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

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 deforma- tion,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 de- formed 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.