On the Glass in Coal Fly Ashes: Recent Advances
On the Glass in Coal Fly Ashes: Recent Advances
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煤飞灰中的玻璃：最新进展
DOI：
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发表时间：
1987
期刊：
影响因子：
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通讯作者：
E. E. Berry
中科院分区：
文献类型：
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作者：
R. Hemmings;E. E. Berry
本文综述了近年来粉煤灰中玻璃态铝硅酸盐相的研究进展，并从描述其形成机理、组成、结构关系和化学反应性的新模型的发展方面进行了讨论。表征技术，如电子显微镜，X-射线衍射，红外和拉曼光谱，核磁共振和穆斯堡尔谱，热分析，酸溶解，硅烷化，和密度分馏已被用作实验探针，并揭示了一系列的信息，从宏观，通过微观，纳米结构水平的玻璃相。灰中复杂的颗粒间和颗粒内的不均匀性不仅可以在大量的化学和矿物学分析中观察到，而且可以在组成玻璃的分子水平上观察到。灰的颗粒大小，密度和玻璃组合物之间的显着关系已被观察到，并导致一个新的建议机制灰形态的基础上，在锅炉火焰中的矿物前体熔体的温度-粘度效应。提出了粉煤灰颗粒结构的微晶玻璃模型，并从CaO-SiO2-Al2O3和FeO-Fe2O3-Al2O3-SiO2系统的相关系、碱金属和碱土金属离子对铝硅酸盐玻璃的改性以及玻璃析晶和相分离的微观不均匀性等方面进行了讨论。
Recent advances in the characterization of the glassy aluminosilicate phases in coal fly ashes are reviewed and discussed in terms of the development of new models describing their mechanism of formation, composition, structural relationships and chemical reactivity. Characterization techniques such as electron microscopy, x-ray diffraction, infrared and Raman spectroscopy, nuclear magnetic resonance and Mossbauer spectroscopies, thermal analysis, acid dissolution, silanation, and density fractionation have been used as experimental probes, and reveal a range of information relating to the glass phases from the macro, through the micro, to the nano-structural levels. Complex inter- and intra-particle heterogeneity in ash is observable not only in bulk chemical and mineralogical analyses but also at the molecular level in the constituent glasses. Remarkable relationships between ash particle size, density and glass composition have been observed and lead to a new proposed mechanism for ash morphogenesis based on temperature-viscosity effects in the mineral precursor melts in the boiler flame. A glass-ceramic model for fly ash particle structure is proposed and discussed in terms of phase relations in the CaO–SiO 2 –Al 2 O 3 and FeO–Fe 2 O 3 –A1 2 O 3 –SiO 2 systems, modification of the aluminosilicate glasses by alkali and alkaline earth metal cations, and microheterogeneity involving glass devitrification and phase separation.