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Microscopic behavior and metallic iron morphology from reduction of iron oxide by CO/H 2 in a fluidized bed
Author(s) -
Lu Feng,
Wen Liangying,
Zhong Hong,
Xu Jian,
Zhang Shengfu,
Duan Huamei,
Yang Zhongqing
Publication year - 2018
Publication title -
journal of applied crystallography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.429
H-Index - 162
ISSN - 1600-5767
DOI - 10.1107/s1600576718014747
Subject(s) - wüstite , iron oxide , adsorption , oxide , metal , thermogravimetric analysis , diffusion , magnetite , scanning electron microscope , chemical engineering , chemistry , analytical chemistry (journal) , materials science , inorganic chemistry , metallurgy , thermodynamics , composite material , chromatography , organic chemistry , physics , engineering
Fe 2 O 3 particles reduced by CO or H 2 exhibit different metallic iron morphology. To determine the mechanism of metallic iron formation during the reduction of iron oxide particles by CO/H 2 in a fluidized bed, an innovative multiscale method was used. This method was validated by experimental results. Density functional theory calculations demonstrate that the CO molecule has a strong stretching effect on the iron ion of wustite in the vertical direction, but the H 2 molecule has no directional force on the structure of wustite. The energy released from CO reduction is used to overcome the energy barrier of iron ion diffusion. However, H 2 addition will hinder iron ion diffusion by consuming energy. By analysis of the thermogravimetric curves of Fe 2 O 3 reduction, it was found that the adsorption ability of H 2 on the surface of FeO is weaker than that of CO. However, the reduction rate is higher under H 2 atmosphere, according to Langmuir adsorption isotherm theory. The morphology of metallic iron during the reduction of iron oxide particles by CO/H 2 was observed with a scanning electron microscope equipped with an energy dispersive X‐ray spectroscopy detector