Provided is a multi-functional plugging agent for a coal mine and a preparation method thereof. The preparation method comprises: by taking Ecklonia Kurome Okam as a raw material, mixing an Ecklonia Kurome Okam suspension with phosphorus pentoxide for reaction, then performing biodegradation to obtain an Ecklonia Kurome Okam biological extract, adding urea for neutralization, mixing a neutralization product with an inorganic catalyst and melamine for reaction to obtain a bio-based plugging synergist solution, finally cooling the bio-based plugging synergist solution, and mixing the cooled bio-based plugging synergist solution with a certain amount of pentaerythritol and ammonium polyphosphate to obtain the multi-functional plugging agent for the coal mine based on the Ecklonia Kurome Okam biological extract. According to the invention, not only a coal crack can be effectively plugged for a long time, but also an efficient flame-retardant effect can be achieved in a complete period of coal spontaneous combustion.

Provided is a multi-functional plugging agent for a coal mine and a preparation method thereof. The preparation method comprises: by taking Ecklonia Kurome Okam as a raw material, mixing an Ecklonia Kurome Okam suspension with phosphorus pentoxide for reaction, then performing biodegradation to obtain an Ecklonia Kurome Okam biological extract, adding urea for neutralization, mixing a neutralization product with an inorganic catalyst and melamine for reaction to obtain a bio-based plugging synergist solution, finally cooling the bio-based plugging synergist solution, and mixing the cooled bio-based plugging synergist solution with a certain amount of pentaerythritol and ammonium polyphosphate to obtain the multi-functional plugging agent for the coal mine based on the Ecklonia Kurome Okam biological extract. According to the invention, not only a coal crack can be effectively plugged for a long time, but also an efficient flame-retardant effect can be achieved in a complete period of coal spontaneous combustion.

A method for ecological filling with mixed coal gangue and fly ash includes the following steps: S1: construction of a double-impermeable base layer: leveling a pit or gully, laying a fly ash-based cementitious material, compacting and curing; spraying a layer of polymer waterproof coating on a surface of the fly ash-based cementitious material, and fully curing to obtain a double-impermeable protective structure; S2: three-dimensional layered filling: dumping coal gangue and fly ash in sequence on the double-impermeable protective structure formed in S1, where the coal gangue and the fly ash are three-dimensionally layered and well graded; the coal gangue is coal gangue after coal washing, which is used as an aggregate; the fly ash is used as a filler and cementitious material to achieve a compact filling structure; and S3: rolling: rolling by a roller after the three-dimensional layered filling.

A method for slope geological disaster treatment and mineral resource recovery includes the following steps: S1: dividing a mountain top into a plurality of treatment sections and treatment segments; S2, selecting an easy-to-slide area at the upper portion of a first treatment segment and blasting an easy-to-slide body to make the easy-to-slide body roll down to a bottom of the slope; S3, forming a regular initial slope bench; S4, mining coal at the coal seam in a grouped mining adit manner, and laying grouting pipelines in the primary mining adits; S5, forming closed mining adits; S6, excavating secondary mining adits at intervals of the primary mining adits in sequence; S7, continuing mining in an adjacent second treatment segment in the same manner; and S8, continuing mining the first treatment segment of the second treatment section in the same manner.

The present invention provides for a compressible grout mix for filling an annular gap between a tunnel rock wall surface and a tunnel liner of a tunnel in a rock formation subject to time dependent deformation after excavation and a method of filling the annular gap between a tunnel rock wall surface and a tunnel liner of a tunnel in a rock formation subject to time dependent deformation after excavation utilizing the compressible grout mix for resilient absorption of forces in the hardened state of the compressible grout mix exerted by the time dependent deformation of the rock wall surface into the tunnel opening. The method includes:

a. providing the compressible grout mix comprising hydraulic binding agent, bentonite clay, polymer foam particles, water-reducing admixture, water and air,

b. placing the compressible grout mix in the annular gap between the tunnel wall rock surface and the tunnel liner, and

c. allowing the compressible grout mix to set, wherein the compressible grout mix in the hardened state has a compressible ratio greater than the anticipated time dependent deformation.

A method for filling a gap with a filler material, enabling prevention of inflow of the filler material into an air removing tool through its opening before complete removal of air from the gap, and enabling uniform filling of the gap with the filler material. The gap is between an existing conduit and a lining material provided inside the existing conduit. The method includes: inserting an air removing tool into an air removing hole bored through the lining material, and bringing a leading end face of the air removing tool into contact with the inner circumferential surface of the existing conduit; and injecting the filler material into the gap while expelling air from the gap through a leading end of the air removing tool, the air removing tool including, at its leading end, an air removing portion through which air is discharged.

A method for efficiently treating spontaneous ignition of the remaining coal in a large area goaf of a shallow-buried coal bed, which method integrates leaking stoppage, airflow control and fast inerting and cooling so as to efficiently prevent and treat the spontaneous ignition of the remaining coal in the large area goaf of the shallow-buried coal bed.

A synergistic mining method for underground mining, separation and filling for a close distance coal seam group is applicable to the mining engineering field. Full-mechanized caving mining is carried out for a close distance coal seam group, an underground coal gangue separation system and a filling face are designed according to the yield of gangue in the production process; the gangue produced in the mining process is transported centrally into an underground coal gangue separation chamber, and the separated gangue is transported to the filling face for filling and mining; the gangue produced at the filling face is transported back to the filling face for backfilling after underground washing separation. The method separates nearby and filling at selected locations, reduces the damage and disturbance to the underground rock mass that may be caused by a conventional mining method, and solves problems in treatment of strong dynamic pressure in advance.

A synergistic mining method for underground mining, separation and filling for a close distance coal seam group is applicable to the mining engineering field. Full-mechanized caving mining is carried out for a close distance coal seam group, an underground coal gangue separation system and a filling face are designed according to the yield of gangue in the production process; the gangue produced in the mining process is transported centrally into an underground coal gangue separation chamber, and the separated gangue is transported to the filling face for filling and mining; the gangue produced at the filling face is transported back to the filling face for backfilling after underground washing separation. The method separates nearby and filling at selected locations, reduces the damage and disturbance to the underground rock mass that may be caused by a conventional mining method, and solves problems in treatment of strong dynamic pressure in advance.

Provided is a method for recovering room-type coal pillars by cemented filling of reserved roadways, which is especially suitable for safe and efficient recovery of left coal pillars in room-type mining faces in mining areas where the ecological system is fragile, such as in western China. In the method, by constructing reserved roadways in two adjacent rows of room-type goafs, excavating coal pillar roadways in room-type coal pillars, and finally interconnecting the reserved roadways with the coal pillar roadways to form a U-shaped working face, room-type left coal pillars are recovered. Thus, not only the workload of roadway excavation is reduced, but also the recovery ratio of the coal resources is maximized. The method provides a novel technical model for the recovery of room-type left coal pillars in mining areas, such as in western China.