Mining method for coal seam with variable coal seam thickness

Abstract

The invention discloses a mining method for a coal seam with a variable coal seam thickness. The mining method comprises the following steps that a connection roadway is excavated in a critical area of a first coal seam and a second coal seam in advance; the first coal seam is stoped in a one-time full-height mining mode; when the working face is pushed to a set distance away from the connection roadway, the end support and the reversed loader are disconnected; the working face continues to be pushed forwards, and the area between the end support and the reversed loader is supported; when the working face is pushed to be opposite to the connection roadway, transporting to the rear part of the working face bracket through the connection roadway, and arranging a rear scraper conveyer; the tail of the reversed loader is moved backwards and connected with an end support to construct top coal caving equipment; and the second coal seam is stoped in a top coal caving mode. According to the mining method, mining of the coal seam with the variable coal thickness can be achieved, and a series of problems of coal wall caving, low resource recovery rate, high mining cost, large workload and the like existing in mining of the coal seam with the variable coal thickness in the prior art are solved.

Description

Technical Field

[0001] The invention relates to the technical field of coal seam mining, and in particular to a method for mining a thickening coal seam. Background Art

[0002] During underground mining, the thickness of some coal seams varies greatly in the direction of mining, that is, the coefficient of variation of the coal seams is large, and the thickest area of ​​the coal seam can be more than twice that of the thinnest area. For such variable coal seams, the current mining methods used are comprehensive mining, full-height mining at one time, top coal caving, and multi-stage mining with multiple sets of equipment. However, these mining methods have problems such as coal wall spalling, low resource recovery rate, high mining cost, and heavy workload in the actual mining process, and cannot fully meet the mining needs of thickness variable coal seams. Summary of the invention

[0003] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0004] To this end, an embodiment of the present invention proposes a method for mining coal seams with variable coal seam thickness. The method for mining coal seams with variable coal seam thickness can realize the mining of coal seams with large variations in coal seam thickness, avoiding a series of problems existing in the prior art for the mining of coal seams with such variations in coal thickness, such as coal wall spalling, low resource recovery rate, high mining cost, and heavy workload.

[0005] A mining method for a thickened coal seam according to an embodiment of the present invention, wherein the thickened coal seam includes a first coal seam and a second coal seam arranged sequentially in a mining direction, wherein the first coal seam is thinner than the second coal seam, and the mining method includes the following steps:

[0006] S1: pre-excavating a connecting tunnel in the critical area between the first coal seam and the second coal seam;

[0007] S2: mining the first coal seam by mining the whole coal seam at one time;

[0008] S3: When the working face is advanced to the set distance from the connecting tunnel, the connection between the end support and the transfer machine is disconnected;

[0009] S4: Continue to advance the working face forward and support the area between the end support and the transfer machine;

[0010] S5: When the working face is advanced to be opposite to the connecting tunnel, the workpiece is transported to the rear of the working face support through the connecting tunnel and a rear scraper conveyor is arranged;

[0011] S6: moving the tail of the transfer machine backward and connecting it to the end support to construct a top coal caving device;

[0012] S7: mining the second coal seam by top coal caving.

[0013] In some embodiments, in step S4, the area between the end support and the transfer machine is supported by temporary support, and the temporary support includes at least one of the following: point columns, wood piles, and single hydraulic props.

[0014] In some embodiments, in step S5, the working surface support includes a middle hydraulic support and a transition support, and the rear scraper conveyor is connected to the rear of the middle hydraulic support and the transition support.

[0015] In some embodiments, the full-height mining equipment includes a front scraper conveyor, which is arranged in front of the working face support, and the front scraper conveyor is docked with the transfer machine by an end unloading arrangement or a cross side unloading arrangement.

[0016] In some embodiments, the front scraper conveyor is connected to the transfer machine through an end unloading arrangement. After the rear scraper conveyor is transported to the rear of the working surface support through the connecting lane, the rear scraper conveyor is connected to the transfer machine through a cross side unloading arrangement.

[0017] In some embodiments, the front scraper conveyor is docked with the transfer machine in a cross-side unloading arrangement, and step S5 also includes the following steps:

[0018] S51: transporting the middle trough and the tail drive part of the rear scraper conveyor to the rear of the working surface support via the connecting lane;

[0019] S52: disconnecting the middle trough and transition trough of the front scraper conveyor, and then moving the transition trough and the driving part of the front scraper conveyor backward and connecting them with the middle trough of the rear scraper conveyor to construct a complete rear scraper conveyor;

[0020] S53: transporting the end-discharge transition trough and the driving part to the front scraper conveyor via the connecting lane and connecting them to the middle trough of the front scraper conveyor to construct a new front scraper conveyor.

[0021] In some embodiments, step S6 further includes the following steps:

[0022] Part of the transport trough of the transfer machine is transported to the front side of the tail of the transfer machine through the connecting lane to fill the missing part between the front scraper conveyor and the rear scraper conveyor.

[0023] In some embodiments, during the top coal caving process, a single-row advance support, a rear advance support and a front advance support are arranged in sequence along the mining direction in the transport lane serving the working face, and the single-row advance support is arranged on the non-production side of the transfer machine and connected to the rear advance support;

[0024] The construction of the top coal caving equipment comprises the following steps:

[0025] The single-row leading support is transported to the non-production side of the transport lane via the connecting lane and connected to the rear of the rear leading support.

[0026] In some embodiments, an auxiliary transport lane is provided beside the transport lane, and the auxiliary transport lane is connected with the transport lane through a connecting lane, and the single-row advance support and the rear scraper conveyor are transported through the auxiliary transport lane and the connecting lane.

