Study on Microscopic Pore Structures of Coal Based on Nuclear Magnetic Resonance Technology
XU Xiaomeng
MA Hongxing
TIAN Jianwei
WANG Jiajian
LI Guangyao
Abstract:To study the microscopic pore structure characteristics of coal,the pore types,connectivity and pore size distribution features of coal samples are monitored by nuclear magnetic resonance (NMR).Combining the results of X-ray diffraction (XRD) and computed tomography (CT) scanning,the internal phase composition,mineral composition and pore morphology of coal are also summarized.Results show that:various mineral compositions are found in the investigated coal,including kaolinite,calcite and pyrite;the minerals mainly include in the coal cleat system;the spectrum of T2 transverse relaxation time of the tested coal is a typical triplet curve;according to the T2 value,three times intervals of 0.5 ms to 5 ms,5 ms to 100 ms,and >100 ms represent the features of adsorption pores,seepage pores,diffusion pores,respectively.The T2 cutoff value falling in the range of 10 ms to 20 ms demonstrates that the measured samples have a highly developed microscopic pores and a relatively developed pore structure.The test results of NMR are consistent with the results of 3D visualization analysis of CT scanning,and NMR can make up the deficiency of CT scanning on the micro scale by showing the internal pore characteristics of coal samples.
Keywords:nuclear magnetic resonance (NMR)pore structureX-ray computed tomography (X-CT)relaxation timepore size distribution
Publication Date:2017-01-01
Online Publishing Date:2025-08-15(First online date of this platform, not the publication date of the document)
Pages:4( 1-4 )
Safety in Coal Mines

Safety in Coal Mines

PKUISTIC
ISSN:1003-496X
Year, Vol.(Issue):2017,48(2)