还原剂组分对高磷鲕状赤铁矿直接还原效果的影响

分别以活性炭、焦炭、无烟煤1和褐煤为还原剂，并添加混合钠盐脱磷剂，通过直接还原焙烧-磨矿-弱磁选对鄂西高磷鲕状赤铁矿石进行提铁降磷试验，发现灰分、固定碳和挥发分3种组分含量的不同导致4种还原剂对所获直接还原铁指标（铁品位、铁回收率、磷含量）的影响也不相同，但由于还原剂中3种组分的影响相互交织在一起，因而较难分别归纳出各组分对直接还原铁指标的影响规律。为此，又引入另6种还原剂，采取将不同单一还原剂进行复配，使复配还原剂只有1种组分的含量发生改变的方法进行了进一步研究，结果表明：还原剂中挥发分的含量较高有利于提高直接还原铁的铁回收率，但对直接还原铁的铁品位和磷含量有不利影响；还原剂中固定碳的含量较高也有利于提高所获直接还原铁的铁回收率而对直接还原铁的铁品位影响不大，但对降磷不利；还原剂灰分含量过高对直接还原铁的铁品位、铁回收率和磷含量都有不利影响。以上研究成果为采用直接还原焙烧-弱磁选工艺对高磷鲕状赤铁矿石进行提铁降磷时合适还原剂的选择提供了有益的参考。

Effects of Components of Reductants on Direct Reduction of High-phosphorus Oolitic Hematite

With activated carbon，coke，anthracite 1，and lignite as reductants，and with the addition of mixed sodium salts dephosphorization agent，through the direct reduction roasting-grinding-low intensity magnetic separation process，the experiment of iron increase and phosphorus removal for high-phosphorus oolitic hematite from Western Hubei Province was carried out.It is found that three components of ash，fixed carbon and volatile content in different lead to the different effect of four kinds of reductants on the obtained direct reduction iron(DRI) indexes(iron grade，iron recovery，and phosphorus content).However，due to the influence of three components in reductants is intertwined together，it is difficult to summarize respectively the influence law of each component on DRI index.Therefore，other 6 kinds of reductants were introduced.Through the blending of different single reductants，and the blended reductants has only one component changed，the further research was conducted.The results indicated that the reductants with higher volatile are beneficial to increasing iron recovery，but not beneficial to iron grade and phosphorus content.The reductants with higher fixed carbon are beneficial to iron recovery，and have little effect on iron grade，but not favorable for phosphorus removal.The reductants with over high ash are not benefit to iron grade，iron recovery，and phosphorus content.The above research results provide valuable references to selecting suitable reductants for iron increase and phosphorus removal by direct reduction roasting and low intensity magnetic separation technology for high phosphorus oolitic hematite.