Thermodynamics and crystallization kinetics of REEs in CaO–SiO₂–Ce₂O₃ system

Rare earth elements (REEs) have become increasingly important as ceramic materials. The RE‐bearing slags contain massive REEs resources, whereas the lack of thermodynamic and kinetic data of REEs has brought great difficulties to efficient recovery of REEs from RE‐bearing slags and the application in ceramics. According to the compositions of the RE‐bearing slags in industrial production, the isothermal phase equilibria of CaO–SiO 2 –Ce 2 O 3 system at 1500°C and 1300°C were constructed by means of liquid‐quenching method combined with a series of analyses, which provides the thermodynamic data for the equilibria of REEs. On this basis, the crystallization behaviors of the RE phase (Ce 9.33− x Ca x (SiO 4 ) 6 O 2−0.5 x ) was investigated, and the temperature range in which the RE phase crystallized singly in RE‐bearing slags with a selected compositions was acquired. CCT and TTT diagrams for CaO–SiO 2 –Ce 2 O 3 system were established to characterize the crystallization kinetics of the RE phase, and the favorable conditions for its crystallization and growth in RE‐bearing slags were determined. In this study, the complete thermodynamic and kinetic basic data of REEs in CaO–SiO 2 –Ce 2 O 3 system are provided for RE‐bearing slags.