Influence of titanium-bearing slag diluents on combustion performance of pulverized coal injection
LI Yan-jiang1，Lü Qing1，BAI Rui-guo2，CUI Shi-qiang1，LI Hong-wei1，WANG Yan1
（1. College of Metallurgy and Energy， North China University of Science and Technology， Tangshan 063009， Hebei， China 2. Chengde Company， Hebei Iron and Steel Group， Chengde 067102， Hebei， China）
Abstract：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 process 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 diameter of unburned pulverized coal was 4.30 μm，which was 5.48 μm smaller than that without the addition of slag diluent. On the other hand，the addition of MgO made the size and the distribution of pulverized coal become uniform. Combining the effects of the addition of MgO on the slag dilution and the combustion ratio，the study concluded that the optimal mass percent of MgO was 1.20%.
2016, Vol. 51 