[0027] In some embodiments, the working surface is arranged with a plurality of middle hydraulic supports, the plurality of middle hydraulic supports are arranged in sequence along the extension direction of the working surface, and transition supports are provided at both ends of the plurality of middle hydraulic supports;

[0028] The middle hydraulic support comprises a telescopic plug plate and a tail beam. During the process of mining the full height at one time, the telescopic plug plate is retracted and the tail beam is lowered to the lowest position;

[0029] The height adjustment range of the middle hydraulic support is determined by the following method:

[0030] Taking the maximum coal thickness revealed by the drilling diagram of the working face as a reference, and then floating and setting parameters on the reference as the maximum height adjustment of the middle hydraulic support;

[0031] The minimum height adjustment of the middle hydraulic support is determined according to the well development method and the actual situation of the existing equipment.

[0032] Beneficial effect: The mining method of coal seams with variable thickness according to the embodiment of the present invention can realize the mining of coal seams with large variations in coal seam thickness, avoiding a series of problems existing in the prior art for the mining of coal seams with such variations in coal thickness, such as coal wall spalling, low resource recovery rate, high mining cost, and heavy workload. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a side schematic diagram of the support and transportation system of an embodiment of the present invention.

[0034] Figure 2 1 is a schematic top view of a support and transportation system according to an embodiment of the present invention.

[0035] Figure 3It is a schematic diagram of the working face equipment layout during a full-height mining process according to an embodiment of the present invention.

[0036] Figure 4 It is a schematic diagram of the process of switching from a full-height working face equipment for primary mining to a top coal caving working face equipment in an embodiment of the present invention.

[0037] Figure 5 It is a schematic diagram of the arrangement of working face equipment during top coal caving in an embodiment of the present invention.

[0038] Reference numerals:

[0039] 1-transfer machine; 2-crusher; 3-front advance support; 4-rear advance support; 5-first jack; 6-second jack; 7-single-row advance support; 8-end support; 9-front scraper conveyor; 10-rear scraper conveyor; 11-transition support; 12-transport lane; 13-connecting lane; 14-auxiliary transport lane; 15-middle hydraulic support; 16-coal mining machine; 17-return air lane; 18-full-height conveyor for one-time mining. DETAILED DESCRIPTION

[0040] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0041] The present invention is based on the inventor's discovery and understanding of the following facts and problems:

[0042] For coal mining working faces where the thickness of the coal seam thickens in one direction in the mining direction and the coefficient of variation of the coal seam is large (the maximum coal thickness is about 2 times the minimum coal thickness), the three mining methods currently used are full-process fully mechanized mining, one-time mining of full height, face relocation and face change, and full-process fully mechanized mining with top coal caving. However, each of the three mining methods has its own disadvantages:

[0043] (1) Full-process comprehensive mining and one-time mining at full height process In order to mine as much top coal as possible, the maximum height adjustment of the hydraulic support often needs to meet the mining requirements of the maximum coal thickness, which makes the contradiction between improving the resource recovery rate and the existing hydraulic support technology level prominent. That is, to ensure the resource recovery rate, it is necessary to increase the maximum height adjustment of the hydraulic support, which will lead to the following problems: 1. When the mining height is large, the spalling phenomenon is serious, and large pieces of coal can enter the pedestrian passage in front of the frame and inside the frame. In addition, the distance between the ends of the frame beam is too large, which is prone to safety problems such as roof collapse and frame collapse; 2. When the coal thickness is small, the hydraulic support maintains a low posture for a long time, and the ear plate of the balance jack of the protective beam breaks frequently.

[0044] (2) The mining method of moving and changing working faces mainly divides the working face into two sections for mining, and moves and changes the face once in the middle. This method requires the purchase of two sets of three-machine equipment for the working face (hydraulic support, coal mining machine, and scraper conveyor), and requires two eye cutting and excavation operations, two working face equipment installation operations, and two working face equipment withdrawal operations; in addition, a sufficiently wide coal pillar needs to be left between the first section of the stop mining line and the second section of the working face eye cutting to ensure the safety of the excavation process.

[0045] The disadvantages of the technology of moving and changing working faces are: 1. The equipment investment is doubled; 2. The workload of cutting, excavating, installing equipment, and withdrawing equipment is doubled; 3. A sufficiently wide coal pillar needs to be left between the stopping line of the first working face and the cutting line of the second working face, resulting in a large amount of coal being unable to be mined, seriously affecting the economic benefits.

[0046] (3) The disadvantages of the fully mechanized top coal caving technology are: 1. The working face advances slowly; 2. The top coal recovery rate is generally between 65% and 80%, while the machine-mined coal recovery rate can reach 98%. The comprehensive resource recovery rate of the fully mechanized top coal caving technology is significantly lower than that of the fully mechanized one-time mining full-height technology; 3. Under the condition of a small mining-caving ratio, the difficulty of caving coal increases and the gangue content of the coal is high.

[0047] Based on the above situation, an embodiment of the present invention proposes a mining method for a coal seam with a thickening thickness.

[0048] It should be noted that the mining method of the embodiment of the present invention is implemented based on a matching top coal caving support and transportation system.

[0049] like Figure 1 and Figure 2 As shown, the top coal caving working face support and transportation system (hereinafter referred to as the top coal caving support and transportation system) of the embodiment of the present invention includes a transfer machine 1, a crusher 2, a front advance support 3, a rear advance support 4, a first jack 5, a second jack 6, a single row advance support 7, an end support 8, a front scraper conveyor 9, a rear scraper conveyor 10 and a plurality of transition supports 11. Both the first jack 5 and the second jack 6 can be push jacks.

