A thermodynamic study of BaO-BaF2-Cr2O3 system fluxes used for dephosphorization of chromium-containing iron melts

Activities of Cr2O3 in BaO-BaF2-Cr2O3 ternary fluxes are determined using a -Mo.Cr+Cr(2)O(3)parallel to ZrO2(MgO)parallel to{Cu-Cr}(alloy) + (Cr2O3)(f luxes). Mo+ solid electrolyte cell in conditions of BaO-BaF2-Cr2O3 system f luxes equilibrium with {Cu-Cr} alloy. Effects of Cr2O3 mole fraction, X-BaO /X-BaF2 ratio, and temperature on activities of Cr2O3 are investigated. The results indicate that Cr2O3 activities increase with an increase of its mo le fraction, decrease with an increase of XBaO/XBaF2 ratio, and decrease wi th an increase of system temperature. It can be concluded from XRD and chem ical analysis that the isothermal phase diagrams of BaO-BaF2-Cr2O3 fluxes a re composed of nine zones at 1523 K and four zones at 1673 K, respectively. Isoactivity diagrams of the ternary system are given here. Additionally, t he factors affecting dephosphorization and chromium retention of the fluxes are also investigated.