Effect of Ce₂O₃ on Viscosity and Structure for CaO–SiO₂–Al₂O₃-based Mold Flux

Abstract

The viscosity of 30%CaO-30%SiO₂-15%Al₂O₃-5%MgO-10%Na₂O-10%CaF₂-xCe₂O₃ (mass%, x = 0, 5, 10, 15) were measured by the rotating column method, and then the viscosity and the T_br (break temperature) of the mold flux were analyzed based on the results. Meanwhile, the structural characteristics of the mold flux were investigated using Raman spectroscopy and XRD (X-ray diffraction). The results show that Ce₂O₃ predominantly destroys the silicate network structure at high temperature, reduces the polymerization degree of the mold flux, simplifies the high-temperature structure of the mold flux, and reduces the friction resistance of viscous flow. From the apparent phenomenon, the viscosity of the mold flux decreases at high temperature. In addition, with the increase of Ce₂O₃ content in the mold flux, Ca₄Si₂O₂F changes to Ce_9.33(SiO₄)₆O₂, which enhances the crystallization ability of the mold flux and increases the T_br of the mold flux.