Phosphorus Partition and Phosphate Capacity of TiO2 Bearing Basic Oxygen Steelmaking Slags

The phosphorus partition (LP) and phosphate capacity (CPO3-4)were measured for TiO2 bearing basic oxygen steelmaking slags in the CaO–SiO2–MgO–FetO–(TiO2–MnO–Al2O3–P2O5) system at 1650°C. The effect of slag and metal additions were tested by varying the TiO2 content from 0.0 to 18.0 mass% and the [Ti] content from 0.009 to 0.301 mass%. A recently published LP model was used to assess the experimental LP data using the measured slag composition and temperature. Experimental LP data from this study and literature data were used to modify the published model to include titania. Increasing the TiO2 concentration of the slag was found to decrease the LP and CPO3-4 of basic oxygen steelmaking (BOS) slags. Capacity values in the range of 2.2×1016 to 1.5×1018 at 1650°C were obtained. An empirical model for determining CPO3-4 was developed for BOS slags using a large dataset of published slag and pO2 data for relevant slag systems, including published data for titania bearing slags. The predicted CPO3-4 from the empirical model was found to agree with the experimentally determined CPO3-4 data from this study.