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.