Interval filling up-down layered mining method for ultra-thick coal seam

Abstract

The invention relates to the technical field of coal mining, and discloses an ultra-thick coal seam interval filling up-down layered mining method which comprises the following steps: firstly, dividing an ultra-thick coal seam into a plurality of layers from top to bottom or from bottom to top; secondly, starting from the layer at the bottommost end, a solid filling coal face is arranged, materials conveyed in the goaf are tamped and filled, and a filling body is formed; monitoring internal stress and deformation of the filling body in the goaf after the filling layer mining is finished again; after it is determined that deformation of the filling body is stable, fully mechanized coal mining faces are arranged layer by layer from bottom to top, and caving method mining is conducted; and finally, an uplink and downlink combined circular mining mode is adopted until all the layers are mined. The mining efficiency of resources is improved through the mining sequence of layered interval filling and uplink and downlink combination; rock stratum movement is effectively controlled through filling mining, surface subsidence is reduced, and the surface ecological environment is protected; and meanwhile, green, efficient and safe mining of a mine is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of coal mining, and particularly relates to a method for interval filling and up-and-down slicing mining of extremely thick coal seams. Background Art

[0002] With the continuous growth of energy demand, coal, as one of the main global energy sources, its efficient and safe mining technology is particularly important. Among coal resources, extremely thick coal seams have attracted attention due to their large reserves and high mining potential. However, the mining of extremely thick coal seams faces a series of technical problems, such as surface subsidence, mine safety, low resource recovery rate, etc., which limit the effective development of extremely thick coal seams.

[0003] Currently, for the mining of extremely thick coal seams "under buildings, railways, and water bodies" in China, there are mainly three types of mining methods: The first type includes slicing mining and top coal caving mining methods. Although these methods have high mining efficiency, they use the caving method to manage the roof, which has a serious impact on the surface environment; The second type includes methods such as limited thickness mining, strip mining, and grouting subsidence reduction mining, which protect the surface environment to a certain extent, but their mining rate is low and the production cost is high, resulting in a large amount of resource waste; The third type is mainly filling mining and other methods, which effectively inhibit rock movement, protect the surface ecological environment, and improve the resource recovery rate, but their process is complex and the production efficiency is low.

[0004] In view of the above problems, it is urgent for those skilled in the art to propose a method for interval filling and up-and-down slicing mining of extremely thick coal seams with high mining efficiency, reduced impact on the surface environment, reduced resource waste, and green, efficient, and safe mining. Summary of the Invention

[0005] The present invention provides a method for interval filling and up-and-down slicing mining of extremely thick coal seams to solve the problems in the prior art.

[0006] In order to achieve the above object, the technical solutions adopted by the present invention are as follows:

[0007] A method for interval filling and up-and-down slicing mining of extremely thick coal seams of the present invention includes the following steps:

[0008] S1: Divide the coal seam: Divide the extremely thick coal seam into multiple slices;

[0009] S2: Upward mining: Starting from the bottommost slice, arrange a solid filling coal mining face, convey materials to the goaf for ramming and filling to form a filling body;

[0010] S3: Monitoring of the filling body: After the filling slicing mining is completed, monitor the internal stress and deformation of the filling body in the goaf to ensure the stability of the filling body.

[0011] S4: Downward mining: After the filling body is confirmed to be stable in deformation, the fully mechanized mining face is arranged layer by layer from bottom to top, and the caving method is used for mining;

[0012] S5: Circular mining: repeat steps S2 and S4 until all layers are mined.

[0013] Furthermore, the layer thickness in step S1 is determined according to mining technical conditions and the upper limit of mining of fully mechanized caving support, so as to ensure that each layer can be mined independently.

[0014] Furthermore, in the step S2, a solid filling coal mining working face is arranged, and an artificial false top and false bottom are manufactured with metal mesh and bamboo fence.

[0015] Furthermore, when the solid filling coal mining working face is arranged in step S2, the return air and transport chute of the upper layer working face are arranged on the upper part of the stable coal seam, the length of the working face increases layer by layer, and the filling material of the lower layer is solid material.

[0016] Furthermore, the solid material includes one or more of gangue, fly ash, or construction waste.

[0017] Furthermore, in step S3, a stress monitoring system is used to monitor the internal stress and deformation of the filling body.

