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

摘要

Activities of Cr2O3 in BaO-BaF2-Cr2O3 ternary fluxesare determined using a -Mo . Cr+Cr2O3II ZrO2(MgO)II { Cu-Cr}alloy+ (Cr2O3)fluxes . Mo+ solid electrolyte cell in conditions of BaO-BaF2-Cr2O3 system fluxes equilibrium with {Cu-Cr} alloy. Effectsof Cr2O3 mole fraction, XBaOIXBaF2 ratio, and temperature onactivities of Cr2O3 are investigated. The results indicate that Cr2O3activities increase with an increase of its mole fraction, decrease withan increase of XBaOIXBaF2 ratio, and decrease with an increase ofsystem temperature. It can be concluded from XRD and chemicalanalysis that the isothermal phase diagrams of BaO-BaF2-Cr2O3fluxes are composed of nine zones at 1523 K and four zones at 1673K, respectively. Isoactivity diagrams of the ternary system are givenhere. Additionally, the factors affecting dephosphorization andchromium retention of the fluxes are also investigated.