[0050] The crusher 2 is arranged in the middle of the transfer machine 1. For example, the transfer machine 1 can be arranged in the transport lane 12 of the working surface and extend along the transport lane 12, specifically along the Figure 1 The crusher 2 can be installed in the middle of the transfer machine 1 in the front-to-back direction. When in use, the transfer machine 1 can transfer the coal mined from the working face to the belt conveyor, while the crusher 2 can realize the crushing operation of the block structure such as coal.

[0051] Both the front advance support 3 and the rear advance support 4 can straddle the transfer machine 1, wherein the front advance support 3 can be adjacent to the head of the transfer machine 1, and the rear advance support 4 can be adjacent to the tail of the transfer machine 1, and the crusher 2 is located between the front advance support 3 and the rear advance support 4.

[0052] For example, the front advance bracket 3 and the rear advance bracket 4 can be generally gate-shaped, and the front advance bracket 3 and the rear advance bracket 4 are both arranged in the transport lane 12 and cross the top of the transfer machine 1. The front advance bracket 3 can be located in front of the rear advance bracket 4, and the front advance bracket 3 and the rear advance bracket 4 can realize the advance protection of the transfer machine 1 and the crusher 2.

[0053] The first jack 5 is connected between the front advance support 3 and the crusher 2, and the second jack 6 is connected between the crusher 2 and the rear advance support 4. Figure 1 and Figure 2 As shown, two first jacks 5 and two second jacks 6 can be provided, and the two first jacks 5 can be respectively provided on the left and right sides of the transfer machine 1, and the two first jacks 5 are connected between the front advance support 3 and the crusher 2, and the two second jacks 6 can also be respectively provided on the left and right sides of the transfer machine 1, and the two second jacks 6 are connected between the rear advance support 4 and the crusher 2.

[0054] The single-row advance bracket 7 is arranged on the non-production side of the transfer machine 1 and is connected to the rear advance bracket 4, and the rear advance bracket 4 is located between the crusher 2 and the single-row advance bracket 7. For example, Figure 1 and Figure 2 As shown, compared with the front advance bracket 3 and the rear advance bracket 4, the single-row advance bracket 7 can be a single-row bracket, the non-production side of the transfer machine 1 can be the right side of the transfer machine 1, and the single-row advance bracket 7 can be only arranged on the right side of the transfer machine 1 and connected to the rear of the rear advance bracket 4. When in use, the single-row advance bracket 7 can move synchronously with the rear advance bracket 4 in the front and rear directions.

[0055] The end bracket 8 includes a third jack, and the third jack is connected to the tail of the transfer machine 1. The tail of the transfer machine 1 can be the rear end of the transfer machine 1, and the rear end of the transfer machine 1 can be provided with a push beam and other structures. The third jack can be installed at the base of the end bracket 8, and the third jack can be connected to the push beam and other structures of the transfer machine 1.

[0056] The rear scraper conveyor 10 is located between the front scraper conveyor 9 and the end bracket 8, the front scraper conveyor 9 is connected to the transfer machine 1, and the rear scraper conveyor 10 is connected to the transfer machine 1. For example, Figure 2As shown, both the front scraper conveyor 9 and the rear scraper conveyor 10 can be arranged in the working surface and extend in the left-right direction, and the front scraper conveyor 9 is arranged in front of the rear scraper conveyor 10. The front scraper conveyor 9 can be directly connected to the transfer machine 1 by an end unloading arrangement, and there is no rigid connection between the front scraper conveyor 9 and the transfer machine 1, that is, the front scraper conveyor 9 can move independently of the transfer machine 1. The rear scraper conveyor 10 can be connected to the transfer machine 1 by a cross side unloading arrangement, so that the rear scraper conveyor 10 and the transfer machine 1 can move synchronously.

[0057] A plurality of transition brackets 11 are arranged between the front scraper conveyor 9 and the rear scraper conveyor 10 . The transition bracket 11 includes a fourth jack and a connecting piece. The fourth jack is connected to the front scraper conveyor 9 , and the connecting piece is connected to the rear scraper conveyor 10 .

[0058] For example, Figure 2 As shown, three transition brackets 11 may be provided. In some other embodiments, two, four, or other numbers of transition brackets 11 may be provided. The three transition brackets 11 may be arranged at intervals in the left-right direction, and in the front-back direction, the three transition brackets 11 may be located between the front scraper conveyor 9 and the rear scraper conveyor 10. The base of each transition bracket 11 may be provided with a fourth jack, and the front end of the fourth jack may be connected to the front scraper conveyor 9, so that the front scraper conveyor 9 can be moved forward and pushed by the fourth jack. The top beam of each transition bracket 11 may be designed as an integral top beam.

[0059] The connecting piece can be a jack, a chain, etc. The base of each transition bracket 11 can be connected to the rear scraper conveyor 10 at the rear through the connecting piece, so that the rear scraper conveyor 10 can be driven to move forward when the transition bracket 11 moves forward.

[0060] The mining method of the embodiment of the present invention is also implemented based on a matching one-time mining full-height support and transportation system (hereinafter referred to as the mining full-height support and transportation system).

[0061] like Figure 3 As shown, the one-time mining full-height support and transportation system of the embodiment of the present invention mainly includes a one-time mining full-height conveyor 18, a working face support, an end support 8, a transfer machine 1, etc. The working face support mainly includes a plurality of middle hydraulic supports 15 and transition supports 11 located at both ends of the plurality of middle hydraulic supports 15. The one-time mining full-height conveyor 18 is located at the front side of the working face support, and the end support 8 and the transfer machine 1 are both located in the transport lane 12.

