RU2151293C1 - Method of difficult-to-cave roof control in mining of coal seams by powered mining set - Google Patents

Abstract

FIELD: coal industry, particularly, rock pressure control, precisely, methods of difficult-to-cave roofs control in breakage faces in mining coal seams by powered mining set. SUBSTANCE: method includes artificial caving of strong roof at preset distance of pillar extraction by reorientation of location of formed rock blocks parallel to face edge with displacement of roof caving boundary in direction of goat beyond the limits of longwall working space due to provision of maximum span of main roof by formation of slots in pillars near belt heading. Slots are made by drilling and blasting operations. EFFECT: provision of trouble-free operation of powered mining set in extraction of seams with difficult-to-cave roofs. 2 cl, 6 dwg

Description

 The invention relates to the coal industry, in particular to the field of rock pressure control, and in particular to methods for controlling hard-to-collapse roofs in working faces when mining coal seams with mechanized complexes.

 A known method of controlling the roof of its complete collapse, the essence of which is that they collapse the direct roof by its natural destruction by detecting it as a result of excavation of the coal seam, which bucks the main roof, while the roof is planted either on special supports or on the bottom with their partial reinforcement by additional racks, as well as without any reinforcement (see A.K. Kovrizhin, V.F. Krylov, S.I. Zapreev, Roof management in treatment faces at the mines of Kuzbass, M., Nedra, 1969 , WITH 47-51, 52-54).

 The disadvantage of this method is the impossibility of its use in the mining of formations with hard-to-collapse roofs, when the displacement of the roof occurs almost instantly, which leads to the emergency state of the mechanized roof support and lava.

 A known method of controlling hard-collapsible roofs using advanced torpedoing, which we adopted as a prototype, the essence of which lies in the fact that in front of the front of the treatment work in long wells drilled in the roof over a coal seam, a large amount of explosives (explosives), resulting in destruction the main roof into blocks approximately equal to the natural collapse step (see Katkov G.A., Ostapenko V.N., Zhurilo A.A. (IHD named after A.A. Skochinsky) Management of hard-to-break roofs using the advanced method torpedoing: review / TsNIIEIugol. - M., 1982, p. 6).

 The disadvantages of this method are the necessity of drilling a large amount of holes (wells) through the rock, i.e. characterized by the high complexity of drilling operations, their charging and lack of control on the effective impact on the roof, limited by the scope (see source of information above, p. 25), as well as the orientation of the formation and collapse of the main roof blocks with support on a mechanized support, which leads to the inclination of the blocks and the redistribution of loads on it, causing the landing "dry", which leads the lining in an emergency state.

 The objectives of the invention are to remedy the above-mentioned disadvantages, ensuring trouble-free operation of the mechanized complex during mining of formations with hard-to-collapse roofs.

 This is achieved by the fact that at a given working distance of the pillar, a hard roof is artificially planted by reorienting the placement of the resulting rock blocks parallel to the bottom edge with a shift of the roof collapse direction in the direction of the blockage beyond the lava working space by creating a maximum span of the main roof by creating gaps in the pillars about conveyor drift and the formation of a side pillar with protective support platforms (shoulders), while the formation of cracks is carried out with the help of Drilling and blasting operations.

 Indeed, the displacement of the boundary of the roof collapse from the bottom in the direction of the blockage ensures the operation of the mechanized complex under the protection of the main roof console.

 This technical solution is implemented by artificially increasing the span of the main roof in a direction perpendicular to the movement of the lava, which initiates the initial landing, while increasing the span of the main roof is carried out by forming a gap in the conveyor drift at a certain distance, leaving the supporting coal mass on which the main roof, protecting mechanized support during the initial landing.

 The invention is illustrated by drawings, where in FIG. 1 shows the nature and form of the primary landings of hard hard-to-collapse roofs in the traditional way of managing the roof by complete collapse; in FIG. 2 is a section AA of FIG. 1; in FIG. 3 is a diagram of the formation of a gap in the side of a conveyor drift with the leaving of a coal support mass; in FIG. 4 is a section BB of FIG. 3; in FIG. 5 shows the nature and shape of the primary landings of hard hard-to-collapse roofs using the proposed method of roof management; in FIG. 6 is a section CC of FIG. 5.

 In order to better perceive the proposed invention, we first present the usual traditional way of controlling the roof.

 In FIG. Figures 1 and 2 show lava 1, limited by ventilation 2 and conveyor 3 drifts, equipped with a mechanized complex 4. Management of the hard-to-collapse roof is carried out by the traditional method (complete collapse), which is accompanied by the occurrence of significant loads on the mechanized roof supports, leading to their emergency state, especially during initial landings .

 It was established by operating experience that the primary collapse of the main roof 5 has an elliptical shape, the main cracks 6 of which are located inside as a “closed envelope”, while the base of the collapse console breaks off in the depth of the lava massif at a distance of 5-8 m from the face bottom (edge), the end of which hangs over the mechanized roof support (Fig. 2), leading it to an emergency state. Faults of the main roof also occur in the depth of the entire supporting perimeter along the conveyor and ventilation drifts at a distance of 5-8 m from the side and cause extremely difficult conditions for their maintenance. Direct roof 7 is destroyed in a similar way. Point "P" - the point of application of the resultant force of collapse.

 The essence of the invention (Fig. 3, 4, 5, 6) consists in the fact that certain measures create conditions in the lava under which the powered roof supports work under the protection of the main roof console.

 To achieve this, at a given distance of working out the column, the transverse size (span) of the main roof collapse plate is artificially increased in the direction perpendicular to the movement of the lava, and the initial landing is initiated. The span of the main roof is increased due to the formation of a slit in the side of the conveyor drift 3 (zone "A", Fig. 3) and the supporting section of the coal mass (zone "B", Fig. 3) to hold the main roof. An air gap is created below the conveyor drift by drilling holes 8 in length up to 40 m in a coal mass with a distance between them of the order of 0.8-1.0 m, in which explosive charges are blasted.

 With an increase in the span of the main roof, a redistribution of the acting forces occurs, while the resultant weight of the overlying rocks, located at the point “P” of the intersection of the diagonals of the reference perimeter, moves from the middle of the worked out space to the side of the array above which the gap is formed, while the formation and collapse of the main roof occurs parallel to the chest of the face outside the working space of the lava with the preservation of the console of the main roof over the lining (Fig. 5, 6). Mechanized lining, being protected by the main roof console (Fig. 6), resting on the supporting section “B” of the coal mass along the sides and in front of the face, does not experience destructive loads and works in operational mode.

 Additionally, the use of the invention allows to significantly reduce the complexity of drilling holes, because the latter are carried out on coal, not on rock, and also to reduce the consumption of explosives during drilling and blasting operations to create cracks in the sides of the conveyor drift.

Claims (2)

 1. A method for controlling a hard-collapsible roof when developing coal seams with mechanized complexes, including planting a roof by complete collapse, characterized in that at a given working distance of the pillar, a hard roof is artificially planted by reorienting the placement of the formed rock blocks parallel to the edge of the face with the displacement of the collapse of the roof in the direction blockage beyond the working space of the lava by creating the maximum span of the main roof through the formation of a slit her in pillars near the conveyor drift and the formation of airborne pillars with protective support platforms.  2. The method according to claim 1, characterized in that the formation of cracks is carried out by means of drilling and blasting operations.

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