ABSTRACT

As higher-grade ores become depleted, there will be a greater focus on developing suitable beneficiation strategies to treat low-grade hematite-goethite ores containing higher levels of impurities such as silica and alumina. The processes selected to reduce impurity levels of these lower-grade iron ores will depend on the ore mineralogy and a thorough understanding of the separation process dynamics. The major concentration methods that may be applied to upgrade lower-grade lump iron ores include magnetic separation, wet and dry heavy media separation, and air-pulsed jigging. The technologies applicable to beneficiating iron ore fines include wet and dry gravity and magnetic separation, flotation, and roasting followed by magnetic separation. A commercial flowsheet is expected to involve the implementation of several of these separation technologies. Here the performance of different separation technologies, their testing methodologies, and difficulties in removing silica and alumina from low-grade iron ores are reviewed.

摘要

随着高品位矿石的枯竭，将更加注重开发合适的选矿策略来处理含有较高杂质（如二氧化硅和氧化铝）的低品位赤铁矿-针铁矿。为降低这些低品位铁矿石的杂质水平而选择的工艺将取决于矿石矿物学和对分离过程动力学的透彻了解。可用于提升低品位块状铁矿石的主要选矿方法包括磁选、干湿重介质分离和空气脉冲跳汰。适用于铁精粉选矿的技术包括干湿重磁选、浮选、焙烧后磁选。预计商业流程图将涉及其中几种分离技术的实施。本文回顾了不同分离技术的性能、它们的测试方法以及从低品位铁矿石中去除二氧化硅和氧化铝的困难。