Effect of coalification and maceration on pore differential development characteristics of high-volatile bituminous coal

•The difference in pore characteristics between vitrain and durain initially increases and then decreases with the increase in pore size.•Physical compaction considerably reduces the pore volume of the vitrain during the early evolution stage of high-volatile bituminous coal but has no effect on the durain.•The pore volume and specific surface area of vitrain and durain in the high-volatile bituminous coal reach their maximum near the first coalification jump point.