A Thermodynamic‐Kinetic Model for Basic Oxygen Furnace Tapping: Improved Prediction of Phosphorus and Steel‐Slag Evolution

Coupling advanced computational thermodynamics with kinetic modeling is a leading approach in studying the chemical composition of steel and slag in the steelmaking process. In this study, the effective equilibrium reaction zone method is employed to establish a tapping model by implementing the continuous reactions in the last stage of the basic oxygen furnace (BOF) process. Plant trials are performed during the tapping process by measuring the steel and slag composition before and after tapping, alongside recording relevant operational data. The initial steel and slag compositions before tapping are found to be near equilibrium (NE) and far from equilibrium (FFE). When FFE initial conditions are considered, the accuracy of phosphorus (P) content predictions improved compared to the model previously reported in the literature, while both models showed accurate predictions under the NE initial conditions. Further analysis confirmed that the dephosphorization reaction in the BOF continued throughout the tapping process, which should be considered in developing the tapping process model.