[0062] It should be noted that the variant coal seam of the present invention mainly refers to a coal seam that gradually becomes thicker in the mining direction of the coal seam, and the variant coal seam can be divided into a first coal seam and a second coal seam according to the thickness in the mining direction, wherein the first coal seam can be half the thickness of the second coal seam, and the first coal seam must be mined before the second coal seam.

[0063] Based on the above support and transportation system, the mining method of the thickened coal seam according to the embodiment of the present invention comprises the following steps:

[0064] S1: A connecting tunnel 13 is excavated in advance in the critical area between the first coal seam and the second coal seam. Figure 3 As shown, an auxiliary transport tunnel 14 can be provided next to the transport tunnel 12. Before the formal mining of the working face, the critical area between the first coal seam and the second coal seam can be determined first. The critical area is the junction of the first coal seam and the second coal seam. Then, a connecting tunnel 13 can be excavated at the critical area. The connecting tunnel 13 generally extends in the left and right directions and connects the transport tunnel 12 and the auxiliary transport tunnel 14.

[0065] S2: Mining the first coal seam by full-height mining. For example, after the above-mentioned full-height mining support and transportation system is installed, the first coal seam can be mined by comprehensive integrated mining full-height mining. Specifically, the coal cut by the coal mining machine 16 can be transported to the transfer machine 1 by the full-height conveyor 18, and then directly transported to the belt conveyor by the transfer machine 1 and transported out of the working face. The original middle hydraulic support 15 and transition support 11 can support the roof of the working face tunnel, while the original front advance support 3, rear advance support 4, and end support 8 can support the advance section and the triangle area.

[0066] S3: When the working face is advanced to a set distance from the connecting tunnel 13, the connection between the end support 8 and the transfer machine 1 is removed.

[0067] For example, Figure 4 As shown, the set distance can be a spacing space that can meet the needs of arranging subsequent single-row advance brackets 7, rear scraper conveyors 10 and other equipment, and can also be regarded as a part of the transport lane 12. When the working surface is advanced to the set distance position from the connecting lane 13, the connection between the end bracket 8 and the transfer machine 1 can be manually disassembled, so that the end bracket 8 will not move synchronously with the transfer machine 1 during the subsequent advancement of the working surface.

[0068] S4: Continue to advance the working face forward, and support the area between the end bracket 8 and the transfer machine 1. For example, after the connection between the end bracket 8 and the transfer machine 1 is removed, the working face can continue to advance. In the process of advancing the working face forward, due to the lack of timely support of the end bracket 8, the tail of the transfer machine 1 and the end bracket 8 will gradually increase the distance and an empty roof will appear between the two. At this time, the roof between the two needs to be supported in time to avoid the roof from collapsing, thereby ensuring the safety of mining.

[0069] S5: When the working face is advanced to the position opposite to the connecting lane 13, the rear scraper conveyor 10 is transported to the rear of the working face support through the connecting lane 13 and arranged. Figure 5 As shown, when the head of the coal mining machine 16 of the working face is facing the connecting tunnel 13 in the left and right direction, the rear scraper conveyor 10 used for top coal mining can be transported to the rear of the working face support through the above-mentioned auxiliary transport tunnel 14 and the connecting tunnel 13 and the installation layout of the rear scraper conveyor 10 can be completed.

[0070] It should be noted that, since the transfer machine 1 and the end bracket 8 are separated in advance, the components of the rear scraper conveyor 10 can be transported through the gap between the transfer machine 1 and the end bracket 8, thereby facilitating the installation and arrangement of the rear scraper conveyor 10.

[0071] S6: Move the tail of the transfer machine 1 backward and connect it to the end bracket 8 to construct the top coal caving equipment. For example, after the installation and arrangement of the rear scraper conveyor 10 is completed, the tail of the transfer machine 1 can be moved backward and reconnected to the end bracket 8. If the length of the transfer machine 1 is not enough, it can be supplemented by adding a transport trough.

[0072] It should be noted that the top coal caving equipment can be understood as the above-mentioned top coal caving support and transportation system, and the above-mentioned full-height conveyor 18 for one-time full-height mining can be constructed as a front scraper conveyor 9, thereby meeting the transportation needs of the coal mined by the front side coal mining machine 16.

[0073] S7: mining the second coal seam by top coal caving. Figure 5 As shown, after the above-mentioned full-height support and transportation system is completely converted into a top coal caving support and transportation system, the second coal seam can be mined through the converted top coal caving support and transportation system. During the mining process, the coal cut by the coal mining machine 16 can be transported to the transfer machine 1 via the front scraper conveyor 9, and the coal dropped from the top plate can be transported to the transfer machine 1 via the rear scraper conveyor 10. The coal on the transfer machine 1 can be transferred to the belt conveyor and finally transported out of the working face.

[0074] After cutting a certain depth, the front scraper conveyor 9 can be pushed forward by the pushing jacks of the multiple middle hydraulic supports 15 of the working surface and the fourth jack of the above transition support 11. Then the first jack 5 can be used to realize the forward movement of the above front advance support 3, and finally the first jack 5, the second jack 6, the third jack, etc. can be used to realize the overall forward movement of the transfer machine 1, the crusher 2, and the rear scraper conveyor 10.

