Hostname: page-component-cd4964975-g4d8c Total loading time: 0 Render date: 2023-04-01T06:11:19.394Z Has data issue: true Feature Flags: { "useRatesEcommerce": false } hasContentIssue true

A microstructural study of acid-activated montmorillonite from Choushan, China

Published online by Cambridge University Press:  09 July 2018

Hongping He*
Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, WushanGuangzhou, 510640
Jiugao Guo
Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, WushanGuangzhou, 510640
Xiande Xie
Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, WushanGuangzhou, 510640
Hongfu Lin
Zhejiang Foreign Trade Company for Industrial Minerals, Hangzhou 310000
Liyun Li
Laboratory of Magnetic Resonance and Atom and Molecular Physics, Wuhan Institute of Physics, Chinese Academy of Sciences, Wuhan 430071, P. R. China


Bentonite samples from Choushan treated at various acid concentrations were studied using chemical analysis, XRD, 29Si and 27Al MAS NMR to investigate the microstructure of the activated montmorillonites. Two types of structural units were formed during the activation: (1) (SiO)3SiOH, in which up to 15% of Si is bound; (2) Q4(0Al), a major building unit when the acid concentration is >10%. A significant 27Al signal at 55.0 ppm was recorded for both untreated montmorillonite and (to a much greater extent) in acid-treated montmorillonites. This was interpreted as arising from four-fold coordinated Al located in the ‘bulk’ octahedral sheet of montmorillonite. In the course of activation, the removal of one of a pair of octahedral Al ions from montmorillonite removes two hydroxyl groups and leaves the other Al of the pair in four-fold coordination.

Research Article
Copyright © The Mineralogical Society of Great Britain and Ireland 2002

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)


Adams, S.J., Hawkes, G.E. & Curzon, E.H. (1991) A solid state 29Si nuclear magnetic resonance study of opal and other hydrous silica. American Mineralogist, 76, 18631871.Google Scholar
Breen, C., Madejová, J. & Komadel, P. (1995) Correlation of catalytic activity with infra-red, 29Si MAS NMR and acidity data for HCl-treated fine fractions of montmorillonite s. Applied Clay Science, 10, 219230.CrossRefGoogle Scholar
Christidis, G.E., Scott, P.W. & Dunham, A.C. (1997) Acid activation and bleaching capacity of bentonites from the islands of Milos and Chios, Aegean, Greece. Applied Clay Science, 12, 329347.CrossRefGoogle Scholar
Drachman, S.R., Roch, G.E. & Smith, M.E. (1997) Solid state NMR characterization of the thermal transformation of Fuller's Earth. Solid State Nuclear Magnetic Resonance, 9, 257267.CrossRefGoogle Scholar
Guo, J.G., Li, L.Y. & Yuan, H.Z. (1995) 27Al and 29Si MAS NMR study of montmorillonite. Chinese Science Bulletin, 40, 437439.Google Scholar
Keito, B., Moriaki, K., Tetsuyuki, W. & Takamichi, T. (1992) Bleaching of alkali-refined vegetable oils with clay minerals. Journal of the American Oil and Chemical Society, 69, 232236.Google Scholar
Komadel, P., Madejová, J., Janek, M., Gates, W.P., Kirkpatrick, R.J. & Stucki, J.W. (1996) Dissolution of hectorite in inorganic acids. Clay and Clay Minerals, 44, 228236.CrossRefGoogle Scholar
Komarneni, S., Fyfe, C.A., Kennedy, K. & Strobl, H. (1986) Characterization of synthetic and naturally occurring clays by 27Al and 29Si magic-angle spinning NMR spectrosc opy. Journal of the American Ceramic Society, 69, C45 C47.CrossRefGoogle Scholar
Kumar, P., Jasra, R.V. & Bhat, T.S.S.G. (1995) Evolution of porosity and surface acidity in montmorillonite clay on acid activation. Industrial Engineering Chemistry Research, 34, 14401448.CrossRefGoogle Scholar
Legrand, A.P., Taibi, H., Hommel, H., Tougne, P. & Leonardelli, S. (1993) Silicon functionality distribution on the surface of amorphous silica by 29Si solid state NMR. Journal of Non-crystalline Solids, 155, 122130.CrossRefGoogle Scholar
Lin, H.F., Yuan, W.S., Wang, Y.M., Li, P.Q., Cai, H.S. & Yang, X.Z. (1989) A study of properties, crystalline structure and surface characteristics of activated montmorillonite. Pp. 318 in: The Study of Volcanic Geology and Mineral Resources (Lin, H.F. & Li, P.Y., editors). Institute of Mineralogical Resources, Hangzhou, China.Google Scholar
Morgan, D.A., Shaw, D.B., Sidebottom, M.J., Soon, T.C. & Taylor, R.S. (1985) The function of bleaching earths in the processing of palm, palm kernel and coconut oils. Journal of the American Oil and Chemical Society, 62, 292299.CrossRefGoogle Scholar
Rhodes, C.N. & Brown, D.R. (1992) Structural characteristics and optimisation of acid-treated montmorillonite and high-porosity silica supports for ZnCl2 alkylation catalysts. Journal of the Chemical Society Faraday Transactions, 88, 22692274.CrossRefGoogle Scholar
Rupert, J.P., Granquist, W.T. & Pinnavaia, T.J. (1987) Catalytic properties of clay minerals. Pp. 275318 in: Chemistry of Clays and Clay Minerals (Newman, A.C.D., editor). Monograph 6, Mineralogical Society, London.Google Scholar
Srasra, E., Bergaya, F., van Damme, H. & Arguib, N.K. (1989) Surface properties of an activated bentonite. Decolorization of rape-seed oil. Applied Clay Science, 4, 411421.CrossRefGoogle Scholar
Thomas, C.L., Hickey, J. & Stecker, G. (1950) Chemistry of clay cra cking cat alysts. Indust rial and Engineering Chemistry, 42, 866871.CrossRefGoogle Scholar
Tkac, I., Komadel, P. & Müller, D. (1994) Acid-treated montmorillonites a study by 29Si and 27Al MAS NMR. Clay Minerals, 29, 1119.CrossRefGoogle Scholar
Woessner, D.E. (1989) Characterization of clay minerals by 27Al nuclear magnetic resonance spectroscopy. American Mineralogist, 74, 203215.Google Scholar
Wu, P.X., Zhang, H.F. & Guo, J.G. (1999) Surface structural change of acid-treated montmorillonite. Acta Mineralogica Sinica, 19, 1520.Google Scholar