Thermodynamic Activity of Components in CaO-MgO-Al₂O₃-SiO₂ Refining Slag System

In order to explore the relationship between refining slag,molten steel and inclusion,the activity of components in CaO-MgO-Al₂O₃-SiO₂ refining slag is calculated by Factsage software.The results indicate that a_Al2O3,a_CaO,a_MgO,a_SiO2 at 1 600℃ ranges from 0.003 to 0.04,from 0.35 to 0.9,from 0.49 to 0. 9,from 0.000 08 to 0.000 5,respectively,when w_MgOis 5%.With the MgO content increasing to 7%,liquid phase zones of refining slag has reduced.In addition,the activity of refining slag has small fluctuation.Furthermore,with the MgO content increasing to 10%,a_Al2O3 can be increased by improving the Al₂O₃ content and decreasing the basicity(R) at the high basicity.On the contrary,a_CaO、a_MgO and a_SiO2 can be increased by improving the basicity and decreasing the content of Al₂O₃.In addition,the activity of refining slag obtained from hot experiments and thermodynamic simulation are consistent,which indicates that the thermodynamic simulation by Factsage is feasible in predicting the activity of refining slag.