[0075] The mining method for thickening coal seams in the embodiment of the present invention realizes the segmented mining of coal seams, wherein the first coal seam can be mined by a one-time full-height mining method that is more suitable for the mining method, while the second coal seam, due to its thickness, can be mined by a more suitable top coal caving method, thereby avoiding the problems of coal wall spalling and low resource recovery rate caused by only a single mining method in the prior art.

[0076] Secondly, by directly adjusting the original support and transportation system, the transformation of the support and transportation system for full-height mining into the support and transportation system for top coal caving can be achieved. Compared with the moving method adopted in the existing technology, the overall operation process is simpler, more efficient, and less costly. It also greatly reduces the overall labor intensity, which is conducive to ensuring the overall mining efficiency.

[0077] In some embodiments, in step S4, the area between the end support 8 and the transfer machine 1 is supported by temporary support, and the form of temporary support includes at least one of the following: point columns, wood piles, and single hydraulic props.

[0078] Specifically, after the transfer machine 1 and the end support 8 are dismantled and connected, as the working face advances one step, the above-mentioned temporary support method can be used in time to temporarily support the top plate in front of the end support 8, thereby realizing the support of the working face as it moves, and fully ensuring the safety of mining.

[0079] In some embodiments, in step S5, the working surface support includes a middle hydraulic support 15 and a transition support 11, and the rear scraper conveyor 10 is connected to the rear of the middle hydraulic support 15 and the transition support 11. For example, after the rear scraper conveyor 10 is assembled behind the working surface support, the rear scraper conveyor 10 can be connected to the middle hydraulic support 15 and the transition support 11 in the working surface support by chains, jacks, etc., so that the rear scraper conveyor 10 can move forward with the movement of the working surface support.

[0080] In some embodiments, the full-height mining equipment includes a front scraper conveyor 9, that is, a full-height mining conveyor 18. The front scraper conveyor 9 is arranged in front of the working face support. When the first coal seam is mined by full-height mining, the front scraper conveyor 9 can be connected to the transfer machine 1 by an end unloading arrangement or a cross-side unloading arrangement.

[0081] For example, the front scraper conveyor 9 can be directly connected to the transfer machine 1 by end unloading. There is no rigid connection between the front scraper conveyor 9 and the transfer machine 1, that is, the front scraper conveyor 9 can move independently of the transfer machine 1. When in use, the front scraper conveyor 9 can be independently pushed forward with the help of the jacks of the middle hydraulic support 15 and the transition support 11.

[0082] In other embodiments, the front scraper conveyor 9 may also be connected to the transfer machine 1 in a cross-side unloading arrangement, so that the front scraper conveyor 9 can move forward synchronously with the transfer machine 1.

[0083] In some embodiments, the front scraper conveyor 9 is connected to the transfer machine 1 by an end-unloading arrangement, and after the rear scraper conveyor 10 is transported to the rear of the working face support through the connecting tunnel 13, the rear scraper conveyor 10 is connected to the transfer machine 1 by a cross-side unloading arrangement. Therefore, after the installation and arrangement of the rear scraper conveyor 10 is completed, the full-height conveyor 18 for primary mining can be directly converted into the front scraper conveyor 9 for top coal caving without any changes due to the end-unloading arrangement, thereby simplifying the overall conversion process.

[0084] The rear scraper conveyor 10 is connected to the transfer machine 1 by a cross-side unloading arrangement, so that the rear scraper conveyor 10 and the transfer machine 1 can move synchronously, fully meeting the use needs of top coal caving production.

[0085] In some embodiments, the front scraper conveyor 9 is connected to the transfer machine 1 by a cross side unloading arrangement, that is, the above-mentioned one-time full-height conveyor 18 is directly connected to the transfer machine 1 by a cross side unloading arrangement. At this time, step S5 also includes the following steps:

[0086] S51: transport the middle trough and tail drive unit of the rear scraper conveyor 10 to the rear of the working face support via the connecting lane 13. For example, the middle trough and tail drive unit of the rear scraper conveyor 10 can be transported to the rear of the above-mentioned middle hydraulic support 15 and transition support 11 via the auxiliary transport lane 14 and the connecting lane 13 by traction equipment.

[0087] S52: disconnect the connection between the middle trough and the transition trough of the front scraper conveyor 9, and then move the transition trough and the driving part of the front scraper conveyor 9 backward and connect them with the middle trough of the rear scraper conveyor 10 to construct a complete rear scraper conveyor 10. Therefore, since the head driving part of the front scraper conveyor 9 is arranged in a cross-side unloading manner, by dismantling the head driving part and the transition trough of the front scraper conveyor 9 and directly using them as the head driving part and the transition trough of the rear scraper conveyor 10, the installation and arrangement of the rear scraper conveyor 10 is facilitated, and the installation requirements of the cross-side unloading arrangement of the rear scraper conveyor 10 are also met.

[0088] Specifically, the connection mechanism between the middle groove of the front scraper conveyor 9 and the head transition groove can be a dumbbell pin. When disassembling, the dumbbell pin can be directly removed, so that the middle groove of the front scraper conveyor 9 can be separated from the head transition groove and the head driving part.

[0089] S53: transport the end-unloading transition trough and driving part to the front scraper conveyor 9 via the connecting lane 13 and connect them to the middle trough of the front scraper conveyor 9 to construct a new front scraper conveyor 9. Since the transition trough and the head driving part of the front scraper conveyor 9 are replaced by the rear scraper conveyor 10, it is only necessary to transport the end-unloading transition trough and the head driving part to the front scraper conveyor 9 via the auxiliary transport lane 14 and the connecting lane 13 and connect them to the remaining middle trough, thereby meeting the installation requirements of the front scraper conveyor 9 adopting the end-unloading arrangement.

