梅山铁矿弱磁精矿品位影响因素分析与提质降杂试验研究

Analysis of Influence Factors on Low Intensity Magnetic Concentrate in Meishan Iron Mine and Experimental Study on Quality Improvement and Impurity Reduction

针对梅山铁矿弱磁精矿品位低的问题,采用矿物解离分析仪测定了矿样中各矿物的含量和铁矿物的嵌布粒度。研究结果表明:弱磁精矿中含有8.184%的低品位菱铁矿;磨矿产品均匀性不够且磨矿分级效率较差,同时存在过磨和欠磨现象,粗粒级中与以石英为主的硅酸盐矿物连生体多;梅山铁矿1粗1扫弱磁选别工艺存在缺陷,没有弱磁精选作业,选别过程中磁性矿物机械夹杂严重,较多的单体硅酸盐矿物进入弱磁精矿。通过采用细磨弱磁1粗1扫、1中磁立环高梯度扫选工艺,利用梅山铁矿现有磁选生产流程工业试验,在弱磁给矿铁品位为48.56%时,精矿产率为60.79%、铁品位为64.17%、回收率为80.33%、SiO_2含量为2.58%,细磨提铁降硅效果明显,得到了铁品位63%以上的球团铁精矿。

Aiming at the low grade of low intensity magnetic concentrate in Meishan iron mine, by the mineral liberation analyser （MLA） , Contents of various minerals in sample ore and iron minerals dis- seminated grain size were determined. The research resuhs showed that low intensity magnetic concentrate contained 8. 184% siderite with low grade; grinding products uniformity was insufficient and grinding effi- ciency was poorer. Over grinding and less grinding phenomenon existed at the same time, the major sili- cate mineral intergrowth consisted of quartz primarily in coarse particles; One roughing- one scavenging low intensity magnetic process without low intensity magnetic cleaning had defects in Meishan iron mine, and the mechanical entrainment of magnetic minerals was serious in selection process, more monomer sili- cate minerals entered low intensity magnetic concentrate. Utilizing actual magnetic separation production flow chart industrial experiment in Meishan iron mine, under low intensity magnetic feeding with iron grade of 48.56% , iron concentrate with yield of 60.79% , iron grade of 64.17% , recovery rate of 80. 33% and containing 2.58% SiO2 was obtained via fine grinding low intensity magnetic one roughing- one scavenging-one medium intensity magnetic scavenging by vertical ring high gradient process. The effect of fine grinding iron improvement and silicon reduction was obvious and pellets of iron concentrate with iron grade of more than 63% could be produced.