A self-forming lane mining method with active filling of top cutting, crushing and expansion in a large mining height working face without coal pillars

Abstract

This invention discloses a method for actively filling pillarless self-forming roadway in ultra-high mining faces by cutting, breaking, and expanding the roof. It belongs to the field of coal mining technology. The method uses a multi-directional expansion and fracturing method of the roof, backfilling of coal gangue after the working face is erected, and advanced vertical high-level grouting on the surface to three-dimensionally control the unfilled space in the pillarless self-forming roadway method. This solves the problem of instability caused by large unfilled space in the surrounding rock of the roadway under ultra-high mining conditions. It avoids geological disasters such as large deformation of the surrounding rock, rockburst, and coal and gas outburst caused by stress concentration above the coal pillar. It also reduces mining damage and ecological damage to the entire mine goaf.

Description

Technical Field

[0001] The invention relates to the technical field of coal mining, in particular to a method for self-forming laneway mining with active filling of top cutting, crushing and expansion in a super-large mining height working face without coal pillars. Background Art

[0002] Coal is the main energy source in my country, accounting for more than 50% of the primary energy production and consumption structure for a long time, and is the "ballast stone" of my country's energy security and stability supply. The self-forming roadway mining technology without coal pillars is one of the effective technologies to maintain the sustainable development of my country's coal resources. This technology maintains the original recovery roadway by cutting the top to relieve pressure, and uses the crushing and expansion of the collapsed gangue to achieve goaf-side roadway retention and coal-free mining. The self-forming roadway mining technology without coal pillars can not only reduce the stress concentration of the surrounding rock and reduce the accumulation of gas in the roadway in terms of safety; but also greatly reduce the excavation volume of the recovery roadway, improve the recovery rate of coal resources, and reduce the cost of coal mining in terms of economy. This technology has been included in the "Energy Production and Consumption Revolution Strategy (2016-2030)" (Development and Reform Foundation

[2016] No. 2795) by the National Development and Reform Commission and the Energy Bureau to encourage and promote it, and has broad application prospects and high research value.

[0003] The extra-large mining height working face refers to the working face with a mining height of more than 5m and a large thickness of the mined coal seam. The self-forming roadway mining technology without coal pillars has been widely used in thin and medium-thick coal seams, but it has encountered technical bottlenecks in the application process of the extra-large mining height working face in thick coal seams. The self-forming roadway technology without coal pillars mainly relies on the formation of gravel side protection roadway by the gangue that collapses and expands in the goaf under the action of cutting the top. Under the conditions of extra-large mining height in thick coal seams, a super-large space is formed after the working face is mined, the overburden movement is violent, and the broken and expanded gangue formed by the collapse of the roof is difficult to completely fill the goaf. A stable bearing structure cannot be formed between the roof of the remaining roadway and the gangue in the goaf. Compared with thin and medium-thick coal seams, when the extra-large mining height working face in thick coal seams is cut into roadways, the supporting pressure of the roadway surrounding rock will increase significantly, the impact of the gangue collapse in the goaf will increase, the period of the gravel side reaching stability will be lengthened, and the stability control of the roadway surrounding rock will become more difficult. Summary of the invention

[0004] The purpose of the present invention is to provide a method for self-forming laneway mining with active filling of roof cutting, crushing and expansion in a working face with extra-large mining height, which can solve the instability problem caused by the large unfilled space of surrounding rock in laneway formed under extra-large mining height conditions by jointly performing three-dimensional regulation of the unfilled space through multi-directional roof expansion technology, coal gangue filling technology behind the working face frame and advanced vertical high-position grouting technology on the surface.

[0005] To achieve the above-mentioned purpose, the present invention provides a method for mining a self-forming tunnel without coal pillars by actively filling the roof by cutting and crushing the working face with a very large mining height, which adopts a multi-directional roof expansion method, coal gangue filling behind the working face frame and advanced vertical high-position grouting on the surface to jointly perform three-dimensional regulation of the unfilled space in the self-forming tunnel without coal pillars method.