[0090] In some embodiments, step S6 also includes the following steps: transporting part of the transport trough of the transfer machine 1 to the front side of the tail of the transfer machine 1 via the connecting lane 13 to fill the missing part between the front scraper conveyor 9 and the rear scraper conveyor 10.

[0091] Specifically, due to the addition of the rear scraper conveyor 10, the original length of the transfer machine 1 cannot meet the use needs of top coal caving mining. Several transport troughs of the transfer machine 1 can be transported into the transport tunnel 12 via the auxiliary transport tunnel 14 and the connecting tunnel 13, and the added transport troughs can be connected between the tail of the transfer machine 1 and the front side of the transfer machine 1, thereby increasing the length of the transfer machine 1 and meeting the use needs of top coal caving mining.

[0092] In some embodiments, Figure 1 and Figure 2 As shown, during the top coal caving process, a single-row advance support 7, a rear advance support 4 and a front advance support 3 are arranged in sequence along the mining direction in the transport tunnel 12 serving the working face. The single-row advance support 7 is arranged on the non-production side of the transfer machine 1 and is connected to the rear advance support 4. Specifically, the non-production side can be the right side of the transfer machine 1. The single-row advance support 7 can be arranged only on the right side of the transfer machine 1, and the top beam and base of the single-row advance support 7 can be respectively connected to the top beam and base of the rear advance support 4 by connecting beams, etc. The single-row advance support 7 can enhance the overall support area, thereby fully meeting the use needs of the advance support.

[0093] The above-mentioned top coal caving equipment comprises the following steps: transporting the single-row advance support 7 to the non-production side of the transport tunnel 12 via the connecting tunnel 13 and connecting it to the rear of the rear advance support 4.

[0094] Specifically, the single-row advance bracket 7 is transported to the non-production side of the transport lane 12 via the auxiliary transport lane 14 and the connecting lane 13, and is located behind the above-mentioned rear advance bracket 4. Then, the top beam and the base of the single-row advance bracket 7 can be rigidly connected to the top beam and the base of the right frame of the rear advance bracket 4 through a non-retractable connecting beam. At this time, the movement of the single-row advance bracket 7 is consistent with the rear advance bracket 4 in front, and the single-row advance bracket 7 can cooperate with the lagging end bracket 8 to protect the top of the machine head triangle area.

[0095] In some embodiments, an auxiliary transport lane 14 is provided beside the transport lane 12. Figures 3 to 5 As shown, the auxiliary transport lane 14 can be arranged on the side of the transport lane 12 away from the working surface, the auxiliary transport lane 14 can extend along the extension direction of the transport lane 12, the auxiliary transport lane 14 is connected to the transport lane 12 through the connecting lane 13, the connecting lane 13 can extend along the left and right direction, the left end of the connecting lane 13 can be connected to the transport lane 12, and the right end of the connecting lane 13 can be connected to the auxiliary transport lane 14. The head drive part, head transition trough, single-row advance bracket 7, etc. of the above-mentioned front scraper conveyor 9 can be transported to the working surface through the connecting lane 13 and the auxiliary transport lane 14. In other embodiments, if the above-mentioned full-height conveyor 18 itself adopts an end-unloading arrangement, the head drive part and head transition trough of the rear scraper conveyor can be transported to the working surface via the auxiliary transport lane 14 and the connecting lane 13.

[0096] In some embodiments, Figures 3 to 5 As shown, a plurality of middle hydraulic supports 15 are arranged on the working surface, and the plurality of middle hydraulic supports 15 are arranged in sequence along the extension direction of the working surface, and transition supports 11 are provided at both ends of the plurality of middle hydraulic supports 15. Four transition supports 11 may be provided on the left side of the plurality of middle hydraulic supports 15, and three transition supports 11 may be provided on the right side of the plurality of middle hydraulic supports 15.

[0097] The middle hydraulic support 15 includes a telescopic plug plate and a tail beam. During the process of mining at full height, the telescopic plug plate is retracted and the tail beam is lowered to the lowest position. The lowest position is the lowest point where the tail beam can swing downward. This can prevent the collapse of the top plate from causing an impact on the rear of the support.

[0098] In some embodiments, the height adjustment range of the middle hydraulic support 15 is determined by the following method: taking the maximum coal thickness revealed by the drilling map of the working face as a benchmark, and then floating up the set parameters on the benchmark as the maximum height adjustment of the middle hydraulic support 15, and determining the minimum height adjustment of the middle hydraulic support 15 based on the well development method and the actual situation of the existing equipment.

[0099] Specifically, the middle hydraulic support 15 can adopt the basic configuration of a two-column shielding top coal caving support, which has the function of top coal caving and is also equipped with a swing tail beam and a retractable plug plate. The height adjustment range of the middle hydraulic support 15 can be determined by the distribution range of the coal thickness in the first half (the first coal seam). When determining, the extreme abnormal values ​​can be eliminated, and the maximum coal thickness revealed by the drilling map in the mining direction of the working face is used as the benchmark, and then a certain parameter is floated as the maximum height adjustment of the hydraulic support.

[0100] The difference between the maximum height and the minimum height of the bracket is the bracket's height adjustment range. The larger the height adjustment range, the wider the bracket's application range, but an excessively large height adjustment range makes it difficult to design the bracket structure and reduces reliability. Therefore, when determining the minimum height adjustment, the minimum height adjustment of the bracket can be determined based on the well field development method and the existing equipment technology level, with the maximum size allowed by the well and the height adjustment range allowed by the existing equipment technology level as constraints.

