Effect of Temperature on Dephosphorization of Hot Metal in Double‐Slag Converter Steelmaking Process by High‐Temperature Laboratorial Experiments

The influence of temperature on the dephosphorization of hot metal at the low temperature range of 1300–1450 °C with the slag of the low basicity (CaO/SiO2) of about 1.8 is investigated using high‐temperature laboratorial experiments. The results show that with increasing temperature, the phosphorus contents in hot metal decrease first and then increase. The phosphorus can be removed from the initial content of 0.246% to the final content of 0.066% with the highest dephosphorization ratio of 73.2% at 1375 °C. The P2O5 content in slag increases first and then decreases. When the actual dephosphorization temperature is 1350–1375 °C being about 60 °C higher than the conversion temperature of decarbonization and dephosphorization, a very high LP of about 25 can be obtained. Moreover, the dephosphorization slag at the temperature from 1300 to 1400 °C is mainly comprised of three mineralogical phases: phosphorus‐rich, metal oxide (RO), and CaO–FeO–SiO2 phases. When the temperature is increased to 1425 and 1450 °C, the dephosphorization slag is mainly comprised of liquid slag containing Ca3(PO4)2 and RO phase. The influence of temperature on the dephosphorization of hot metal at the low temperature range of 1300–1450 °C with the slag basicity (CaO/SiO2) of about 1.8 is investigated using high‐temperature laboratorial experiments. The results show that the phosphorus contents in hot metal decrease first and then increase with increasing temperature.