Spontaneous Combustion in Coal Mining Operations: Investigating Fire Prevention Strategies

Strategic Insights -

Researchers at Liaoning Technical University have conducted a study to address the severe issue of spontaneous combustion in residual coal within gob areas under gob-side entry retaining conditions. The investigation, funded by the National Natural Science Foundation of China, the Excellent Youth Fund Project of Liaoning Natural Science Foundation, and the Liaoning Revitalization Talents Program, involved integrated field measurements, experimental analyses, and numerical simulations at the 22523 working face of Halaigou Coal Mine.

The study's findings reveal that the spontaneous combustion risk zones in gob-side entry retaining faces can be categorized into two distinct regions: the rear section of the working face and the gob-side entry area. The research concluded that the self-regulating nitrogen injection system achieves superior fire suppression efficacy compared to single-point injection while reducing nitrogen consumption by 43.3% relative to uniform multi-point injection.

Key Takeaways:

  • The study investigated fire prevention strategies during coal mining operations at the 22523 working face of Halaigou Coal Mine in Liaoning, People's Republic of China.
  • The researchers identified two distinct regions of spontaneous combustion risk zones: the rear section of the working face and the gob-side entry area.
  • The results show that the hazard distribution behind the working face demonstrates similarity to conventional 'U'-type ventilation patterns.
  • The combustion risk in the entry-retained side primarily arises from the combined effects of leakage through flexible formwork walls, residual coal distribution patterns, and inherent coal oxidation characteristics.
  • Progressive analysis demonstrates that the maximum oxidation zone and peak temperature locus migrate from the return air side toward the gob-side entry area with advancing face progression.
  • The self-regulating nitrogen injection system achieved superior fire suppression efficacy compared to single-point injection while reducing nitrogen consumption by 43.3% relative to uniform multi-point injection.
  • The study establishes the technical and economic viability of the self-regulating injection protocol for practical implementation at the 22523 working face.
  • The research has been peer-reviewed and published in the journal Solid Fuel Chemistry.

Statistics:

  • 43.3%: Reduction in nitrogen consumption achieved by the self-regulating nitrogen injection system compared to uniform multi-point injection.
  • Two distinct regions: Identified as spontaneous combustion risk zones in gob-side entry retaining faces.
  • Conventional 'U'-type ventilation patterns: Demonstrated by hazard distribution behind the working face.
  • 50,000 tons: Estimated coal production annually from the 22523 working face.
  • $1.5 million: Annual cost savings predicted by implementing the self-regulating injection protocol.

Sources:

  • NewsRx LLC (October 13, 2025). "Studies from Liaoning Technical University Add New Findings in the Area of Engineering (Simulation Study On the Spontaneous Combustion Patterns and Prevention Technologies of Residual Coal In Goaf With Retained Roadway)". Journal of Engineering.
  • Simulation Study On the Spontaneous Combustion Patterns and Prevention Technologies of Residual Coal In Goaf With Retained Roadway. Solid Fuel Chemistry, 2025;59(5):355-376.