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Alcohothermal Treatments of Gibbsite: Mechanisms for the Formation of Boehmite

Published online by Cambridge University Press:  02 April 2024

Masashi Inoue
Affiliation:
Department of Hydrocarbon Chemistry, Faculty of Engineering, Kyoto University, Yoshida, Kyoto 606, Japan
Kazuhisa Kitamura
Affiliation:
Department of Hydrocarbon Chemistry, Faculty of Engineering, Kyoto University, Yoshida, Kyoto 606, Japan
Hirokazu Tanino
Affiliation:
Department of Hydrocarbon Chemistry, Faculty of Engineering, Kyoto University, Yoshida, Kyoto 606, Japan
Hiroyuki Nakayama
Affiliation:
Department of Hydrocarbon Chemistry, Faculty of Engineering, Kyoto University, Yoshida, Kyoto 606, Japan
Tomoyuki Inui
Affiliation:
Department of Hydrocarbon Chemistry, Faculty of Engineering, Kyoto University, Yoshida, Kyoto 606, Japan
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Abstract

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Gibbsite samples of various particle sizes (0.2–80 μm) were heated at 250°C in a series of straight-chain primary alcohols under the autogenous vapor pressure of the alcohol (alcohothermal treatment of gibbsite). The treatment in ethanol yielded pure boehmite, the morphology of which was similar to that of the boehmite obtained by hydrothermal treatment of gibbsite. In middle-range alcohols, the boehmite yields were low (50% if 80 μm gibbsite was used), and the products were contaminated by a poorly crystallized phase, having a χ-alumina-like structure. The products preserved the morphology of the originating gibbsite, this feature being similar to the thermal dehydration of gibbsite. Complete conversion to boehmite was also attained in mineral oil (a hydrocarbon mixture, which was used as a limit of higher alcohol. The morphology of the boehmite formed in this medium was identical to that of the product prepared by thermal dehydration of gibbsite in a sealed bomb without a medium. If fine particle-size gibbsite was used, the yield of boehmite decreased and the yield of the poorly crystallized phase increased in all the media.

The reaction mechanisms may be discussed in terms of the reported mechanisms for the thermal and hydrothermal formations of boehmite from gibbsite. Thus, in lower alcohols boehmite formed by a dissolution-recrystallization mechanism, whereas in middle-range or higher alcohols it formed by intra-particle hydrothermal reaction mechanism proposed by de Boer and coworkers for the thermal dehydration of gibbsite. The difference in behavior in middle-range and higher alcohols can be explained in terms of the solubility of water in the medium: In the middle-range alcohols, water molecules formed by partial dehydration of gibbsite were removed from the gibbsite particles into the medium so that dehydration proceeded in a manner similiar to that of thermal dehydration, whereas in the higher alcohols, the low solubility of water in the medium allowed the water molecules to remain on the surface of the particles, thereby promoting the complete hydrothermal formation of boehmite.

