Characteristics of Pore and Fracture of Coal with Bursting Proneness Based on DIC and Fractal Theory

Yutao Li,Bin Liu,Yixin Zhao,Honghua Song,Bo Zhang,Yaodong Jiang

doi:10.3390/en13205404

Yutao Li, Bin Liu + Show 4 more

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https://doi.org/10.3390/en13205404

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Abstract

Coal is a complex heterogeneous and anisotropic material conformed with fractal characteristics. The pore and fracture characteristics have important influence on the dynamic disasters including rock burst and gas outburst, however, the relationship between them is not accurately investigated due to inadequate research method. The pore and fracture distribution of coal with different bursting proneness were obtained by comprehensive application of MIP, LTNAD, SEM, and X-ray CT, and then fractal theory and DIC were used to research the pore and fracture characteristics. The result indicated that the modification of MIP result by LTNAD result could effectively eliminate the adverse effect of coal matrix compressibility, exactly reflect the distribution of pore and fracture in coal, and the pore distribution of coal with different bursting proneness were quite different. Gray scale image from SEM and 3D reconstruction technology based on X-ray CT could show the geological structure, fracture structure, and pore structure characteristics of coal. The study of LTNAD, SEM, and X-ray CT showed that these methods complemented each other, the coal had fractal properties, and the fractal dimension value had a positive correlation with the bursting proneness of coal sample.

Highlights

Nowadays, coal provides more than 27% of the energy worldwide, while about 40% of the global electricity generation comes from coal, and the share is estimated to increase to 43% in 2030 dramatically, it is believed that coal is an important guarantee of human energy security [1,2]
Characterization of Pore Based on mercury intrusion porosimetry (MIP) and low temperature nitrogen adsorption/desorption (LTNAD)
MIP and LTNAD could measure the distribution of pore with different size, the coal matrix deformed under high mercury injection pressure during the MIP, which would lead to distortion matrix deformed under high mercury injection pressure during the MIP, which would lead to of result and needed to be corrected [26]

Summary

Introduction

Coal provides more than 27% of the energy worldwide, while about 40% of the global electricity generation comes from coal, and the share is estimated to increase to 43% in 2030 dramatically, it is believed that coal is an important guarantee of human energy security [1,2]. Coal is anisotropic rock developed by plant remains undergone long and complicated biological, chemical, and geological processes, contains complex pore and fracture. It is widely, though not universally, accepted that coal could be summarized into three components: organic component (coal matrix), inorganic component (mineral matter) and defect (pore and fracture) [3,4,5]. Mercury intrusion porosimetry (MIP), Energies 2020, 13, 5404; doi:10.3390/en13205404 www.mdpi.com/journal/energies

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