Nuclear magnetic resonance experimental study on pore characteristics of high rank coal with different bedding

doi:10.16265/j.cnki.issn1003-3033.2021.09.012

Abstract

Abstract: In order to study pore distribution characteristics of high rank coal with different bedding, NMR experiments were carried out under different centrifugal forces of saturated coal samples. Firstly, three high rank coals with parallel bedding and three vertical bedding were selected. Then, T₂ pattern and NMR porosity of saturated coal samples under different centrifugal forces were measured by low field NMR system. The results show that adsorption pores are the most developed in high-rank coal, followed by seepage pores and cracks. Water in large pores and cracks of coal samples is easy to be ejected under centrifugal force, but water in tiny pores is difficult to be ejected. Parallel and vertical stratification of coal sample with the increase of centrifugal force, peak, peak area of T₂ spectrum and nuclear magnetic porosity have been gradually decreases, parallel and vertical stratification of coal sample nuclear magnetic accords with exponential function relationship between porosity and centrifugal force. T_2C (T₂ cutoff value) vertical stratified coal sample is 1.44 times that of parallel stratified coal sample. T_2C of vertical stratified coal sample increases with the increase of centrifugal force, while T_2C of parallel stratified coal sample increases first and then decreases with the increase of centrifugal force.

Key words: different bedding, high-rank coal, porosity, nuclear magnetic resonance(NMR), centrifugal force, T₂ spectrum

CLC Number:

X936

LIU Jiajia, HU Jianmin, YANG Ming, FANG Yingxiang, JIA Gaini. Nuclear magnetic resonance experimental study on pore characteristics of high rank coal with different bedding[J]. China Safety Science Journal, 2021, 31(9): 83-89.

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