Method for efficiently treating spontaneous ignition of remaining coal in large area goaf of shallow-buried coal bed

A method for efficiently treating spontaneous ignition of remaining coal in a large-area goaf of a shallow-buried coal seam, comprising the steps of:

• pre judging whether the remaining coal in the goaf ignites spontaneously;
• once it is found that the remaining coal in the goaf ignites spontaneously, first, enclosing the high-temperature spontaneous ignition area of the remaining coal in the goaf;
• then, injecting nitrogen continuously at a high flow into the large-area underground goaf to decrease the oxygen concentration in the goaf;
• next, using an air pressure-balancing fire prevention and extinguishment technique to reduce air leakage into the goaf, and releasing sulfur hexafluoride tracer gas at the same time to conduct qualitative analysis on air leakage passages that communicate with the goaf and carrying out leaking stoppage for the air leakage passages;
• drilling ground surface fire extinguishing drill holes,
• then, using the ground surface fire extinguishing drill holes to carry out treatment and detection, injecting a fire extinguishing material to treat the spontaneous ignition of the coal in the goaf and utilizing the drill holes to judge whether the spontaneous ignition of the coal in the goaf is extinguished or not;
• and,
• finally, grouting bodying mortar and high-concentration coal ash slurry into the high-temperature spontaneous ignition area of the coal and the drill holes.