某鲕状赤褐铁矿流化床磁化焙烧-磁选工艺

采用流化床反应器作为磁化焙烧装置,以高纯N2和CO混合气体作为还原气体,考察了550~800℃下,云南某地区的鲕状赤褐铁矿磁化焙烧-磁选的影响因素. 结果表明,未经过预处理的矿粉采用磁化焙烧-磁选分离,精矿中铁品位可提高至约55%,铁回收率<70%;经过预处理的矿粉,精矿中铁品位可提高至60.18%,铁回收率达85.91%. 预处理矿粉形成了多孔疏松结构,使还原气体易进入铁矿颗粒内部,有利于Fe3O4生成,提高了磁选指标.     

Separation and recovery of iron from a low-grade carbonate-bearing iron ore using magnetizing roasting followed by magnetic separation

In this study, a process of magnetizing roasting followed by low-intensity magnetic separation (MR-LMS), which is used to separate and recover iron from a low-grade carbonate-bearing iron ore (containing 34.6 wt.% Fe), was investigated. A magnetic concentrate containing 65.4 wt.% Fe with an iron recovery rate of 92.6 wt.% was obtained under optimal conditions: roasting temperature of 800°C, roasting time of 8 min, bitumite ratio of 10:100, grinding fineness of around 85 wt.% passing 38 µm, and magnetic intensity of 0.12 T. In addition, the phase transformation and magnetic properties were analyzed by X-ray diffraction (XRD) and vibrating sample magnetometry (VSM) to reveal the mechanism.