关键词: 焦炭, 矿焦耦合反应, 溶损行为, 光学组织, 气孔结构

Abstract: The carbon peaking and carbon neutrality goals has proposed higher standards for the low carbon ironmaking of blast furnace. The evaluation of coke quality from the ore-coke coupling reaction is of great significance for understanding the reaction behavior of coke in blast furnace and reducing the carbon emission of blast furnace. To investigate the solution loss behavior of coke during the ore-coke coupling reaction, the ore-coke coupling experiment on two kinds of coke with different thermal properties with sinter and pellet were carried out by the home-made supported large-scale thermogravimetric detector. The carbon solution loss rate of coke and the ore reduction degree during reaction were analyzed, and the size, optical textures, and pore structures of cokes before and after the reaction were measured. The results showed that the total weight loss ratio of the coke-pellet coupling reaction was more than that of the coke-sinter coupling reaction, and the carbon solution loss rate of coke had a positive correlation with the reduction degree of ore. The slope k value of the fitting linear equation was proposed as the coupling reaction parameter to characterize the ore-coke coupling degree, and the k values of the coupling reactions between cokes and pellet were about 1.94~2.69 times higher than that of cokes and sinter, which indicated that improving the reducibility of ore can increase the coupling degree of the ore-coke co-reaction. Also, the greater coupling degree could aggravate the erosion of the pore wall on the surface of cokes and increased the solution loss and shrinkage degree of cokes, but it can weaken the erosion of the internal optical structures for cokes by the ore-coke coupling reaction. However, improving the reactivity of coke could reduce the k value of the ore-coke coupling reaction, and the coupling degree of the ore-coke co-reaction was weakened, which can mitigate the effect of ore-coke coupling reaction on the erosion of coke pores and reduce the solution loss and shrinkage degree of coke, but it can aggravate the erosion of the internal optical structure for cokes. Therefore, matching the performance of coke and ore can get the higher coupling degree of the ore-coke co-reaction, which can weaken the degradation of coke strength, and improve the efficiency of blast furnace.

Key words: coke, ore-coke coupling reaction, solution loss behavior, optical texture, pore structure