Abstract The crystallization behavior of a CaO-SiO2-MgO-Al2O3 slag system with varying Al2O3/SiO2 mass ratios from 0.03 to 1.10 has been investigated using a confocal laser scanning microscopy (CLSM). The resulting continuous cooling transformation (CCT) and time-temperature-transformation (TTT) curves showed that the initial crystallization temperature increased and the incubation time for crystallization slightly decreased with increasing Al2O3/SiO2 ratio. The crystal growth rate first increased and then decreased with decreasing isothermal temperature. X-ray diffraction (XRD) analysis suggested that Ca2MgSi2O7 or Ca3MgSi2O8 precipitated as the primary phase at lower Al2O3/SiO2 ratios, while the Ca2Al2SiO7 phase was preferred at higher Al2O3/SiO2 ratios. The observed crystalline phases correlated well with the expected thermodynamic predictions from FactSage. In addition, structural analysis using 27Al magic angle spinning nuclear magnetic resonance (27Al MAS-NMR) microscopy of the as-quenched slags indicated the presence of a higher ratio of tetrahedral [AlO4]5-structural units with increasing Al2O3/SiO2 ratio, which enhanced the polymerization of tetrahedral [AlO4]5- and [SiO4]4- structural units to form Ca2Al2SiO7.

中文翻译：

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使用激光共聚焦扫描显微镜观察 Al 2 O 3 /SiO 2 质量比对 CaO-SiO 2 -MgO-Al 2 O 3 渣结晶行为的影响

摘要 使用共聚焦激光扫描显微镜 (CLSM) 研究了 Al2O3/SiO2 质量比从 0.03 到 1.10 变化的 CaO-SiO2-MgO-Al2O3 渣体系的结晶行为。得到的连续冷却转变 (CCT) 和时间-温度-转变 (TTT) 曲线表明，随着 Al2O3/SiO2 比的增加，初始结晶温度升高，结晶孵育时间略有减少。随着等温温度的降低，晶体生长速率先增大后减小。X 射线衍射 (XRD) 分析表明 Ca2MgSi2O7 或 Ca3MgSi2O8 在较低的 Al2O3/SiO2 比率下作为主相沉淀，而在较高的 Al2O3/SiO2 比率下优选 Ca2Al2SiO7 相。观察到的结晶相与 FactSage 的预期热力学预测非常相关。此外，使用 27Al 魔角旋转核磁共振 (27Al MAS-NMR) 显微镜对淬火后的渣进行结构分析表明，随着 Al2O3/SiO2 比的增加，存在更高比例的四面体 [AlO4]5-结构单元，即增强了四面体 [AlO4]5- 和 [SiO4]4- 结构单元的聚合形成 Ca2Al2SiO7。