鲕状赤铁矿的磁化焙烧特性与转化过程分析  

Characteristics of magnetic roasting and analysis of phase transformation process of oolitic iron ore

作　　者：罗立群[1,2] 陈敏[1,2] 杨铖[1,2] 徐俊[1,2] 刘斌[1,2] 

机构地区：[1]武汉理工大学资源与环境工程学院,湖北武汉430070 [2]武汉理工大学矿物资源加工与环境湖北省重点实验室,湖北武汉430070

出　　处：《中南大学学报（自然科学版）》2015年第1期6-13,共8页Journal of Central South University:Science and Technology

基　　金：国家"十二五"科技支撑计划项目(2013BAB03B03);武汉理工大学本科生创新计划团队项目(126708001)~~

摘　　要：以鄂西某鲕状赤铁矿为研究对象,考察焙烧温度、焙烧时间和物料粒度等因素对磁化焙烧效果的影响,利用X线衍射（XRD）定量分析技术,结合显微镜下观察统计等手段,探讨鲕状赤铁矿物的磁化焙烧特性、相态转化及焙烧变化规律。研究结果表明：含铁鲕粒多数由粒径为1~2μm的致密同心外形壳和10μm的多孔状、似针铁矿的小颗粒包裹而成,中间夹带有黏土状的高岭石;对含铁（TFe）49.02%的鲕状赤铁矿,在800℃和60 min的焙烧条件下获得含铁为56.74%,铁回收率为95.54%的较优结果,物料粒度对磁化焙烧矿的质量有较大影响。当温度≤800℃时,很少发生过还原生成Fe O和Fe2Si O4,但含磷与含硅矿物均有相变;当温度为900℃时,生成Fe O的质量分数达23.61%,形成弱磁性的Fe3O4-Fe O固熔体,不利于焙烧矿的弱磁选分离。磁化焙烧过程仅改变铁相,而鲕粒结构未变,磁化还原由表及里受扩散作用控制,与鲕粒粒径和致密度密切相关。Magnetic roasting accompanied by different temperatures, roasting time and samples＇ particles were carried out for the beneficiation of an oolitic iron ore in west of Hubei Province. Characteristics of magnetic roasting, iron minerals＇ phase transformation and their composition variation on oolitic iron ore were investigated using X-ray diffraction（XRD） quantitative analysis, combining microscope observation with roasting particles statistics data. The results indicate that mineral particles containing iron are mainly composed of different oolitic concentric shells from 1 μm to 2 μm and closely enwrapped by tiny particles about 10 μm and porous, like goethite sandwiching clayey kaolinite. An iron ore concentrate with total iron content of 56.74% at a recovery rate of 95.54% can be obtained, performed at 800 ℃for 60 min under a little of reduction atmosphere condition and iron content of 49.02% to raw sample. Meanwhile, it strongly influences magnetic roasting processing by particle size of samples. The phase transformation of wuestite Fe O and iron silicate Fe2 Si O4 is hardly formed below 800 ℃ and the traces of those minerals transformation of contenting phosphorus and silicon may be detected. At 900 ℃, the formation of wuestite Fe O is experimentally confirmed up to 23.61%, forming weakly magnetically solidified-melted mixture Fe3O4-Fe O and making against weakly magnetic separation after magnetic roasting samples. Magnetic roasting processing of oolitic iron ore can achieve iron phase transformation and the configuration of oolitic particles does not change. Magnetization transformation is mainly controlled by chemical diffusion from surface to interior in turn and has compact relation of oolitic particles＇ size and porosity.

关 键 词：鲕状赤铁矿 磁化焙烧 XRD定量分析 相态变化 

分 类 号：TD92[矿业工程—选矿] TD924