Al_(2)O_(3)-MgO和Al_(2)O_(3)-MgO-SiO_(2)体系的热力学优化与计算

Thermodynamic optimization and calculation of the Al_(2)O_(3)-MgO and Al_(2)O_(3)-MgO-SiO_(2) systems

文献中Al_(2)O_(3)-MgO二元体系的热力学参数在外推至多元系时与实验数据存在偏差,本工作基于热力学数据的严格评估,采用CALPHAD(calculation of phase diagram)方法对该体系进行热力学重新优化,并在此基础上进一步完善Al_(2)O_(3)-MgO-SiO_(2)体系的热力学描述。优化过程中,采用离子双亚点阵模型描述液相,用CEF(compound energy formalism)化合物能量模型描述固相。所得Al_(2)O_(3)-MgO体系和Al_(2)O_(3)-MgO-SiO_(2)体系的相图热力学计算结果与绝大部分实验数据相吻合,是构建Al_(2)O_(3)-SiO_(2)-MgO-CaO-Fe_(2)O_(3)-Na_(2)O六元体系热力学数据库的基础,并可为大宗铝硅酸盐固废材料化设计与高值化应用提供理论依据。

Since the thermodynamic parameters of Al_(2)O_(3)-MgO binary system in the reported literatures deviated from the experimental data when it was extrapolated to the multivariate system,the calculation of phase diagram(CALPHAD)method was used in this work to re-optimize the system based on the rigorous evaluation of the thermodynamic data.Subsequently,the thermodynamic description of the Al_(2)O_(3)-MgO-SiO_(2) system was further improved.In the optimization process,the ionic two-sublattice model was used to describe the liquid phase and compound energy formalism(CEF)model was used to describe the solid phase.The results of thermodynamic optimization and calculation of Al_(2)O_(3)-MgO and Al_(2)O_(3)-MgO-SiO_(2) phase diagrams are in good agreement with most experimental data.This work is the basis of constructing a thermodynamic database of Al_(2)O_(3)-SiO_(2)-MgO-CaO-Fe_(2)O_(3)-Na_(2)O system,and can provide guidance for the high-value utilization of bulk aluminosilicate solid waste.