Reduction kinetics of iron oxide pellets with H2 and CO mixtures
来源期刊：International Journal of Minerals Metallurgy and Materials2015年第7期
论文作者：Hai-bin Zuo Cong Wang Jie-ji Dong Ke-xin Jiao Run-sheng Xu
文章页码：688 - 696
摘 要：Reduction of hematite pellets using H2–CO mixtures with a wide range of H2/CO by molar（1:0, 3:1, 1:1, 1:3, and 0:1） at different reducing temperatures（1073, 1173, and 1273 K） was conducted in a program reducing furnace. Based on an unreacted core model, the effective diffusion coefficient and reaction rate constant in several cases were determined, and then the rate-control step and transition were analyzed. In the results, the effective diffusion coefficient and reaction rate constant increase with the rise in temperature or hydrogen content. Reduction of iron oxide pellets using an H2–CO mixture is a compound control system; the reaction rate is dominated by chemical reaction at the very beginning, competition during the reduction process subsequently, and internal gas diffusion at the end. At low hydrogen content, increasing temperature takes the transition point of the rate-control step to a high reduction degree, but at high hydrogen content, the effect of temperature on the transition point weakens.
Hai-bin Zuo1，Cong Wang1，Jie-ji Dong2，Ke-xin Jiao2，Run-sheng Xu2
1. State Key Laboratory of Advanced Metallurgy, University of Science and Technology of Beijing2. School of Metallurgical and Ecological Engineering, University of Science and Technology of Beijing
摘 要：Reduction of hematite pellets using H2–CO mixtures with a wide range of H2/CO by molar（1:0, 3:1, 1:1, 1:3, and 0:1） at different reducing temperatures（1073, 1173, and 1273 K） was conducted in a program reducing furnace. Based on an unreacted core model, the effective diffusion coefficient and reaction rate constant in several cases were determined, and then the rate-control step and transition were analyzed. In the results, the effective diffusion coefficient and reaction rate constant increase with the rise in temperature or hydrogen content. Reduction of iron oxide pellets using an H2–CO mixture is a compound control system; the reaction rate is dominated by chemical reaction at the very beginning, competition during the reduction process subsequently, and internal gas diffusion at the end. At low hydrogen content, increasing temperature takes the transition point of the rate-control step to a high reduction degree, but at high hydrogen content, the effect of temperature on the transition point weakens.
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