模拟转炉底吹氧气和石灰粉的冷态及热态试验

Cold and thermal simulation test of bottom blowing oxygen and lime powder in converter

为了研究转炉底吹氧气和石灰粉的冶炼工艺,进行了冷态和热态模拟试验。冷态模拟试验通过改变气源压力的方法,基本实现了对石灰粉流量的控制。喷粉罐的中路气流和下路气流发挥了主要作用。在内径6 mm的输粉管和喷粉枪内径5 mm的条件下实现了5 min之内喷吹石灰粉6~9 kg的目标。平均粉气比为11.2~23.3 kg/m^(3),输粉气平均流速达到34.4~113.0m/s。热模拟试验发现仅靠底吹石灰粉及11.44%~27.22%氧量,就可以实现15.8%~50%的脱磷率。通过减少底吹枪环缝宽度及增大冷却气甲烷流量等措施,可以减少炉底的侵蚀和底吹枪的烧损,但目前还不能满足工业生产需要,还需进一步改进。

In order to study the smelting process of bottom blowing oxygen and lime powder in converter,cold and hot simulation tests were carried out.In the cold simulation test,the flow rate of lime powder is basically controlled by changing the gas source pressure.The middle air flow and the lower air flow play major roles in powder conveying.Under the condition that the inner diameter of powder conveying pipe is 6 mm and the inner diameter of bottom blowing gun is 5 mm,the goal of injecting 6-9 kg lime powder in5 minutes is achieved.The average powder gas ratio is 11.2-23.3 kg/m3,and the average velocity of powder gas is 34.4-113.0 m/s.It is found that the dephosphorization rate of 15.8%-50%can be achieved only by bottom blowing lime powder and 11.44%-27.22%oxygen.The erosion of the converter bottom and the burning loss of the bottom blowing lance can be reduced by reducing the annular gap width of the bottom blowing lance and increasing the methane flow rate.However,it still needs further improvement for the actual industrial application.