爆炸冲击对高阶煤微晶结构的影响特征*

为探究爆炸冲击荷载对煤微晶结构的影响，以河南赵固二矿山西组二1煤层高阶无烟煤为研究对象，利用炸药对煤样进行爆炸冲击试验，通过改变炸药量控制冲击荷载的大小，并对冲击过后的煤样进行X射线衍射测试，分析在不同强度冲击荷载作用下煤样微晶结构的变化规律。研究结果表明:煤样的峰值应变随着冲击荷载的增大而升高；与原煤相比，受冲击荷载之后煤样XRD图谱的002峰与100峰均变的更高且陡，衍射峰位置向θ值大的一侧偏移；与原煤样相比，受冲击荷载之后煤体的微晶结构参数发生规律性变化，面层间距（d002）表现出减小的趋势，单元堆砌度（Lc）、单元延展度（La）以及（La/Lc）表现出增大的趋势；微晶结构变化快慢也呈现一定的规律性，随着煤样受到冲击荷载的增大，面层间距呈现减小的趋势；单元堆砌度与单元延展度呈现增加的趋势，前期增加缓慢，后期增加迅速；受冲击煤样的微晶结构更加有序，从微观结构上解释了冲击载荷对煤微晶结构的影响。

Influence characteristics of blasting impact on microcrystalline structure of high rank coal

In order to explore the influence of blasting impact load on the microcrystalline structure of coal,taking the high rank anthracite of Shanxi group Ⅱ-1 coal seam in Zhaogu No.2 coal mine of Henan province as the research object,the explosives were used to conduct the blasting impact tests on the coal samples,and the impact load was controlled by changing the amount of explosives,then the X-ray diffraction tests were carried out on the coal samples after impact to analyze the change laws of the microcrystalline structure of coal samples under impact loads with different strengths.The results showed that the peak strain of coal sample increased with the increase of impact load.Compared with the raw coal,both the 002 peak and 100 peak in the XRD spectrum of coal sample changed higher and steeper after the impact load,and the position of diffraction peak shifted to the side with larger θ value.Compared with the raw coal samples,the microcrystalline structure parameters of coal changed regularly after the impact load,and the surface layer spacing (d002) presented the decreasing trend,while the unit stacking degree (Lc),unit ductility (La) and (La/Lc) presented the increasing trend.The change rate of microcrystalline structure also presented a certain regularity,with the increase of impact load on the coal sample,the surface layer spacing presented the decreasing trend.The unit stacking degree and unit ductility presented the decreasing trend,which increased slowly in the early stage and increased rapidly in the later stage.The microcrystalline structure of the impacted coal sample was more orderly,which explained the influence of impact load on the microcrystalline structure of coal from the microstructure.