Thermodynamic Study on BaO-BaF_2-Fe_xO Slags Used for Dephosphorization of Chromium-Containing Hot Metal

摘要

Electrochemical measurements of the solid-oxide galvanic cell, Mo | Mo + MoO_2 | ZrO_2 (MgO) Fe+(Fe_xO)+Ag|Fe, have been made at temperatures of 1473K and 1573K in order to obtain the activities of Fe_xO in BaO-BaF_2-Fe_xO slags used for dephosphorization of chromium-containing hot metal. The Fe_xO activities show a significant dependence upon the molar ratio of BaO/BaF_2. Within the homogeneous liquid region, the substitution of BaF_2 for BaO has an effect of raising the Fe_xO activity. From these activity data, the phase diagrams of the system BaO-BaF_2-Fe_xO are drawn at 1473K and 1573K. The temperature dependence of the activity coefficient of Fe_xO at a fixed BaO/ BaF_2 molar ratio can be expressed by formula RTlnγ_((Fe_xO)) = constant.