Aiming at the unsatisfactory removal rate of various inclusions in refining process of spring steel in a steel plant, this study proposes a unequal flow bottom blowing method with an inlet flow ratio of 2:1, and its effectiveness is verified by numerical simulation and actual production. The numerical simulation results show that under the 2:1 bottom blowing method, the molten steel has greater axial flow strength, which is conducive to the inclusion floating to the slag layer. The removal rate of inclusions under the 2:1 bottom blowing method is about 8% higher than that of the equal flow. The production results are consistent with the numerical simulation, when the inlet flow is 100 NL/min, the inclusion removal rate under 2:1 bottom blowing method is about 18% higher than that of equal flow, meanwhile, the total number of inclusions and large size inclusions are lower than that of equal flow.

Slag splashing operations at the end of the converter blow process can improve the furnace liner life and the converter operation rate. However, the effect of factors on slag splashing at actual dimensions is yet to be fully understood. A three-dimensional transient mathematical model coupled with the response surface analysis has been established to investigate the effects of the amount of remaining slag, oxygen lance height, and top-blowing nitrogen flowrate on the slag splashing process in a 120 ton top-blown converter. The predicted splashing density is validated by the experimental data. The numerical simulation results show that the splashing density and the splashing area ratio increase with the amount of remaining slag, which has the greatest effect on slag splashing. As the oxygen lance height decreases, the splashing density and the splashing area ratio first increase and then decrease. The top-blowing nitrogen flowrate is positively correlated with the splashing area ratio. When the oxygen lance height is high, the impact of the top-blowing nitrogen flowrate on the splashing density is not significant. The splashing density increases with increasing top-blowing nitrogen flowrate as the oxygen lance height is low.