某微细嵌布贫赤铁矿石直接还原-弱磁选试验

湖南某赤铁矿石铁品位约27%，大部分铁矿物嵌布粒度在5 μm左右。对该矿石进行煤基直接还原-弱磁选试验研究，主要考察了还原温度、还原时间对还原效果的影响以及磨矿细度、磁场强度对弱磁选效果的影响。试验结果表明：将原矿压团后与烟煤（煤与矿的质量比为2∶1）在1 150 ℃下还原焙烧100 min，所得还原矿的金属化率为93.41%；还原矿磨至-0.043 mm占90.22%后在63.68 kA/m的磁场强度下经1次弱磁选，可获得铁品位为75.71%、金属化率为92.11%、铁回收率为91.12%的铁精矿。

Research of Superfine Low Grade Hematite by Coal-based Direct -Reduction-low Intensity Magnetic Separation

A hematite assay 27.2%Fe and most iron minerals occurr at 5 μm.Effects of various factors inducling reduction temperature,reduction time and grinding fineness on direct reduction-low intensity magnetic separation were discussed.The results show that iron ore concentrate assaying 75.71% Fe,metallization degree at 92.11% and iron recovery at 91.12% are obtained under the following conditions: the briquettes are reduced at 1 150 ℃ for 100 min(mass ratio of soft coal to briquettes is 2) and the reduced briquettes are separated at the grinding fineness of 90.22% less than 0.043 mm and field strength of 63.68 kA/m.