内蒙古大坝沟超贫磁铁矿石选矿试验

内蒙古大坝沟超贫磁铁矿石铁品位仅15.68%，且有21.81%的铁以硅酸铁形式存在，同时有少量磁铁矿因呈微细粒包裹于石榴石、黑云母中而难以解离。为了给该矿石的开发利用提供依据，对其进行了选矿工艺研究。结果表明：采用块矿干选-闭路高压辊磨-粉矿干选抛尾工艺处理该超贫磁铁矿石，可以预先抛除产率达54.16%、铁品位为7.71%的合格尾矿，从而使矿石铁品位由15.72%提高到25.19%，而磁性铁损失率仅4.68%；预选精矿经阶段磨矿-细筛分级-阶段弱磁选，可以获得铁品位为65.52%、作业铁回收率为78.14%的合格铁精矿，其对原矿的铁回收率为57.39%。

Beneficiation Tests on Ultra Low Grade Magnetite Ore from Dabagou in Inner Mongolia

An ultra low grade magnetite from Dabagou, Inner Mongolia only contains iron grade of 15.68%, and 21.81% iron exists in form of ferric metasilicate.Meanwhile few fine magnetite grains are parceled in garnet and biotite, so it is hard to liberate.Beneficiation tests were carried out in order to provide basis for developing the ore.The results showed that iron tailing with production rate of 54.16% and iron grade of 7.71% was discarded by dry separation of lump ores, closed-circuit high pressure roller mill, and dry separation of fine ores, which increased iron grade from 15.72% to 25.19% with only 4.68% of magnetic iron lost.Iron concentrate with iron grade of 65.52%, total Fe recovery of 57.39% and Fe recovery of 78.14% was received by dealing with primary concentrate through the process of stage grinding, fine screen classification and stage low intensity magnetic separation.