构造煤中矿物质对孔隙结构的影响研究

Analysis of mineral effect on coal pore structure of tectonically deformed coal

为查明矿物质对构造煤孔隙结构的影响,在构造煤宏观和显微构造变形及其孔隙结构特征分析的基础上,结合显微组分鉴定和工业分析实验研究,探讨了构造煤中矿物质对煤体变形和孔隙结构的影响。为突显孔隙结构对构造变形的响应和表征作用,提出了干燥无灰基和密度校正法,以期降低矿物质对孔隙结构的影响。研究表明:一般矿物质含量相对较高的煤体在相近的构造条件下,变形程度往往强于低矿物质含量的煤体,构造煤中黏土矿物发育区构造变形程度多会增强、变形性质可向韧性转变。同生矿物对构造煤的孔隙结构的影响主要体现在密度、组分和变形影响等方面,且以密度影响最为显著。密度校正法可有效消除密度的影响,使得体积孔容和体积孔比表面积能更好的反映构造煤的孔隙发育和构造破坏程度。

To evaluate the mineral effect on coal deformation and pore structure,the authors conducted an analysis on the macro-and microscopic deformation,pore size distribution,maceral identification,and a proximate analysis on the characteristics of tectonically deformed coals. In order to enhance the response of pore structure to the coal deformation,the disturbing effect of minerals should be reduced. The results show that the relatively high mineral content in tectonically deformed coal is generally intensely deformed,with the structural deformation increase and the brittle to ductile transition in deformation behavior in clay mineral development areas. The effect of mineral on tectonically deformed coal pore structure appears to the development of density effect,components effect,and deformation effect,which cause the decrease of pore volume and pore surface area with the increase of mineral content.The density effect can be effectively reduced by the density correction,and the volume-pore volume and volume-pore surface area can better response to the fracture development degree and the structural deformation of tectonically deformed coal.