Effect of fluidized magnetizing roasting on iron recovery and transformation of weakly magnetic iron mineral phase in iron tailings
Wenbo Li 1, 2,   Yuexin Han 1  
,   Xiao Liu 1,   Yan Shan 1,   Yanjun Li 1
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School of Resource and Civil Engineering, Northeastern University
State Key Laboratory of Mineral Processing, Beijing 102628, PR China.
Yuexin Han   

School of Resource and Civil Engineering, Northeastern University
Publication date: 2019-05-27
Physicochem. Probl. Miner. Process. 2019;55(4):906–916
The eastern tailings of the Anshan mining area are generally categorized as high silicon-bearing iron tailings, and the iron mainly exists in the form of hematite–limonite with an iron grade of 10.60%. In order to recover iron minerals and reduce the influence of the tailings on the environment, a method for pre-enrichment through the combination of low intensity magnetic separation and high intensity magnetic separation with fluidized magnetizing roasting and subsequent low intensity magnetic separation was developed to treat the eastern tailings of the Anshan mining area. The effects of gas-flow rate, H2 concentration, roasting temperature, and roasting time on the quality of the final iron concentrate were discussed. Moreover, the iron phase transformation and change in magnetism of the sample were studied. The results indicated that an iron concentrate with an iron grade of 65.30% and a recovery of 85.85% could be obtained under the conditions of gas-flow rate of 8 m3/h, H2 concentration of 50%, and fluidized magnetizing roasting at 600 ℃ for 20 s. X-ray diffraction analysis, phase analysis, and magnetism analysis on the roasted materials indicated that the hematite–limonite could be transformed into magnetite during the fluidized magnetizing roasting process, and effective separation of iron and gangues could be easily achieved by the weak magnetic separation.