Experimental study on spontaneous water infiltration and absorption characteristics in different coal grades

doi:10.16265/j.cnki.issn1003-3033.2025.08.1322

Abstract

Abstract:

In order to understand the characteristics of water transport during spontaneous infiltration and absorption of coal of different rank, coal samples from Mengtai Manlailiang mine, Jiulishan mine, Tiandiwangpo mine, and Pingdingshan No.10 mine were taken as the research objects, The T₂ spectrum of water in the coal sample at different times during the imbibition process was measured by using the low-field NMR experimental system, and the variation of water in the coal sample with time and space during the imbibition process was explored based on the change of water quality in the coal sample. The results show that the wettability of low-rank coal is better than that of high-rank coal and medium-rank coal, and the imbibition capacity of low-rank coal is the largest under the same experimental conditions, followed by high-rank coal, and the imbibition capacity of medium-rank coal is the smallest. According to the change of water in the process of coal sample imbibition with time, the coal sample imbibition process can be divided into three stages: the initial stage of imbibition, the middle stage of imbibition and the late stage of imbibition. In the early stage of imbibition, the sensitivity of low-rank coal to hydraulic action is higher than that of high-rank coal and medium-rank coal, and the imbibition velocity of low-rank coal is the largest, followed by medium-rank coal, and the imbibition velocity of high-rank coal is the smallest. In the middle and late stages of imbibition, the imbibition rate of high-rank coal is larger than that of medium-rank coal. In the process of imbibition and sorption, water will be transported from the pores with smaller pore size to the pores with larger pore size due to capillary force in the micropores/mesopores of the same magnitude, and the resistance of water in the lower rank coal is less than that in the higher rank coal.

Key words: different coal ranks, moisture in coal, spontaneous imbibition, wetting effect, low-field nuclear magnetic resonance(NMR), capillary force

CLC Number:

X936

YANG Ming, JIANG Shuwei, XU Jing, ZHOU Ziheng, WANG Mingyang, GAO Jianliang. Experimental study on spontaneous water infiltration and absorption characteristics in different coal grades[J]. China Safety Science Journal, 2025, 35(8): 110-117.

Figures/Tables 8

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煤样	工业分析				最大镜质组反射率/%	接触角/(°)
煤样	M_ad/%	A_ad/%	V_daf/%	FC_ad/%	最大镜质组反射率/%	接触角/(°)
G1	0.90	14.92	9.76	75.96	2.77	56.1
G2	1.46	13.65	7.53	80.82	3.09	58.2
Z1	0.69	9.50	23.45	68.75	1.41	77.2
D1	10.86	5.44	27.49	60.69	0.42	41.2

渗吸时间	测样时间间隔
0~60	15
60~240	30
240~2 880	240
2 880~7 200	360
7 200~12 000	480
12 000~13 440	1 440