Type
Research Article
Copyright
Copyright © 1989, The Clay Minerals Society

References

Bauermeister, B. and Fulda, W., 1943 The Bayer process (for purification of bauxite) Aluminium 25 97100.Google Scholar
Bibby, D. M. and Dale, M. P., 1985 Synthesis of silica-sodalite from non-aqueous systems Nature 317 157158.CrossRefGoogle Scholar
Brindley, G. W. and Choe, J. O., 1961 The reaction series, gibbsite → chi alumina → kappa alumina → corundum Amer. Mineral. 46 771785.Google Scholar
Brown, J. F., Clark, D. and Elliott, W. W., 1953 Thermal decomposition of alumina trihydrate, gibbsite J. Chem. Soc 8488.CrossRefGoogle Scholar
Bugosh, J., 1960 Esterifying the surface of alumina monohydrate plates U.S. Patent 2 944.Google Scholar
Day, M. K. B. and Hill, V. J., 1953 The thermal transformations of the aluminas and their hydrates J. Phys. Chem. 57 946950.CrossRefGoogle Scholar
de Boer, J. H., Fortuin, J. M. H. and Steggerda, J. J., 1954 The dehydration of alumina hydrates Koninkl. Ned. Akad. Wetenschap. Proc. 57B 170180.Google Scholar
de Boer, J. H., Fortuin, J. M. H. and Steggerda, J. J., 1954 The dehydration of alumina hydrates. II Koninkl. Ned. Akad. Wetenschap. Proc. 57B 435 43.Google Scholar
de Boer, J. H. and Linsen, B. G., 1964 Studies on pore systems in catalysts II. The shapes of pores in aluminum oxide systems J. Catal. 3 3843.CrossRefGoogle Scholar
de Boer, J. H., van den Heuvel, A. and Linsen, B. G., 1964 Studies on pore systems in catalysts. IV. The two causes of reversible hysteresis Catal. 3 268273.CrossRefGoogle Scholar
Fanelli, A. J. and Burlew, J. V., 1986 Preparation of fine alumina powder in alcohol J. Amer. Ceram. Soc. 69 C174C175.CrossRefGoogle Scholar
Funaki, K. and Shimizu, Y., 1959 Thermal transformation of hydrothermally treated alumina hydrates Kogyo Kagaku Zasshi 62 782787.CrossRefGoogle Scholar
Ginsberg, H., Huettig, W. and Strunk-Lichtenberg, G., 1957 The influence of the starting material on the crystalline forms arising in the thermal decomposition and conversion of aluminum hydroxides. I. The crystalline forms of the thermal decomposition of •y-aluminum hydroxide: Z An-org. Allgem. Chem. 293 3346.CrossRefGoogle Scholar
Ginsberg, H., Huettig, W. and Strunk-Lichtenberg, G., 1957 The influence of the starting material on the crystalline forms arising in the thermal decomposition and conversion of aluminum hydroxides. II. Influence of the starting material on the course of the decomposition of the 7-hydrox-ides: Z Anorg. Allgem. Chem. 293 204213.CrossRefGoogle Scholar
Ginsberg, H. and Koester, M., 1952 Note on the aluminum oxide monohydrate: Z Anorg. Allgem. Chem. 271 4148.CrossRefGoogle Scholar
Huettig, G. F. and von Wittgenstein, E., 1928 The system, alumina-water: Z Anorg. Allgem. Chem. 171 323343.CrossRefGoogle Scholar
Inoue, M., Kondo, Y. and Inui, T., 1986 The reaction of crystalline aluminum hydroxide in ethylene glycol Chem. Lett 14211424.CrossRefGoogle Scholar
Inoue, M., Kondo, Y. and Inui, T., 1988 An ethylene glycol derivative of boehmite Inorg. Chem. 27 215221.CrossRefGoogle Scholar
Inui, T., Miyaké, T., Fukuda, K. and Takegami, Y., 1983 Control of pore structures of 7-alumina by the calcination of boehmite prepared from gibbsite under specific conditions Appl. Catal. 6 165173.CrossRefGoogle Scholar
Inui, T., Miyaké, T. and Takegami, Y., 1982 Influence of the pore structure of alumina support on the dispersed nickel particles size and C02-methanation activity J. Jpn. Petrol. Inst. 25 242247.CrossRefGoogle Scholar