[0006] Preferably, the multi-directional roof cracking method uses artificial directional cracking technology to perform full-space top cutting and crushing, and the steps include:

[0007] Mark the slotting and drilling holes at the corresponding positions on the top plate;

[0008] Drill holes for construction at the drilling positions, drill directional energy-gathering holes and strong expansion holes, and all slit holes are located in the same plane;

[0009] Install an energy-gathering device in the directional energy-gathering hole, and install a multi-directional fracturing tube in the strong-release fracturing hole;

[0010] Multi-directional blasting is used to carry out multi-directional fracturing.

[0011] Preferably, the gangue filling behind the working face frame adopts a one-cut-one-filling method to fill the goaf behind the working face, and the steps include:

[0012] S1. Set up hydraulic supports on the working surface;

[0013] S2. A gangue filling system is arranged behind the hydraulic support. The gangue filling system lifts the gangue from the well and crushes it, and then transports it to the filling system behind the hydraulic support of the working face through a transportation pipeline;

[0014] S3. Use the filling system behind the hydraulic support to fill the mining face with coal gangue and compact it.

[0015] Preferably, the hydraulic support includes a front top beam, a rear top beam, an auxiliary column, an adjustment column, a column, a base and a four-bar linkage. A multi-porous bottom-discharge scraper conveyor is arranged under the rear top beam. The front top beam and the rear top beam are connected. A column is arranged between the front top beam and the base. One end of the four-bar linkage is connected to the base, and the other end is connected to the connecting port of the front top beam and the rear top beam. An auxiliary column is arranged between the rear top beam and the four-bar linkage. An adjustment column is arranged between the multi-porous bottom-discharge scraper conveyor and the four-bar linkage. A discharge hole is arranged on the multi-porous bottom-discharge scraper conveyor.

[0016] Preferably, the filling system behind the hydraulic support in step S2 includes a porous bottom discharge conveyor, a bridge belt conveyor and a chute conveyor belt conveyor.

[0017] Preferably, in step S3, the filling system behind the hydraulic support fills the mining working face with coal gangue and compacts the coal gangue, including:

[0018] (1) Cut one step, move the frame, and push the machine according to the regular cycle machine;

[0019] (2) Extend the head, middle trough and tail of the porous bottom-discharging scraper conveyor into place;

[0020] (3) Start the multi-hole bottom-discharging scraper conveyor on the working face, and then start the bridge belt conveyor and the chute waste belt conveyor to fill the goaf with waste rock;

[0021] (4) The multi-hole bottom-discharging scraper conveyor is filled from the front to the rear. The discharge holes of the multi-hole bottom-discharging scraper conveyor are opened in sequence, and the goaf behind the frame of the section is filled with waste rock. When the waste rock in the area behind the frame corresponding to the discharge hole is filled to the height of the conveyor bottom, the discharge hole is closed and the discharge holes are opened backward in sequence;

[0022] (5) Fill the middle and upper part of the filled material and push the filled material;

[0023] (6) Fill the unfilled discharge hole, close the discharge hole after filling, fill the middle and upper part of the filling material and fill the filling space after compaction;

[0024] (7) Repeat steps (4) to (6) until the entire working surface is filled and compacted, and then stop the first round of filling;

[0025] (8) Move the multi-hole bottom-discharging scraper conveyor one step distance from the front to the rear of the machine, repeat the above steps, and finally close all the discharge holes to complete the filling work.

[0026] Preferably, when filling through the discharge holes in step (4), at most three discharge holes are opened.

[0027] Preferably, the surface advanced vertical high-position grouting is performed to bond and fill the separation space by grouting, and the steps include:

[0028] Configure slurry according to the mining speed of the working face;

[0029] The location of the underground tunnel is determined by transparent geological detection technology, and upper S-shaped grouting is carried out within 30m of the tunnel from the surface.

