中阶煤的孔隙特征研究  

Study on Pore Characteristics of Medium Rank Coal

作　　者：董宪伟 李晓茜[1] 董轩萌 王福生 DONG Xian-wei;LI Xiao-xi;DONG Xuan-meng;WANG Fu-sheng(School of Emergency Management and Safety Engineering,North China University of Science and Technology,Tangshan Hebei 063210,China;Hebei Provincial Key Laboratory of Mining Development and Safety Technology,Tangshan Hebei 063210,China;College of Mining Engineering,North China University of Technology,Tangshan Hebei 063210,China)

机构地区：[1]华北理工大学应急管理与安全工程学院,河北唐山063210 [2]河北省矿业开发与安全技术重点实验室,河北唐山063210 [3]华北理工大学矿业工程学院,河北唐山063210

出　　处：《华北理工大学学报（自然科学版）》2024年第3期44-51,共8页Journal of North China University of Science and Technology：Natural Science Edition

基　　金：国家自然科学基金资助项目(基于同位素指纹图谱溯源技术的矿井CO异常来源解析研究,编号:51974128)。

摘　　要：明确煤体的孔隙结构对煤层气的开采及瓦斯突出危险性评价有重要意义。为了解中阶煤孔隙特征,首先通过扫描电子显微镜测试煤层表面,后采用低温液氮吸附法和压汞法分析孔隙结构,并对测得实验数据进行绘图,研究其分形特征。结果表明:钱家营焦煤(QJY)、宁夏1/3焦煤(NX)、东欢坨气煤(DHT)三种煤样的吸附等温曲线均属于Ⅱ类吸附曲线,且呈倒"S"型。东欢坨煤的比表面积最大,宁夏煤次之,钱家营煤的比表面积较小,煤的变质程度与比表面积呈现明显的负相关性。孔径在≥50 nm的孔含量与平均孔径呈正相关;3个煤样中孔径≤10 nm的孔容占比均最大,煤孔隙主要是由微孔组成。孔隙发育情况:DHT>NX>QJY;钱家营煤与东欢坨煤的分形维数都呈现出吸附孔D _(2)>渗流孔D 1的特征,其微小孔的孔隙结构比较复杂,且无规则性。宁夏煤吸附孔的分形维数D_(2)=2.890,在2~3之间,微小孔具有分形特征。Clarifying the pore structure of coal is of great significance for the extraction of coalbed methane and the evaluation of gas outburst risk.In order to obtain the pore characteristics of medium rank coal,the surface of the coal seam was first tested using a scanning electron microscope,and then studied using low-temperature liquid nitrogen adsorption and mercury intrusion methods.The measured experimental data was plotted to study its fractal characteristics.The results show that the adsorption isotherm curves of Qianjiaying coking coal(QJY),Ningxia 1/3 coking coal(NX),and Donghuantuo gas coal(DHT)belong to Class II adsorption curves and exhibit an inverted"S"shape.Donghuantuo coal has the largest specific surface area,followed by Ningxia coal,and Qianjiaying coal has a smaller specific surface area.The degree of coal metamorphism shows a significant negative correlation with the specific surface area.The pore content with a pore size of≥50 nm is positively correlated with the average pore size;The proportion of pore volume with a pore size≤10 nm is the highest among the three coal samples,and the coal pores are mainly composed of micropores.Pore development:DHT>NX>QJY;The fractal dimensions of Qianjiaying coal and Donghuantuo coal show a characteristic of adsorption pore D_(2)>D 1,and the pore structure of their micro pores is relatively complex and irregular.The fractal dimension D_(2) of coal adsorption pores in Ningxia is 2.890,ranging from 2 to 3,and the micropores have fractal characteristics.

关 键 词：孔隙特征 低温液氮吸附法 压汞法 分形维数 

分 类 号：TD712[矿业工程—矿井通风与安全]