Phase Equilibria of the CaO-SiO 2 -Sc 2 O 3 Ternary System

Phase equilibria of the CaO-SiO 2 -Sc 2 O 3 system at 1400 and 1600 °C were examined by using quenching technology followed by sample characterization using electron probe microanalysis wavelength-dispersive spectroscopy, scanning electron microscopy and x-ray diffraction. The Sc 2 O 3 solubility in the solid solution phase of Ca 2 SiO 4 and the range of the liquid phase region was determined at experimental temperatures (T = 1400, 1500, 1600 °C). Phase diagrams were established according to the phase relations, further supporting the exploration of the feasibility of rare earth elements recovery from pyrometallurgical smelting slag.