1993 Volume 33 Issue 8 Pages 847-854
In this report, oxygen potential, PO2*, at the interface between slag and molten iron of high carbon concentration is estimated from the experimental results of the authors' previous kinetic study of phosphorus reaction. The method of the estimation of PO2* is based on an assumption that a quasi-equilibrium is established in the slag-metal system at the time point when the phosphorus reaction changes its direction from dephosphorization to rephosphorization.
The estimated PO2* ranges in the order of 10–11–10–10 Pa. The PO2* increases with the increase in Fe3+/(Fe2++Fe3+) in the slag and decreases with increasing the intensity of mechanical stirring employed in the experiments. The oxygen potential of the bulk slag, PO2, s, is calculated with a regular solution model, and the comparison of the bulk slag's PO2, s with the interfacial oxygen potential, PO2*, shows that PO2* is 2-3 order or magnitude smaller than PO2, s. The slag-metal interfacial oxygen potentials, PO2*, obtained from the experimental data, are also compared with those calculated from a mathematical model which simulates the simultaneous reactions in the gas/slag/metal reaction system including Ar-O2 atmosphere. The calculated interfacial oxygen potentials agree with the experimental data reasonably well.