Mechanism analysis of effect of MgO on reduction swelling behaviour of iron pellets in CO/H_(2)atmosphere based on first-principles calculations  

作　　者：Hong-ming Long Jing-shu An Xing-wang Li Ting Wu Sheng-ping He Jie Lei 

机构地区：[1]School of Metallurgical Engineering,Anhui University of Technology,Ma’anshan,243032,Anhui,China [2]Key Laboratory of Metallurgical Emission Reduction and Resource Comprehensive Utilization(Anhui University of Technology),Ministry of Education,Ma’anshan,243002,Anhui,China [3]College of Materials Science and Engineering,Chongqing University,Chongqing,400044,China

出　　处：《Journal of Iron and Steel Research International》2025年第1期73-84,共12页钢铁研究学报(英文版)

基　　金：support from the National Natural Science Foundation of China(52174290).

摘　　要：To explain the influence mechanism of MgO on the consolidation and reduction characteristics of roasted iron pellets,the properties and structure of pellets were investigated from multi-dimensions.It indicated that the MgO addition decreased the reduction swelling index(RSI)and reduction degree of pellets in both CO and H_(2)atmospheres.During the stepwise reduction process of Fe2O3→Fe3O4→FeO,the reduction behaviour of pellets in CO and H_(2)was similar,while the reduction rate of pellets in H_(2)atmosphere was almost twice as high as that in CO atmosphere.During the stepwise reduction process of FeO→Fe,the RSI of pellets showed a logarithmic increase in CO atmosphere and a linear decrease in H_(2)atmosphere.As investigated by first-principles calculations,C and Fe mainly formed chemical bonds,and the CO reduction process released energy,promoting the formation of iron whiskers.However,H and Fe produced weak physical adsorption,and the H_(2)reduction process was endothermic,inhibiting the generation of iron whiskers.With Mg2+doping in FexO,the nucleation region of iron whiskers expanded in CO reduction process,and the morphology of iron whiskers transformed from“slender”to“stocky,”reducing RSI of the pellets.

关 键 词：MGO CO atmosphere H_(2)atmosphere Reduction degree Reduction swelling index First-principles calculation 

分 类 号：TG1[金属学及工艺—金属学]