工程科学学报，第37卷，第2期163-167,2015年2月 Chinese Journal of Engineering,Vol.37,No.2:163-167,February 2015 DOI:10.13374/j.issn2095-9389.2015.02.004:http://journals.ustb.edu.cn 氧化亚铁颗粒氢还原过程的结构演变 杨晓波，胡晓军区，陈志远，党杰，方飞，周国治 北京科技大学钢铁治金新技术国家重点实验室，北京100083 ☒通信作者，E-mail:huxiaojun(@ustb.edu.cm 摘要采用热重法实验研究了773~1273K氧化亚铁的等温氢还原动力学，发现873K温度以上，反应动力学曲线有明显 转折，说明反应机理发生了变化.在973~1073K的温度范围，出现了反常的温度效应，即反应速率随温度升高而减小.为讨 论产物结构对反应动力学的影响，分别对不同温度的反应产物，以及一定温度不同还原状态（不同反应时间）的产物进行形貌 观察.结果显示，随着反应温度升高，还原产物表面的孔洞增多，枝状特征显著增加，而973K和1023K时表面的烧结现象明 显.一定温度下，随着反应进行，表面的孔洞增多，并逐渐出现烧结.973K和1023K温度条件下反应产物大体保留原来的大 颗粒外形，而1173K时还原2min开始，就大量出现枝状产物，并逐渐烧结.结合产物形貌变化和反应动力学曲线，反应前期 为界面化学反应控速，随着反应进行，还原的金属铁发生烧结现象，致密的结构阻碍了产物气体向外扩散，反应控速环节转变 为产物气体的外扩散，还原速率也随之降低. 关键词氢还原：还原动力学：温度效应：氧化亚铁 分类号TF55 Structure evolution in the reduction process of FeO powder by hydrogen YANG Xiao-bo,HU Xiao-jun,CHEN Zhi-yuan,DANG Jie,FANG Fei,CHOU Kuo-Chih State Key Laboratory of Advanced Metallurgy,University of Science and Technology Beijing,Beijing 100083,China Corresponding author,E-mail:huxiaojun@ustb.edu.cn ABSTRACT The isothermal hydrogen reduction kinetics of FeO powder at 773-1273 K was investigated by thermogravimetry. Above 873 K,there was a turning point in the kinetic curve,which indicated that the reduction mechanism changed.An unusual temperature effect that the reduction rate decreased with increasing temperature was observed from 973 K to 1073 K.To discuss the effect of product structure on the reduction rate of iron oxide,the morphology of samples reduced at different temperatures and for different reaction time was observed by scanning electron microscopy.It was shown that holes on the sample surface increased gradual- ly,the dendritic characteristic appeared with increasing temperature,and the sintered phenomenon was obvious at 973 K and 1023 K. At a certain temperature,holes on the sample surface increased and the sintered phenomenon appeared gradually with prolonging reac- tion time.At 973 K and 1023K,the sample kept fairly the original shape,but at 1173K,just reacted for 2 min,a large number of dendritic products appeared and sintered gradually.Combining the morphology and kinetic curves,it can be summarized that interfa- cial chemical reaction is the rate-limiting step in the initial stage of hydrogen reduction.But as the reaction proceeds,the reduced iron sinters and the compact structure of the reduced product hinders the outward diffusion of produced gas.The rate-limiting step changes to the outward diffusion of produced gas,which leads to the decrease of the reduction rate of iron oxide by hydrogen. KEY WORDS hydrogen reduction:reduction kinetics:temperature effect:ferrous oxide 随着全球对C02温室气体排放越来越严格的限制，传统的碳治金工艺面临巨大挑战.因此，近年来治 收稿日期：2013-10-24 基金项目：国家自然科学基金资助项目(51090384,50834007)：北京市优秀人才培养资助项目(2010D009006000001)工程科学学报，第 37 卷，第 2 期: 163--167，2015 年 2 月 Chinese Journal of Engineering，Vol． 