Preparation and industrial test of high grindability semi-coke for blast furnace injection
HE Jiang-yong1, ZOU Chong1, ZHAO Jun-xue1, REN Meng-meng1, YU Nan1, LI Yan-xiong2
1. School of Metallurgical Engineering, Xi’an University of Architecture and Technology, Xi’an 710055, Shaanxi, China; 2. Inner Mongolia Zhengneng Chemical Industry Group Co., Ltd., Erdos 017200, Nei Monggol, China
Abstract：Poor grindability is the key problem restricting the application of semi-coke in blast furnace injection. On the basis of investigating the grindability index of a large number of industrial semi-coke, the surface morphology, mineral elements, functional groups, microcrystalline structure and pore structure of the semi-coke were characterized by SEM, XRF, FTIR, XRD and N2 adsorption respectively. The influence mechanism of pyrolysis conditions and microstructure on the grindability index of the semi-coke were analyzed. The industrial test of preparing highly grindable semi-coke was carried out. More than 50% of the industrial semi-coke from the main production area shows poor grindability (grindability index＜52). The lower the value of w(Si+Al)/w(Ca) in the ash composition, the higher the grindability index of the semi-coke. In the ash composition the main elements Si and Al show a point-like aggregated distribution in the form of oxides, showing a significant inhibitory effect on grindability, while Ca shows a diffuse distribution, showing a positive contribution to grindability. The pyrolysis temperature corresponding to the highest grindability index may be different. Below the transition temperature, the increase of specific surface area and d002 (interlayer spacing of aromatic layers) and the weakening of matrix strength due to the decomposition and depolymerization of organic matter inside the particles jointly promote the grindability index. Above the transition temperature, the increase of matrix strength of semi-coke caused by polycondensation reaction is the main reason for the decrease of grindability index. Both basic research and industrial test research show that taking the selected raw coal as the pyrolysis raw material and adjusting the pyrolysis conditions, a high-quality blast furnace injection semi-coke with high grindability index, stable composition, high calorific value and excellent combustion performance can be produced.
何江永, 邹冲, 赵俊学, 任萌萌, 俞楠, 李彦雄. 高炉喷吹用高可磨兰炭的调控制备与工业试验[J]. 钢铁, 2023, 58(4): 11-20.
HE Jiang-yong, ZOU Chong, ZHAO Jun-xue, REN Meng-meng, YU Nan, LI Yan-xiong. Preparation and industrial test of high grindability semi-coke for blast furnace injection[J]. Iron and Steel, 2023, 58(4): 11-20.
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2023, Vol. 58 
