Coal and Gas Outburst Dynamics in Mining Systems

Coal and gas outbursts are catastrophic phenomena in underground coal mining, characterised by the rapid ejection of coal fragments and high-pressure gas from a working face or borehole. These events arise from the sudden release of stored elastic and gas internal energy when in-situ stress and gas pressure exceed the mechanical strength of the coal mass. A complex interplay of geological factors—such as seam depth, tectonic stress, seam permeability and gas content—controls the initiation, propagation and scale of an outburst. Advances in laboratory experimentation, numerical simulation and field monitoring have elucidated the multiphysical mechanisms driving outbursts, informed risk-identification criteria and underpinned the development of targeted prevention strategies. Improved understanding of fracture propagation, energy dissipation and two-phase flow dynamics has global significance for enhancing mine safety, optimising gas drainage and mitigating greenhouse-gas emissions.

Research from Nature Portfolio

Recent experimental work employing a mid-scale physical simulation system has provided new insights into outburst initiation and evolution. A three-dimensional model of a coal seam, bounded by roof and floor strata and subjected to controlled gas charging, enabled detailed measurement of gas pressure and temperature fluctuations during adsorption–desorption cycles. The outburst propagation velocity was determined by analysing coal particle trajectories, revealing a mass-weighted average of approximately 17 m/s. Particle-size analysis showed preferential mobilisation of fine coal fractions, while energy accounting demonstrated that gas potential energy far exceeds elastic strain energy in driving low-threshold outbursts. This platform offers a robust approach to quantifying energy partitioning, particle breakage and flow behaviour under realistic mining conditions.

Coal and Gas Outburst Dynamics in Mining Systems publication trend

The graph below shows the total number of articles in coal and gas outburst dynamics in mining systems across all publications each year (not limited to Nature Index journals).

Technical terms

Coal and gas outburst: sudden ejection of coal and high-pressure gas from a mine opening resulting from rapid depressurisation and rock failure.

Gas desorption: release of methane or other gases from the coal matrix into pore spaces when external pressure decreases.

Multiphysics coupling: integrated simulation of interacting physical phenomena such as mechanical deformation, fluid flow, heat transfer and gas migration.

Discrete Element Method (DEM): numerical technique modelling granular materials as assemblies of particles to capture fracture, fragmentation and contact mechanics.

Lattice Boltzmann Method (LBM): computational fluid dynamics approach that simulates fluid flow and transport by tracking particle distribution functions on a discrete lattice.

References

1. Laboratory Study Phenomenon of Coal and Gas Outburst Based on a Mid-scale Simulation System. Scientific Reports (2019).
2. Numerical modelling of gas outburst from coal: a review from control parameters to the initiation process. International Journal of Coal Science & Technology (2023).
3. Numerical Simulation Study on the Multi-Physical Field Response to Underground Coal and Gas Outburst under High Geo-Stress Conditions. Minerals (2022).
4. Mechanical criterion for coal and gas outburst: a perspective from multiphysics coupling. International Journal of Coal Science & Technology (2021).