Advanced characterization of seepage pores in deformed coals based on micro-CT.

The advanced quantitative characterization of seepage pores of deformed coals in Zhongliangshan Southern coalmine, Chongqing, was studied by mico-CT. The results show that the pore diameter of deformed coals is commonly less than 10 μm, but the pores distribution characteristics are different among various types of deformed coals. Pore numbers and areal porosity increase with the intensity of tectonic deformation. For primary-cataclastic coal, the primary pore is the major pore types, and interbreccia pores from angular particles increase in cataclastic coal with stress increasing. For granulated coal, intergranular pores and micro-fractures are well-developed, and mean pore diameter increases. The intense shear failure resulted in the brittle-ductile deformation, including local wrinkle structure and dusty mylonite in flake coal. Coal particles filled in some fractures and pores, which results in the reduction of mean pore diameter. The spatial visualization of pores indicate that porosity, pore surface area, pore volume and the distribution of max connective pores group increases along with stress strengthen. [ABSTRACT FROM AUTHOR]