[0018] Furthermore, in the process of mining the layers by caving method in step S4, the return air and transportation chute of the lower layer working face are arranged at the lower part of the filling body, the length of the working face is increased layer by layer, and the upper filling layer is used as an artificial false top and false bottom to improve the recovery rate and safety of mining.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The present invention improves the mining efficiency of resources through the mining sequence of layered interval filling and combined up and down movement. The filling mining of the present invention effectively controls the movement of rock layers, reduces surface subsidence, and protects the surface ecological environment; the filling body is used as an artificial false top and false bottom to improve the stability of the working face and reduce the safety risks in the mining process; at the same time, the green, efficient and safe mining of the mine is realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Attached Figure 1 This is a schematic diagram of the up-and-down stratified mining of the thick coal seam with interval filling in this embodiment. Figure One ;

[0022] Attached Figure 2 This is a schematic diagram of the up-and-down stratified mining of the thick coal seam with interval filling in this embodiment. Figure Two ;

[0023] Attached Figure 3Schematic diagram of interval filling and up-and-down slicing mining of extremely thick coal seams in this embodiment Figure Three ;

[0024] Appendix Figure 4 Schematic diagram of interval filling and up-and-down slicing mining of extremely thick coal seams in this embodiment Figure Four ;

[0025] Appendix Figure 5 Schematic diagram of interval filling and up-and-down slicing mining of extremely thick coal seams in this embodiment Figure Five ;

[0026] Appendix Figure 6 Schematic diagram of interval filling and up-and-down slicing mining of extremely thick coal seams in this embodiment Figure Six ;

[0027] Appendix Figure 7 Schematic diagram of interval filling and up-and-down slicing mining of extremely thick coal seams in this embodiment Figure Seven ;

[0028] Appendix Figure 8 Schematic diagram of interval filling and up-and-down slicing mining of extremely thick coal seams in this embodiment Figure Eight ;

[0029] Appendix Figure 9 Schematic diagram of interval filling and up-and-down slicing mining of extremely thick coal seams in this embodiment Figure Nine ;

[0030] Appendix Figure 10 Schematic diagram of interval filling and up-and-down slicing mining of extremely thick coal seams in this embodiment Figure Ten .

[0031] Reference numerals: 1 is the overlying strata; 2 is the underlying strata; 3 is the unmined coal seam; 4 is the coal seam being mined; 5 is the roadway; 6 is the goaf. Detailed implementation manners

[0032] In order to make the purpose and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0033] Embodiment

[0034] Referring to Appendix Figures 1 - 10 , a method for interval filling and up-and-down slicing mining of extremely thick coal seams in this embodiment includes the following steps:

[0035] S1: Divide the coal seam: First, divide a thick coal seam with a total thickness of 15 meters between the overlying strata 1 and the underlying strata 2 - the unmined coal seam 3 into 3 layers, with each layer having a thickness of 5 meters. The thickness of each layer is determined according to the current fully-mechanized caving support mining technical conditions and the mining upper limit. The thickness of each layer is selected based on the requirements of the caving mining thickness under the current mining technical conditions and the consideration that the caving and swelling of the upper reserved layer after caving can fill the goaf 6; to ensure that each layer can be mined independently. In other specific embodiments, the thick coal seam can be divided into multiple layers according to the thickness of the thick coal seam, as well as the mining technical conditions and the mining upper limit.

[0036] S2: Upward mining: Starting from the bottommost layer, arrange a solid backfilling coal mining face. In each backfilling layer, lay a metal mesh and bamboo fence to create an artificial false roof and false floor. The return air and transportation gateways of the upper layer working face, i.e., the roadway 5, are arranged above the stable coal seam. The working face length increases layer by layer. Through conveying equipment, convey one or more of other solid materials such as gangue, fly ash, or construction waste into the goaf 6 for ramming and backfilling to form a backfill body. The thickness of the backfill body in each backfilling layer is controlled at about 3 meters to ensure the stability and sufficient supporting force of the backfill body, and to ensure the safe mining of the coal seam 4 being mined.

[0037] S3: Monitoring of the backfill body: After the backfilling layer is mined, use a stress monitoring system to monitor the internal stress and deformation of the backfill body in the goaf 6. The monitoring results show that the backfill body reaches a stable state within two weeks, ensuring the safety of subsequent mining.

[0038] S4: Downward mining: After determining that the deformation of the backfill body is stable, arrange a fully-mechanized mining face layer by layer from bottom to top for caving mining. During the process of mining the caving layer, the return air and transportation gateways of the lower layer working face, i.e., the roadway 5, are arranged below the backfill body. The working face length increases layer by layer, and use the previous backfilling layer as the artificial false roof and false floor. To improve the recovery rate and safety of mining. In this step, the downward mining sequence is adopted, and all the mining caving layers are mined one by one from top to bottom first.

