环缝式底吹供气元件在铁水提钒中的应用

 为了解决提钒炉熔池搅拌能力不强造成的半钢残钒和炉渣中金属铁高的问题,在提钒转炉的含钒铁水提钒过程中采用环缝式底吹供气元件,设计了适用于铁水提钒的底吹工艺,开展了工业试验研究。通过调研发现,毛细管式透气砖在提钒炉使用过程中存在底吹搅拌强度不高,容易堵塞的问题,因此把毛细管式透气砖改为环缝式供气元件。在此基础上,利用数值模拟计算、冷态模拟试验确定出合适的提钒底吹和顶吹工艺模式,以此制定工业试验方案。数值模拟结果表明,随着底吹供气元件距炉底中心距离的增加,熔池死区面积比例增加,选取底吹元件最佳开孔位置在距离工作层中心0.45D处(D为熔池直径),能获得最佳的熔池搅拌效果。水模试验结果表明,在顶吹流量为11 000～15 400 m3/h条件下,合适的底吹供气强度为0.05～0.08 m3/(t·min)。工业试验结果表明,底吹工艺优化后,半钢中钒质量分数和碳质量分数平均值分别为0.033%和3.35%,分别比工艺优化前钒质量分数降低0.004%,碳质量分数提高0.1%;钒渣中氧化钒质量分数和金属铁质量分数平均值分别为18.99%和22.25%,较工艺优化前氧化钒质量分数增加0.67%,金属铁质量分数降低3%。由此说明工艺优化后,熔池搅拌条件改善,钒氧反应更充分。实践证明,环缝式底吹供气元件具有底吹强度大、维护容易、不易堵塞,安全可靠的特点,适用于提钒转炉铁水提钒工艺。

Application of circular seam bottom blow gas supply element in extracting vanadium from vanadium-containing hot metal

In order to solve the problem of residual vanadium in semi-steel and high metal iron in slag caused by the poor stirring ability of molten bath for vanadium extraction furnace, a circular seam bottom blow gas supply element was adopted in the process of vanadium extraction from vanadium-containing hot metal in vanadium extraction converter. A bottom blow process suitable for vanadium extraction from hot metal was developed, and industrial trial was carried out. Through investigation, it is found that the capillary-type gas-permeable brick has the problem of low bottom blowing stirring intensity and easy blockage during use of vanadium-extracting furnace. Change the capillary-type gas-permeable brick to circular seam bottom blow gas supply element. On this basis, the appropriate bottom blowing and top blowing process modes for vanadium extraction were determined by numerical simulation calculation and cold state simulation experiment, and the industrial test plan was formulated accordingly. The numerical simulation results show that with the increase of distance between the bottom blow gas supply element and the center of furnace bottom, the percentage of dead zone in the molten bath increases. The best opening position of the bottom blow element is selected at 0.45D from the center of the working layer (D is the diameter of the molten bath). The results of water model experiment show that under the condition of top blowing flow rate of 11 000-15 400 m3/h, the suitable bottom blowing gas supply intensity is 0.05-0.08 m3/(t·min). Industrial test results show that after optimization of bottom blow process, the average values of vanadium and carbon mass percent in the semi-steel are 0.033% and 3.35%, respectively, the former is 0.004% lower than that before the process optimization, and the later increases by 0.1%. The average values of vanadium oxide mass percent and metallic iron mass percent in vanadium slag are 18.99% and 22.25%, respectively. Compared with the process before optimization, the vanadium oxide mass percent increases by 0.67% and the metallic iron mass percent decreases by 3%. This shows that after the process is optimized, the stirring conditions of molten bath are improved, and the vanadium oxide reaction is more complete. The practice has proved that the circular seam bottom blow gas supply element has the characteristics of high bottom-blowing strength, easy maintenance, not easy to be blocked, safe and reliable, and is suitable for the process of vanadium extraction from hot metal in vanadium extraction converters.