Distribution of Oxygen between Liquid Iron and Fe_tO-(CaO+MgO)-(SiO₂+P₂O₅) Phosphate Slags

Abstract

Equilibrium phosphorus distribution between slags and liquid iron has been studied at the temperature range from 1300 to 1680°C in order to examine the approximate validity of the regular solution model for phosphate slags. The slag systems studied were of Fe_tO-P₂O₅-M_xO_y(M_xO_y= CaO, MgO, SiO₂) ternary and of Fe_tO-P₂O₅ -CaO-M_xO_y(M_xO_y= MgO, SiO₂) quaternary.
In continuation of our previous paper concerning the solubility of the crucible materials and ferric-ferrous equilibrium, the present paper shows the results of oxygen distribution between slags and metal. As the results, it was confirmed that the regular solution model was satisfied for all the experimental results, and the interaction energies concerning phosphate ion, α_{Ca²⁺-P⁵⁺}, α_{Mg²⁺-P⁵⁺} and α_{Si⁴⁺-P⁵⁺} were determined.The iron oxide activity and oxygen content in metal could be estimated within the accuracy of±10% by the model.