煤体冲击破碎试验参数k值的实验研究

Research on Parameter k Value of Coal Body Impact Crushing Experiment

为量化k值的范围,确定煤样受冲击后破碎成小粒径需要多少消耗能,本文对5种不同硬度的块煤在不同冲击能量下进行破碎实验,基于新表面说公式A=k(1/d-1/D),探讨k值与坚固性系数值、破碎比功的关系。实验结果表明:坚固性系数为0.36~2.82的煤样的k值范围是174.43~1547.08 J·mm;k值与坚固性系数值呈良好的线性关系且随着单位质量煤的破碎功成倍增加,k值缓慢增加,取均值后拟合公式为k_(1)=487.2f+9.2214(线性拟合度为99.93%)。k_(1)值与破碎比功拟合结果说明:k值与破碎比功呈现良好的线性关系(线性拟合度为99.84%),拟合公式为k_(2)=5.1695w-27.645。可见k值可以反映煤抵抗外力破碎的难易程度,是煤抵抗外力的重要指标。

In order to quantify the scope of the k value and study how much energy consumption is needed for breaking coal sample into small particle size by impact crushing, in this paper, five lump coals with different hardness were carried out the broken experiment under different impact energies. Based on the formula A=k(1/d-1/D) of the new surface theory, the relationship between the k value and the sturdiness coefficient value and the crushing specific work was discussed. The test results show that the scope of k value of coal samples with sturdiness coefficient 0.36~2.82 is 174.43~1 547.08 J·mm;the k value has a good linear relationship with sturdiness coefficient, and with the doubling of crushing work per unit mass of coal, k value increases slowly, and the fitting formula is k_(1)=487.2f+9.221 4(linear fitting degree is 99.93%) by the average value. The fitting results of the k value and the crushing specific work show that the k value and the crushing specific work present a good linear relationship(linear fitting degree was 99.84%), and the fitting formula is k_(2)=5.169 5w-27.645.Therefore, the k value can reflect the difficulty for the coal to resist external force crushing and is an important index of the coal to resist external force.