Control on low melting point area in a CaO-SiO₂-Al₂O₃-MnO system

The compositions of low melting point inclusions in a CaO-SiO₂-Al₂O₃-MnO system were calculated and analyzed by thermodynamic software FactSage. The results show that the area of low melting point inclusions first increases then decreases with the alumina and calcium oxide contents accumulating. However, it always increases with the silica and manganese oxide contents rising. To obtain low melting point inclusions, the alumina and silica contents should be approximately controlled to 20% and 30%, respectively, the CaO content restricted to 25%-30%, and CaO/SiO₂ should be 0.8-1.