CN108252651B - Method for fully mechanized mining face multipoint dispersion parallel type blast hole presplitting roof - Google Patents

Abstract

The invention discloses a method for fully mechanized mining face multipoint dispersion parallel type blast hole pre-splitting roof, which determines a drilling machine supporting angle according to the maximum mining height and the minimum mining height of a support arranged in a cutting hole on site, and determines the final hole depth and angle of the blast hole, the interval of the blast hole and the number of the blast holes according to the lithology of the roof; the invention provides a method for pre-splitting a top plate by using multi-point dispersion parallel type blast holes on a fully mechanized mining face, which is beneficial to complete collapse of the top plate, reduces the collapse impact range of a suspended roof to the maximum extent and improves the collapse efficiency of the top plate.

Description

Method for pre-split roof of multi-point scattered parallel blasthole in fully mechanized mining face

technical field

The invention belongs to the field of coal mining, and particularly relates to a method for pre-splitting roofs of multi-point dispersed parallel blastholes in fully mechanized mining faces.

Background technique

After the installation of the fully mechanized caving face, the initial mining and initial caving shall be carried out. According to the past experience and methods, in order to ensure the smooth initial caving of the working face, it is necessary to arrange multiple groups of deep hole blastholes in the upper and lower grooves to the side of the working face, respectively. Along with the advancing process of the working face, it can achieve the purpose of pre-splitting the roof in advance and make the roof collapse smoothly. However, this method takes a long time to drill holes, consumes a lot of manpower, material resources, and man-hours, and the comprehensive pre-splitting effect is not good, so it is often advanced on the working face. The roof will collapse when it is about 30-40m. The overhang area is large, and the shock wave accompanying the collapse is more harmful to the working face operators and mechanical equipment. The dust and toxic and harmful gases raised when the roof collapses in a large area prone to accidents.

SUMMARY OF THE INVENTION

Purpose of the invention: In order to overcome the deficiencies in the prior art, the present invention provides a method for pre-splitting the roof of the fully mechanized mining face with multi-point dispersed parallel blastholes, which is conducive to the complete collapse of the roof and reduces the suspended roof to the greatest extent. The caving impact range improves the roof caving efficiency.

Technical scheme: in order to achieve the above object, the technical scheme of the present invention is as follows:

The method for pre-splitting roof of multi-point scattered parallel blasthole in fully mechanized mining face includes the following steps:

Step 1: Determine the drilling rig support angle according to the maximum and minimum mining heights of the brackets installed in the cutting hole, and determine the depth and angle of the final hole of the blasthole, the distance between the blastholes, and the number of blastholes according to the lithology of the roof;

Step 2: Drill holes in the cutting holes of the coal mining face, the holes are set at the distance between the mining side coal wall and the coal wall of the working face, and the holes are inclined to the top plate of the working face and parallel to the working face. The blastholes are evenly set along the incision tendency of the working face at equal intervals;

Step 3: Set the first group of blastholes in the upper trough, the first group of blastholes includes upper trough holes S1 and upper trough holes S2, and the upper trough holes S1 are spaced from the upper trough mining side coal wall and working face The coal wall is set, and the upper slotted blasthole S1 is inclined to the top plate of the working face and parallel to the slotted direction; the upper slotted blasthole S2 is set at a distance of one meter from the upper slotted blasthole S1; Auxiliary blastholes are set at intervals along the length of the groove;

Step 4: Repeat the construction operation steps of Step 3 in the lower slot, and the distribution of blast holes in the lower slot is consistent with the distribution of blast holes in the upper slot;

Step 5: Place blasting charge packs in the cut holes, upper and lower blastholes. When sealing the mud, first use a number of water cannon mud to gently smash into the bottom of the blasting charge bag, and then use clay mud to seal it. Clay mud is sealed to the orifice;

Step 6: The blasting is carried out in the order from the cutting hole of the working face to the lower groove to the upper groove. The blastholes arranged in the cutting hole of the working face are blasted in groups from the nose to the tail of the machine. The blastholes arranged in the upper and lower grooves are blasted from the inside. Carry out group blasting outwards in turn;

Step 7: Observe the roof collapse in the goaf during the advancing process of the working face. If the roof collapses sufficiently, the advance pre-split blasting work is completed. Continue to punch holes until the top plate collapses.

