Surface Tension Prediction of Multicomponent Slags of the CaO-SiO2-Al2O3-FeO-Fe2O3 System Based on Microstructure Analysis

The proper understanding and description of the surface tension of melt are important to the slag design in metal smelting. Aiming at this issue, a structure-related model was developed to predict the surface tension of the CaO-SiO2-Al2O3-FeO-Fe2O3 system. In the present work, the melt structures of quinary slags were measured by Raman spectroscopy, and the role of each component and the transformation mechanism of the surface tension were clearly elucidated. The content of the oxygen bond was calculated on the basis of the spectral results and enriched by the Lagrange interpolation method. Then, a new surface tension model depending on oxygen bond data was established. The prediction result showed that the current model could satisfactorily predict the surface tension of the CaO-SiO2-Al2O3-FeO-Fe2O3 system with overall average deviation of 8.05 pct and root-mean-square error of 0.0428 N m(-1). The model was evaluated and compared with Tanaka's model in the CaO-SiO2-Al2O3-FeO-Fe2O3 system and its subsystems. The comparison result showed that the current model had better agreement between the predicted values and the experimental data of the surface tension. The structure-related model developed in this work can achieve accurate prediction of the surface tensions for the steelmaking slag in the metal smelting process.