[0030] Therefore, the present invention adopts the above-mentioned extra-large mining height working face top cutting and crushing active filling non-coal pillar self-forming lane mining method, which has the following beneficial effects:

[0031] (1) The technology of self-forming tunnel without coal pillars is regulated by multi-directional roof expansion technology, coal gangue filling behind the working face, and advanced vertical high-position grouting on the surface, thus avoiding geological disasters such as large deformation of tunnel surrounding rock, rock burst, and coal and gas outburst caused by stress concentration above the coal pillars, and reducing mining damage and ecological damage in the entire mine goaf;

[0032] (2) Through coordinated regulation of gangue filling, grouting and roof collapse, the entire goaf is filled, so that the full-height mining method can be directly realized in one-time mining without coal pillars and self-forming lanes in ultra-large mining height, and the mining volume and crushing volume can be balanced, thereby reducing coal mine disasters caused by mine pressure and realizing green mining.

[0033] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a schematic diagram of the controlled mining method of the present invention;

[0035] Figure 2 This is a cross-sectional diagram of the surface advanced vertical high-position grouting of the present invention;

[0036] Figure 3 It is a top view of the surface advanced vertical high-position grouting of the present invention;

[0037] Figure 4 This is a schematic diagram of coal gangue filling behind the working face frame of the present invention;

[0038] Figure 5 It is a schematic diagram of the layout of the mining area of ​​the gangue filling system of the present invention;

[0039] Figure 6 This is a schematic diagram of the underground gangue preparation and conveying unit of the present invention;

[0040] Figure 7 This is a schematic diagram of the structure of the hydraulic support of the present invention;

[0041] Figure 8 This is a schematic diagram of the multi-directional cracking method of the roof of the present invention;

[0042] Reference numerals

[0043] 1. Gangue bin; 2. Gangue crushing and processing plant; 3. Carrier; 4. Trackless rubber-wheeled vehicle; 5. Gangue preparation and conveying unit; 51. Retractable belt conveyor for return air chute of working face; 511. Machine tail; 512. Transition bend; 513. Loader; 514. Machine head; 53. Underground gangue slag preparation machine; 54. Gangue pump; 6. Hydraulic support; 61. Front top beam; 62. Rear Top beam; 63, auxiliary column; 64, adjustment column; 65, column; 66, base; 67, four-bar linkage; 68, multi-hole bottom-discharge scraper conveyor; 69, discharge hole; 7, coal gangue filling; 8, coal mining machine; 9, grouting hole; 10, key layer; 11, UHPC material filling; 12, tunnel; 13, strong release expansion hole; 14, directional energy focusing hole; 15, coal body. DETAILED DESCRIPTION

[0044] Example

[0045] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0046] Reference Figure 1-8 The present invention provides a method for mining a self-forming lane without coal pillars by actively filling the roof with cutting, crushing and expansion in a super-large mining height working face, which adopts a multi-directional roof expansion method, coal gangue filling behind the working face frame and advanced vertical high-position grouting on the surface to jointly perform three-dimensional regulation of the unfilled space in the self-forming lane without coal pillars method.

[0047] (1) Multi-directional roof cracking method: After the roof collapses, it will break and expand, and its volume will increase compared to the original volume. By artificially adopting the directional cracking technology to cut and crush the roof in the entire space, the volume of the collapsed rock mass will be increased, and the block size control and crushing and expansion regulation will be carried out to make the gangue formed after the roof collapse fully broken and expanded, further filling the mining space.

[0048] The steps include:

[0049] Use spray paint to mark the cutting and drilling holes at the corresponding positions of the top plate in advance, with a drilling spacing of 600mm.

[0050] The drilling holes are constructed at the drilling angles of 10° and 30° perpendicular to the top plate. The holes at an angle of 10° perpendicular to the top plate are directional energy-gathering holes 14, and the holes at an angle of 30° perpendicular to the top plate are strong expansion holes 13. All the slit drill holes are located in the same plane.

[0051] An energy focusing device is installed in the directional energy focusing hole 14, specifically:

[0052] Place explosives into the first energy focusing device, install detonators and fuses, then pass the fuses through the second energy focusing device, and connect the second energy focusing device to the first energy focusing device with a connector, then start loading charges and install fuses in the second tube, repeat the above steps, complete the loading of all energy focusing devices in sequence, use continuous charging and place a detonator in each energy focusing device.

