不同软硬煤的结构差异性研究

Research on Structural Difference for Different Soft and Hard Coal Samples

为研究不同软硬煤的微结构差异性特征,以山西潞安王庄煤矿为工程背景,针对6种不同软硬煤样,采用电镜扫描(SEM)分析了表面形貌特性,并结合低温液氮吸附法研究了软硬煤的孔隙结构特征,对不同变质变形程度煤样的微结构差异性进行了对比分析。研究结果表明:构造变形对软煤的表面结构有显著影响,软煤较对应的硬煤表面更粗糙,拥有更复杂的表面孔隙结构;煤化作用对孔隙结构具有差异显著,煤的孔径随变质程度的增加而逐步变小;孔总比表面积随煤化程度的加深而变大,所有煤样微孔比表面积所占比例均超过了60%,比表面积主要由微孔贡献;软煤的平均孔径始终小于对应的硬煤,而孔比表面积始终大于相应的硬煤;构造变形使得煤体结构变得更复杂,构造软煤具有超前演化特征。

In order to investigate the microstructural difference of different soft and hard coal,taking Wangzhuang Coal Mine of Shanxi Lu＇an Group as the engineering background.Aimed at 6 different soft and hard coal samples,the scanning electron microscopy（SEM） was used to analyze the surface morphology features.The pore structural characteristics of these soft and hard coal samples were also studied combined with low temperature liquid nitrogen adsorption method.The comparison of microstructural difference was made among soft and hard coal samples with different metamorphism and deformation degree.The research results show that tectonic deformation has significant influence on surface structure of soft coal.Compared with hard coal,soft coal has more rough surface and contains more complex pore structure.Coalification also has great impact on pore structure.The pore diameter of coal gradually declines with increasing coalification,but the total specific surface area increases.For all the studied samples,micropore occupies more than 60% of the total specific surface area,making it as the main contributor.The average pore diameter of soft coal is always smaller than that of corresponding hard coal,but it is inverse for pore specific surface area.Tectonic deformation complicates the pore structure of coal,and tectonic soft coal has precocious evolution characteristics.