贵州三甲煤矿突出煤体结构参数及孔隙特征研究

Study on pore characteristics of gas outburst coal in Sanjia Coal Mine of Guizhou Province

为揭示突出煤体与原生煤体微晶结构参数和孔隙结构差异,基于XRD、低温液氮吸附、压汞等实验方式并结合分形维数理论,研究了三甲煤矿突出孔洞内外煤样结构参数和分形特征。结果表明:突出煤侧链含量、芳氢率和芳碳率高于原生煤;并且突出煤具有更好的生烃潜力;突出煤芳香度I1与I2均大于原生煤,说明突出煤脂肪官能团高于芳香结构官能团;由于煤中稠环结构产生一定改变,突出煤有效堆砌芳香片数低于原生煤;煤化度指标有小幅度升高,说明原生煤中侧链的含量低于突出煤,导致相对的芳香环数量增大;根据压汞数据得到原生煤的综合几何分形维数为3.30,突出煤为3.37;突出煤和原生煤微孔表面积分形维数分别为2.62和2.13,小孔表面积分形维数分别为2.45和2.23。

In order to reveal the differences in microcrystalline structure parameters and pore structure between gas outburst coal and raw coal, this paper studied the structural parameters and fractal characteristics of coal samples inside and outside outburst holes in Sanjia Coal Mine based on XRD, low-temperature liquid nitrogen adsorption, mercury injection and other experimental methods combined with fractal dimension theory. The results show that the side chain content, aromatic hydrogen rate and aromatic carbon rate of gas outburst coal are higher than those of raw coal;outburst coal has better hydrocarbon potential;the outburst coal I1and I2are larger than the raw coal, indicating that the aliphatic functional groups of the gas outburst coal are higher than the aromatic structural functional groups;due to the change of the dense ring structure in coal, the number of effective stacking aromatic slices of gas outburst coal is lower than that of raw coal;the coalification index increased slightly, indicating that the content of side chain in raw coal was lower than that in gas outburst coal, resulting in an increase in the number of relative aromatic rings. According to the mercury injection data, the comprehensive geometric fractal dimension of the raw coal is 3.30,and the gas outburst coal is 3.37. The fractal dimensions of micropore surface area of gas outburst coal and raw coal are 2.62 and2.13 respectively, and the fractal dimensions of micropore surface area are 2.45 and 2.23 respectively.