岩浆侵入后煤层物质组成及孔隙结构特征研究  

Study on the material composition and pore structure characteristics of coal seams after magma intrusion

作　　者：翟成[1,2] 徐鹤翔 徐吉钊 王帅 ZHAI Cheng;XU Hexiang;XU Jizhao;WANG Shuai(School of Safety Engineering,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China;National Engineering Research Center for Coal Gas Control,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China)

机构地区：[1]中国矿业大学安全工程学院,江苏徐州221116 [2]中国矿业大学煤矿瓦斯治理国家工程研究中心,江苏徐州221116

出　　处：《采矿与安全工程学报》2023年第3期587-598,共12页Journal of Mining & Safety Engineering

基　　金：国家杰出青年科学基金项目(51925404);国家自然科学基金项目(52104228);中国博士后科学基金项目(2021M693409);中国矿业大学研究生创新计划项目(2023WLJCRCZL191)。

摘　　要：为研究岩浆侵入后煤层物质组成和孔隙结构的变化规律,基于FTIR、XRD和低场核磁共振,研究了岩浆厚度、距煤层的距离对煤层的影响特征,并基于COMSOL软件模拟了煤层温度变化过程。结果表明:岩浆侵入使煤中挥发分含量下降,灰分含量增加,并增加了煤中矿物种类;煤层受热升温导致煤中羧基含量降低,酯类含量略有升高;V1、H1和H2三个试样发生热解,脂肪链长度缩短,但芳香结构无明显变化;热环境促使煤中孔隙发育,有效孔隙度增大,孔隙连通性增强;随热液流体渗入煤中的无机矿物改变煤矿物组分的同时,填充煤中孔隙,导致H1和V1试样饱水T2谱面积减小,孔隙连通性减弱,不利于瓦斯在煤层中的运移;模拟温度低于300℃的试样不发生热解或仅发生轻微热解,侵入过程中所有试样的最高温度均低于600℃,对应试样中芳香结构聚合度无明显变化;岩浆厚度越大、距煤层距离越小,则煤层受热演化的程度越大,对应的温度更高,受高温影响的时间延长。In order to study the changes in the material composition and pore structure of the coal seam after magma intrusion,the influence characteristics of magma thickness and distance from the coal seam on the coal seam were studied based on FTIR,XRD and LF-NMR,and we also simulated the temperature change process of the coal seam using COMSOL.The results show that magma intrusion decreases the volatile content in coal and increases its ash content and mineral types.The heating of coal seam leads to a decrease in carboxyl content and a slight increase in ester content.V1,H1 and H2 were pyrolyzed,shortening the length of fat chains but not significantly changing the aromatic structure.The thermal environment promotes the pore development in coal,increasing effective porosity and enhancing pore connectivity.With the infiltration of hydrothermal fluid into coal,inorganic minerals change the composition of coal and fill the pores in coal,resulting in the decrease of saturated T2 spectrum area of H1 and V1 samples and weakening pore connectivity,which is unfavorable for the gas migration in coal seams.The samples with simulated temperature below 300℃did not undergo pyrolysis or only slightly pyrolyzed,and the maximum temperature of all samples during the invasion was lower than 600℃,and the polymerization degree of aromatic structure in the corresponding samples had no significant change.The greater the magma thickness and the smaller its distance from the coal seam,the greater the degree of thermal evolution of the coal seam,which corresponds to the extension of higher temperature and time affected by high temperature.

关 键 词：岩浆侵入 煤层 物质组成 孔隙结构 温度 

分 类 号：TD712[矿业工程—矿井通风与安全]