Abstract
27Al,29Si MAS NMR studies of kaolinite and its thermal transformation products show that in the kaolinite-mullite reaction series there is an extensive segregation of Al2O3 and SiO2 and the reaction of Al2O3 with SiO2 to form mullite is the main path of mullite formation. At about 850° C, the peak intensity of A1(V) reaches its maximum and with the further rise of temperature the A1(V) signal completely disappears. At about 950°C, γ-Al2O3 accounts for about 71% of the material phases containing Al atoms. In the series there is no obvious presence of Al-Si spinel. The27Al and29Si MAS NMR spectra show that there is an obvious difference between the temperature points for Al-O2(OH)4 octahedral sheet collapsing and Si-O4 tetrahedral sheet breaking down.
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References
Brown, I. W. M. et al., 1985, Outstanding problem in the kaolinite-mullite reaction sequence investigated by29Si and27Al solid-state nuclear magnetic resonance: II, High temperature transformations of metakaolinite: J. Am. Ceram. Soc., v. 68, p. 298–301.
Chakraborty, A. K. et al., 1978, Comment on “Interpretation of the Kaolinite-Mullite Reaction Sequence from Infrared Absorption Spectra”: J. Am. Ceram. Soc., v. 61, p. 90–91.
Guo Jiugao et al., 1991, The29Si and27Al MAS NMR spectra of mullite sintered at different temperatures: Kexue Tongbao (Chinese Science Bulletin), v. 36, p. 1467–1470.
Mackenzie, K. J. D. et al., 1985, Outstanding problem in the kaolinite-mullite reaction sequence investigated by29Si and27Al solid-state nuclear magnetic resonance: I: metakaolinite: J. Am. Ceram. Soc., v. 68, p. 293–297.
Rocha, J. and J. Klinowski, 1990,29Si and27Al magic-angle-spinning NMR studies of the thermal transformation of kaolinite: Phys. Chem. Minerals, v. 17, p. 179–182.
Sanz, J. et al., 1988, Aluminum-27 and silicon-29 magic-angle spinning nuclear magnetic resonance study of the kaolinite-mullinite transformation: J. Am. Ceram. Soc., v. 71, p. C418–421.
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Hongping, H., Cheng, H., Jiugao, G. et al. 29Si,27Al magic-angle-spinning nuclear magnetic resonance (MAS NMR) studies of kaolinite and its thermal transformation products. Chin. J. of Geochem. 14, 78–82 (1995). https://doi.org/10.1007/BF02840386
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DOI: https://doi.org/10.1007/BF02840386