甘肃某镜铁矿尾矿磁化焙烧—弱磁选试验

甘肃某镜铁矿尾矿中尚含有22.39%的铁,且铁主要以镜铁矿形式存在,其次以菱铁矿形式存在。为了给该尾矿的综合利用提供技术支持,以甘肃某焦化厂生产的半焦化煤粉作为还原剂,对该尾矿进行了磁化焙烧—弱磁选工艺研究。结果表明:在煤粉与原尾矿的质量比为1.5%、温度为750℃的条件下磁化焙烧60 min,可使原尾矿中绝大部分的镜铁矿和菱铁矿转化为磁铁矿;焙烧矿磨至-0.074 mm占87.36%后经1次弱磁粗选和1次弱磁扫选—粗、扫选所得粗精矿按0.045 mm筛分—筛下物1次弱磁精选—精选精矿与筛上物合并,可以获得铁品位为54.57%、铁回收率为78.97%的最终铁精矿。

Magnetizing Roast-Low Intensity Magnetic Separation of a Specularite Tailing from Gansu

There are 22.39% iron in specularite tailing from Gansu.Iron mainly exists in form of specularite,and then siderite.In order to provide technical basis for comprehensive utilization of the tailing,the process of magnetizing roast-low intensity magnetic separation was carried out with half coking coal produced by a coking plant in Gansu Province as reductant.The results indicated that: with coal fines to raw tailings mass ratio of 1.5%,roasting at 750 ℃ for 60 min,most of specularite and siderite in tailings were converted to magnetite.With the roast product grinding at 87.36% passing 0.074 mm,and through the process of one rough low intensity magnetic separation,one scavenging low intensity magnetic separation,and mixed rough concentrate screened by 0.045 mm size,one cleaning low intensity magnetic separation for underflows,and concentrate mixed with the overflows,the iron concentrate with iron grade of 54.57% and recovery of 78.97% was achieved finally.