Characterization of mullite in silicoaluminous fly ash by XRD, TEM, and {sup 29}Si MAS NMR[X-Ray Diffraction, Transmission Electron Microscopy, Magic Angle Spinning Nuclear Magnetic Resonance]
Mullite contained in a silicoaluminous fly ash (originating from power plant of La Maxe, near Metz in the east of France) issue from bituminous coal combustion has been studied by X-ray diffraction, nuclear magnetic resonance of {sup 29}Si spinning at magic angle, and transmission electron microscopy linked with energy-dispersive spectroscopy. By using results from X-ray diffraction and nuclear magnetic resonance spectroscopy, an average value of 0.25 for x, the oxygen holes rate in mullite Al{sub 4+2x}Si{sub 2{minus}2x}O{sub 10{minus}x}, could be determined. Thus, Al{sub 2}O{sub 3} content is only slightly higher than those corresponding to the classical formula (Al{sub 2}O{sub 3}){sub 3}{sm_bullet}(SiO{sub 2}){sub 2}. It is shown also that the composition is heterogeneous and depends on the crystallites; Ti and Fe are impurities substituting for Al in the structure. The average chemical formula of the mullite determined here is Al{sub 4.61}Fe(0.05)Ti{sub 0.02}O{sub 9.65}.
- Research Organization:
- Univ. Henti Poincare, Vandoeuvre (FR)
- OSTI ID:
- 20023166
- Journal Information:
- Cement and Concrete Research, Vol. 30, Issue 2; Other Information: PBD: Feb 2000; ISSN 0008-8846
- Country of Publication:
- United States
- Language:
- English
Similar Records
Analysis of local cation arrangement in mullite using [sup 29]Si magic-angle spinning nuclear magnetic resonance spectra
Stability and phase evolution of mullite in reducing atmosphere