Abstract: On the basis of theoretical analysis of dephosphorization, by using low lance position smelting and low end¬point oxygen tapping, increasing diameter of tapping hole and reducing the end-point temperature, and optimizing bottom blowing process to reduce the carbon-oxygen equilibrium, a better dephosphorization effect is achieved. The results of production and application show that after adopting large tapping hole and optimizing bottom blowing process, the tapping time of 300 t converter is shortened to 5. 1 min, shortened by 1. 9 min； the end-point temperature of IF steel is reduced to 1670.6 T , reduced by 17.4 °C ；the carbon-oxygen product is reduced to 13.3 , reduced by 8.9; the end-point oxygen is reduced to 422.5 x 10. Under the condition of increase of hot metal phosphorus by 0.010% ,decrease of lance position by 30 cm and decrease of end-point oxygen by 153.3 x 10^-6,the average end-point phosphorus content after process optimization is reduced to 0.012 4% , which can meet the requirements of dephosphorization effect of IF steel smelting in converter.

Key words: 300 t BOF, Dephosphorization, Tapping Time, End-Point Temperature, Carbon-Oxygen Equilibrium, End-Point Oxygen