Understanding the Relationship Between Structure and Thermophysical Properties of CaO-SiO{sub 2}-MgO-Al{sub 2}O{sub 3} Molten Slags
- Peking University, Department of Energy and Resources Engineering, College of Engineering (China)
- South University of Science and Technology of China, School of Environmental Science and Engineering (China)
In the present work, the relationship between the microscopic structure and macroscopic thermophysical properties in a basic CaO-SiO{sub 2}-MgO-Al{sub 2}O{sub 3} quaternary system was identified using Fourier transformation infrared, Raman and {sup 27}Al magic angular spinning nuclear magnetic resonance (MAS-NMR) techniques. The Raman spectra quantitatively proved that with increasing Al{sub 2}O{sub 3} content, the concentrations of the symmetric units of Q{sup 0}(Si) and Q{sup 2}(Si) decreased, while those of the asymmetric units of Q{sup 1}(Si) and Q{sup 3}(Si) increased; consequently, the degree of polymerization of the networks increased, which resulted in an increase in slag viscosity. The {sup 27}Al MAS-NMR spectra demonstrated that three structural units of Al atoms, namely, AlO{sub 4}, AlO{sub 5}, and AlO{sub 6}, mainly existed in the networks. With increasing Al{sub 2}O{sub 3} content, the concentration of AlO{sub 4} slightly decreased, while those of AlO{sub 5} and AlO{sub 6} increased; overall, Al{sub 2}O{sub 3} acted as a network former in the present system. The increasing Al{sub 2}O{sub 3} content led to additional AlO{sub 6} and Si-NBO-Ca-NBO-Al frameworks, which replaced Si-NBO-Ca-NBO-Si in the networks (NBO: non-bridging oxygen) and induced a change in the primarily precipitated crystalline phase from Ca{sub 2}MgSi{sub 2}O{sub 7} and Ca{sub 2}Al{sub 2}SiO{sub 7} to MgAlO{sub 4}.
- OSTI ID:
- 22857924
- Journal Information:
- Metallurgical and Materials Transactions B, Process Metallurgy and Materials Processing Science, Vol. 49, Issue 2; Other Information: Copyright (c) 2018 The Minerals, Metals & Materials Society and ASM International; http://www.springer-ny.com; Country of input: International Atomic Energy Agency (IAEA); ISSN 1073-5615
- Country of Publication:
- United States
- Language:
- English
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