球磨-细筛回路循环负荷对磨矿过程参数的影响研究

The Effects of Circulating Load of Ball Mill-fine Screen Loop on Grinding Process Parameters

考察了球磨-细筛回路不同循环负荷下磨矿产品粒度、磨机总给矿粒度及磨矿过程参数的变化,为生产上调整循环负荷,优化磨矿产品粒度提供了理论依据。通过控制钨矿石球磨-细筛回路的磨矿时间来改变循环负荷量,而后对闭路磨矿平衡条件下磨机总给矿开展批次磨矿试验,并基于破碎速率函数与破碎分布函数的总体平衡模型讨论了磨矿过程参数的变化。试验及分析结果表明:随着循环负荷的提高,磨机总给矿粒度趋于变细;破碎分布函数中细粒级权重及变化率都趋于减小,粗粒级权重及变化率则趋于增加;各粒级的破碎速率趋于降低,且变化幅度都逐渐减小。研究结果表明提高循环负荷会降低磨机总给矿粒度,降低各粒级磨矿速率,但有利于减少磨矿产品中细粒级的产生,有助于减轻过粉碎,降低过粉碎粒级的钨品位及金属分布率,提高磨矿产品质量。

The changes of the particle size of grinding products,the total feeding particle size of the mill and the parameters of grinding process were investigated under different cyclic loads in the ball milling-fine screen circuit,which provided a theoretical basis for adjusting the cyclic load and optimizing the particle size of the grinding product in production.Taking a tungsten ore as raw material,and the cyclic load was changed by controlling the grinding time of ball milling-fine screen circuit,and then the batch grinding tests were carried out on the total feed of the mill under the closed-circuit grinding balance condition,and the changes in the parameters of the grinding process were discussed based on the mass population balance model of the crushing rate function and the crushing distribution function.The test and analysis results show that with the increase of the cyclic load,the total feeding grain size tends to become finer.In the crushing distribution function,the weight and change rate of the fine particle tend to decrease,while the weight and change rate of the coarse particle tend to increase.The crushing rate of each particle size tends to decrease,and the variation range is gradually reduced.The results show that increasing the cyclic load can reduce the total feeding grain size of the mill and reduce the grinding rate of each grain size,but it is beneficial to reduce the generation of fine particles in the grinding products,reduce the over-grinding,reduce the tungsten grade and metal distribution rate of over-grinding grain size,and improve the quality of grinding products.