Further, the blastholes in the cut hole shall be blasted from the completion of the installation of the hydraulic support on the working face to the trial production. The blastholes outside the 35m range of the coal wall of the working face shall be blasted with the mining advance of the working face to 35m of the coal wall of the working face.

Further, the blasting is carried out in groups of sub-groups, one group at a time, and no more than 3 blastholes per blasting; 2 blasting in the upper slot, 1 blasting in the lower slot, and each blasting in the incision hole. 3, the charge is forward charge, and the explosives in the group are connected in series.

Further, it includes a drill rod, one end of the drill rod is mounted with a detachable drill bit, the drill bit includes a base body and a cutter integrally provided on the base body, the base body is a cone structure, and the base body and the The drill rod is coaxially arranged, the small end of the base body faces outward, and the small end of the base body is provided with a blade assembly, the blade assembly includes a number of crushing blades arranged in a circular array, and three sets of the cutters are equidistant. The spacers are provided on the outside of the base body, and the cutter is above the top end of the base body.

Further, the cutter is an inclined wedge block structure, and the inclined wedge surface of the cutter faces the axis of the drill rod, and the inclined wedge surface is inclined to the side away from the end of the base body. At least one knife-edge insert is inlaid on the upper part, the knife-edge insert is arranged opposite to the blade assembly, and at least one reinforcement insert is inlaid on the outer side of the tool, and the reinforcement insert is a strip-shaped cemented carbide, and the The reinforcing inserts are arranged parallel to the axial direction of the drill rod, and the outer edges of the reinforcing inserts protrude from the outer side surface of the tool.

Further, water outlet holes are formed through the base body, a plurality of the water outlet holes are respectively arranged close to the cutter, and the water outlet holes are arranged inclined toward the inclined wedge surface of the adjacent cutter.

Beneficial effects: The present invention changes the previous thinking mode of centralized pre-splitting along the groove, and adopts the method of arranging multi-point scattered parallel blastholes in the cutting hole and the upper and lower grooves in advance to pre-split the working face roof, which is conducive to the complete collapse of the roof. , to minimize the area of the overhanging roof, reduce the impact range of the overhanging roof collapse, improve the roof collapse efficiency, ensure the safety of the fully mechanized mining face, and complete the initial mining and initial release efficiently and smoothly; it also includes a This kind of drill pipe is used for blast hole drilling, which can effectively adapt to different geological conditions for blast hole drilling and reduce the phenomenon of sticking.

Description of drawings

Accompanying drawing 1 is the step block diagram of the present invention;

Accompanying drawing 2 is the top view of blasthole arrangement of the present invention;

Accompanying drawing 3 is the front view of blasthole arrangement of the present invention;

Figure 4 is a schematic view of the drill pipe structure of the present invention.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings.

As shown in the accompanying drawings 1 to 3, the method for the multi-point scattered parallel blasthole pre-split roof in the fully mechanized mining face includes the following steps:

Step 1: Determine the drilling rig support angle according to the maximum and minimum mining heights of the brackets installed in the cutting hole, and determine the depth and angle of the final hole of the blasthole, the distance between the blastholes, and the number of blastholes according to the lithology of the roof;

Step 2: Drill holes in the cutting holes of the coal mining face, the holes are set at the distance between the mining side coal wall and the coal wall of the working face, and the holes are inclined to the top plate of the working face and parallel to the working face. The blastholes are evenly set along the incision tendency of the working face at equal intervals;

Step 3: Set the first group of blastholes in the upper trough, the first group of blastholes includes upper trough holes S1 and upper trough holes S2, and the upper trough holes S1 are spaced from the upper trough mining side coal wall and working face The coal wall is set, and the upper slotted blasthole S1 is inclined to the top plate of the working face and parallel to the slotted direction; the upper slotted blasthole S2 is set at a distance of one meter from the upper slotted blasthole S1; Auxiliary blastholes are set at intervals along the length of the groove;

Step 4: Repeat the construction operation steps of Step 3 in the lower slot, and the distribution of blast holes in the lower slot is consistent with the distribution of blast holes in the upper slot;

Step 5: Place blasting charge packs in the cut holes, upper and lower blastholes. When sealing the mud, first use a number of water cannon mud to gently smash into the bottom of the blasting charge bag, and then use clay mud to seal it. Clay mud is sealed to the orifice;

Step 6: The blasting is carried out in the order from the cutting hole of the working face to the lower groove to the upper groove. The blastholes arranged in the cutting hole of the working face are blasted in groups from the nose to the tail of the machine. The blastholes arranged in the upper and lower grooves are blasted from the inside. Carry out group blasting outwards in turn;

Step 7: Observe the roof collapse in the goaf during the advancing process of the working face. If the roof collapses sufficiently, the advance pre-split blasting work is completed. Continue to punch holes until the top plate collapses.

