Multifractal Interpretation of Images of Coal Specimen Surfaces to Assess the Degree of Coal Tectonic Disturbance

Abstract

AbstractThe possibility of using multifractal interpretation of microimages of coal specimen surfaces to quantify the degree of coal tectonic disturbance was studied. For this, for a series of scanning electron microscopy images (SEMI) of coal specimens taken from outburst-nonhazardous and outburst zones of coal seams, Chebyshev multifractal signatures were restored using generalized multifractal analysis (GMA) based on the use of Chebyshev polynomial kernels. The obtained signatures are considered as alternatives to traditional multifractal spectra for characterization of the surface structure of coals. In the course of the research, it was established that multifractal signatures for disturbed coals from outburst zones are usually greater than signatures for undisturbed coals from outburst-nonhazardous zones, which agrees well with our results obtained for model configurations of disturbed elements generated for different values of the disturbance threshold. The parameters of multifractal signatures that can be used to separate coals with different degrees of disturbance were revealed. The values of these parameters are found which are characteristics of highly disturbed coals from outburst zones and slightly disturbed coals from outburst-nonhazardous zones of coal seams. Based on the results of the study, it can conclude that a multifractal interpretation of SEMI of coal specimen surfaces can be used to determine the degree of coal disturbance. KeywordsMultifractalTectonically disturbed coalScanning electron microscopy