基于施-Kojovic模型的煤冲击破碎试验研究

Experiment Study on Impact Crushing of Coal Based on S-Kojovic Model

介绍了用于模拟矿物单位破碎能量与粒度减小程度之间关系的施-Kojovic模型,并用该模型对3种澳大利亚煤样的落重锤破碎、旋转破碎和床层破碎等3种冲击破碎方式进行了试验研究。结果表明,施-Kojovic模型能够很好地模拟煤的多种冲击破碎过程,其决定系数R2平均值可达0.975。在床层破碎中,使煤发生破碎首先需要克服平均为253.20 J/kg的最小单位破碎能量,而在其他2种破碎方式下,最小单位破碎能量的值可以忽略不计。冲击破碎中煤样所能达到的最大粒度减小程度和破碎效率与其破碎方式有关,两者由大到小的顺序均为旋转破碎、落重锤破碎和床层破碎。另外,受高灰矿物质助磨作用的影响,在床层破碎中同一种煤的硬度随灰分的增高而减小。

The paper introduced the S-Kojovic model to simulate the relationship between the unit crushing energy of the mineral and the particle size reduced. The model was applied to the experiment study on the three impact crushing methods of three Australia coal sam- ples, including the hammer drop crushing, rotary crushing and bed crushing. The study results showed that the S-Kojovic model could be well to simulate several impact crashing processes of coal and the related coefficient R2 average value could reach 0. 975. In the bed crush- ing, coal crushing firstly should overcome a min unit crushing energy of 253.20 J/kg in average. In other two crushing modes, the min u- nit crushing energy value could be neglected in calculation. In the impact crushing, the max particle reduced degree and crushing efficien- cy of the coal sample would be related to the crushing method. The sequence from big to small of the two would be the rotary crushing, hammer drop crushing and the bed crushing. In addition, with the auxiliary milling role influence of the high ash mineral, in the bed crushing, the hardness of the same coal would be reduced with the ash content increased.