Production of low phosphorous steel from low silicon high phosphorous hot metal in BOF.

The article focuses on optimizing the dephosphorization process in Basic Oxygen Furnace (BOF) steelmaking when using hot metal with low silicon (≤0.5%) and high phosphorus (average 0.17%) content, a challenging condition due to low heat generation and slag formation. Analysis of plant data and trials at Tata Steel demonstrated that reducing lime addition by 12% did not adversely affect phosphorus removal, while a 19% reduction increased phosphorus in steel, indicating excess lime leads to unreacted free lime in slag and higher costs without benefits. Additionally, modifying the lime addition pattern—adding lime in multiple batches during 10–25% of the oxygen blow—improved lime dissolution and enhanced dephosphorization efficiency. These findings support a refined operating practice that balances lime quantity and addition timing to achieve low phosphorus steel from high-phosphorus, low-silicon hot metal more cost-effectively.