焦炭与烧结矿在耦合反应过程中的溶损特性

为了研究高炉冶炼中焦炭的溶损行为,选用2种不同反应性的焦炭考察焦炭与烧结矿在不同温度下的耦合反应,研究不同温度下焦炭溶损与烧结矿还原的关系。研究结果表明,焦炭溶损和烧结矿还原的耦合反应随着反应温度的升高逐渐加剧,且焦炭反应性提高有利于烧结矿的还原。焦炭溶损率与烧结矿还原度呈正线性相关性,焦炭反应性(CRI)与拟合曲线的斜率k呈反比,而与截距b呈正比,截距可以表征焦炭对烧结矿的初始还原能力。耦合反应后焦炭的光学各向异性指数OTI增大、平均孔径和气孔率大幅增大,反应性较大的焦炭易于在焦炭表面溶损,反应后的孔径较大;而反应性较小的焦炭在反应过程中CO₂气体易于扩散至焦炭内部均匀溶蚀各级气孔。

Solution loss characteristics of cokes in coke-sinter coupling reaction

In order to investigate the solution loss behavior of cokes in blast furnace, two kinds of cokes with different reactivities were selected, and the coupling reactions of cokes and sinter at different temperatures were studied to clarify the relationship between the solution loss of cokes and the reduction of sinter. The results showed that the coupling reaction between cokes solution loss reaction and reduction reaction of sinter was accelerated gradually with the increase of temperature, and a higher reactivity of coke was beneficial to the reduction of sinter. There was a positive linear correlation between solution loss ratio of coke and reduction degree of sinter. Also, the coke reactivity index (CRI) was inversely proportional to k and directly proportional to b, and the intercept b can be used to characterize the initial reducibility of coke to sinter. The coke-sinter coupling reaction greatly increased the OTI, average pore size and porosity of cokes. The solution loss reaction of the coke with higher reactivity was easy to take place on the surface of cokes, and the pore size of cokes after reaction was larger. For the coke with lower reactivity, CO₂ gas was easy to diffuse into the inside of cokes, and all levels of pores were uniformly eroded by CO₂.