Isothermal section of CaO-SiO2-La2O3 system within specific region at 1673-1473 K

So far, the relevant phase equilibrium relations and the type of equilibrium phase fields in the CaO-SiO2-La2O3 basic slag system phase diagram are still unknown, which restricts the smelting process and application in materials of rare earth elements. In the current work, phase equilibrium relations within specific region of CaO-SiO2-La2O3 system at 1673-1473 K were studied experimentally by using the thermodynamic equilibrium experiment followed by X-ray diffraction (XRD), scanning electron microscope (SEM), and energy dispersive spectrometer (EDS). According to the experimental results, the existence of ternary compound CaO·3SiO2·2La2O3 was determined, it is confirmed to be a solution solid phase. The sub-solidus phase relations between different solid phases were also determined. Finally, the isothermal sections of CaO-SiO2-La2O3 system within specific region at 1673 K, 1573 K and 1473 K were obtained, respectively. The experimental results can not only enrich the phase diagram information of silicate system, but also have practical significance for the application of rare earth in materials.