Three-phase foam for preventing spontaneous combustion of coal in goaf

To enhance the efficiency of mine fire control, the technology of three-phase foam for preventing spontaneous combustion of coal in goaf was developed. The producing flow of three-phase foam and the main technical parameters were introduced. The chemical dynamics equations of spontaneous combustion of coal in goaf were set up. According to control the parameters in the equation: the reactant mass concentration of C, O2, the temperature (T) of coal and surroundings, the hole rate (γ) of goaf, etc, the mechanism of three-phase foam for preventing spontaneous combustion of coal in goaf was studied. By the application of three-phase foam in workface N2703 of Daxing coal mine with fire and high temperature, the change on concentration of CO and O2 in sampling gas and temperature in goaf was discussed. The results show that the effect of three-phase foam for preventing spontaneous combustion of coal in goaf is excellent, and it is a new technology with wide foreground for mine fire prevention.