New trends in basic oxygen furnace depho

Phosphorus is generally regarded as an impurity that must be removed in steel production, except for specific grades where it serves as an alloying element. This study reviews recent trends and methods for phosphorus removal during the basic oxygen furnace (BOS) steelmaking process, with a focus on two main approaches: hot metal dephosphorization and the double-slag practice. The literature indicates that the double-slag method is effective when the phosphorus content in hot metal exceeds 0.100%, while maintaining low-phosphorus grades requires careful management of tapping temperatures, ideally keeping them below a maximum allowable phosphorus content of 0.007%. Although the tap-to-tap time associated with the double-slag process is slightly longer than that of conventional methods, it is deemed more economical than establishing a separate hot metal dephosphorization unit, particularly if low-phosphorus grades do not dominate the product mix. Additionally, the injection of a CO2-O2 mixture into the BOS has shown promising results for enhancing dephosphorization efficiency. However, there is currently no successful method established for the recycling of BOS dephosphorization slag.