Phosphorus Partition and Phosphate Capacity of Basic Oxygen Steelmaking Slags

Abstract

The phosphorus partition (L_P) and phosphate capacity (C_PO4³⁻) were measured for slags in the CaO–SiO₂–MgO–Fe_tO–(MnO–Al₂O₃–TiO₂–P₂O₅) system over temperatures representative of basic oxygen steelmaking. The measured L_P values were found to be in good agreement with those predicted from the model of Assis et al. The oxygen potential of the slag-metal systems studied was also evaluated and used in combination with the measured L_P to calculate the C_PO4³⁻ of the slags. Capacity values in the range of 7.77×10¹⁶ to 4.27×10¹⁹ for temperatures 1550°C to 1700°C were obtained.

Correlations of C_PO4³⁻ with common measures of slag basicity (v-ratio and optical basicity) were sought and reported. Consistent with other researchers it was found that the L_P and C_PO4³⁻ increased with increasing slag basicity and decreasing temperature.