高铁赤泥悬浮磁化焙烧-弱磁选提铁工艺

Recovery Process of Iron from High-Iron Red Mud Through Suspension Magnetization Roasting-Low Intensity Magnetic Separation Technology

高铁赤泥中的铁含量较多,是一种潜在的铁矿资源.因此,研发创新性工艺和技术以实现赤泥中铁的回收利用和赤泥减量很有必要.针对拜耳法高铁赤泥,制定了悬浮磁化焙烧-弱磁选的工艺流程,并研究了焙烧温度、焙烧时间、还原气CO浓度和总气量对磁化焙烧效果的影响.结果表明,在最佳焙烧条件下,焙烧矿经过弱磁选别,可获得磁选精矿TFe品位为56.40%,回收率为88.46%的指标.通过对原料和焙烧产品的XRD分析、铁的化学物相分析、SEM-EDS分析和VSM分析可知,赤泥中的弱磁性的赤铁矿在磁化焙烧过程中被还原成了强磁性的磁铁矿.

High-iron red mud contains a lot of iron,which is a potential iron ore resource.Therefore,it is of great significance to develop innovative processes and technologies to realize the recycling of iron in red mud,and at the same time to achieve red mud reduction.A novel process of suspension magnetization roasting-low intensity magnetic separation was developed for the Bayer high-iron red mud.The effects of roasting temperature,roasting time,reducing gas CO concentration and total gas volume on the magnetization roasting effect were studied.The experiment results show that the desired indexes with iron grade of 56.40%and recovery of 88.46%were obtained from the roasted ore after the low intensity magnetic separation under the optimal roasting conditions.The results of XRD analysis,chemical phase analysis of iron,SEM-EDS analysis and VSM analysis indicate that hematite phase present in the raw material was transformed into magnetite phase during the suspension magnetization roasting process.