高阶原生煤与构造煤的孔隙及分形特征研究

Study on pore structure and fractal characteristics of high-rank intact coal and tectonic coal

为了研究高阶原生煤和构造煤的孔隙结构与分形特征,采用压汞法、低压N2吸附法和低压CO_(2)吸附法对所选的煤样进行了研究,比较了原生煤与构造煤之间的孔径分布、孔容和比表面积、孔型和连通性以及分形维数差异。结果表明:构造煤以开放型孔为主,并比原生煤具有更好的连通性;原生煤和构造煤二者的Dubinin-Radushkevic(D-R)和微孔比表面积之和都占到了总比表面积的99%以上,从而为瓦斯的吸附提供了更多的空间;构造煤较大的孔容和比表面积造成其高瓦斯含量的特征;构造煤渗流孔孔隙简单,吸附孔孔隙结构复杂性较低,孔隙表面相对光滑,提高了瓦斯在孔隙中的运移能力。

In order to study the pore structure and fractal characteristics of high-rank intact coal and tectonic coal,the selected coal samples were studied by mercury intrusion method and low pressure N2 adsorption method and low pressure CO_(2) adsorption method.The pore size distribution,pore volume and specific surface area,pore shape and connectivity,and fractal dimension differences between intact coal and tectonic coal were compared.The results show that tectonic coal is dominated by open pores and has better connectivity than intact coal.The sum of their Dubinin-Radushkevic(D-R)and micropore specific surface area of both intact coal and tectonic coal accounts for more than 99% of the total specific surface area,thus providing more space for gas adsorption.Moreover,the larger pore volume and specific surface area of tectonic coal result in its high gas content.The seepage pores of tectonic coal are simple,the adsorption pores have low pore structure complexity,and the pore surface is relatively smooth,which improves the gas migration ability in the pores.