A method for mining adjacent synchronous open-pit coal boundary pressure coal

Abstract

The application discloses a kind of adjacent homodromous asynchronous open-pit mine junction pressure coal mining method, including along the ditch, construction of liaison bridge, steep slope treatment, support column alternate coal mining, detouring and residual coal recovery.The application reduces the secondary stripping cost along the ditch, and the ditch can be backfilled in the later stage, without affecting the capacity and stability of the internal dump site;The liaison bridge provides a path for the lagging mine dump, without affecting the normal production of the mine;Steep slope treatment can minimize the amount of end pressure coal, and support column alternate coal mining ensures both mining rate and safety during mining, while the synchronous construction of the two sections can speed up the recovery progress without affecting the normal advancement of the open-pit mine;The construction position of the application is far away from the open-pit mining working line, without affecting the normal production of the mine, and the overall use of new technology is not required, as the mine's existing equipment, workers and management methods can achieve the implementation, which is easy to implement.

Description

Technical Field

[0001] This invention relates to a method for mining coal under pressure, specifically a method for mining coal under pressure at the boundary of adjacent asynchronous open-pit mines in the same direction. Background Technology

[0002] Open-pit mine planning needs to consider factors such as regional coal reserves, geological conditions, and development capacity. Therefore, for single, contiguous coalfields with large and widely distributed coal reserves, it is easy to see multiple open-pit mines being constructed simultaneously or sequentially on the same coalfield. Currently, there is relatively little theory and practice regarding the collaborative design, construction, and development of two open-pit mines. This results in a large amount of coal seam accretion at the boundary between adjacent, co-directional, asynchronous open-pit mines. During the mining process, this portion of coal resources requires extensive secondary stripping, which involves long transportation distances for the stripped material, complicates mine management, increases production costs in adjacent mining areas, and reduces the overall efficiency of coal resource development. Therefore, there is an urgent need to propose a method for mining coal seam accretion at the boundary between adjacent, co-directional, asynchronous open-pit mines. Summary of the Invention

[0003] To address the problems existing in the prior art, this invention provides a method for mining coal at the boundary of adjacent asynchronous open-pit mines in the same direction, which reduces secondary stripping and ensures both the mining rate and the safety of the mining process.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a method for mining coal at the boundary of adjacent asynchronous open-pit mines in the same direction, comprising the following steps: Leave a ditch along the side: During the process of dumping soil in the advance mine, the dumping site in the advance mine located at the junction of the two mines stops dumping soil and reserves a mining trench with a width of B. The mining trench continues to extend as the open-pit mine advances. Construct a connecting bridge: When the lagging mine mining line advances beyond the starting position of the backfill trench by one step, the stripping material is dumped at a position parallel to the backfill trench and the lagging mine mining line, and a passage connecting the spoil dump in the advanced mine and the boundary end wall in the advanced mine is constructed, which is called the connecting bridge. Steep slope handling: After the construction of the connecting bridge is completed, starting from the side of the spoil heap in the lagging mine, along the direction of the open-pit mine, the steep slope treatment of the boundary wall between the advanced mine and the lagging mine will begin, the transportation passage on the boundary wall will be eliminated, and the slope angle of the boundary wall will be adjusted to the safe extreme value. Alternating coal mining with support pillars: The coal seam below the junction end wall is divided into several sections along the direction of open-pit mine advance. Each section is 20-30m wide and is numbered sequentially from the starting position of the mining trench as No. 1, No. 2, No. 3, No. 4...N. First, using section 2 as a support pillar, sections 1 and 3 are simultaneously mined from the bottom of the backfill pit and the delayed mine pit, using an end-face coal mining machine in conjunction with a conveyor belt. The mined coal is transported out via connecting bridges and delayed mine transport routes. After sections 1 and 3 are mined, the open-pit stripping material is backfilled within these sections to prevent collapse. During the backfilling of sections 1 and 3, sections 5 and 7 are mined and backfilled using section 6 as a support pillar, following the same method. After backfilling of sections 1 and 3 is completed, sections 2 and 4 are mined and backfilled using section 3 as a support pillar. This process continues, allowing for simultaneous mining and backfilling with support pillars to accelerate coal recovery until all sections are mined. Detour for soil removal: During the above steps, the mining and internal dumping of both the advanced and delayed mines continue uninterrupted. The stripping material from the delayed mine is first transported via a connecting bridge, then through the advance mine's internal dumping site to the delayed mine's internal dumping site for disposal, ensuring uninterrupted mining and waste disposal. In this process, once a section is fully mined, the stripping material can be backfilled into the corresponding section, providing support for the end walls while also reducing the stripping transport distance and lowering costs. Residual coal recovery: Before the first step of coal recovery under the boundary wall within the range is about to be completed, follow the above steps and proceed with the next cycle of retaining ditches along the wall, constructing connecting bridges and treating steep slopes along the direction of open-pit mine advancement; Before alternating coal mining with support pillars in the next cycle, the coal under the connecting bridge in the previous cycle is divided into 2-3 sections. Mining equipment is deployed from the bottom of the lagging mine pit to mine the remaining coal, maximizing the recovery rate. After the residual coal is recovered, the alternating coal mining with support pillars, bypass soil removal, and residual coal recovery steps are carried out in the next cycle. This process is repeated to achieve continuous step-by-step mining of coal under pressure at the boundary of adjacent asynchronous open-pit mines in the same direction.