37，No． 2: 163--167，February 2015 DOI: 10． 13374 /j． issn2095--9389． 2015． 02． 004; http: / /journals． ustb． edu． cn 氧化亚铁颗粒氢还原过程的结构演变 杨晓波，胡晓军，陈志远，党 杰，方 飞，周国治 北京科技大学钢铁冶金新技术国家重点实验室，北京 100083  通信作者，E-mail: huxiaojun@ ustb． edu． cn 摘 要 采用热重法实验研究了 773 ～ 1273 K 氧化亚铁的等温氢还原动力学，发现 873 K 温度以上，反应动力学曲线有明显 转折，说明反应机理发生了变化． 在 973 ～ 1073 K 的温度范围，出现了反常的温度效应，即反应速率随温度升高而减小． 为讨 论产物结构对反应动力学的影响，分别对不同温度的反应产物，以及一定温度不同还原状态( 不同反应时间) 的产物进行形貌 观察． 结果显示，随着反应温度升高，还原产物表面的孔洞增多，枝状特征显著增加，而 973 K 和 1023 K 时表面的烧结现象明 显． 一定温度下，随着反应进行，表面的孔洞增多，并逐渐出现烧结． 973 K 和 1023 K 温度条件下反应产物大体保留原来的大 颗粒外形，而 1173 K 时还原 2 min 开始，就大量出现枝状产物，并逐渐烧结． 结合产物形貌变化和反应动力学曲线，反应前期 为界面化学反应控速，随着反应进行，还原的金属铁发生烧结现象，致密的结构阻碍了产物气体向外扩散，反应控速环节转变 为产物气体的外扩散，还原速率也随之降低． 关键词 氢还原; 还原动力学; 温度效应; 氧化亚铁 分类号 TF55 Structure evolution in the reduction process of FeO powder by hydrogen YANG Xiao-bo，HU Xiao-jun ，CHEN Zhi-yuan，DANG Jie，FANG Fei，CHOU Kuo-Chih State Key Laboratory of Advanced Metallurgy，University of Science and Technology Beijing，Beijing 100083，China  Corresponding author，E-mail: huxiaojun@ ustb． edu． cn ABSTＲACT The isothermal hydrogen reduction kinetics of FeO powder at 773 ～ 1273 K was investigated by thermogravimetry． Above 873 K，there was a turning point in the kinetic curve，which indicated that the reduction mechanism changed． An unusual temperature effect that the reduction rate decreased with increasing temperature was observed from 973 K to 1073 K． To discuss the effect of product structure on the reduction rate of iron oxide，the morphology of samples reduced at different temperatures and for different reaction time was observed by scanning electron microscopy． It was shown that holes on the sample surface increased gradual￾ly，the dendritic characteristic appeared with increasing temperature，and the sintered phenomenon was obvious at 973 K and 1023 K． At a certain temperature，holes on the sample surface increased and the sintered phenomenon appeared gradually with prolonging reac￾tion time． At 973 K and 1023 K，the sample kept fairly the original shape，but at 1173 K，just reacted for 2 min，a large number of dendritic products appeared and sintered gradually． Combining the morphology and kinetic curves，it can be summarized that interfa￾cial chemical reaction is the rate-limiting step in the initial stage of hydrogen reduction． But as the reaction proceeds，the reduced iron sinters and the compact structure of the reduced product hinders the outward diffusion of produced gas． The rate-limiting step changes to the outward diffusion of produced gas，which leads to the decrease of the reduction rate of iron oxide by hydrogen． KEY WOＲDS hydrogen reduction; reduction kinetics; temperature effect; ferrous oxide 收稿日期: 2013--10--24 基金项目: 国家自然科学基金资助项目( 51090384，50834007) ; 北京市优秀人才培养资助项目( 2010D009006000001) 随着全球对 CO2 温室气体排放越来越严格的限 制，传统的碳冶金工艺面临巨大挑战． 因此，近年来冶