含钛炉渣稀释剂对喷吹煤粉燃烧性能的影响

 根据承钢高炉冶炼条件，以其高炉喷吹煤粉作为试验原料，利用煤粉燃烧炉模拟现场高炉风口区域煤粉的燃烧过程，探讨加入含钛炉渣稀释剂CaF2和MgO后，对煤粉燃烧性能的影响，并结合扫描电镜（SEM）观察未燃煤粉颗粒表面结构的变化。试验结果表明，煤粉中添加CaF2后燃烧率有所提高，但提高幅度不大，SEM图未燃煤粉的颗粒减小，这说明CaF2对高炉内煤粉的燃烧有一定的促进作用；添加MgO后煤粉燃烧率明显提高，当添加MgO质量分数为1.20%时，煤粉燃烧率提高了12.41%，此时未燃煤粉SEM图平均粒径为4.30 μm，比未加入稀释剂未燃煤粉的粒径小5.48 μm，并且组织颗粒的大小及分布比较均匀，综合考虑炉渣稀释剂MgO对承钢含钛炉渣的稀释作用和对高炉内煤粉燃烧的影响，含钛炉渣稀释剂MgO的最佳添加质量分数为1.20%。

Influence of titanium-bearing slag diluents on combustion performance of pulverized coal injection

According to the conditions of Cheng Steel blast furnace,the current study used pulverized coal injection of Cheng Steel Blast Furnace as raw materials and used pulverized coal combustion furnace to simulate the combustion pro-cess of actual pulverized coal in the tuyere zone. The influence of titanium-bearing slag diluents,such as CaF2 and MgO added into the pulverized coal on the combustion performance was discussed. The scanning electron microscopy (SEM) was also applied to observe the change of structures on the surface of coal powder. Main results show that the addition of CaF2 could improve the combustion ratio of pulverized coal in the blast furnace,while the benefit was not so obvious, though the unburned coal particles decreased in size. The coal combustion ratio increased significantly with the addition of MgO. When the mass percent of MgO was 1.20%,the coal combustion ratio increased by 12.41%and the average di-ameter of unburned pulverized coal was 4.30μm,which was 5.48 μm smaller than that without the addition of slag dilu-ent. On the other hand,the addition of MgO made the size and the distribution of pulverized coal become uniform. Com-bining the effects of the addition of MgO on the slag dilution and the combustion ratio,the study concluded that the opti-mal mass percent of MgO was 1.20%.