混合稀土精矿还原焙烧磁选工艺研究

Study on Reduction Roast and Magnetic Separation Process of Mixed Rare Earth Concentrate

利用还原焙烧技术将内蒙古某混合稀土精矿中铁矿物还原为金属单质,经过磁选分离实现了铁与稀土、铌等元素的高效分离及富集。通过单因素实验考察了还原温度、焙烧时间、配碳量条件对还原焙烧效果的影响,以及不同焙烧温度下稀土和铌富集、回收的情况。在焙烧温度1175℃,焙烧时间90 min,配碳量C/O为1.5的优化条件下,铁金属化率达到92.52%,磁性物中铁品位为89.71%,铁回收率为92.12%,而非磁性物中铌品位及回收率为3.85%和87.92%;稀土品位及回收率达到7.15%和88.23%。

The reduction roasting technology was used to reduce the iron minerals in a mixed rare earth concentrate from Inner Mongolia to elemental metals,and then the magnetic separation technology was used for high efficient separation and enrichment of iron,rare earth,niobium and other elements.The effects of reduction temperature,roasting time and carbon content on the reduction roasting were investigated by single factor experiments,as well as the enrichment and recovery of rare earth and niobium at different roasting temperatures.Under the optimized conditions of roasting temperature of 1175℃,roasting time of 90 min and C/O ratio of 1.5,the iron metallization rate reaches 92.52%,the iron grade and recovery rate in magnetic materials are 89.71%and 92.12%,the niobium grade and recovery rate in non-magnetic materia-ls are 3.85%and 87.92%,and the rare earth grade and recovery rate are 7.15%and 88.23%,respectively.