球磨机钢球球径制度对磨碎速率的影响研究

利用实验室Φ240×90锥形球磨机对-1.7+1.18 mm石灰石进行了批次磨矿试验,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钢球球径制度对磨矿速率的影响。单一球径钢球试验结果表明,大直径钢球对粗级别的磨碎速率相对较高,但对细粒级的磨碎速率衰减很快;小直径钢球对粗级别的磨碎速率较低,但对细粒级有较高的磨碎速率。采用两种球径配合的钢球制度,并以破碎分布函数作为钢球球径级配方案的依据,可综合单一球径钢球制度的优点,既保证粗粒矿石有较高的磨碎速率,又能保持对细粒级的磨碎速率衰减较慢。

Effect of Diameter Regime of Ball Charge on Grinding Rate in Ball Mill

Batch grinding tests were conducted for limestone with feed size of -1.7+1.18 mm using a laboratorial conical ball mill (Φ240×90). The effect of the ball size regime on grinding efficiency was investigated by a mass population balance model based on breakage rate function and breakage distribution function. The results of the single diameter ball charge showed that big steel balls could bring a higher breakage rate for the coarse size fraction, but a rapidly declined breakage rate for the fine size fraction. On the contrary, small balls brought a lower breakage rate for the coarse size fraction, but a comparatively high breakage rate for the fine size fraction.  It is concluded that  when adopting a regime of two kinds of balls with a size distribution referring to the breakage distribution function, high breakage rate for coarse size fraction and slow attenuation of breakage rate for fine size fraction can be both ensured.