[0005] Furthermore, the reserved width B in the step of leaving a trench along the side is greater than 50m.

[0006] Furthermore, the step distance in the construction of the connecting bridge is less than 50m.

[0007] Furthermore, the width of the section is 20-30m.

[0008] Furthermore, the boundary between the two mines divides the section into two equal parts.

[0009] Compared with existing technologies, this invention reduces secondary stripping costs by using a retaining trench along the side slope. Subsequent soil removal can be used to backfill the trench, without affecting the capacity and stability of the internal spoil heap. The connecting bridge provides a passage for spoil removal in lagging mines, without affecting normal mine production. Steep slope treatment minimizes coal pressure on the end slopes. Alternating mining with support pillars ensures both mining efficiency and safety during the mining process. Simultaneous construction of the two sections accelerates the mining progress without affecting the normal progress of the open-pit mine. The construction location of this invention is far from the open-pit mine's working line, so it will not affect normal mine production. The entire invention does not use any new technologies and can be implemented using existing mine equipment, workers, and management methods, making it easy to implement. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the segmentation of the present invention; In the diagram: 1-Advanced mine; 2-Lagging mine; 3-Boundary between the two mines; 4-Dumping site within the advanced mine; 5-Recovery trench; 6-Mining line of the lagging mine; 7-Connecting bridge; 8-Boundary end wall; 9-Dumping site within the lagging mine; 10-Direction of open-pit mine advancement; 11-Section; 12-Bottom of the lagging mine pit. Detailed Implementation

[0011] The invention will now be further described with reference to the accompanying drawings.

[0012] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0013] like Figure 1 As shown, the present invention provides a technical solution, including the following steps: two adjacent open-pit mines in the same coalfield, with the same mining direction, but with asynchronous construction and mining, the open-pit mine mined first is called the advanced mine 1, and the open-pit mine mined later is called the lagging mine 2.

[0014] Along the side retaining ditch: During the internal dumping process of the advance mine 1, the internal dumping site 4 of the advance mine, located on the side of the junction of the two mines 3, stops dumping soil and reserves a mining trench 5 with a width of B. The width of the mining trench 5 at the bottom of the pit is not less than the minimum construction width B, which is generally 50m. The mining trench 5 continues to extend as the open-pit mine advances.

[0015] Construction of connecting bridge: When the lagging mine mining line 6 advances beyond the starting position of the backfill trench 5 by one step, the stripping material is dumped at a position parallel to the backfill trench 5 and the lagging mine mining line 6, and a passage connecting the spoil heap 4 in the advanced mine and the boundary end wall 8 in the advanced mine 1 is constructed, which is called connecting bridge 7; one step is generally less than the normal pit bottom width of the open mine, that is, 50m. This 50m is mainly to reserve time for subsequent construction so that it will not be overtaken by the spoil heap.

[0016] Steep slope treatment: After the construction of the connecting bridge 7 is completed, starting from the side of the spoil heap 9 in the lagging mine, along the direction of open-pit mine advancement 10, space can be freed up as soon as possible for subsequent steps. Steep slope treatment can then be carried out on the boundary end slope 8 in the advanced mine 1 and the lagging mine 2 respectively. The transportation passage on the boundary end slope 8 will be eliminated, and the slope angle of the boundary end slope 8 will be adjusted to a safe extreme value to minimize the amount of coal pressed down below. Steep slope treatment can minimize the amount of coal pressed down on the end slope, reduce the amount of subsequent mining, and speed up the progress.

