应力作用前后煤孔隙结构变化规律实验研究  

Experimental Study on the Change of Coal Pore Structure under Different Stress Loading Conditions

作　　者：任少魁 REN Shaokui(Shenyang Research Institute,China Coal Technology&Engineering Group,Fushun 113122,China;State Key Laboratory of Coal Mine Safety Technology,Fushun 113122,China)

机构地区：[1]中煤科工集团沈阳研究院有限公司,辽宁抚顺113122 [2]煤矿安全技术国家重点实验室,辽宁抚顺113122

出　　处：《煤》2025年第4期39-42,共4页Coal

基　　金：国家自然科学基金(52174230)。

摘　　要：本研究针对阳泉五矿15号煤层无烟煤,采用压汞法和液氮吸附法对煤样在应力作用前后的孔隙结构进行测试,探究了煤在应力作用前后孔隙结构的变化。结果表明:应力作用后煤样的分形维数表面的不规则程度D_(1)降低了1.9%,使孔隙表面更加光滑,而煤基质中的毛细凝聚和渗流状态D_(2)增加了1.2%,使孔隙结构的非均质性增强,不利于瓦斯的吸附和扩散;应力对不同孔径段的孔比表面积有不同的影响,其中对100~400 nm中孔比表面积的影响最大,增加了约2.5倍,而对小孔和微孔的影响较小,总比表面积降低了约5%;应力作用导致煤样总孔容减小,开放孔数量减少,半封闭孔数量增加,孔隙连通性变差。In this study,the pore structure of coal samples before and after stress was tested by mercuric pressure method and liquid nitrogen adsorption method for anthracite from the No.15 coal seam of Yangquan the No.5 Coal Mine,and the change of pore structure of coal before and after stress was investigated.The results showed that the fractal dimension D_1(representing the degree of surface irregularity) of the coal samples decreased by 1.9% after the stress effect,making the pore surfaces smoother,while D_2(representing the state of capillary coalescence and seepage in the coal matrix) increased by 1.2%,which suggests that the non-homogeneity of the pore structure is enhanced,which is unfavorable to the adsorption and diffusion of gas.The stress had different effects on the pore specific surface area of different pore size segments,with the largest effect on the specific surface area of 100~400 nm mesopores,which increased by about 2.5 times,and a smaller effect on small pores and micropores,with the total specific surface area decreasing by about 5%;the stressing effect resulted in a decrease in the total pore volume of the coal samples,a decrease in the number of open pores,an increase in the number of semi-closed pores,and a deterioration in the connectivity of the pores.

关 键 词：应力 压汞 低温液氮 孔隙结构 分形维数 

分 类 号：TD712[矿业工程—矿井通风与安全]