Abstract: The effects of operation parameters of combined blowing converter on the volumetric mass transfer coefficient between slag and steel are studied with a cold model with water simulating steel, oil simulating slag and benzoic acid as the transferred substance between water and oil.The results show that, with lance level of 2.1m and the top blowing rate of 25000Nm^3/h, the volumetric mass transfer coefficient changes most significantly when the bottom blowing rate ranges from 384 to 540Nm^3/h. The volumetric mass transfer coefficient reaches its maximum when the lance level is 2.1m, the top blowing rates is 30000NmS/h, and the bottom blowing rate is 384Nm^3/h with tuyeres located symmetrically at 0.66D of the converter bottom.

Key words: combined blowing converter, cold modeling, volumetric mass transfer coefficient