School of Resource and Geosciences, China University of Mining and Technology MOE Key Lab of Coal Bed
Methane Resources and Reservoir Formation Process School of Earth Science and Engineering, Hebei University
of Engineering

为深入探讨不同矿物对褐煤孔隙结构特征的影响,以二连盆地三大凹陷主褐煤层为研究对象,采用全岩及黏土X射线衍射、扫描电子显微镜、低温氮吸附、压汞试验等分析测试手段,对样品的矿物质特征和孔隙特征进行了分析,并重点探讨了矿物对孔隙结构的影响作用。结果表明,二连盆地三大凹陷主煤层褐煤矿物以黏土矿物及石英为主,其他矿物含量较小,黏土矿物以高岭石为主;矿物多为与有机质伴生,呈分散状分布在有机质中;研究区褐煤有3种类型的吸附/解吸滞后线,孔体积分布以双峰发育为主;分形维数为2.473~2.616,吸附孔分形维数总体大于渗流孔分形维数,总孔隙分形维数主要受吸附孔控制;孔隙分形维数与腐植组含量、黏土矿物呈负相关关系,而与惰质组含量、灰分、石英含量呈正相关关系;煤中有机显微组分、矿物组分对孔隙分形维数的影响分别主要取决于腐植组含量及石英含量。

In order to discuss the different mineral affected to the crack structure features of the lignite, with three large depression major lignite seams in Erlian Ba sin as the object, with the applications of the full rock and clay X-ray difraction, scanning electron microscope, cryogenic adsorption, pressure mercury test and other a nalysis and test means, the mineral features and crack features of the samples were analyzed and the minerals affected to the crack structures were discussed. The re sults showed that the minerals of the lignite in the three depression major seams of Erlian Basin would be clay mineral and quartz mainly. Other mineral contents would be low. The clay minerals would be kaolinite mainly. The minerals mostly were the organic concomitants and were dispersedly distributed in the organics. In the study ar ea, the lignite would have three types sorption and desorption delay curves and the distribution of the borehole volume would be the double peak development mainly. T he fractal dimension would be 2.473 ~ 2.616. The fractal dimension of the adsorption borehole would be higher than the fractal dimension of the seepage borehole gene rally. The fractal dimension of the crack was mainly controlled by the adsorption borehole. The fractal dimension of the crack would have a negative correlation to the h umus contents and clay minerals and would have a positive relationship to the inertinite contents, ash yield and quartz contents. The organic maceral and mineral conte nts of the coal would be affected to the crack fractal dimension and mainly depended on the humus contents and quarts contents individually.