Experimental Study on the Thermodynamics of the CaO-SiO2-Ce2O3 System at 1873 K
Experimental Study on the Thermodynamics of the CaO-SiO2-Ce2O3 System at 1873 K
复制标题
DOI：
10.1007/s11663-018-1471-9
复制
发表时间：
2018-12
期刊：
影响因子：
--
通讯作者：
Zengwu Zhao;Xuexin Chen;Björn Glaser;B. Yan
中科院分区：
文献类型：
--
作者：
Zengwu Zhao;Xuexin Chen;Björn Glaser;B. Yan
通过传统的平衡和淬火方法结合扫描电子显微镜-电子探针微分析（SEM-EPMA）和淬火样品的X射线衍射（XRD）测量，确定了1873 K还原气氛下CaO-SiO2-Ce2O3体系中的相关系。基于这些分析，构建了大部分等温相图。此外，采用化学平衡法测量了熔体中Ce2O3在1873 K时的热力学活性。利用测得的活度数据，基于正则解模型提出了估计Ce2O3活度系数的经验公式。研究发现，对于相同Ce2O3含量的熔体，随着熔体碱度（CaO与SiO2之比）的升高，Ce2O3的热力学活性逐渐增大。这意味着，从热力学角度来看，碱度的增加有利于含Ce矿物相的富集和沉淀。
The phase relations in the CaO-SiO2-Ce2O3 system under the reducing atmosphere at 1873 K were determined by the conventional equilibrium and quenching method combined with scanning electron microscopy-electron probe microanalysis (SEM-EPMA) and X-ray diffraction (XRD) measurements on the quenched samples. Based on these analyses, a large part of the isothermal phase diagram was constructed. Furthermore, the thermodynamic activities of Ce2O3 in the melts at 1873 K were measured by the chemical equilibrium method. Using the measured activity data, an empirical formula to estimate the activity coefficient of Ce2O3 was proposed based on the regular solution model. It was found that, for the melts with the same Ce2O3 contents, the thermodynamic activities of Ce2O3 increase gradually with the rise of basicity (the ratio of CaO to SiO2) of the melts. This implies that, from the thermodynamic point of view, the increase of basicity is favorable to the enrichment and precipitation of Ce-containing mineral phases.