[0101] In some embodiments, the power of the coal mining machine 16 used in the above mining method can be determined by the instantaneous coal falling amount corresponding to the maximum cutting height, and the drum diameter can be determined by the cutting range, which should be 0.55 to 0.6 of the maximum cutting height.

[0102] A specific example of the mining method according to the embodiment of the present invention is described below.

[0103] The mining method of the embodiment of the present invention mainly includes three stages: comprehensive mining of full height at one time, transformation of comprehensive mining of full height at one time to top coal caving, and comprehensive mining of top coal caving.

[0104] (1) Comprehensive mining full-height stage process: Equipment installation is carried out in the working face cut, where the front scraper conveyor 9 adopts end unloading or cross-side unloading at the head and is arranged in front of the working face support. The coal mining machine 16 sits astride the front scraper conveyor 9. The working face support adopts a comprehensive mining top coal caving frame type. The rear plug plate is in a retracted state and the tail beam is lowered to the lowest position to avoid the collapse of the roof from causing impact on the rear of the hydraulic support.

[0105] (2) Conversion process of fully mechanized mining from full-height mining to fully mechanized mining with top coal caving: When the thickness of the coal seam reaches the critical value for process conversion, ① when the working face advances to a set distance behind the connecting tunnel 13 (the set distance should be able to meet the space requirements for equipment layout), the connection between the end support 8 and the tail push beam of the transfer machine 1 is removed, and the end support 8 no longer advances with the working face;

[0106] ② The working face continues to move forward. After each step, temporary support measures (point columns, wood piles, single hydraulic props, etc.) are used to temporarily support the top plate in front of the end support 8, and support is provided as the work progresses until the working face stops advancing after reaching the set distance. At this time, the working face head is facing the connecting lane 13, and it is ensured that all hydraulic supports of the working face and the leading section are in the top support state;

[0107] ③ The tail drive part and the middle trough of the rear scraper conveyor 10 are transported to the rear of the working surface through the auxiliary transport lane 14 and the connecting lane 13 by the traction equipment, and connected with the rear of the base of the middle support and the transition support 11. The connection method generally uses chains, jacks, etc., and moves about two transport troughs at the tail of the transfer machine 1 together with the tail push beam backward and connects with the end support 8;

[0108] ④ If the front scraper conveyor 9 adopts the end unloading arrangement: the transition trough and the head driving part of the rear scraper conveyor 10 are transported to the rear of the working face support through the auxiliary transport lane 14 and the connecting lane 13, and connected with the middle trough of the rear scraper conveyor 10. At this time, the rear scraper conveyor 10 is arranged in a cross side unloading manner;

[0109] If the front scraper conveyor 9 adopts the cross-side unloading arrangement: disconnect the connection between the middle trough and the transition trough of the front scraper conveyor 9, disconnect the connection between the transfer machine 1 and the head drive part of the front scraper conveyor 9, move the transition trough and the head drive part of the front scraper conveyor 9 backward, and connect them with the rear scraper conveyor 10. The rear scraper conveyor 10 is now in the cross-side unloading arrangement, and the transition trough and the head drive part of the front scraper conveyor 9 are transported to the front of the working face support through the auxiliary transport lane 14 and the connecting lane 13, and connected with the middle trough of the front scraper conveyor 9. The front scraper conveyor 9 is now in the end unloading arrangement;

[0110] ⑤ Transport the transport troughs of several sections of the transfer machine 1 into the transport lane 12 through the auxiliary transport lane 14 and the connecting lane 13, and add them to the gap of the transfer machine 1 section between the head drive parts of the front scraper conveyor 9 and the rear scraper conveyor 10;

[0111] ⑥ The single-row advance support 7 (two-link advance support) is transported to the rear of the rear advance support 4 on the non-production side of the transport lane 12 through the auxiliary transport lane 14 and the connecting lane 13, and the top beam and the base of the two-link advance support are respectively hard-connected with the top beam and the base of the right frame of the rear advance support 4 through a non-retractable connecting beam. At this time, the movement of the two-link advance support is consistent with the rear advance support 4, and it can cooperate with the lagging end support 8 to protect the head triangle area. At this point, the conversion from the fully-mechanized mining full-height process to the fully-mechanized mining top coal caving is completed.

[0112] (3) Comprehensive mining top coal caving stage process: At this time, the front scraper conveyor 9 adopts the end unloading arrangement, and the rear scraper conveyor 10 adopts the cross-side unloading arrangement. In addition, on the transport lane side, the head drive part of the rear scraper conveyor 10 is arranged vertically to increase the pedestrian space behind the front scraper conveyor 9. When mining is resumed to the stop line, the coal mining operation of the entire working face is completed.

[0113] Beneficial effects of the mining method for thickening coal seams according to the embodiment of the present invention:

[0114] 1) A novel mining process is provided for coal mining faces where the coal seam thickness thickens unidirectionally in the mining direction and the coal seam variation coefficient is large (the maximum coal thickness is about 2 times the minimum coal thickness).

[0115] 2) This process optimizes the working face supporting technology and equipment design, and uses a set of equipment in the working face mining process, thereby integrating two types of processes: comprehensive mining of full height in one go and comprehensive mining of top coal caving, thus realizing lean production of coal resources.

[0116] 3) The head drive part and transition trough of the front scraper conveyor can be used to connect the transfer machine with the middle trough of the rear scraper conveyor, ensuring the efficiency of process conversion and reducing the difficulty of managing spare parts.

