Contribution Oral Presentation
Some insights on interdiffusion in the magnesiowustite solid solution under the conditions of the novel flash ironmaking technology (FIT)
Recent work by the authors on the interaction of MgO-14.5 wt.% C refractory with Fe/FeO under the conditions of the novel flash ironmaking technology (FIT) developed in the University of Utah showed the formation of a magnesiowustite ((Fe,Mg)O) solid solution. In this work, interdiffusion in the (Fe,Mg)O solid solution has been discussed by analysing the experimental data for two different cases viz. the Fe-MgO-C and the FeO-MgO-C interactions. Kinetics models for each of these cases have been developed based on the counterdiffusion of Fe2+ and Mg2+ cations in the (Fe,Mg)O solid solution. Using the kinetics models and the experimentally determined composition profiles obtained from EPMA, the interdiffusion coefficient (D_(Fe-Mg)) has been determined as function of composition using the Boltzman-Matano analysis. Also, an average value of the interdiffusion coefficient (D ̅_(Fe-Mg)) has been calculated such that it reasonably reproduces the concentration profiles of both cations. The interdiffusion phenomenon was a thermally activated process, as expected, with an activation energy of 375 kJ/mol.