Experimental Investigation of the Adsorption Characteristics of Mixed Coal and Variations of Specific Surface Areas before and after CH<sub>4</sub> Adsorption

Pengxiang Zhao; Hui Liu; Shugang Li; Haifei Lin; Yongyong Jia; Min Yan; Meiqi Yuan; Jia Lin

doi:10.3390/app9030524

Applied Sciences (Feb 2019)

Experimental Investigation of the Adsorption Characteristics of Mixed Coal and Variations of Specific Surface Areas before and after CH<sub>4</sub> Adsorption

Pengxiang Zhao,
Hui Liu,
Shugang Li,
Haifei Lin,
Yongyong Jia,
Min Yan,
Meiqi Yuan,
Jia Lin

Affiliations

Pengxiang Zhao: College of Safety Science and Engineering, Xi’an University of Science & Technology, Xi’an 710054, China
Hui Liu: College of Safety Science and Engineering, Xi’an University of Science & Technology, Xi’an 710054, China
Shugang Li: College of Safety Science and Engineering, Xi’an University of Science & Technology, Xi’an 710054, China
Haifei Lin: College of Safety Science and Engineering, Xi’an University of Science & Technology, Xi’an 710054, China
Yongyong Jia: College of Safety Science and Engineering, Xi’an University of Science & Technology, Xi’an 710054, China
Min Yan: College of Safety Science and Engineering, Xi’an University of Science & Technology, Xi’an 710054, China
Meiqi Yuan: College of Safety Science and Engineering, Xi’an University of Science & Technology, Xi’an 710054, China
Jia Lin: School of Civil School of Civil, Mining and Environmental Engineering, University of Wollongong, Wollongong, NSW 2500, Australia

DOI: https://doi.org/10.3390/app9030524
Journal volume & issue: Vol. 9, no. 3
p. 524

Abstract

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Tectonic coal is a kind of soft coal that is generated during tectonic movement. Gas outbursts usually occur in seams containing both virgin coal and tectonic coal. To reveal the adsorption characteristics of this type of coal seam (containing both virgin coal and tectonic coal), both tectonic coal and virgin coal were collected from the same longwall face and a series of laboratory tests were conducted, including coal sorption tests and pore specific surface measurements. Both the tectonic coal and virgin coal were crushed into coal powder (0.18⁻0.25 mm) for the coal sorption tests. In these laboratory tests, different mass ratios between tectonic coal and virgin coal were tested. We found that with the increase of the percentage of tectonic coal, the adsorption volume showed a rising trend, reached its maximum value, and then decreased. The specific surface areas of the mixed coal samples had the same evolution trends as those of the adsorption volume. From the laboratory tests, we found that when the mass ratio of virgin coal to tectonic coal was 1:1, both the adsorption volume and the specific surface areas reached their maximum values. Due to the percentage variation of the tectonic coal in the panel with the advancement of the longwall face, when the tectonic coal accounted for 50% of the total coal, the gas content would rise. Thus, proper measures should be adopted for outburst hazards control. The mathematical model between the change of specific surface area and the stress and strain of pore expansion before and after gas adsorption was established, and the relationship between the change of pore structure and gas emission before and after gas adsorption was obtained. It provides a theoretical basis for further research on coal and gas outburst mechanisms.

Published in Applied Sciences

ISSN: 2076-3417 (Online)
Publisher: MDPI AG
Country of publisher: Switzerland
LCC subjects: Technology: Engineering (General). Civil engineering (General); Science: Biology (General); Science: Physics; Science: Chemistry
Website: http://www.mdpi.com/journal/applsci

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