Research on complex air leakage method to prevent coal spontaneous combustion in longwall goaf.

Kun Wang,Haibo Tang,Yong Miao,Fengqi Wang,Dapeng Liu,Hongbo Zhao

doi:10.1371/journal.pone.0213101

Kun Wang, Haibo Tang + Show 4 more

Open Access

https://doi.org/10.1371/journal.pone.0213101

Copy DOI

Abstract

Spontaneous combustion of coal is one of the major hazards threatening production safety during longwall mining. Mining-induced voids, which provide passages for air leakage, are the key factor triggering spontaneous combustion of coal in longwall goafs. In this study, a comprehensive method, which combined pressure balance, grouting injection, and filling fissures, was proposed to prevent spontaneous combustion of coal in longwall goafs with complex air leakage. Field engineering practice was carried out in Sitai Coal Mine in China. The results demonstrated that with the application of the proposed method, in the working face, the concentration of CO was decreased from 31ppm to 0 and the air leakage quantity was decreased from 261 to below 80 m3min-1. The gas samples analysis from the gob areas also indicated that concentrations of O2 and CO were successively decreased, indicating that the risk of spontaneous combustion of coal in goafs was eliminated. The above mentioned analysis indicates that, the method proposed in this study is useful and efficient. Successful application of this technology could provide reference for the treatment of other coal mines.

Highlights

China is the largest coal-producing and consuming country in the world, and 90% of coal comes from the longwall mining faces [1, 2]
Majority of underground coal fires are caused by spontaneous combustion of coal, and the longwall gob area is one of the main places that is prone to spontaneous coal combustion [6]
The prevention method on of spontaneous combustion of coal in longwall gob areas caused by these air leakage passages was proposed

Summary

Introduction

China is the largest coal-producing and consuming country in the world, and 90% of coal comes from the longwall mining faces [1, 2]. A comprehensive method, which combined pressure balance, grouting injection, and filling fissures, was proposed to prevent spontaneous combustion of coal in longwall goafs with complex air leakage. One of the main reasons for the spontaneous combustion of coal in longwall gob areas is mining-induced air leakage passages [9].

Results

Conclusion