Hostname: page-component-78c5997874-94fs2 Total loading time: 0 Render date: 2024-11-17T22:59:44.523Z Has data issue: false hasContentIssue false
  • English
  • Français

Dehydroxylation and Transformations of the 2:1 Phyllosilicate Pyrophyllite at Elevated Temperatures: An Infrared Spectroscopic Study

Published online by Cambridge University Press:  01 January 2024

Ling Wang ,
Ming Zhang ,
Simon A. T. Redfern  and
Zhenyu Zhang
Ling Wang*
Affiliation:
Changsha Institute of Geotectonics, Chinese Academy of Sciences, Changsha, 410013, P.R. China Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, UK
Ming Zhang
Affiliation:
Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, UK
Simon A. T. Redfern
Affiliation:
Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, UK
Zhenyu Zhang
Affiliation:
Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, P. R. China
*
*E-mail address of corresponding author: wangling@ms.csig.ac.cn
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.

The thermally-induced dehydroxylation and transformations of the 2:1 phyllosilicate pyrophyllite have been studied using infrared spectroscopy in the frequency range 350–11000 cm−1 and the temperature range 200–1500°C. The dehydroxylation of pyrophyllite to pyrophyllite dehydroxylate occurs between 500 and 900°C. It is characterized by a decrease in the intensity of the OH signals and phonon bands of pyrophyllite and the eventual disappearance of these features as well as the appearance of extra signals related to pyrophyllite dehydroxylate and an intermediate phase. Our results are consistent with previous observations that the SiO4 tetrahedral sheet structure still exists in pyrophyllite dehydroxylate, that the Si-O-Al linkages and 2:1 structure remain in the pyrophyllite dehydroxylate, and that AlO5 trigonal bipyramids form.

Two extra OH bands at 3690 and 3702 cm−1 and their overtones at 7208 and 7234 cm−1 are observed, for the first time, in samples annealed at the temperature range 550–900°C. Our results suggest that the formation and dehydroxylation of the extra OH species can be strongly affected by kinetic effects. The experimental evidence shows that the dehydroxylation of pyrophyllite is a two-stage process. The appearance of these additional OH bands is interpreted in terms of an unknown intermediate phase, and may be related to the second endothermic peak observed at high temperatures in DTA experiments. Pyrophyllite dehydroylate decomposes into a Si-rich amorphous phase and mullite in the temperature range 950–1100°C. Cristobalite is observed in the temperature range 1150–1500°C.

Keywords

CristobaliteDehydroxylationIR SpectroscopyIntermediate PhaseMullitePyrophyllite DehydroxylateTransformation
Type
Research Article
Information
Clays and Clay Minerals , Volume 50 , Issue 2 , April 2002 , pp. 272 - 283
Copyright
Copyright © 2002, The Clay Minerals Society

