硫酸渣磁化焙烧过程中铁的转化规律及分离试验研究

采用磁化焙烧-磁选工艺回收硫酸渣中的铁,考察了焙烧温度、焙烧时间、煤粉用量以及磨矿细度等因素对铁精矿质量的影响,最终确定了焙烧温度750 ℃、焙烧时间50 min、还原剂煤粉用量8%为最佳焙烧条件。物相分析结果表明,磁化焙烧后硫酸渣中的铁主要以磁铁矿形式存在。焙烧矿磨矿细度为-0.045 mm粒级占87.31%时,采用一粗一扫闭路磁选工艺可获得铁品位65.58%、回收率96.99%的铁精矿,且精矿中的铁99%为磁性铁。

Reclaiming of Iron Resource from Sulfuric Acid Slag by Magnetizing Roasting-Magnetic Separation and Transformation of Iron Phase Therein

A flowsheet of magnetizing roasting-magnetic separation was introduced to reclaim iron resource from sulfuric acid slag. After analyzing the influence of processing factors such as roasting temperature, roasting time, dosage of anthracite and grinding fineness on the quality of iron concentrate, the best roasting conditions were determined, including roasting time of 50 min, roasting temperature of 750 ℃, and dosage of anthracite of 8%. The phase analysis shows that, after magnetizing roasting, the main iron mineral is magnetite. Using a closed-circuit magnetic separation with one stage of roughing and one stage of scavenging to treat the roasted product grinded to -0.045 mm 87.31%, the iron grade and recovery of the concentrate reached 65.58% and 96.99%, respectively, and magnetic iron in the concentrate accounted for 99% of the total iron resource.