The blasthole in the cut hole shall be blasted from the completion of the installation of the hydraulic support on the working face to before the trial production. The blastholes outside the 35m range of the wall shall be blasted with the mining advance of the working face to 35m of the coal wall of the working face.

The blasting is carried out by sub-group blasting, one group at a time, and no more than 3 blastholes per blasting; 2 blasting in the upper slot, 1 blasting in the lower slot, and 3 blasting in the incision hole each time. The charge adopts forward charge, and the explosives in the group are connected in series.

The invention changes the previous thinking mode of centralized pre-splitting along the groove, and adopts the method of arranging multi-point scattered parallel blastholes in the cutting hole and the upper and lower grooves in advance to pre-split the working face roof, which is conducive to the complete collapse of the roof, and the maximum It reduces the area of the overhanging roof, reduces the impact range of the overhanging roof collapse, improves the roof collapse efficiency, ensures the safety of the fully mechanized mining face, and can efficiently and smoothly complete the initial mining and initial caving. In the actual production application, the support is fully advanced within the range of 5-10m of the cut hole, and the roof completely collapses. Compared with the previous method, the collapse can only be achieved within the range of 30-40m, which shortens the roof collapse step distance of 25-30m. The working face within the range of -30m can be caving top coal for mining, which can increase the coal mining output and improve the economic benefits.

The following is an example of the actual application in a coal mining operation in Aksu area. The fully mechanized caving face is arranged in a regular rectangle. The length of the cut hole is 60m, the length of the upper groove is 706.2m, and the length of the lower groove is 703.5m. The average working face is The strike length is 704.9m, the coal seam thickness is 5.2~5.8m, the average is 5.5m, the coal seam dip angle is 22°~30°, the working face slope is about 27° on average, and the cutting hole length of the working face is 58.6m. No fault structure was exposed during the excavation process, and the geological conditions of the working face were simple. The working face adopts ZF4800/17/30 hydraulic support and ZFG4800/19/32 type transition hydraulic support to support the roof. The drilling rig support angle is determined according to the maximum and minimum mining height of the support installed in the cut hole on site, and is determined according to the lithology of the roof. The depth and angle of the end hole of the blasthole, as well as the distance between the blastholes and the number of blastholes, finally determine the blasthole setting plan.

After the cutting hole and brushing of the working face are completed, a KHYD155 rock drilling rig is arranged in the cutting hole at a distance of 3m and 90m from the coal wall on the mining side of the upper trough respectively. The KHYD155 rock drilling rig is used to construct pre-split roof holes in the cut holes according to the design requirements. After the drilling in the cut holes is completed, the drilling rigs are transported to the pre-split roof holes in the upper and lower grooves for construction. According to the comprehensive consideration of the roof lithology, previous experience of pre-splitting the roof of similar working face, the adaptation conditions of the selected rock drilling rig, and the influence of the equipment in the trough, the pre-split roof hole is designed as follows:

Roof hole design for pre-splitting in the cut hole: The first group of blastholes: 3m away from the coal wall on the mining side of the upper trough, 0.5m away from the coal wall of the working face, the angle with the roof of the working face is 75°, and the inclination parallel to the working face (toward the upper end) head direction), the final hole depth is 8m. Other blastholes: the distance between each blasthole and the previous blasthole is 3m, the distance from the coal wall of the working face is 0.5m, the angle with the roof of the working face is 75°, the inclination parallel to the working face (towards the upper end), and the depth of the final hole is 8m. The length of the incision inclination of the working face is 186.5m, and a total of 60 blastholes are arranged.

Design of pre-split roof hole in the upper trough: S1# blasthole: 5m away from the coal wall on the old pond side of the cutting hole, 1.5m from the coal wall on the mining side of the upper trough, and the angle with the roof of the trough is 75°, parallel to the trend of the trough ( toward the gob direction), the final hole depth is 8m.

