关键词: 白云鄂博铁矿尾矿, 悬浮焙烧, 过还原

Abstract: In order to recover iron ore from the tailings of Baiyun Obo Iron Mine， the high intensity magnetic separation preconcentration-suspension roasting-magnetic separation process was used to carry out the iron ore re-concentration test. The results show that the preconcentrated concentrate from tailings of Baiyun Obo Iron Mine with TFe grade of 14.10%， via the total gas volume of preconcentrated concentrate is 600 mL/min， in which the CO concentration is 15%， the roasting temperature is 800 ℃， and the roasting time is 5 min. After roasting， the particle size of the roasted product is d90=39.29 μm， and the magnetic field strength of the magnetic tube is 13.2 mT， the magnetic separation concentrate with TFe grade of 63.88% and total iron recovery of 57.25% can be obtained. The product analysis of each stage in the test shows that too high roasting temperature and too long roasting time will lead to excessive reduction. Meanwhile， the roasting process makes the hematite without cracks in the surface of preconcentrated concentrate change into magnetite with micro-cracks on the surface. The study can provide technical basis for the development and utilization of polymetallic co-associated iron ore resources.

Key words: Bayan Obo iron tailings, Suspension roasting, Excessive reduction