白云鄂博稀土矿物浮选粒度变化规律分析

Analysis on Particle Size Change Law in the Flotation of Rare Earth Minerals in Bayan Obo

对全粒级的白云鄂博稀土原矿与65%稀土精矿进行了批次浮选试验,并分析计算了原矿浮选各间隔时间内精矿的品位和回收率,同时对全粒级的白云鄂博稀土原矿与平均粒径为10,20和30μm的窄粒级65%精矿进行了多级浮选试验,并对不同粒度下的矿物颗粒进行了流体动力学分析。批次浮选试验结果表明,随着浮选时间的延长,各间隔浮选精矿的粒度变细、粒级变窄且原矿浮选精矿的品位和回收率逐渐降低;多级浮选试验结果表明,当浮选时间定为4min时,随着精选次数的增加,颗粒粒级逐渐增大,说明细粒的稀土矿物由于浮选速率较慢,没有得到有效的回收。由流体动力学碰撞-粘附概率分析可知,20μm左右的颗粒浮选速率快,<10μm的颗粒浮选速率低。综合得出结论:采用XFD浮选机浮选时,需要适当延长浮选时间才能够实现对细粒稀土矿物的有效富集。

In this paper,the batch flotation test was carried out on the full-grained rare earth ore and 65%rare earth concentrate in Bayan Obo,and the grade and recovery rate of the concentrate in each interval of the ore flotation were analyzed and calculated.Then,the multi-stage flotation tests were carried out on the full-grained rare earth ore and the narrow-grained 65%concentrate with average particle sizes of 10,20 and 30μm in Bayan Obo.And the mineral particles under different particle sizes were subject to fluid dynamics analysis.The results of batch flotation test showed that,with the extension of flotation time,the particle size of flotation concentrate in each stage became finer,the grain size became narrower,and the grade and recovery rate of ore flotation concentrate gradually decreased.The results of multi-stage flotation test showed that,when the flotation time was set to 4 min,the particle size increased with the increase of the selection times,and the grain size became narrower.Itwas indicated that the fine-grained rare earth minerals had a slow flotation rate and had not been effectively recovered.According to the fluid dynamics analysis on collision-adhesion probability,it was found that the flotation rate of particle with sizes of 20μm was high,and that of<10μm was low.It was concluded that properly prolonging the flotation time can achieve an effective enrichment of fine-grained rare earth minerals when XFD flotation machine was used.