东鞍山含碳酸盐铁矿石悬浮磁化焙烧试验

介绍了一种半工业试验用悬浮焙烧设备，并考察了焙烧温度、还原气体CO及流化气体N₂用量对东鞍山含碳酸盐铁矿石预富集粗精矿悬浮焙烧效果的影响.试验结果表明，在焙烧温度540℃，还原气体CO用量4m³/h及流化气体N₂用量2m³/h的条件下，焙烧物料经磨矿-磁选后可获得铁品位66.1%，回收率91.2%的铁精矿.铁的化学物相、光学显微结构及穆斯堡尔谱分析表明，经悬浮焙烧后弱磁性的菱铁矿和赤铁矿转化为了强磁性的磁铁矿，部分结晶粒度较粗(>100μm)的赤铁矿仅颗粒表面转变为磁铁矿，但这种Fe₂O₃@Fe₃O₄核壳结构的新生磁铁矿由于磁性较强，在后续磁选过程中依然能够得到有效的回收，并不会影响分选效果.

Test on Fluidized Magnetization Roasting of Donganshan Carbonate-Bearing Iron Ore

A pilot-scale fluidized magnetization roasting reactor was introduced and used to study the effects of roasting temperature， flow rates of reducing gas CO and fluidizing gas N₂ on magnetization roasting performance of the pre-concentrate from Donganshan iron ore. The results show that a high-grade ground magnetic concentrate of 66.1% iron with an iron recovery of 91.2% can be obtained from the pre-concentrate after roasting at 540℃ with a gas mixture of CO 4m³/h and N₂ 2m³/h. The iron chemical phase， optical microstructure， and Mossbauer spectrum analyses indicate that weakly magnetic siderite and hematite can be converted to ferromagnetic magnetite successfully. The coarse hematite particles(＞100μm) partly transformed into magnetite， while such particles with a Fe₂O₃@Fe₃O₄ core-shell structure can also be effectively recovered by subsequent magnetic separation after liberating from gangue minerals due to their strong magnetism.