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Xudong Mao, Pritesh Garg, Xiaojun Hu, Yuan Li, Samik Nag, Saurabh Kundu, and Jianliang Zhang, Kinetic analysis of iron ore powder reaction with hydrogen–carbon monoxide, Int. J. Miner. Metall. Mater., 29(2022), No. 10, pp.1882-1890. https://dx.doi.org/10.1007/s12613-022-2512-6
Xudong Mao, Pritesh Garg, Xiaojun Hu, Yuan Li, Samik Nag, Saurabh Kundu, and Jianliang Zhang, Kinetic analysis of iron ore powder reaction with hydrogen–carbon monoxide, Int. J. Miner. Metall. Mater., 29(2022), No. 10, pp.1882-1890. https://dx.doi.org/10.1007/s12613-022-2512-6
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H2–CO混合气体与铁精矿的还原动力学分析

摘要: 为了降低二氧化碳的排放量,氢气作为一种绿色清洁能源在替代部分碳质能源中扮演着越来越重要的角色,在钢铁行业中也引起了广泛的关注并成为了近年来的研究热点。本文使用了热分析仪研究了不同组分下的H2–CO混合气体对铁精矿的还原行为,并采用了显微组织观察、物相分析等手段研究了铁精矿样品反应前后的变化情况。研究结果表明,随着反应的进行,H2的分压对还原速率的影响逐渐增大。在1173和1373 K时,H2还原铁精矿样品的速率分别约为CO还原铁精矿样品的速率的3倍和4倍。在还原反应后期,平均还原速率的对数与混合气体的成分之间成一定的线性关系。此外,H2在1023 K时能够促进碳的沉积。随着H2含量从20vol%增加到100vol%,还原阶段的表观活化能从约35.0增加到45.4 kJ/mol。这一发现表明,该阶段可能的控速环节为气体扩散和界面化学反应相结合的混合控速。

 

Kinetic analysis of iron ore powder reaction with hydrogen–carbon monoxide

Abstract: Iron ore powder was isothermally reduced at 1023–1373 K with hydrogen/carbon monoxide gas mixture (from 0vol%H2/100vol%CO to 100vol%H2/0vol%CO). Results indicated that the whole reduction process could be divided into two parts that proceed in series. The first part represents a double-step reduction (Fe2O3→Fe3O4→FeO), in which the kinetic condition is more feasible compared with that in the second part representing a single-step reduction (FeO→Fe). The influence of hydrogen partial pressure on the reduction rate gradually increases as the reaction proceeds. The average reduction rate of hematite ore with pure hydrogen is about three and four times higher than that with pure carbon monoxide at 1173 and 1373 K, respectively. In addition, the logarithm of the average rate is linear to the composition of the gas mixture. Hydrogen can prominently promote carbon deposition to about 30% at 1023 K. The apparent activation energy of the reduction stage increases from about 35.0 to 45.4 kJ/mol with the increase in hydrogen content from 20vol% to 100vol%. This finding reveals that the possible rate-controlling step at this stage is the combined gas diffusion and interfacial chemical reaction.

 

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