落锤法冲击次数对颗粒煤粒度分布规律的影响

Effect of Impact Times of Drop Hammer Method on Particle Size Distribution of Granular Coal

在分析落锤法测定煤坚固性系数的过程及方法原理的基础上,通过粒度分布函数及级配曲线研究了冲击粉碎次数对颗粒煤粒度分布特征的影响,并指出利用颗粒煤体积量作为恒量指标大小存在的问题。研究结果表明:随着冲击粉碎次数的增加,煤样被粉碎的越来越小,颗粒煤的特征粒径不断减小并逐渐趋于稳定,冲击能的影响幅度以及粒度分布的均匀性也在不断减小,存在使得其粒度分布稳定的临界冲击次数;特征粒径与均匀系数呈现线性增长关系,与颗粒煤级配曲线的不均匀系数及曲率系数的对数呈线性衰减关系。

Drop hammer method is the main method to determine the coefficient of coal hardiness. In the actual measurement process, the problem that existed in the method of determining the volume of coal particles in a certain range was pointed out.Based on the analysis of measurement process and principle, the influence of impact crushing times on particle size distribution characteristics of granular coal was studied by particle size distribution function and gradation curve. The results show that with the increase of impact crushing times, coal sample is crushed smaller and smaller, and the effect of impact crushing energy,characteristic particle size of granular coal and the uniformity are also decreasing gradually and tends to be constant. There is a critical impact number that makes the particle size distribution constant. The uniformity coefficient increases approximately in a line with the characteristic particle size. The non-uniformity coefficient and curvature coefficient of the gradation curve of granular coal show a logarithmic attenuation relationship with the characteristic particle size.