illite, edited by N. D. Naeser and T. H. McCulloh (Springer, New York, 1989) p. 133.
B. Velde and G. Vasseur, Am. Miner. 77, 967 (1992).
A. Inoue, J. Clay Sci. Soc. Jpn. 31, 14 (1991).
D. Eberl, G. Whitney and H. Khoury, Am. Miner. 63, 401 (1978).
N. Giiven and W. L. Huang, Clays Clay Miner. 39, 387 (1991).
D. A. Laird, A. D. Scott and T. E. Fenton, Clays & Clay Miner. 37, 41 (1989).
T. Watanabe, Sci. Repts. Dep. Geol. Kyushu Univ. 13, 225 (1977).
G. Whitney and R. Northrop, Am. Miner. 73, 77 (1988).
G. Whitney, Clays & Clay Miner. 38, 343 (1990).
G. Whitney, Applied Clay Science 7, 97 (1992).
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Sato, T., Murakami, T., Isobe, H. et al. Effect of Crystallochemistry of Starting Materials on the Rate of Smectite to Illite Reaction. MRS Online Proceedings Library 353, 239–246 (1994). https://doi.org/10.1557/PROC-353-239
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DOI: https://doi.org/10.1557/PROC-353-239