1. Key Laboratory of the Ministry of Education of China for High-efficient Mining and Safety of Metal Mines,University of Science and Technology Beijing,Beijing 100083,China ?2. Beijing Key Laboratory on Resource-oriented Treatment of Industrial Pollutants,University of Science and Technology Beijing,Beijing 100083,China ?3. School of Civil and Environmental Engineering,University of Science and Technology Beijing,Beijing 100083,China ?4. School of Water Resources Environment,China University of Geosciences,Beijing 100083,China
Orthogonal Experiments on Direct Reduction of Carbon-bearing Pellets of Bayer Red Mud
1. Key Laboratory of the Ministry of Education of China for High-efficient Mining and Safety of Metal Mines,University of Science and Technology Beijing,Beijing 100083,China ?2. Beijing Key Laboratory on Resource-oriented Treatment of Industrial Pollutants,University of Science and Technology Beijing,Beijing 100083,China ?3. School of Civil and Environmental Engineering,University of Science and Technology Beijing,Beijing 100083,China ?4. School of Water Resources Environment,China University of Geosciences,Beijing 100083,China
ժҪ To recycle residual iron efficiently in Bayer red mud,three-factor three-level orthogonal experiments on carbon-bearing pellets of Bayer red mud were conducted on the basis of their characteristics. The influences of CaO dosage,temperature and roast-ing time on total iron content and iron recovery of reduced iron powder were studied. Results showed that these factors slightly influenced iron recovery,but significantly influenced total iron content. The principal factor influencing total iron content was CaO dosage,followed by temperature and roasting time. An increase in CaO dosage could decrease total iron content,whereas an increase in temperature and an extension of roasting time could improve total iron content. The reduced iron powder with total iron content of 88.41% and iron recovery rate of 97.97% can be obtained under the optimal conditions of temperature of 1 275 ��C,roasting time of 60 min and CaO dosage of 7.5%. The X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses of the reduced pellets showed that iron minerals in red mud were almost completely reduced to metallic iron. The principal factor influencing the total iron content of reduced iron powder was the grain size of metallic iron particles. An increase in CaO dosage hindered the growth of metallic iron particles,whereas an increase in temperature and an extension of roasting time could neutralise the effect of CaO dosage. Therefore,CaO dosage should be decreased when iron minerals in red mud can be adequately reduced into metallic iron.
Abstract��To recycle residual iron efficiently in Bayer red mud,three-factor three-level orthogonal experiments on carbon-bearing pellets of Bayer red mud were conducted on the basis of their characteristics. The influences of CaO dosage,temperature and roast-ing time on total iron content and iron recovery of reduced iron powder were studied. Results showed that these factors slightly influenced iron recovery,but significantly influenced total iron content. The principal factor influencing total iron content was CaO dosage,followed by temperature and roasting time. An increase in CaO dosage could decrease total iron content,whereas an increase in temperature and an extension of roasting time could improve total iron content. The reduced iron powder with total iron content of 88.41% and iron recovery rate of 97.97% can be obtained under the optimal conditions of temperature of 1 275 ��C,roasting time of 60 min and CaO dosage of 7.5%. The X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses of the reduced pellets showed that iron minerals in red mud were almost completely reduced to metallic iron. The principal factor influencing the total iron content of reduced iron powder was the grain size of metallic iron particles. An increase in CaO dosage hindered the growth of metallic iron particles,whereas an increase in temperature and an extension of roasting time could neutralise the effect of CaO dosage. Therefore,CaO dosage should be decreased when iron minerals in red mud can be adequately reduced into metallic iron.
��������:The National High Technology Research and Development Programme of China
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ni wen
E-mail: niwen@ces.ustb.edu.cn
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Dun-cheng FAN,Wen NI,Ai-yun YAN,Jian-yue WANG,Wei-hua CUI. Orthogonal Experiments on Direct Reduction of Carbon-bearing Pellets of Bayer Red Mud[J]. �й������ڿ���, 2015, 22(8): 686-693.
Dun-cheng FAN,Wen NI,Ai-yun YAN,Jian-yue WANG,Wei-hua CUI. Orthogonal Experiments on Direct Reduction of Carbon-bearing Pellets of Bayer Red Mud. Chinese Journal of Iron and Steel, 2015, 22(8): 686-693.
2015, Vol. 22 
