Thermodynamic Database of P_2O_5-containing Oxide Systems for the Dephosphorization Process in Steelmaking

摘要

The Na_2O-MgO-CaO-FeO-Fe_2O_3-Al_2O_3-SiO_2-P_2O_5 system is a basic oxide system for the Basic Oxygen Furnace (BOF) process as well as the hot metal dephosphorization process. Numerous experimental investigations on this oxide system are being carried out to find out an advanced process route for P removal from molten iron. In spite of their industrial importance, however, phase equilibria in oxide systems containing P_2O_5 have not been well investigated due to the complexity of their chemistry. No systematic thermodynamic modeling of these systems has been conducted to date, either. In order to meet the strong demands of steelmaking and other industries, new systematic thermodynamic modeling of the P_2O_5-containing oxide systems (Na_2O-MgO-CaO-FeO-Fe_2O_3-Al_2O_3-SiO_2-P_2O_5) and key phase diagram experiments have been carried out over the past years. In the present study, the results of the thermodynamic modeling of unary, binary and ternary P_2O_5-containing systems and the applications of the thermodynamic database to the dephosphorization by multi-component slag in BOF process are presented in comparison with experimental data. All thermodynamic calculations were performed using FactSage thermodynamic software.