Characteristics and early warning technology for gas-oil explosion inHuanglong Mining Area

The gas emission in Huanglong mining area is characterized by strong randomicity, instability in gas composition, and great difficulty in prevention and control. In this research, laboratory experiments are conducted to study the explosion limit of gas-oil mix in a 10-Litter spherical multi-component gas explosion reactor. An early warning technology for gas-oil explosion is proposed which integrates with prevention and control of CH4 and coal spontaneous combustion in mine gob. Moreover, an early warning index system and early warning gas-oil explosion system are constructed. The results show that CH4 concentration in gas-oil mix decreases to 13%～67% and the concentration of C3H8 and C4H10 increase to 10%～30%. The gas-oil in Huanglong mining area shows significant anisotropy. Due to increase of hydrocarbon composition, the explosion limit of gas-oil changes to 1.85%～9.85%. The results also indicate that the risk degree of gas-oil explosion is 4.32, which is 2.15 times higher than average risk degree for coal mines. Furthermore, the early warning limit of CH4 is determined to be 0.38% in return airway in Huanglong mining area. The formula of monitoring index is determined as CO、φ(C2H4)/φ(C2H6) based on the oxidation heating experiment of coal spontaneous combustion. The research provides a significant reference for prevention and control of gas-oil explosion in coal mines.