Deoxidation equilibria of calcium and magnesium in liquid iron

Calcium-oxygen and magnesium-oxygen equilibria in liquid iron saturated with CaO-SiO(2)-Al(2)O(3)-MgO slags were studied at 1873 K using CaO, Al(2)O(3), and MgO crucibles. The applicability of the first-order and second-order interaction coefficients between Ca and O and between Mg and O was studied by comparing the Ca-O and Mg-O equilibria observed in the present and previous experiments with the calculated ones from the respective interaction coefficients. As a result, the interaction coefficients obtained in the present work by using a new method were found to explain the measured solubilities of CaO and MgO. The phase stability region in Fe-Al-M (M = Ca, Mg)-O system was described at 1873 K.