Equilibria between Alumina Crucible and Carbon Dissolved in Iron

Abstract

Using the static method, a thermodynamic study has been carried out on the reaction between alumina crucible and carbon dissolved in iron in the temperature range of 1430°∼1700°C. The results were as follows: (1) The reaction being studied can be formulated as, Al₂O₃ (solid) + 3C (in molten Fe) = 3CO (gas) + 2Al (in molten Fe). (2) The standard free energy change of the reaction (where the standard state of activity of aluminium is defined as a_Al⁄N_Al=1, when N_Al→0) has been obtaied as, ΔG°_{1703−1973°K}=308,710−144.78T (3) Deoxidation constants of aluminium obtained from this study were in agreement within experimental error with the results by dynamic method of previous investigator and with calculated values based upon the hypothesis of regular solution for dilute solution of Al in Fe-Al binary system.