隐晶质鲕状赤铁矿磁化焙烧过程中铁物相转变规律  

Iron phase transformation law of cryptocrystalline oolitic hematite during magnetization roasting

作　　者：张汉泉[1] 张鹏飞 许鑫 杨帆[1] 朱健 路漫漫[1] ZHANG Hanquan;ZHANG Pengfei;XU Xin;YANG Fan;ZHU Jian;LU Manman(School of Resources and Safety Engineering,Wuhan Institute of Technology,Wuhan 430074,Hubei,China)

机构地区：[1]武汉工程大学资源与安全工程学院,湖北武汉430074

出　　处：《钢铁研究学报》2022年第10期1057-1066,共10页Journal of Iron and Steel Research

基　　金：国家自然科学基金资助项目(51974204,51474161);武汉工程大学第十二届研究生教育创新基金资助项目(CX2020362)。

摘　　要：鲕状赤铁矿具有含磷高、易泥化,铁与脉石矿物呈鲕状嵌布结构等特点,常规的重选和浮选等工艺难以取得较好的选矿指标。磁化焙烧-磁选工艺是利用高磷鲕状赤铁矿最有效的手段之一。X射线衍射(XRD)分析结果表明,在750℃的条件下,焙烧矿中磁铁矿的相对质量分数最大。焙烧温度高于800℃会发生过还原现象,生成富氏体,不利于焙烧矿的弱磁选。光学显微镜分析表明磁化焙烧过程不会破坏鲕状赤铁矿的鲕粒结构,只发生铁物相的转变。赤铁矿到磁铁矿的晶型转变由表及里,但是多数鲕状赤铁矿颗粒不会完全磁化,磁化焙烧效果与粒度有关。全铁品位为43.74%的矿样,在焙烧温度750℃、焙烧时间60 min的条件下,弱磁选可得到全铁品位为55.42%,铁回收率为85.66%的人工磁铁矿,磁铁矿转化率在90%以上。It is difficult to obtain good beneficiation indexes by conventional gravity separation and flotation processes due to the characteristics of high phosphorus content, easy argillization, and oolitic structure of iron and gangue minerals of oolitic hematite. The magnetization roasting-magnetic separation technology is one of the most useful methods for utilizing the high-phosphorus oolitic hematite. The X-ray diffraction analysis results show that the relative mass fraction of magnetite in the roasted ore under the condition of 750 ℃ is the most. When the roasting temperature was higher than 800 ℃, the hematite would be over-reduced, which is not conducive to the magnetic separation of roasted ore. The optical microscope analysis indicates that the magnetization roasting will not destroy the oolitic structure of oolitic hematite, and only the transformation of iron phase occurs. The crystal transformation from hematite to magnetite occurred from surface to inside, but the most oolitic hematite particles will be not completely magnetized, and the effect of magnetization roasting is related to the particle size. For the ore sample with a total iron grade of 43.74%, under the roasting temperature of 750 ℃ and roasting time of 60 min, the weak magnetic separation can obtain an artificial magnetite with a total iron grade of 55.42% and an iron recovery of 85.66%, and the conversion rate of magnetite is more than 90%.

关 键 词：鲕状赤铁矿 磁化焙烧 铁物相 磁选 

分 类 号：TD951[矿业工程—选矿]