低品位含钛磁铁矿氢还原-富钛分选的可行性分析

Feasibility analysis of hydrogen reduction-titanium-rich separation of low-grade titanium magnetite

钒钛磁铁矿是一种富含铁、钒、钛的特色矿产资源,综合利用价值高,由于类质同象及微细粒嵌布等因素影响,铁与钛难以实现高效分离并综合利用。结合钒钛磁铁矿自身矿物学特征和理论热力学计算,提出“氢还原-富钛分选”新方法来实现钛铁分离,通过铁氧化物和钛铁氧化异步还原,使得铁氧化物转化成金属铁,而钛铁氧化物基本不还原,利用铁矿物和钛铁矿物存在明显的磁性差异的特性实现高效分离。在本试验条件下,随着还原温度和还原时间的提高,钛回收率降低,铁回收率增加;较高的还原温度和较长的还原时间不利于实现钛铁同步分离。在还原温度为900℃、还原时间为50 min、还原气氛为30%H_(2)+70%Ar(体积分数)、磁选磁场强度电感为0.8 A的条件下,可获得TFe品位为78.32%、回收率为98.12%的铁精矿以及钛品位为20.92%、回收率为33.11%的富钛矿。化学成分分析、X射线衍射(XRD)分析和光学显微镜分析结果均表明钛铁矿物与铁矿物实现了有效的分离,钛在富钛矿中有效富集。最后,对磁选产物的综合利用提出了远景展望,一方面铁精矿可以为高炉或直接还原工艺生产提供原料,不仅可以降低生产成本和铁损,还可以缩短冶炼周期;另一方面,富钛矿可以制备高附加值的FeTi30合金,理论计算均满足要求。这为实现钒钛磁铁矿资源氢还原-富钛分选处理后产物综合利用提供了重要研究方向。

Vanadium-titanium magnetite is a characteristic mineral resource rich in iron,vanadium and titanium,which has high comprehensive utilization value.Due to isomorphism and micro-particle embedding,it is difficult to achieve efficient separation and comprehensive utilization of iron and titanium.Based on the mineralogical characteristics and thermodynamic calculation of vanadium-titanium magnetite,a new method of"hydrogen reductiontitanium-rich separation"is proposed to realize titanium-iron separation.Through asynchronous reduction of iron oxide and titanium-iron oxide,iron oxide is transformed into metal Fe,while titanium-iron oxide is basically not reduced,and iron minerals and ilmenite are separated efficiently due to obvious magnetic differences.Under the experimental conditions,with the increase of reduction temperature and time,the recovery rate of titanium decreases and the recovery rate of iron increases.The high reduction temperature and long reduction time are not conducive to the simultaneous separation of ferrotitanium and titanium.Under the conditions of reduction temperature of 900℃,reduction time of 50 min,reduction atmosphere of 30%H_(2)+70%Ar(volume percent),and magnetic field intensity inductance of 0.8 A,iron concentrate with TFe grade of 78.32%and recovery of 98.12%and titanium-rich ore with Ti grade of 20.92%and recovery of 33.11%can be obtained.The results of chemical composition analysis,Xray diffraction(XRD)analysis and optical microscope analysis all show that ilmenite is effectively separated from iron minerals,titanium is effectively enriched in perovskite-rich ore.Finally,the comprehensive utilization of magnetic separation products is prospected.On the one hand,iron concentrate can be produced by blast furnace or direct reduction process to provide raw materials,which can not only reduce production cost and iron loss,but also shorten smelting cycle.On the other hand,high value-added FeTi30 alloy can be prepared from titanium-rich ore,and the theoretical calculation meets the requirements.This provides an important research direction for realizing the com-prehensive utilization of products after hydrogen reduction-titanium-rich separation treatment of vanadium-titanium magnetite resources.