海砂矿球磨微观解离与细粒级磁选受力分析

为拓宽铁矿石来源,提高海砂品位以应用于长流程炼铁系统,对一种印尼海砂矿进行了球磨磁选实验,并利用X射线衍射(XRD)、扫描电镜(SEM)以及激光粒度分析(LPSA)等方法,研究了其在不同球磨阶段的微观解离特点、粒度与磁感应强度对精矿品位与回收率的影响以及细粒级下磁选过程中的受力机理.结果表明:球磨至一定阶段后,矿石粒度已较小,连生体基本以包裹体形式存在,很难继续解离,故此时继续降低矿石粒度对精矿品位的提升意义不大;另外,当矿石较细时,水阻力将成为磁选过程中的主要作用力,细粒级矿粒将不能到达磁鼓表面,故此时精矿回收率较低.

Ball-Milling Micro-dissociation of Ironsand and Magnetic Force at Fine Level

To broaden the iron ore sources and raise the grade of ironsand for long process ironmaking system， the ball-milling and magnetic separation were conducted on a ironsand from Indonesia. The analysis methods of X-ray diffraction (XRD)， scanning electron microscopy (SEM)， and laser particle size analyzer (LPSA) were used to investigate the micro-dissociation characteristics in different ball-milling stages， the influence of particle size and magnetic induction intensity on the concentrate grade and recovery and the force mechanism of fine ironsand in the process of magnetic separation. After the ball-milling to a certain stage， the granularity of ironsand is small and the locked mineral is in the form of inclusions which is hard to continue to disintegrate. Therefore， it makes little sense to reduce the ironsand granularity for the promotion of concentrate grade. In addition， when the ore is fine， water resistance will become the main force in the process of magnetic separation and the fine particles will not be able to reach the surface of the drum， and lead to a lower concentrate recovery rate.