[0053] A multi-directional fracturing tube is installed in the strong fracturing hole 13.

[0054] A multi-directional blasting method is adopted to carry out multi-directional fracturing according to the hardness of the roof rock, and the collapse degree of the roof rock mass is controlled by adjusting different fracturing angles.

[0055] (2) Gangue filling behind the working face: After normal machine cutting, gangue filling is carried out behind the working face, using a one-cut-one-filling method to fill the goaf behind the face. The steps include:

[0056] S1. A hydraulic support is set up on the working surface. The hydraulic support 6 includes a front top beam 61, a rear top beam 62, an auxiliary column 63, an adjustment column 64, a column 65, a base 66 and a four-bar linkage 67. A multi-hole bottom-discharge scraper conveyor 68 is arranged under the rear top beam 62. The front top beam 61 is connected to the rear top beam 62. A column 65 is arranged between the front top beam 61 and the base 66. One end of the four-bar linkage 67 is connected to the base 66, and the other end is connected to the connection port of the front top beam 61 and the rear top beam 62. An auxiliary column 63 is arranged between the rear top beam 62 and the four-bar linkage 67. An adjustment column 64 is arranged between the multi-hole bottom-discharge scraper conveyor 68 and the four-bar linkage 67. A discharge hole 6 is arranged on the multi-hole bottom-discharge scraper conveyor 68.

[0057] S2. A gangue filling system is arranged behind the hydraulic support 6. The gangue filling system lifts the gangue from underground into the well and crushes it, and then transports it to the filling system behind the hydraulic support of the working face through a transport pipeline.

[0058] The gangue filling system includes a gangue bin 1, a gangue crushing and processing plant 2, a carrier 3, a trackless rubber-wheeled vehicle 4 and a gangue preparation and conveying unit 5. The gangue preparation and conveying unit 5 includes a working face return air chute retractable belt conveyor 51, an underground gangue slag preparation machine 52 and a gangue pump 53. The filling system behind the hydraulic support 6 includes a porous bottom discharge conveyor 68, a bridge belt transfer machine and a chute gangue belt conveyor.

[0059] The specific steps include: the gangue filling system transports the underground gangue to the gangue bin 1, the gangue crushing and processing plant 2 crushes the gangue in the gangue bin 1, the carrier 3 transports the gangue slag to the trackless rubber-wheeled vehicle 4, the trackless rubber-wheeled vehicle 4 transports the gangue slag to the tail 511 of the underground gangue loader 51, and the gangue slag passes through the transition bend 512 of the working face return air chute retractable belt conveyor 51, the loader 513, the head 514 and the underground gangue slag preparation machine 53 in sequence, and is transported to the porous bottom-discharging scraper conveyor 68 through the gangue pump 54.

[0060] S3, using the filling system behind the hydraulic support to fill the mining face with coal gangue and compact it. The steps include:

[0061] (1) Cut one step, move the frame, and push the machine according to the regular cycle machine;

[0062] (2) Extend the nose, middle trough and tail of the porous bottom-discharging scraper conveyor 68 into place;

[0063] (3) Start the multi-hole bottom-discharging scraper conveyor 68 on the working face, and then start the bridge belt conveyor and the chute waste rock belt conveyor transportation equipment to fill the goaf with waste rock;

[0064] (4) The multi-hole bottom-discharging scraper conveyor 68 is filled from the front to the rear. The first discharge hole 69 of the multi-hole bottom-discharging scraper conveyor 68 is opened to fill the goaf behind the frame with waste rock. When the waste rock in the area behind the frame corresponding to the first discharge hole 69 is filled to the height of the conveyor bottom, the first discharge hole 69 is closed and the second discharge hole 69 is opened backward in sequence. When discharging, a maximum of three discharge holes 69 are opened.

[0065] (5) The second discharge hole 69 is unloaded, and the adjustment column 64 is started to move the porous bottom discharge scraper conveyor 68 downward to fill the middle and upper part of the filled material and push the filled material. After the pushing is completed, the adjustment column 64 is started to return to the original position.

