Analysts evaluating the 3406 fully mechanized top-coal caving face have mapped precise goaf temperature zones to mitigate spontaneous combustion risks, according to recent engineering evaluations. By combining temperature-programmed oxidation experiments with COMSOL multiphysics modeling, researchers identified critical indicator gases and established an integrated fire prevention scheme utilizing grouting and nitrogen injection.
Identifying Spontaneous Combustion Indicator Gases
Laboratory testing of coal samples from the working face confirms a tangible risk of spontaneous combustion, according to experimental data. Temperature-programmed oxidation tests isolating heating behaviors identified carbon monoxide (CO) and ethylene (C2H4) as primary indicator gases. Mining engineers rely on these specific chemical signatures to detect early-stage oxidation deep within the strata before thermal runaway occurs.
Mapping the Goaf Three Zones via COMSOL Modeling
Using COMSOL software, technical teams precisely divided the goaf area into distinct thermodynamic zones based on oxygen concentration and air leakage distribution. According to the spatial analysis, the asphyxiation zone is distributed in the deep goaf at 230 to 261 meters from the working face. The oxidation zone spans the return-side goaf at 12 to 230 meters and the intake-side goaf at 70 to 261 meters. Meanwhile, the heat dissipation zone lies closer within 12 to 70 meters, with the maximum width of the active oxidation zone reaching 218 meters.
Targeted Fire Prevention and Control Technology
To neutralize the identified oxidation hazards, operators deployed an integrated mitigation strategy combining grouting and nitrogen injection across the goaf area. The intervention prevented spontaneous combustion events, maintaining operational stability across the fully mechanized caving environment.
Frequently Asked Questions
What gases indicate spontaneous combustion in top-coal caving faces?
Laboratory oxidation experiments identify carbon monoxide (CO) and ethylene (C2H4) as the primary indicator gases for spontaneous coal combustion.
How wide is the oxidation zone in the studied goaf?
According to COMSOL modeling results, the maximum width of the oxidation zone reaches 218 meters, requiring targeted engineering controls.
What methods prevent goaf fires in modern underground mines?
Operators implement integrated fire prevention schemes combining grouting and nitrogen injection to isolate reactive coal from oxygen and reduce thermal accumulation.
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