Thermodynamic Modeling of the CaF_2 Containing Slags and Its Applications to Steelmaking Process

摘要

Preliminary thermodynamic modeling results of the fluorine containing oxide system, CaO-MgO-Al_2O_3-SiO_2-F, is presented in the present study. The thermodynamic modeling can reproduce all reliable experimental data within experimental error limits. The thermodynamic properties of cuspidine (Ca_4Si_2F_2O_7) phase are well reproduced. It should be mentioned that new two-sublattice Modified Quasichemical Model can accurately describe the thermodynamic properties of the oxy-fluorine liquid phase. Several practical calculations for steelmaking slag and mould flux were performed to show the applicability of the present thermodynamic modeling to steelmaking process. We are conducting the thermodynamic modeling of the CaO-MgO-Al_2O_3-SiO_2-Na_2O-F system as well as new phase diagram experiments to build up accurate thermodynamic database for the oxy-fluoride system, which can be applied to various steel refining process and mould flux design.