Abstract:Through the thermo- calculation and static analysis, it has been found the main factors which influence the carbon- oxygen equilibrium in BOF. And the controlling technology ofdecreasing the φC·φO product were confirmed by experiments. The results show that the methods include lowering the tapping temperature from 1682℃ to 1676℃, maintaining the BOF bottom thickness within 600~700mm and bottom stirring eithin 800~1000m3/h.The low φC·φO product (0.0023) has been realized on the No.2 BOF of Shougang Jingtang, reaching the domestic leading level. This technology saves Al alloy about 88.5kg per heat and the cost of 16.1million yuan.