Abstract: In order to estimate the effect of LF feeding materials on chemical compositions of refining slag, slag mass and slag materials cost, based on the element conservation law, the feeding materials’ components and the sample analysis results of steel and slag of the 75t LF in a certain steel plant were calculated, and the volatilization rate and dissolution rate of each element were obtained. To simplify calculations, some assumptions were made, then the relationships of the slag compositions, slag mass and slag materials cost with feeding materials mass were deduced and programmed using the VisualBasic software, and dynamic estimations on chemical compositions of refining slag, slag mass and slagging materials cost were achieved with the programmed model. The industrial verification results showed that the absolute errors between estimation values and real values of CaO, SiO2, Al2O3, MgO, slag mass and slag materials cost were -3.17%~3.61%, -0.97%~1.44%, -2.69%~0.46%, -1.59%~2.49%, -10~70kg and -0.7~0.7yuan/t respectively. The 45 steel’s refining slag was optimized with the LF estimation model, and the slag materials cost was decreased by 7.4yuan/t.

Key words: ladle furance, refining slag, dynamic estimation