School of Chemistry and Chemical Engineering, Wuhan University of Science and Technology, Wuhan, Hubei, China.
Key Laboratory of Hubei Province for Coal Conversion and New Carbon Materials, Wuhan, Hubei, China.
PLoS One. 2021 Jan 11;16(1):e0245124. doi: 10.1371/journal.pone.0245124. eCollection 2021.
The reaction characteristics and mechanism of coke with different coke reactivity indices (CRIs) in the high-temperature zone of a blast furnace should be fully understood to correctly evaluate the coke quality and optimize ironmaking. In this work, low-CRI coke (coke A) and high-CRI coke (coke B) were charged into a thermogravimetric analyzer to separately study their microstructural changes, gasification characteristics, and reaction mechanism under simulated cohesive zone conditions in a blast furnace. The results show that both coke A and coke B underwent pyrolysis, polycondensation, and graphitization during the heat treatment. The pyrolysis, polycondensation, gasification speed, and dissolution speed rates of coke B were higher than those of coke A. Direct and indirect reduction between sinter and coke occurred in the cohesive zone and had different stages. The consumption rate of coke B was faster than that of coke A during the coke-sinter reduction. The carbon molecules of coke A must absorb more energy to break away from the skeleton than those of coke B.
为了正确评价焦炭质量和优化炼铁工艺，需要充分了解高炉高温区不同反应性指数（CRI）焦炭的反应特性和机理。在这项工作中，将低 CRI 焦炭（焦炭 A）和高 CRI 焦炭（焦炭 B）装入热重分析仪中，分别研究它们在模拟高炉黏聚带条件下的微观结构变化、气化特性和反应机理。结果表明，焦炭 A 和焦炭 B 在热处理过程中都经历了热解、缩聚和石墨化。焦炭 B 的热解、缩聚、气化速度和溶解速度比焦炭 A 高。在黏聚带中发生了烧结矿和焦炭之间的直接和间接还原，且具有不同的阶段。在焦炭-烧结矿还原过程中，焦炭 B 的消耗速度比焦炭 A 快。焦炭 A 的碳原子必须吸收更多的能量才能从骨架中脱离出来，这比焦炭 B 更难。