S2# blasthole: 5m away from the coal wall on the old pond side of the cutting hole, 2.5m from the coal wall on the side of the upper trough, and the angle with the roof of the trough is 75°, parallel to the trend of the trough (towards the goaf), and the end hole Depth 8m.

Other blastholes: The distance between each group of blastholes is 3m from the previous group of blastholes, and the other parameters of each group of blastholes refer to the construction of S1# and S2# blastholes.

Design of pre-split roof hole in the lower trough: X1# blasthole: 5m away from the coal wall on the side of the cutting hole, 1.5m from the coal wall on the mining side of the lower trough, with an angle of 75° with the roof of the trough, parallel to the trend of the trough (towards the side of the trough) gob direction), and the final hole depth is 8m. Other blastholes: The distance between each blasthole is 3m from the previous blasthole, and the rest parameters of each group of blastholes refer to X1# blasthole construction.

After the blasthole construction is completed, the blasting is carried out in groups and sequentially to ensure the advancement of the working face and the recovery of the coal seam.

As shown in Figure 4, a drill pipe 1 used for multi-point dispersed parallel blasthole pre-split roof in fully mechanized mining face, one end of the drill pipe 1 is equipped with a detachable drill bit, which is convenient for maintenance and replacement. The drill bit includes a base body 8 and a cutter 2 integrally arranged on the base body 8. The base body 8 is a conical structure, and the base body 8 is coaxially arranged with the drill rod. The small end of the base body 8 faces outward, and The small end of the base body 8 is provided with a blade assembly 5, and the blade assembly 5 includes a number of crushing blades arranged in a circular array. 2 is higher than the top of the base body 8 . Due to the fact that in the actual mining work, the soil properties are different in different regions, regions, and depths, and there are various environments such as hard, viscous or loose soil. When the viscous soil is high, sticking or sticking of the drill is very likely to occur, which leads to the wear of the drill pipe and greatly affects the progress. The drill pipe in the present invention can effectively solve the problems of soil sticking and sticking. The cutting tool is first broken and the broken soil is diverted, so that the broken soil has more space to move to the outside of the drilling hole, which avoids the accumulation of soil between the cutting tool and the soil to be drilled, and reduces the occurrence of clay sticking and sticking. situation, and at the same time further soil breaking is carried out by the blade assembly 5, preventing the formation of large clods.

The tool 2 is a wedge block structure, and the wedge surface 7 of the tool faces the axis of the drill rod, and the wedge surface 7 is inclined to the side away from the end of the base body 8. At least one knife-edge insert 6 is inlaid on the surface 7, and the knife-edge insert 6 is arranged opposite to the blade assembly 5. The drilled soil moves toward the middle area enclosed by the cutter through the wedge, and is broken when the drill rod rotates. The blade is broken, and at the same time, the blade insert 6 plays the role of increasing the strength of the tool and reducing the wear of the tool. The outer side of the tool 2 is inlaid with at least one strengthening insert 3, and the strengthening insert 3 is a strip of cemented carbide. The reinforcing inserts 3 are arranged parallel to the axial direction of the drill rod, and the outer edges of the reinforcing inserts 3 protrude from the outer surface of the tool 2 . During drilling, the reinforced inserts 3 and the knife-edge inserts 6 are used to crush the gravel or hard objects in the soil, so as to improve the life of the tool.

The base body 8 is provided with water outlet holes 4 penetratingly therethrough. A plurality of the water outlet holes 4 are respectively disposed close to the cutter 2 , and the water outlet holes 4 are arranged obliquely toward the inclined wedge surface of the adjacent cutter 2 . It can reduce the heat of the drill hair when drilling, increase the durability of the tool, and at the same time, it can also reduce the heat and flush the inserts 6 on the wedge surface to prevent sticking.

The above is only the preferred embodiment of the present invention, it should be pointed out that: for those skilled in the art, without departing from the principle of the present invention, several improvements and modifications can also be made, and these improvements and modifications are also It should be regarded as the protection scope of the present invention.

