Fire-prevention and extinguishing material for plugging air leakage in underground barrier pillar of coal mine and use method thereof

A use method of a fire-prevention and extinguishing material for plugging an air leakage in an underground barrier coal pillar of a coal mine, wherein the fire-prevention and extinguishing material for plugging the air leakage has a layered structure and comprises an upper fabric layer, an intermediate layer, and a lower fabric layer;

• the intermediate layer is arranged between the upper fabric layer and the lower fabric layer;
• a plurality of fiber filaments are arranged in the intermediate layer, and the plurality of fiber filaments are evenly distributed in the intermediate layer, and two ends of each of the plurality of fiber filaments are connected to the upper fabric layer and the lower fabric layer, respectively, such that the intermediate layer has a flexible deformability;
• the intermediate layer is filled with a cement powder such that the cement powder is evenly distributed around the plurality of fiber filaments;
• the upper fabric layer is made of a flame-retardant flexible material, and the upper fabric layer is configured to deform under a pressure to block off oxygen and plug the air leakage in the underground barrier coal pillar;
• the lower fabric layer is made of a water-soluble polyvinyl alcohol fiber, and when in contact with water, the lower fabric layer is dissolved such that the cement powder in the intermediate layer is mixed with the water to produce a cement slurry and the cement slurry is filled into fractures of the underground barrier coal pillar and solidified to plug the air leakage in the underground barrier coal pillar;
• and the use method comprises following steps:
• step 1, fixing to a roadway roof:
• in a roadway, laying the fire-prevention and extinguishing material for plugging the air leakage from top to bottom along a surface of the underground barrier coal pillar with air leakage, and arranging a top anchor rod at a top of the fire-prevention and extinguishing material for plugging the air leakage to fix the fire-prevention and extinguishing material for plugging the air leakage to the roadway roof, wherein the lower fabric layer faces towards the surface of the underground barrier coal pillar;
• step 2, fixing to the underground barrier coal pillar:
• at two sides of the fire-prevention and extinguishing material for plugging the air leakage, arranging fixing anchor rods at intervals of 1.5 m to 2 m from the roadway roof downwards, such that the fire-prevention and extinguishing material for plugging the air leakage is fixed to and pressed against the underground barrier coal pillar and the lower fabric layer is closely attached to the surface of the underground barrier coal pillar;
• step 3, spraying water for plugging the air leakage:
• spraying water with an underground water pipe evenly to the upper fabric layer of the fire-prevention and extinguishing material for plugging the air leakage, the water entering the intermediate layer through the upper fabric layer and mixing with the cement powder to produce the cement slurry, and continuing spraying water, the water coming in contact with the lower fabric layer to dissolve the lower fabric layer, and then the cement slurry in the intermediate layer flowing from the dissolved lower fabric layer to the surface of the underground barrier coal pillar, flowing into the fractures of the underground barrier coal pillar, and solidifying to plug the air leakage in the underground barrier coal pillar;
• and
• step 4, plugging the air leakage under a pressure:
• when the underground barrier coal pillar is deformed under the pressure, the plurality of fiber filaments and the upper fabric layer deforming as the underground barrier coal pillar is deformed and still covering the surface of the underground barrier coal pillar after the deforming to plug the air leakage in the underground barrier coal pillar because the plurality of fiber filaments and the upper fabric layer are flexible.