海砂矿深度还原--磁选分离实验研究

Experimental research on the deep reduction-magnetic separation of ironsand

应用化学分析、扫描电镜观察和X射线衍射分析方法研究海砂矿的基础物性.采用煤基深度还原-磁选工艺,系统考察矿粉中Fe和Ti的还原分离行为,并明确还原温度、还原时间、碳氧比、磁感应强度和磨矿粒度对还原磁选效果的影响规律.结果表明:海砂矿主要由钛磁铁矿和钛赤铁矿组成;较优的还原分离工艺参数为还原温度1300℃、还原时间30 min、碳氧摩尔比1.1、磁感应强度50 mT和磨矿细度-0.074 mm质量分数86.34%.在此工艺条件下,可以获得金属化率94.23%的还原产物,磁选指标分别达到精矿铁品位97.19%和尾矿钛品位57.94%,对应的铁、钛回收率为90.28%和87.22%,有效地实现海砂矿中铁钛元素的分离富集.

The basic characteristics of ironsand were systematically studied by chemical analysis, scanning electron microscopy and X-ray diffraction. A series of experiments were performed to investigate reduction-magnetic separation for Fe and Ti from iron- sand. The effects of reduction temperature, reduction time, carbon ratio, magnetic density, and grinding fineness on the reduction- magnetic separation process were investigated. It could be found that the ironsand mainly consisted of titanomagnetite and titanohema- tite. The optimal process parameters were obtained as follows： reduction temperature, 1300 ℃ ; reduction time, 30 min; C/O molar ratio, 1.1; magnetic density, 50 mT; and the grinding fineness of -0. 074 μm, 86. 34%. Under such conditions, the metallization rate, the iron grade of magnetic substance and the iron recovery reached to 94.23%, 97.19% and 90. 28%, respectively, and the titanium grade of non-magnetic substance and the titanium recovery were 57. 94% and 87.22% , respectively. The effective separation of iron and titanium could be achieved in this reduction-magnetic separation process.