With the process measures including increasing temperature of liquid in BOF tapping ( steel Q235A/Q35B 1 660 ~ 1 670 °C

steel Q345A/Q345B 1 665 ~ 1 675℃

end [C]≥O. 06%

end [P]≤0.025% )

intensifying ladle turnover administration

reducing down slag amount

adding modifier or desulphurizing agent for slagging and desulphurization in advance and accurately calculating alloys addition during tapping

and controlling ladle bottom argon blowing rate to protect reoxidation of liquid and slag entrapment

the average power on time for refining steel Q235B and steel Q345B in 150 t LF decreases respectively from 8. 10 min and 9. 39 min to 2. 60 min and 3. 13 min

the average electric power consumption reduces respectively from 17. 33 kWh/t and 20. 09 kWh/t to 5. 55 kWh/t and 6. 69 kWh/t

and the average LF refining time decreases respectively from 40 min and 42 min to 20. 1 min and 22. 4 min

all refining indexes are all meet the requirement with getting better economic performance.