References

Bailey, S.W., (1966) The status of clay mineral structures Clays and Clay Minerals 14 1–23 10.1346/CCMN.1966.0140101.CrossRefGoogle Scholar
Bray, H.J. and Redfern, S.A.T., (2000) Influence of counterion species on the dehydroxylation of Ca2+-, Mg2+-, Na+- and K+-exchanged Wyoming montmorillonite Mineralogical Magazine 64 337–346 10.1180/002646100549238.CrossRefGoogle Scholar
Bray, H.J. Redfern, S.A.T. and Clark, S.M., (1998) Time-temperature-dependent dehydration of Ca-montmorillonite: an in situ X-ray diffraction study Mineralogical Magazine 62 647–656 10.1180/002646198548034.CrossRefGoogle Scholar
Brindley, G.W. and Wardle, R., (1970) Monoclinic and triclinic forms of pyrophyllite and pyrophyllite anhydride American Mineralogist 55 1259 1271.Google Scholar
Drits, V.A. Besson, G. and Muller, F., (1995) An improved model for structural transformations of heat-treated aluminous dioctahedral 2:1 layer silicates Clays and Clay Minerals 43 718–731 10.1346/CCMN.1995.0430608.CrossRefGoogle Scholar
Eberl, D.D., (1979) Synthesis of pyrophyllite polytypes and mixed layers American Mineralogist 64 1091 1096.Google Scholar
Farmer, V.C. and Farmer, V.C., (1974) The layer silicates The Infrared Spectra of Minerals London Mineralogical Society 331–363 10.1180/mono-4.15 Monograph, 4 .CrossRefGoogle Scholar
Fitzgerald, J.J. Dec, S.F. and Hamza, A.I., (1989) Observation of five-coordinated Al in prophyllite dehydroxylate by solid-state 27Al NMR spectroscopy at 14 T American Mineralogist 74 1405 1408.Google Scholar
Fitzgerald, J.J. Hamza, A.I. Dec, S.F. and Bronnimann, C.E., (1996) Solid-state 27Al and 29Si NMR and 1H CRAMPS studies of the 2:1 phyllosilicate pyrophyllite Journal of Physical Chemistry 100 17351–17360 10.1021/jp961499f.CrossRefGoogle Scholar
Frost, R.L. and Barron, P.F., (1984) Solid-state silicon-29 and aluminium-27 nuclear magnetic resonance investigation of the dehydroxylation of pyrophyllite Journal of Physical Chemistry 88 6206–6209 10.1021/j150669a030.CrossRefGoogle Scholar
Guggenheim, S. Chang, Y.H. and Koster van Groos, A.F., (1987) Muscovite dehydroxylation: High-temperature studies American Mineralogist 72 537 550.Google Scholar
Heller, L., (1962) The thermal transformation of pyrophyllite to mullite American Mineralogist 47 156 157.Google Scholar
Heller, L. Farmer, V.C. Mackenzie, R.C. Mitchell, B.D. and Taylor, H.F.W., (1962) The dehydroxylation and rehydroxylation of triphormic dioctahedral clay minerals Clay Minerals Bulletin 5 56–72 10.1180/claymin.1962.005.28.02.CrossRefGoogle Scholar
Ishii, M. Shimanouchi, T. and Nakahirea, M., (1967) Far infrared absorption spectra of layer silicates Inorganica Chimica Acta 1 387–392 10.1016/S0020-1693(00)93207-9.CrossRefGoogle Scholar
Kloprogge, J.T. and Frost, R.L. (1999) An infrared emission spectroscopic study of synthetic and natural pyrophyllite. Neues Jahrbuch für Mineralogie, Monatshefte, 62–74.Google Scholar
Lee, J.H. and Guggenheim, S., (1981) Single crystal X- ray refinement of pyrophyllite — 1Tc American Mineralogist 66 350 357.Google Scholar
MacKenzie, K.J.D. Brown, I.W.M. Meinhold, R.H. and Bowden, M.E.J., (1985) Thermal reactions of pyrophyllite studied by high-resolution solid-state 27Al and 29Si nuclear magnetic resonance spectroscopy Journal of the American Ceramic Society 68 266–272 10.1111/j.1151-2916.1985.tb15320.x.CrossRefGoogle Scholar
Muller, F. Drits, V. Plancon, A. and Robert, J.L., (2000) Structural transformation of 2: 1 dioctahedral layer silicates during dehydroxylation-rehydroxylation reactions Clays and Clay Minerals 48 572–585 10.1346/CCMN.2000.0480510.CrossRefGoogle Scholar
Rayner, J.H. and Brown, G., (1966) Structure of pyrophyllite Clays and Clay Minerals 25 73 84.Google Scholar
Russell, J.D. Farmer, V.C. and Velde, B., (1970) Replacement of OH by OD in layer silicates, and identification of the vibrations of these groups in infrared spectra Mineralogical Magazine 37 869–879 10.1180/minmag.1970.037.292.01.CrossRefGoogle Scholar
Stubican, V. and Roy, R., (1961) Proton retention in heated 1:1 clays studied by infrared spectroscopy, weight loss deuterium uptake Journal of Physical Chemistry 65 1348–1351 10.1021/j100826a018.CrossRefGoogle Scholar
Van der Marel, H.T. and Beutelspacher, H., (1976) Atlas of Infrared Spectroscopy of Clay Minerals and their Admixtures Amsterdam Elsevier 396 pp.Google Scholar
Wang, L. (1994) Metallogeny of pyrophyllite in the coastal region of Southeast China and pyrophyllite’s thermal stability. Ph.D. thesis, Changsha Institute of Geotectonics, Chinese Academy of Sciences (in Chinese).Google Scholar
Wang, L. and Zhang, Z.Y., (1997) High-temperature phases of pyrophyllite and their evolutionary characteristics Chinese Science Bulletin 42 140–143 10.1007/BF03182788.CrossRefGoogle Scholar
Wang, L. and Zhang, Z.Y., (1997) Principles and methods of quantitative analysis on b-axis disorder in 2:1 dioctahedral phyllosilicate Chinese Science Bulletin 42 1980–1992 10.1007/BF02883198.Google Scholar
Wardle, R. and Brindley, G.W., (1971) The dependence of the wavelength of AlKα radiation from alumino-silicates on the Al-O distance American Mineralogist 56 2123 2128.Google Scholar
Wardle, R. and Brindley, G.W., (1972) The crystal structures of pyrophyllite, 1Tc, and of its dehydroxylate American Mineralogist 57 732 750.Google Scholar
Wen, L. Liang, W.X. Zhang, Z.G. and Huang, J.C., (1988) The Infrared Spectroscopy of Minerals Chongqing, China Chongqing University Press 190 pp.Google Scholar
Yang, Y.X. Zhang, N.X. and Su, S.B. (1994) et al. , Clay Minerals of China Beijing Geological Publishing House 297 pp.Google Scholar
Zhang, M. Wruck, B. Graeme-Barber, A. Salje, E.K.H. and Carpenter, M.A., (1996) Phonon-spectroscopy on alkali-feldspars: phase transitions and solid solutions American Mineralogist 81 92–104 10.2138/am-1996-1-212.CrossRefGoogle Scholar