doi:10.16186/j.cnki.1673-9787.2022050018

Received:2022/05/11

Revised:2023/05/29

Published:2024/05/15

Study on early prediction method of coal spontaneous combustion in deep goaf

CHAO Jiangkun1,2, LIU Shuang1, HU Daimin1, HAN Xuefeng1, YU Minggao1, PAN Rongkun1,2

1.College of Safety Science and Engineering，Henan Polytechnic University，Jiaozuo  454000，Henan，China2.Collaborative Innovation Center of Coal Work Safety and Clean High Efficiency Utilization，Jiaozuo  454000，Henan，China

Abstract: Objectives The characteristics of “three highs and one disturbance” in the process of deep mining bring problems such as difficulty in determining the risk area of spontaneous combustion in deep mining areas and unclear early prediction and reporting of coal spontaneous combustion.  Methods Based on the analysis of coal oxidation gas derivation law under deep high stress conditions，the Graham coefficient and alkane ratio of coal bodies under different stresses are calculated.  Results The results showed that the production of CO and CO₂ gas increased with the increase of temperature during the oxidative spontaneous combustion of coal samples under different pressure conditions；Under the same temperature conditions，the production of CO and CO₂ gas showed a trend of increasing and then decreasing with the increase of axial stress.At the same temperature，with the increase of axial stress，the Graham coefficient increases first and then decreases. R₂ reaches the maximum at 6 MPa，R₃reaches the maximum at 9 MPa and R₁ reaches the maximum at 9 MPa；Under the condition of the same axial stress，the Graham coefficient basically changes linearly with the increase of indoor temperature of coal samples.At the same temperature，the alkane ratio of coal samples increases with the increase of axial stress；The alkane ratio under different pressure conditions basically shows an increasing trend with the increase of temperature.  Conclusion The research results offer a theoretical foundation for the early prediction of deep coal spontaneous combustion.  

Key words:coal spontaneous combustion;deep mining;prediction;Graham coefficient;alkane ratio