Technology of stereoscopic curtain grouting for accurate air leakage plugging and efficient fire prevention and extinguishing technology in Shendong Mining Area

To effectively control the hidden danger of coal spontaneous combustion caused by air leakage in shallow buried coal seam in Shendong Mining Area, taking the upper and lower coal seams of Huojitu Well 12 in Daliuta Coal Mine as the research object, the precision air leakage and fire prevention project demonstration was carried out by means of three-dimensional curtain grouting. The scheme calculates the grouting distance and designs the grouting layout using geological profiles to ensure that the grouting body is not affected by mining activities. Different geological conditions are addressed through the design of pilot boreholes, grouting boreholes, and monitoring boreholes. In accordance with the actual conditions of Huojitu Well, a total of 104 boreholes are constructed, with a curtain body length of approximately 1 020 m and a height of about 40 m. Utilizing the segmented ascending grouting method, the grouting height is set at 72 m for the working face cutting eye of the Well 12 lower coal seam, and 12 m for the 205 coal transport section of the Well 12 upper coal seam, with a grouting width of 15 m. The total grouting volume is estimated at 169 569.1 m3. Through the solid curtain grouting, the air leakage of working face 205 in Well 12 lower coal seam is reduced by about 1 000 m3/min and that of working face 207 in Well 12 lower coal seam is reduced by nearly 800 m3/min compared with the same conditions; the effect of plugging leakage air is obvious, and the hidden danger of spontaneous combustion of coal in the working face of Well 12 coal seams is effectively reduced.