[0039] S5: Cyclic mining: Repeat steps S2 and S4 until all layers are mined. During the entire mining process, the surface subsidence is controlled within the safe range, and the resource recovery rate reaches more than 85%, significantly improving the recovery efficiency of resources, and at the same time realizing the green, efficient, and safe mining of the mine.

[0040] In this embodiment, by filling the gob areas of each layer with solid materials, the movement of rock strata is effectively controlled, the surface environment is protected, and at the same time a stable support structure is provided for the mining of the upper layer; there is a certain stagger distance between the mining roadways of adjacent layer working faces. When mining upward, the mining roadway of the upper layer working face is arranged above the stable coal seam, which can better control the deformation of surrounding rocks and reduce the maintenance cost. When mining downward, the mining roadway of the lower layer working face is arranged below the filling body, with high safety. This embodiment first conducts upward mining and then downward mining. Such a mining sequence makes full use of the supporting effect of the filling body, improving the safety of mining; by real-time monitoring the stability of the filling body, the safety of the mining process is ensured, and reliable data support is provided for the mining of the upper layer.

[0041] The beneficial effects of this embodiment: Through the cyclic mining method combining upward and downward mining, the mining efficiency of resources is improved in this embodiment, and at the same time the impact on the surface environment is reduced; the filling solid materials in this embodiment not only have a wide range of sources, low costs but also have good filling performance. By ramming the filling materials, the density and stability of the filling body are ensured, providing a solid foundation for the mining of the upper layer, and at the same time improving the stability of the surrounding rocks of the mining roadway during downward mining; in addition, an advanced stress monitoring system is adopted in this embodiment to real-time monitor the stability of the filling body, ensuring the safety of the mining process, effectively controlling the movement of rock strata, reducing the surface subsidence, and protecting the surface ecological environment; using the filling body as an artificial false roof and false floor improves the stability of the working face and reduces the safety risks during the mining process; at the same time, green, efficient and safe mining of the mine is realized, which has high practical value and popularization prospects.

[0042] The above is only the preferred embodiment of the present application and the description of the applied technical principles. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solution formed by the specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for mining thick coal seams by filling up and down layers, characterized by: The steps include: S1: Divide the coal seam: Divide the thick coal seam into multiple layers; S2: Ascending mining: Starting from the bottom layer, arrange the solid filling coal mining face, compact and fill the goaf with the transported materials to form a filling body; S3: Backfill monitoring: After the backfilling and stratified mining is completed, the internal stress and deformation of the backfill in the goaf are monitored; S4: Downward mining: After the filling body is confirmed to be stable in deformation, the fully mechanized mining face is arranged layer by layer from bottom to top, and the caving method is used for mining; S5: Circular mining: repeat steps S2 and S4 until all layers are mined.

2. The method for mining thick coal seams by interval filling and ascending and descending stratified mining according to claim 1 is characterized by: The layer thickness in step S1 is determined according to mining technical conditions and the upper limit of mining of the fully mechanized caving support.

3. The method for mining thick coal seams by interval filling and ascending and descending stratified mining according to claim 1 is characterized by: In the step S2, a solid filling coal mining working face is arranged, and an artificial false top and false bottom are made with metal mesh and bamboo fence.

4. The method for mining thick coal seams by interval filling and ascending and descending stratified mining according to claim 1 is characterized in that: When the solid filling coal mining working face is arranged in step S2, the return air and transport chute of the upper layer working face are arranged on the upper part of the stable coal seam, the length of the working face increases layer by layer, and the filling material of the lower layer is solid material.

5. The method for mining thick coal seams by interval filling and ascending and descending stratified mining according to claim 4 is characterized by: The solid material includes one or more of gangue, fly ash, or construction waste.

6. The method for mining thick coal seams by interval filling and ascending and descending stratified mining according to claim 1 is characterized by: In step S3, a stress monitoring system is used to monitor the internal stress and deformation of the filling body.

7. The method for mining thick coal seams by interval filling and ascending and descending stratified mining according to claim 1 is characterized by: In the process of mining the layers by the caving method in step S4, the return air and transport chute of the lower layer working face are arranged at the lower part of the filling body, the length of the working face is increased layer by layer, and the upper filling layer is used as an artificial false top and false bottom.

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