Characterization of Coal Porosity for Naturally Tectonically Stressed Coals in Huaibei Coal Field, China

Figure 9

Evolutionary process of nanopore structure in deformed coal. (a) A random area taken from deformed coal. The black circle indicates a solid-solid contact point in deformed coal, number “1” means supermicropores, and number “2” means submicropores; (b) three-dimensional diagram of a small area which was magnified; (c) way 1 of interconversion among the different size nanopores: the parts of the smaller pores become connected or linked together and gradually grow into larger pores. Number “3” means micropores. (d) Way 2: larger pores being separated into two or more smaller pores.