A Thermodynamic Study of BaO-BaF2- Cr2O3 System Fluxes Used for Dephosphorization of Chromium-Containing Iron Melts

Activities of CrO3 BaO-BaF2-Cr2O3 ternary fluxes are delermined using a -Mo.Cr+Cr2O3] ZrO2(MgO)]{Cu-Cr}alloy + (Cr2O3) ,Mo+ solid electrolyte cell in conditions of BaO-BaF2-Cr2O3 system fluxes equilibrium with {Cu-Cr} alloy. Effects of Cr2O3 mole fraction, X(BaO)//X(BaF2) temperature on activities of Cr2O3 are investigated. The results indicate that Cr2O3 activities increase with an increase of its mole fraction, decrease with an increase of (BaO)/X(BaF2) ratio, and decrease with an increase of system temperature. It can be concluded from XRD and chemical analysis that the isothermal phase diagrams of BaO-BaF2-Cr2O3 fluxes are composed of nine zones at 1523 K and four zones at 1673 K, respectively. Isoactivity diagrams of the ternary system are given here. Additionally, the factors affecting dephosphorization and chromium retention of the fluxes are also investigated.