Phosphorus vaporization behaviour from converter slag

The high-P content in convert slag limits its recycling in the steelmaking process. The P could be removed out of the slag as gas when the convert slag is reduced by reductants, such as carbon. Through the experiments and thermodynamic calculations, one of the main dephosphorization products is determined to be P2as the converter slag being reduced by C. In the experiments, the reduction driving force of P2O5is greater than that of FeO; while the actual Gibbs free energy of P2O5is lower than that of FeO at a high temperature in the atmosphere of flowing N2. The dephosphorization of converter slag conforms to the interface chemical reaction model, and a model was established to describe the dephosphorization process in this study. The results indicate the apparent activation energy of the dephosphorization reaction is 165.78 kJ mol-1and the dephosphorization reaction is controlled by the mass transfer of reactants in the slag.