[0066] (6) Fill the second discharge hole 69, close the discharge hole 69 after filling, start the adjustment column 64 to fill the middle and upper part of the filling material of the second discharge hole 69, and fill the filling space after the first discharge hole 69 is compacted. After completion, start the adjustment column 64 to return to its original position.

[0067] (7) When the filling space after the rear of the first discharge hole 69 is compacted is filled, the first discharge hole 69 is closed for compaction, and the filling space after the rear of the second discharge hole 69 is filled. After the first two discharge holes 69 are filled and compacted, if the filling work of the rear area of ​​the third discharge hole 69 is completed, the rear space of the fourth discharge hole 69 is opened for filling, and the rear area of ​​the third discharge hole 69 is compacted. In this way, the material filling and compaction work in the area of ​​one discharge hole 69 is repeated 2 to 3 times to ensure that the filled gangue is compacted, until the entire working surface is filled and compacted, and the first round of filling is stopped.

[0068] (8) Move the multi-hole bottom-discharging scraper conveyor 68 by one step, from the front to the rear, repeat the above steps, and finally close all the discharge holes to end the filling work.

[0069] What should be noted when filling with waste rock:

[0070] (1) During filling, it is necessary to ensure that the porous bottom discharge conveyor 68 at the rear of the hydraulic support 6 is straight.

[0071] (2) When filling, the reasonable filling order is from bottom to top, from the front to the rear of the machine.

[0072] (3) There shall be no misalignment or leakage of gangue at the rear tail beam of the roof.

[0073] Surface advanced vertical high-position grouting: After mining at a very large mining height working face, overburden movement and delamination will occur. Surface advanced vertical grouting is mainly aimed at the middle and high delamination areas, and the delamination space is bonded and filled by grouting. The steps include:

[0074] The slurry is configured according to the mining speed of the working face. Ultra-high performance concrete (UHPC) is used as the slurry. Filling slurries with different viscosities are configured according to the mining speed of the working face. Low-viscosity slurry is used when the mining speed is greater than 5m / day, and medium-to-high concentration slurry is used when the mining speed is less than 5m / day.

[0075] The location of the underground tunnel is determined by transparent geological detection technology, and upper S-shaped grouting is carried out within 30m of the tunnel from the surface.

[0076] Specifically, after determining the location of the underground tunnel, grouting holes 9 are arranged at intervals along the mining direction of the working face within 30m from the tunnel, with a horizontal spacing of 10m and a vertical spacing of half the periodic pressure step. Then the location of the key layer is determined by the key layer 10 theory and the drilling column chart, and the bottom depth position of the grouting hole is the area below the key layer. Finally, upper grouting is performed according to the bottom depth position.

[0077] Therefore, through the above-mentioned ultra-large mining height working face cutting top crushing and expansion active filling coal pillar-free self-forming lane mining method, the three methods of multi-directional roof fracturing method, coal gangue filling behind the working face frame and surface advanced vertical high-position grouting are used to jointly carry out three-dimensional regulation of the unfilled space in the coal pillar-free self-forming lane mining method, thus solving the instability problem caused by the large unfilled space of the surrounding rock in the lane forming conditions of ultra-large mining height.