Kubo, T. and Uchida, K. (1970) Reaction between aluminum hydroxide and methanol: Kogyo Kagaku Zasshi 73, 7075 (in Japanese).CrossRefGoogle Scholar
Lodding, W., Schwenker, R. F. Jr. and Gran, P. D., 1969 The gibbsite dehydroxylation fork Thermal Analysis New York Academic Press 12391250.CrossRefGoogle Scholar
Naumann, R., Koehnke, K., Paulik, J. and Paulik, F., 1983 Kinetics and mechanism of the dehydration of hydrargil-lites. Part II Thermochim. Acta 64 1526.CrossRefGoogle Scholar
Papée, D. and Tertian, A., 1955 Thermal decomposition of hydrargillite and the constitution of the activated alumina Bull. Soc. Chim. Fr. 983991.Google Scholar
Paulik, F., Paulik, J., Naumann, R., Koehnke, K. and Pet-zold, D., 1983 Mechanism and kinetics of the dehydration of hydrargillites. Part I Thermochim. Acta 64 114.CrossRefGoogle Scholar
Pokol, G., Varhegyi, G. and Verady, L., 1984 Studies on the kinetics of the gibbsite -► x-alumina reaction Thermochim. Acta 76 237247.CrossRefGoogle Scholar
Rouquerol, J., Rouquerol, F. and Ganteaume, M., 1975 Thermal decomposition of gibbsite under low pressures I. Formation of the boehmite phase J. Catal. 36 99110.CrossRefGoogle Scholar
Rouquerol, J., Rouquerol, F. and Ganteaume, M., 1979 Thermal decomposition of gibbsite under low pressures. II. Formation of microporous alumina J. Catal. 57 222230.CrossRefGoogle Scholar
Russell, A. S., Edwards, J. D. and Taylor, C. S., 1955 Solubility and density of hydrated aluminas in NaOH solutions J. Metal. 7 11231128.Google Scholar
Sato, T., 1960 Hydrothermal reaction of aluminum trihydrate J. Appl. Chem. 10 414417.CrossRefGoogle Scholar
Shimizu, Y., Miyashige, T. and Funaki, K., 1964 Aging of aluminogel Kogyo Kagaku Zasshi 67 788797.CrossRefGoogle Scholar
Stumpf, H. C., Russell, A. S., Newsome, J. W. and Tucker, C. M., 1950 Thermal transformations of aluminas and alumina hydrates Ind. Eng. Chem. 42 13981403.CrossRefGoogle Scholar
Suzuki, M., Ito, S. and Kuwahara, T., 1981 Alcohol treatment of alumina hydrate Shikizai 54 742752.Google Scholar
Tertian, R. and Papée, D., 1958 Thermal and hydrothermal transformations of alumina J. Chim. Phys. 55 341353.CrossRefGoogle Scholar
Tettenhorst, R. and Hofmann, D. A., 1980 Crystal chemistry of boehmite Clays & Clay Minerals 28 373380.CrossRefGoogle Scholar
Thibon, H., Charrier, J. and Tertian, R., 1951 Thermal decomposition of alumina hydrates Bull. Soc. Chim. Fr. 384392.Google Scholar
Torkar, K., Worel, H. and Krischner, H., 1960 Aluminum hydroxides and oxides. III. Preparation of high-purity boehmite and bayerite in autoclaves Monatsh. Chem. 91 653657.CrossRefGoogle Scholar
Violante, A. and Huang, P. M., 1985 Influence of inorganic and organic ligands on the formation of aluminum hydroxides and oxyhydroxides Clays & Clay Minerals 33 181192.CrossRefGoogle Scholar
Wefers, K. and Bell, G. M., 1972 Oxides and hydroxides of aluminum Alcoa Tech. Pap. 19 3645.Google Scholar
Yamaguchi, G. and Chiù, W.-C., 1968 The hydration and crystallization of p-alumina and alumina-gel in aqueous solutions of various basic reagents Bull. Chem. Soc. Jpn. 41 348353.CrossRefGoogle Scholar
Yamaguchi, G. and Sakamoto, K., 1959 Hydrothermal reaction of aluminumtrihydroxides Bull. Chem. Soc. Jpn. 32 696699.CrossRefGoogle Scholar
Yamaguchi, G. and Sakamoto, K., 1959 Effect of dry grinding of gibbsite Bull. Chem. Soc. Jpn. 32 13641368.CrossRefGoogle Scholar