Solubilities of CaO, MgO, SiO₂ and 2CaO·SiO₂, and Ferric-Ferrous Equilibrium in Fe_tO-(CaO+MgO)-(SiO₂+P₂O₅) Phosphate Slags

Abstract

Equilibrium phosphorus distribution between slag and liquid iron has been studied at a temperature range from 1300 to 1680°C. The slag systems studied were of Fe_tO-P₂O₅-M_xO_y(M_xO_y = CaO, MgO, SiO₂) saturated with M_xO_y crucible, and of Fe_tO-P₂O₅-CaO-M_xO_y(M_xO_y=MgO, SiO₂) saturated with M_xO_ycrucible to clarify the effect of the added oxides on the phosphorus equilibrium and the approximate validity of the regular solution model for the phosphate slags.
Among the results obtained, this paper shows the results concerning the solubility of the crucible materials to the phosphate slags studied and ferric-ferrous ratio in equilibrium. It was confirmed that the mole fraction of ferric oxide in the phosphate slags could be estimated by an assumption of the regular solution model within an error of ± 0.015.