[0078] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A method for self-forming lanes by active filling of top cutting and crushing in a large mining height working face without coal pillars, characterized in that: The unfilled space in the self-forming tunneling method without coal pillars is regulated in three dimensions by adopting the multi-directional roof fracturing method, coal gangue filling behind the working face frame and advanced vertical high-position grouting on the surface; The gangue filling behind the working face frame adopts a one-cut-one-filling method to fill the goaf behind the working face, and the steps include: S1. Set up hydraulic supports on the working surface; The hydraulic support comprises a front top beam, a rear top beam, an auxiliary column, an adjustment column, a column, a base and a four-bar linkage, a multi-hole bottom-discharging scraper conveyor is arranged under the rear top beam, the front top beam is connected to the rear top beam, a column is arranged between the front top beam and the base, one end of the four-bar linkage is connected to the base, and the other end is connected to the connection port of the front top beam and the rear top beam, an auxiliary column is arranged between the rear top beam and the four-bar linkage, an adjustment column is arranged between the multi-hole bottom-discharging scraper conveyor and the four-bar linkage, and a discharge hole is arranged on the multi-hole bottom-discharging scraper conveyor; S2. A gangue filling system is arranged behind the hydraulic support. The gangue filling system crushes the gangue from underground after lifting it to the surface, and then transports it to the filling system behind the hydraulic support on the working face through a transportation pipeline. The filling system behind the hydraulic support includes a multi-hole bottom unloading conveyor, a bridge belt transfer machine and a chute gangue belt conveyor. S3. Use the filling system behind the hydraulic support to fill the mining face with coal gangue and compact it. The specific steps include: (1) Cut one step, move the frame, and push the machine according to the regular cycle machine; (2) Extend the nose, middle trough and tail of the porous bottom-discharging scraper conveyor into place; (3) Start the multi-hole bottom-discharging scraper conveyor on the working face, and then start the bridge belt conveyor and the chute waste rock belt conveyor to fill the goaf with waste rock; (4) The multi-hole bottom-discharging scraper conveyor is filled from the front to the rear. The first discharge hole of the multi-hole bottom-discharging scraper conveyor is opened, and the goaf behind the frame corresponding to the discharge hole is filled with waste rock. When the waste rock behind the frame area corresponding to the first discharge hole is filled to the height of the conveyor bottom, the first discharge hole is closed, and the second discharge hole is opened backward in sequence; (5) Discharge the material from the second discharge hole, start the adjustment column, move the multi-hole bottom discharge scraper conveyor downward, fill the middle and upper part of the filled material, push the filled material, and start the adjustment column to return to its original position after the pushing is completed; (6) Fill the second discharge hole, close the discharge hole after filling, start the adjustment column, fill the middle and upper part of the filling material of the second discharge hole, and fill the filling space after the first discharge hole is compacted. After completion, start the adjustment column to return to its original position; (7) When the filling space that appears after the rear part of the first discharge hole is compacted is filled, the first discharge hole is closed and compacted, and the filling space that appears after the rear part of the second discharge hole is filled at the same time. After the spaces of the first two discharge holes are filled and compacted, if the filling work of the rear area of ​​the third discharge hole is completed, the rear space of the fourth discharge hole is opened for filling, and the rear area of ​​the third discharge hole is compacted at the same time; (8) Repeat steps (4) to (7) until the entire working surface is filled and compacted, and then stop the first round of filling; (9) Move the multi-hole bottom-discharging scraper conveyor one step distance from the front to the rear of the machine, repeat the above steps, and finally close all the discharge holes to complete the filling work.

2. The method for self-forming lanes by active filling of top cutting, crushing and expansion in a large mining height working face according to claim 1 is characterized in that: The multi-directional roof cracking method uses a directional cracking technique to perform full-space roof cutting and crushing, and the steps include: Mark the slotting and drilling holes at the corresponding positions on the top plate; Drill holes for construction at the drilling positions, drill directional energy-gathering holes and strong expansion holes, and all slit holes are located in the same plane; Install an energy-gathering device in the directional energy-gathering hole, and install a multi-directional fracturing tube in the strong-release fracturing hole; Multi-directional blasting is used to carry out multi-directional fracturing.

3. The method for self-forming lanes by active filling of top cutting, crushing and expansion in a large mining height working face according to claim 1 is characterized in that: When filling through the discharge holes in the step (4), at most three discharge holes are opened.

4. The method for self-forming lanes by active filling of top cutting, crushing and expansion in a large mining height working face according to claim 1 is characterized in that: The surface advanced vertical high-position grouting is performed to bond and fill the separation space by grouting, and the steps include: Configure slurry according to the mining speed of the working face; The location of the underground tunnel is determined by transparent geological detection technology, and upper S-shaped grouting is carried out within 30m of the tunnel from the surface.

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