Claims (4)

1. the method for multi-point scattered parallel blasthole pre-split roof in fully mechanized mining face, is characterized in that: comprise the following steps: Step 1: Determine the drilling rig support angle according to the maximum and minimum mining heights of the brackets installed in the cutting hole, and determine the depth and angle of the final hole of the blasthole, the distance between the blastholes, and the number of blastholes according to the lithology of the roof. ) to carry out blast hole drilling; Step 2: Drill holes in the cutting holes of the coal mining face, the holes are set at the distance between the mining side coal wall and the coal wall of the working face, and the holes are inclined to the top plate of the working face and parallel to the working face. The blastholes are evenly set along the incision tendency of the working face at equal intervals; Step 3: Set the first group of blastholes in the upper trough, the first group of blastholes includes upper trough holes S1 and upper trough holes S2, and the upper trough holes S1 are spaced from the upper trough mining side coal wall and working face The coal wall is set, and the upper slotted blasthole S1 is inclined to the top plate of the working face and parallel to the slotted direction; the upper slotted blasthole S2 is set at a distance of one meter from the upper slotted blasthole S1; Auxiliary blastholes are set at intervals along the length of the groove; Step 4: Repeat the construction operation steps of Step 3 in the lower slot, and the distribution of blast holes in the lower slot is consistent with the distribution of blast holes in the upper slot; Step 5: Place blasting charge packs in the cut holes, upper and lower blastholes. When sealing the mud, first use a number of water cannon mud to gently smash into the bottom of the blasting charge bag, and then use clay mud to seal it. Clay mud is sealed to the orifice; Step 6: The blasting is carried out in the order from the cutting hole of the working face to the lower groove to the upper groove. The blastholes arranged in the cutting hole of the working face are blasted in groups from the nose to the tail of the machine. The blastholes arranged in the upper and lower grooves are blasted from the inside. Carry out group blasting outwards in turn; Step 7: Observe the roof collapse in the goaf during the advancing process of the working face. If the roof collapses sufficiently, the advance pre-split blasting work is completed. Continue to punch holes until the roof collapses; A detachable drill bit is installed at one end of the drill rod (1), the drill bit includes a base body (8) and a cutter (2) integrally provided on the base body (8), and the base body (8) is a cone The base body (8) is arranged coaxially with the drill pipe, the small end of the base body (8) faces outward, and the small end of the base body (8) is provided with a blade assembly (5). The blade assembly (5) includes a plurality of crushing blades arranged in a circular array, three sets of the cutters (2) are arranged at equal intervals on the outside of the base body (8), and the cutters (2) are higher than the base body (8). top; The cutter (2) is of an inclined wedge block structure, and the inclined wedge surface (7) of the cutter faces the axis of the drill rod, and the inclined wedge surface (7) is inclined to be away from the end of the base body (8). One side is provided, at least one knife-edge insert (6) is inlaid on the wedge surface (7), the knife-edge insert (6) is arranged opposite to the blade assembly (5), and the outer side of the cutter (2) At least one strengthening insert (3) is inlaid and provided, the strengthening insert (3) is a strip-shaped cemented carbide, and the strengthening insert (3) is arranged parallel to the axial direction of the drill pipe, and the strengthening insert ( The outer edge of 3) protrudes from the outer side of the tool (2). 2. the method for multi-point scattered parallel type blasthole pre-split roof of fully mechanized mining face according to claim 1, is characterized in that: blasthole in the cut hole is blasted before the hydraulic support of the working face is installed to the trial production, and the upper and lower holes are blasted. The blastholes within the range of 35m from the coal wall of the working face along the trough shall be blasted from the completion of the installation of the working face to the trial production. blasting. 3. the method for multi-point scattered parallel type blasthole pre-split roof of fully mechanized mining face according to claim 1, is characterized in that: blasting adopts sub-assembly charge group blasting, blasting one group at a time, every blasting is no more than 3 Blowholes; 2 blasting in the upper slot, 1 blasting in the lower slot, 3 blasting in the incision hole each time, the charge is forward charge, and the explosives in the group are connected in series. 4. The method for multi-point dispersed parallel blasthole pre-split roof in fully mechanized mining face according to claim 1, characterized in that: the base body (8) is provided with water outlet holes (4), a plurality of the water outlet holes (4) The water outlet holes (4) are respectively arranged close to the cutters (2), and the water outlet holes (4) are arranged obliquely toward the inclined wedge surfaces of the adjacent cutters (2).

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