(1. School of Material Science and Engineering, Chongqing University, Chongqing 400044, China;2. Vanadium
Refining and Steel Plant, Pangang Group Xichang Steel and Vanadium Co., Ltd., Xichang 615000, Sichuan, China)
Abstract：Enhancing the mixing capability of top blowing on 200 t combined blowing vanadium extraction converter by optimizing the performance of oxygen lance nozzle was focused，and a physical simulation system was built to optimize the angle，hole number and Ma number of nozzles by studying their effects on the molten pool stirring in various lance height and bottom blowing flux. The results showed that the mixing time decreased and the 1/3 big wave height increased with the hole angle decreasing first, and these two laws turned to opposite trend when the angle was 12°. The mixing time of 12° nozzle was 4.17% smaller than that of original 13° nozzle, and the 1/3 big wave height was 4.21% bigger. The mixing time and the 1/3 big wave height of the 5holenozzle case were 1.88% and 3.35% smaller than those of the 4holenozzle case respectively, and conductivity measurements showed there existed a dead zone in the molten pool of the 5holenozzle case. The mixing time of the nozzle with Ma number 2.10 and 2.20 were 7.36% and 14.31% smaller than those of the nozzle with Ma number 1.99, and the 1/3 big wave height were 8.68% and 14.75% bigger. The order of the affection extent of each parameter was as follow, Ma number> Nozzle hole angle> Nozzle hole number. The optimization results turned to be more outstanding when the bottom blowing flow rate remains low. The industrial application of the optimized nozzle (with 4 hole, 12° and Ma number 2.10) showed the residual w(［V］) in semisteel reduced by 18.8%, the percent of heats with residual w(［V］) ≤0.05% increased by 26.7%, w((V2O5)) in the slag increased by 6.5% and w((TFe)) decreased by 6.6%.