Desorption characterization of soft and hard coal and its influence on outburst prediction index

ABSTRACT

The zoning of the coal seam gas is zonal, which has a significant impact on the prominent prediction indicators, resulting in different prediction results for the same prominent prediction indicators in the same coal seam soft and hard coal. In this paper, the hard coal and soft coal in the coal seam are highlighted. The adsorption and desorption rules of the soft coal and hard coal in the outburst coal seam and its influence on the sensitivity of the outstanding prediction index are studied. The results show that: (1) the initial desorption of soft coal is larger than that of hard coal; (2) the outstanding prediction index has an exponential function relationship with gas pressure; (3) the sensitivity of prediction indicators is different. And concluded that: (1) the initial desorption rate of soft coal is faster than that of hard coal; (2) the outburst prediction index K₁ and Δh₂ increase with the increase of gas adsorption equilibrium pressure; (3) outburst prediction index K₁ is more reliable than Δh₂.

KEYWORDS:

• Adsorption/desorption law
• outburst prediction
• index reliability
• soft coal
• hard coal

Acknowledgments

This study is financially supported by the National Key R&D Program of China (No. 2016YFC0801405), the National Key R&D Program of China (No. 2017YFC0804202), and the Science and Technology Innovation and Entrepreneurship Fund of Tiandi Science & Technology Co., Ltd (No. 2018-TD-QN062), which are gratefully acknowledged. The authors also thank the editor and anonymous reviewers for their valuable advice.

Additional information

Funding

This work was supported by the Science and Technology Innovation and Entrepreneurship Fund of Tiandi Science & Technology Co., Ltd [2018-TD-QN062];National Key R&D Program of China [2016YFC0801405,2017YFC0804202].