A great amount of red mud generated from alumina production by Bayer process not only threatens the environment but also causes waste of secondary resources.High-iron-content red mud from Bayer process was employed to...A great amount of red mud generated from alumina production by Bayer process not only threatens the environment but also causes waste of secondary resources.High-iron-content red mud from Bayer process was employed to recover alumina and ferric oxide by the process of reduction-sintering,leaching and then magnetic beneficiation.Results of thermodynamic analyses show that ferric oxide should be reduced to Fe if reduction of ferric oxide and formation of sodium aluminate and calcium silicate happen simultaneously.Experimental results indicate that alumina recovery of Bayer red mud can reach 89.71%,and Fe recovery rate and the grade of magnetite concentrate are 60.67%and 61.78%,respectively,under the optimized sintering conditions.展开更多
FeCe nanocomposite catalysts with different iron contents were synthesized by a facile co-precipitation method.The as-prepared materials were characterized by various techniques including powder X-ray diffraction(XRD)...FeCe nanocomposite catalysts with different iron contents were synthesized by a facile co-precipitation method.The as-prepared materials were characterized by various techniques including powder X-ray diffraction(XRD),N2 adsorption/desorption and high-resolution transmission electron microscopy(HRTEM).Catalyst with the highest iron content(90 FeCe) shows the best activity for the hydrogen generation via ammonia decomposition.83% NH3 conversion is achieved at 550℃ and nearly full conversion of NH3 is realized at 600℃ with a GHSV of 24000 cm3/(gcat·h).The large content and small size crystal particles of iron species are responsible for the good catalytic performance.Temperatureprogrammed reduction by hydrogen(H2-TPR) was performed to investigate the interaction between cerium and iron species.It is found that slight cerium can exert strong interaction with iron compound thus effectively prevent the self-aggregation of active iron species,so as to improve the catalytic activity for ammonia decomposition.展开更多
基金Project(2005CB623702)supported by the National Basic Research Program of China
文摘A great amount of red mud generated from alumina production by Bayer process not only threatens the environment but also causes waste of secondary resources.High-iron-content red mud from Bayer process was employed to recover alumina and ferric oxide by the process of reduction-sintering,leaching and then magnetic beneficiation.Results of thermodynamic analyses show that ferric oxide should be reduced to Fe if reduction of ferric oxide and formation of sodium aluminate and calcium silicate happen simultaneously.Experimental results indicate that alumina recovery of Bayer red mud can reach 89.71%,and Fe recovery rate and the grade of magnetite concentrate are 60.67%and 61.78%,respectively,under the optimized sintering conditions.
基金Project supported by the Natural Science Foundation of Jiangsu Province (BK20170232,BK20170238)National Natural Science Foundation of China (51908256)。
文摘FeCe nanocomposite catalysts with different iron contents were synthesized by a facile co-precipitation method.The as-prepared materials were characterized by various techniques including powder X-ray diffraction(XRD),N2 adsorption/desorption and high-resolution transmission electron microscopy(HRTEM).Catalyst with the highest iron content(90 FeCe) shows the best activity for the hydrogen generation via ammonia decomposition.83% NH3 conversion is achieved at 550℃ and nearly full conversion of NH3 is realized at 600℃ with a GHSV of 24000 cm3/(gcat·h).The large content and small size crystal particles of iron species are responsible for the good catalytic performance.Temperatureprogrammed reduction by hydrogen(H2-TPR) was performed to investigate the interaction between cerium and iron species.It is found that slight cerium can exert strong interaction with iron compound thus effectively prevent the self-aggregation of active iron species,so as to improve the catalytic activity for ammonia decomposition.
