Hostname: page-component-cd9895bd7-dzt6s Total loading time: 0 Render date: 2024-12-23T12:06:50.415Z Has data issue: false hasContentIssue false
  • English
  • Français

Effects of Acidity on the Hydrothermal Synthesis of Kaolinite from Silica-Gel and Gibbsite

Published online by Cambridge University Press:  28 February 2024

Shigeo Satokawa ,
Ritsuro Miyawaki ,
Yasushi Osaki ,
Shinji Tomura  and
Yasuo Shibasaki
Shigeo Satokawa*
Affiliation:
Engineering Research Association for Artificial Clay, National Industrial Research Institute of Nagoya Kita-ku, Nagoya 462, Japan
Ritsuro Miyawaki*
Affiliation:
Ceramic Technology Department, National Industrial Research Institute of Nagoya Kita-ku, Nagoya 462, Japan
Yasushi Osaki
Affiliation:
Nanyo Research Labolatory, Tosoh Corporation, Shin-nanyo, Yamaguchi 746, Japan
Shinji Tomura
Affiliation:
Ceramic Technology Department, National Industrial Research Institute of Nagoya Kita-ku, Nagoya 462, Japan
Yasuo Shibasaki
Affiliation:
Ceramic Technology Department, National Industrial Research Institute of Nagoya Kita-ku, Nagoya 462, Japan
*
†Present address: Fundamental Technology Research Laboratory, Tokyo Gas Co., Ltd., Shibaura, Minato-ku, Tokyo 105, Japan
‡Present address: National Science Museum, Hyakunincho, Shinjuku-ku, Tokyo 169, Japan.
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

A comparative study is reported in which kaolinite has been hydrothermally synthesized at several pH conditions. The syntheses were carried out at 220 °C for 3 to 10 d with distilled water or acidic solutions using a mixture of silica-gel derived from alkoxide and gibbsite with a Si/Al ratio of 1:1 as the starting material. Use of acidic solution for the synthesis promotes the dissolution of the starting materials and leads to kaolinitization at an earlier stage of the reaction. However, the rate of kaolinitization is found to be rather slow, in comparison to the reaction with distilled water. The synthetic kaolinite was characterized by X-ray powder diffraction pattern. Kaolinite synthesized with distilled water was poorly grown for direction of the stacking. For example, crystallite size along the c*-axis = 155 Å, whereas kaolinite synthesized with acidic solution gave a higher crystallite size along the c*-axis, such as 253 Å in the case of the synthesis with 0.1 N HCl. Hinckley index of the synthetic kaolinite was varied from 0.35 to 0.80 by the acidity of the reaction. Different kaolinitization processes are implied by differences observed in the rate of kaolinitization, which has an influence on the nature of the stacking faults of the kaolinite.

Keywords

Crystallite sizeCrystallizationHydrothermal synthesisKaolinitepHStacking fault
Type
Research Article
Information
Clays and Clay Minerals , Volume 44 , Issue 3 , June 1996 , pp. 417 - 423
Copyright
Copyright © 1996, The Clay Minerals Society

References

Brindley, G.W.. 1980. Order-disorder in clay mineral structures. In: Brindley, G.W., Brown, G., editors. Crystal structures of clay minerals and their X-ray identification. London: Mineralogical Society. 131 p.CrossRefGoogle Scholar
De Kimpe, C.R., Gastuche, M.C. and Brindley, G.W.. 1964. Low-temperature syntheses of kaolin minerals. Am Mineral 49: 1–16.Google Scholar
De Kimpe, C.R.. 1967. Hydrothermal aging of synthetic alumino-silicate gels. Clay Miner 7: 203–214.CrossRefGoogle Scholar
Eberl, D. and Hower, J.. 1975. Kaolinite synthesis: The role of the Si/Al and (alkali)/(H+) ratio in hydrothermal systems. Clays & Clay Miner 23: 301–309.CrossRefGoogle Scholar
Hinckley, D.N.. 1963. Variability in “crystallinity” values among the kaolin deposits of the coastal plain of Georgia and South Georgia. Clays & Clay Miner 11: 229–235.CrossRefGoogle Scholar
Kennedy, G.C.. 1959. Phase relations in the system A12O3-H2O at high temperatures and pressures. Am J Sci 257: 563–573.10.2475/ajs.257.8.563CrossRefGoogle Scholar
La Iglesia, A. and Martin Vivaldi, J.L.. 1973. A contribution to the synthesis of kaolinite. Proc Int Clay Conf, Madrid, 1972. 172–185.Google Scholar
Miyawaki, R., Tomura, S., Samejima, S. and Shibasaki, Y.. 1989. Appropriate pH for hydrothermal synthesis of kaolinite from amorphous mixture of alumina and silica. Reports of the Government Industrial Research Institute, Nagoya. 39: 490–497. (In Japanese with English abstract)Google Scholar
Osaka, J. and Kato, T.. 1984. Syntheses of clay minerals from loose sands under hydrothermal condition. Rep Asahi Glass Found Ind Technol 45: 23–38. (in Japanese with English abstract)Google Scholar
Plançon, A., Giese, R.F. and Snyder, R.. 1988. The Hinckley index for kaolinite. Clay Miner 23: 249–260.CrossRefGoogle Scholar
Rodrique, L., Poncelet, F. and Herbillon, S.. 1973. Importance of silica subtraction process during the hydrothermal kaolinitization of amorphous silico-aluminas. Proc Int Clay Conf, Madrid, 1972. 187–197.Google Scholar
Satokawa, S., Osaki, Y., Samejima, S., Miyawaki, R., Tomura, S., Shibasaki, Y. and Sugahara, Y.. 1994. Effects of the structure of silica-alumina gel on the hydrothermal synthesis of kaolinite. Clays & Clay Miner 42: 288–297.CrossRefGoogle Scholar
Tsuzuki, Y.. 1976. Solubility diagrams for explaining zone sequence in bauxite, kaolin and pyrophyllite-diaspore deposits. Clays & Clay Miner 24: 297–302.CrossRefGoogle Scholar