Transition of Blast Furnace Slag from Silicate-Based to Aluminate-Based: Structure Evolution by Molecular Dynamics Simulation and Raman Spectroscopy

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• 作者：Dong Liang ; Zhiming Yan ; Xuewei Lv ; Jie Zhang…
• 刊名：Metallurgical and Materials Transactions B
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：48
• 期：1
• 页码：573-581
• 全文大小：
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Metallic Materials; Characterization and Evaluation of Materials; Structural Materials; Surfaces and Interfaces, Thin Films; Nanotechnology;
• 出版者：Springer US
• ISSN：1543-1916
• 卷排序：48

文摘

To determine the effect of Al₂O₃ content and Al₂O₃/SiO₂ mass ratio on the structure of molten aluminosilicate systems, CaO-SiO₂-Al₂O₃-MgO-TiO₂ systems were investigated by conducting molecular dynamics (MD) simulation and Raman spectroscopy. The capabilities of different elements to attract O on the basis of bond length are ranked as follows: Si > Al > Ca. The CN_Si-O (approximately 4) and the average CN_Al-O (approximately 4.09) demonstrate that the [AlO₄] tetrahedron is not as stable as the [SiO₄] tetrahedron and that some highly coordinated Al units exist in the slags. Non-bridging oxygen prefers to be coordinated with Si, and Al tends to be localized in polymerized environments as a network intermediate phase. In addition, Ca2+ is more energetically active than Mg2+ as the charge compensation ion. MD results and Raman analysis show that an increase in Al₂O₃ content complicates the structure at a fixed CaO/SiO₂ ratio. In addition, the viscosity of the sample may increase with increasing Al₂O₃ content but is also influenced by polymerization strength. The substitution of Al₂O₃ for SiO₂ simplifies the structure of the slag at a fixed CaO concentration when Al₂O₃/SiO₂ is less than 0.92, as indicated by the (Q4 + Q3)/(Q2 + Q1) ratio of Al and the structure complexity. The results of MD and Raman analysis agree with those of viscosity measurement.