Reduction Kinetics of Hematite Powder in Hydrogen Atmosphere at Moderate Temperatures
Hydrogen has received much attention in the development of direct reduction of iron ores because hydrogen metallurgy is one of the effective methods to reduce CO2 emission in the iron and steel industry. In this study, the kinetic mechanism of reduction of hematite particles was studied in a hydroge...
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MDPI AG
2018-09-01
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| Series: | Metals |
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| Online Access: | http://www.mdpi.com/2075-4701/8/10/751 |
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| author | Zhiyuan Chen Jie Dang Xiaojun Hu Hongyan Yan |
| author_facet | Zhiyuan Chen Jie Dang Xiaojun Hu Hongyan Yan |
| author_sort | Zhiyuan Chen |
| collection | DOAJ |
| description | Hydrogen has received much attention in the development of direct reduction of iron ores because hydrogen metallurgy is one of the effective methods to reduce CO2 emission in the iron and steel industry. In this study, the kinetic mechanism of reduction of hematite particles was studied in a hydrogen atmosphere. The phases and morphological transformation of hematite during the reduction were characterized using X-ray diffraction and scanning electron microscopy with energy dispersive spectroscopy. It was found that porous magnetite was formed, and the particles were degraded during the reduction. Finally, sintering of the reduced iron and wüstite retarded the reductive progress. The average activation energy was extracted to be 86.1 kJ/mol and 79.1 kJ/mol according to Flynn-Wall-Ozawa (FWO) and Starink methods, respectively. The reaction fraction dependent values of activation energy were suggested to be the result of multi-stage reactions during the reduction process. Furthermore, the variation of activation energy value was smoothed after heat treatment of hematite particles. |
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| spelling | doaj.art-cacc0b5eb4384a6299f03ef649c4ad4b2022-12-22T00:54:02ZengMDPI AGMetals2075-47012018-09-0181075110.3390/met8100751met8100751Reduction Kinetics of Hematite Powder in Hydrogen Atmosphere at Moderate TemperaturesZhiyuan Chen0Jie Dang1Xiaojun Hu2Hongyan Yan3Department of Materials Science and Engineering, Delft University of Technology, Mekelweg 2, 2628 CD Delft, The NetherlandCollege of Materials Science and Engineering, Chongqing University, Chongqing 400044, ChinaState Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing, Beijing 100083, ChinaCollege of Metallurgy and Energy, North China University of Science and Technology, 21 Bohai Road, Caofeidian Xincheng, Tangshan 063210, ChinaHydrogen has received much attention in the development of direct reduction of iron ores because hydrogen metallurgy is one of the effective methods to reduce CO2 emission in the iron and steel industry. In this study, the kinetic mechanism of reduction of hematite particles was studied in a hydrogen atmosphere. The phases and morphological transformation of hematite during the reduction were characterized using X-ray diffraction and scanning electron microscopy with energy dispersive spectroscopy. It was found that porous magnetite was formed, and the particles were degraded during the reduction. Finally, sintering of the reduced iron and wüstite retarded the reductive progress. The average activation energy was extracted to be 86.1 kJ/mol and 79.1 kJ/mol according to Flynn-Wall-Ozawa (FWO) and Starink methods, respectively. The reaction fraction dependent values of activation energy were suggested to be the result of multi-stage reactions during the reduction process. Furthermore, the variation of activation energy value was smoothed after heat treatment of hematite particles.http://www.mdpi.com/2075-4701/8/10/751iron oxideshydrogendirection reductionkinetics |
| spellingShingle | Zhiyuan Chen Jie Dang Xiaojun Hu Hongyan Yan Reduction Kinetics of Hematite Powder in Hydrogen Atmosphere at Moderate Temperatures Metals iron oxides hydrogen direction reduction kinetics |
| title | Reduction Kinetics of Hematite Powder in Hydrogen Atmosphere at Moderate Temperatures |
| title_full | Reduction Kinetics of Hematite Powder in Hydrogen Atmosphere at Moderate Temperatures |
| title_fullStr | Reduction Kinetics of Hematite Powder in Hydrogen Atmosphere at Moderate Temperatures |
| title_full_unstemmed | Reduction Kinetics of Hematite Powder in Hydrogen Atmosphere at Moderate Temperatures |
| title_short | Reduction Kinetics of Hematite Powder in Hydrogen Atmosphere at Moderate Temperatures |
| title_sort | reduction kinetics of hematite powder in hydrogen atmosphere at moderate temperatures |
| topic | iron oxides hydrogen direction reduction kinetics |
| url | http://www.mdpi.com/2075-4701/8/10/751 |
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