A risk assessment method to quantitatively investigate the methane explosion in underground coal mine

Methane explosion in underground coal mine is one of the most deadly hazards to the miners and the surrounding environment. An improved analytical hierarchy process (IAHP) was developed to investigate the influencing factors of methane explosion quantitatively. IAHP was validated by statistical data, showing its advantages in reducing bias. Both IAHP results and statistical data indicated that electrical spark, blasting and friction spark were the leading ignition sources. Blasting operation, digging process, explosive charge and gas detect procedure showed the highest influencing weights to methane explosion. A case/example was provided to determine the safety level of an underground coal mine. Implementations were provided to avoid methane explosion in underground coal mines, such as avoiding high methane concentration (10-15 vol.%), taking care of rocks with more than 30% quartz and larger than 70 μm particle size, and using high melting point tool/equipment, and limiting coal pick speed within 1.5 m/s.