Investigation of Tectonically Disturbed Zones of Coal Seams of the Kuznetsk Coal Basin Using SANS

Small-angle neutron scattering (SANS), low-temperature nitrogen adsorption (Brunauer–Emmett–Teller method, or BET) and Raman spectroscopy are used for a comparative analysis of the structural characteristics of the coals of the two seams, Boldyrevsky and Polenovsky, of the Kuznetsk coal basin. SANS measurements show that the microstructure of coal is characterized by surface fractal dimension close to three. The calculated specific surface area of the pore space makes it possible to distinguish the zones of disturbances from the calm areas of the same coal seams. The most sensitive method for the analysis of tectonic disturbances is the Raman spectroscopy, which allows tracing the characteristics of the type of deformation (brittle or ductile) in the disturbed zones. The BET and SANS methods are necessary to understand the dependence of coal Raman spectra on disturbances. Thus, an increase in specific surface area and surface fractal dimensions indicates the potential danger of outbursts in the area of the tectonic disturbances.