2020 年 60 巻 8 号 p. 1602-1609
The liquidus of CaO-SiO2-Al2O3-MgO (5mass%)-Ce2O3 (10mass%) system at 1873 K was determined under the reducing atmosphere by adopting the equilibrium and quench method. Furthermore, the thermodynamic activities of Ce2O3 in the melts and the cerium distribution ratio between slag and liquid tin were measured at 1873 K by chemical equilibrium method. By using the measured activity data, an empirical formula was proposed to estimate the activity coefficient of Ce2O3. From the formula, it was found that Al2O3 behaved like basic oxide in this system. In addition, for the melts with the same Ce2O3 contents, the activity coefficient of Ce2O3 increase gradually with the increase of the basicity of the melts. This implies that the increase of the basicity is favorable to the enrichment and precipitation of Ce-containing mineral phases. Finally, an empirical formula was introduced to express the relationship between the cerium distribution ratio and the composition of melts. It was found that the cerium distribution ratio decreased gradually with the increase of the basicity of the melts, which means that decrease of the basicity is beneficial to the recovery of cerium from liquid metal phase.
