Abstract:

In order to solve the problem that the actual converter bottom blowing effect was difficult to guarantee due to low bottom blowing intensity and the slag splashing technology under high converter campaign life，high efficiency bottom blowing technology for converter steelmaking was developed in Shougang Co.，Ltd. (SGQG). During the development process，a series of key technologies such as optimization of bottom blowing tuyeres arrangement and pool mixing flow field，exposure technology of bottom blowing tuyeres under the conditions of slag splashing，bottom blowing tuyeres long life technology，etc. The optimization of bottom blowing mode was carried out，and the stable control of converter bottom blowing effect was achieved，even at the late age of the campaign，the carbon oxygen product could still be less than 0.0020 under the converter campaign life of about 6500. By applying the above technologies，in the production of ULC and IF steel (converter end point carbon mass fraction was 0.025%~0.05%)，the average reduction of converter end oxygen mass fraction was more than 0.025%，TFe mass fraction in end slag was more than 4%，and the erosion of refractory materials was significantly reduced，converter dephosphorization efficiency was significantly improved.

Key words: converter, combined blowing, bottom blowing intensity, carbon oxygen product, oxygen content of molten steel, dephosphorization