摘要
为研究煤体在构造作用下孔隙结构与分形特征,采用红外光谱、低温氮气吸附法和压汞实验方法,结合分形理论对三甲煤矿突出孔洞内外煤样孔隙分布进行定量分析。结果表明:红外光谱分析得到原生结构煤含氧官能团更多,更容易形成氢键,使得甲烷不易被煤体吸附;通过压汞法(mercury intrusion porosimetry,MIP)与氮气吸附(nitrogen gas adsorption,N_(2)GA)联合分析,构造煤与原生结构煤临界孔径分别为59 nm和86 nm。原生结构煤孔容主要分布在100 nm以下的孔隙中,构造煤各孔容分布差异不大,其中中孔和大孔孔容明显高于原生结构煤,并且构造煤比表面积比原生结构煤增大4倍多,孔容增加24.5%。根据分形理论分析发现,构造煤渗流孔和吸附孔分形维数分别为3.03和3.77,均高于原生结构煤的3.01和3.72;构造煤热力学分形维数高达2.916,构造煤具有更加复杂的孔隙结构和更加粗糙的孔隙表面。
In order to study the pore structure and fractal characteristics of coal under tectonic action,the pore distribution of coal samples inside and outside the outburst hole in Sanjia coal mine was analyzed by using infrared spectroscopy,low temperature nitrogen adsorption method and mercury intrusion experiment method.The results show that the primary structure coal has more oxygen-containing functional groups and is easier to form hydrogen bonds,which makes methane difficult to be adsorbed by coal.Through the joint analysis of mercury intrusion porosimetry(MIP)and nitrogen gas adsorption(N_(2)GA),the critical pore diameters of structural coal and primary structural coal are 59 nm and 86 nm respectively.The pore volume of primary structural coal is mainly distributed in the pores below 100 nm,and there is little difference in the distribution of pore volume of structural coal.Among them,the pore volume of mesopore and macropore is significantly higher than that of primary structural coal,and the specific surface area of structural coal is more than 4 times larger than that of hard coal,and the pore volume is increased by 24.5%.According to the fractal theory analysis,the fractal dimensions of seepage and adsorption pores of structural coal are 3.03 and 3.77,respectively,which are higher than 3.01 and 3.72 of primary structural coal.The thermal fractal dimension of structural coal is as high as 2.916,and the structural coal has more complex pore structure and rougher pore surface.
作者
林华颖
田世祥
焦安军
马瑞帅
许石青
LIN Hua-ying;TIAN Shi-xiang;JIAO An-jun;MA Rui-shuai;XU Shi-qing(College of Mining Engineering, Guizhou University, Guiyang 550025, China)
出处
《科学技术与工程》
北大核心
2021年第33期14451-14458,共8页
Science Technology and Engineering
基金
国家自然科学基金(52104079)
贵州科技计划项目(黔科合支撑〔2020〕4Y050号,黔科合支撑〔2019〕2887号)。
关键词
构造煤
孔隙结构
分形维数
地质作用
tectonic coal
pore structure
fractal dimension
geological effects