[0117] 4) Compared with the full-height mining process in one go: the mining height range of the support adopted in the present invention is relatively low, thus avoiding the problems of spalling and roof collapse when the machine mining height is too large, and the breakage of the ear plate of the balance jack of the protective beam when the support maintains a low posture for a long time.

[0118] 5) Compared with segmented mining: equipment investment is reduced, underground workload is reduced, and a large amount of coal resources are avoided from being idle.

[0119] 6) Compared with the full-process top coal caving process: high propulsion efficiency, high comprehensive resource recovery rate, and reduced coal gangue content.

[0120] In general, the present invention is a lean mining process suitable for specific coal occurrence conditions. It can reduce equipment capital investment, alleviate worker workload, increase resource recovery rate, improve the quality of produced coal, and increase mine safety and efficiency, and has the prospect of large-scale promotion.

[0121] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0122] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0123] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0124] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0125] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0126] Although the above embodiments have been shown and described, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. Changes, modifications, substitutions and variations of the above embodiments by those of ordinary skill in the art are all within the scope of protection of the present invention.

Claims

1. A method for mining a thickening coal seam, characterized in that: The thickened coal seam includes a first coal seam and a second coal seam arranged sequentially in a mining direction, the first coal seam is thinner than the second coal seam, and the mining method includes the following steps: S1: pre-excavating a connecting tunnel in the critical area between the first coal seam and the second coal seam; S2: mining the first coal seam by mining the whole coal seam at one time; S3: When the working face is advanced to the set distance from the connecting tunnel, the connection between the end support and the transfer machine is disconnected; S4: Continue to advance the working face forward and support the area between the end support and the transfer machine; S5: When the working face is advanced to be opposite to the connecting tunnel, the workpiece is transported to the rear of the working face support through the connecting tunnel and a rear scraper conveyor is arranged; S6: moving the tail of the transfer machine backward and connecting it to the end support to construct a top coal caving device; S7: mining the second coal seam by top coal caving.

2. The method for mining a thickening coal seam according to claim 1, characterized in that: In step S4, the area between the end support and the transfer machine is supported by temporary support, and the temporary support includes at least one of the following: point columns, wood piles, and single hydraulic props.

3. The method for mining a thickening coal seam according to claim 1, characterized in that: In step S5, the working surface support includes a middle hydraulic support and a transition support, and the rear scraper conveyor is connected to the rear of the middle hydraulic support and the transition support.

4. The method for mining a thickening coal seam according to claim 1, characterized in that: The mining equipment for full-height mining at one time includes a front scraper conveyor, which is arranged in front of the working face support and is connected to the transfer machine by an end unloading arrangement or a cross side unloading arrangement.

5. The method for mining a thickening coal seam according to claim 4, characterized in that: The front scraper conveyor is connected to the transfer machine through an end unloading arrangement. After the rear scraper conveyor is transported to the rear of the working surface support through the connecting lane, the rear scraper conveyor is connected to the transfer machine through a cross side unloading arrangement.

6. The method for mining a thickening coal seam according to claim 4, characterized in that: The front scraper conveyor is connected to the transfer machine by a cross-side unloading arrangement, and step S5 also includes the following steps: S51: transporting the middle trough and the tail drive part of the rear scraper conveyor to the rear of the working surface support via the connecting lane; S52: disconnecting the middle trough and transition trough of the front scraper conveyor, and then moving the transition trough and the driving part of the front scraper conveyor backward and connecting them with the middle trough of the rear scraper conveyor to construct a complete rear scraper conveyor; S53: transport the end-discharge transition trough and the driving part to the front scraper conveyor via the connecting lane and connect them to the middle trough of the front scraper conveyor to construct a new front scraper conveyor.

7. The method for mining a thickening coal seam according to claim 4, characterized in that: Step S6 also includes the following steps: Part of the transport trough of the transfer machine is transported to the front side of the tail of the transfer machine through the connecting lane to fill the missing part between the front scraper conveyor and the rear scraper conveyor.

8. The method for mining a thickening coal seam according to claim 1, characterized in that: During the top coal caving process, a single-row advance support, a rear advance support and a front advance support are arranged in sequence along the mining direction in the transport lane serving the working face, and the single-row advance support is arranged on the non-production side of the transfer machine and connected to the rear advance support; The construction of the top coal caving equipment comprises the following steps: The single-row leading support is transported to the non-production side of the transport lane via the connecting lane and connected to the rear of the rear leading support.

9. The method for mining a thickening coal seam according to claim 8, characterized in that: An auxiliary transport lane is provided beside the transport lane, and the auxiliary transport lane is connected with the transport lane through a connecting lane. The single-row advance support and the rear scraper conveyor are transported through the auxiliary transport lane and the connecting lane.

10. The method for mining a thickening coal seam according to claim 1, characterized in that: The working surface is provided with a plurality of middle hydraulic supports, the plurality of middle hydraulic supports are arranged in sequence along the extension direction of the working surface, and transition supports are provided at both ends of the plurality of middle hydraulic supports; The middle hydraulic support comprises a telescopic plug plate and a tail beam. During the process of mining the full height at one time, the telescopic plug plate is retracted and the tail beam is lowered to the lowest position; The height adjustment range of the middle hydraulic support is determined by the following method: Taking the maximum coal thickness revealed by the drilling diagram of the working face as a reference, and then floating and setting parameters on the reference as the maximum height adjustment of the middle hydraulic support; The minimum height adjustment of the middle hydraulic support is determined according to the well development method and the actual situation of the existing equipment.

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