[0017] Alternating coal mining with support pillars: This involves removing the coal pressure below position 8 on the interface side, such as... Figure 2 As shown, the open-pit mine is divided into several sections 11 along the direction of advancement 10. Each section 11 is 20-30m wide. The boundary 3 between the two mines divides section 11 into two parts, which are equally divided. Sections 11 are numbered sequentially from the starting position of the mining trench 5 as No. 1, No. 2, No. 3, No. 4...N. First, using section 2 (section 11) as a support pillar, sections 1 and 3 (section 11) are mined simultaneously from the mining trench 5 and the bottom of the delayed mine pit 12. Mining is carried out using an end-face coal mining machine in conjunction with a conveyor belt. The mined coal is transported out through the connecting bridge 7 and the delayed mine 2 transport passage. After sections 1 and 3 (section 11) are mined, the exposed material from the open-pit mine is backfilled in section 11 to prevent collapse. During the backfilling of sections 1 and 3 (section 11), sections 5 and 7 (section 11) are mined and backfilled using the same method, using section 6 (section 11) as a support pillar. After the backfilling of sections 1 and 3 (section 11) is completed, sections 2 and 4 (section 11) are mined and backfilled using section 3 (section 11) as a support pillar. This process continues, with the support pillars in place, to achieve simultaneous mining and backfilling, accelerating the recovery of coal under pressure, until all sections 11 are mined.

[0018] Detour and dumping: During the above steps, the mining and dumping work of the advanced mine 1 and the lagging mine 2 continue to advance. The stripping material of the lagging mine 2 is first transported through the connecting bridge 7, and then through the advanced mine dumping site 4 to the lagging mine dumping site 9 for dumping, so as to achieve uninterrupted mining and dumping. During this process, when a certain section 11 is mined, the stripping material can be backfilled into the corresponding section 11, which provides support for the boundary end wall 8, and at the same time reduces the stripping transportation distance and reduces costs.

[0019] Residual coal recovery: Before the recovery of coal under the boundary wall 8 within the first step is about to be completed, follow the above steps and proceed along the open-pit mine advance direction 10 to begin the next cycle's steps of retaining ditches along the wall, constructing connecting bridges, and treating steep slopes; before alternating coal mining with support pillars in the next cycle, divide the coal under the connecting bridge 7 in the previous cycle into 2-3 sections, and deploy mining equipment from the bottom of the lagging pit 12 to mine the residual coal, maximizing the recovery rate. After the residual coal recovery is completed, continue the steps of alternating coal mining with support pillars, bypassing soil removal, and residual coal recovery in the next cycle, and so on, to achieve continuous step-by-step mining of coal under the boundary of adjacent asynchronous open-pit mines in the same direction.

[0020] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0021] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any minor modifications, equivalent substitutions, and improvements made to the above embodiments based on the technical essence of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for mining coal at the boundary of adjacent asynchronous open-pit mines in the same direction, characterized in that, Includes the following steps: Leave a ditch along the side: During the process of dumping soil in the pre-mine (1), the dumping site (4) in the pre-mine located at the junction (3) of the two mines stops dumping soil and reserves a mining trench (5) with a width of B. The mining trench (5) continues to extend as the open-pit mine advances. Construct a connecting bridge: When the lagging mine mining line (6) advances beyond the starting position of the backfill trench (5) by one step, the stripping material is dumped at the position where the backfill trench (5) is parallel to the lagging mine mining line (6), and a connecting bridge (7) is constructed to connect the spoil dump (4) in the advanced mine and the boundary end wall (8) in the advanced mine (1). Steep slope handling: After the construction of the connecting bridge (7) is completed, starting from the side of the spoil heap (9) in the lagging mine, along the direction of the open-pit mine advance (10), the steep slope treatment of the boundary end slope (8) in the advanced mine (1) and the lagging mine (2) will be carried out respectively, the transportation passage on the boundary end slope (8) will be cancelled, and the slope angle of the boundary end slope (8) will be adjusted to the safe extreme value. Alternating coal mining with support pillars: The coal under the boundary end (8) is divided into several sections (11) along the direction of open-pit mine advance (10). The sections (11) are numbered sequentially from the starting position of the mining trench (5) as No. 1, No. 2, No. 3, No. 4...N. First, using section 2 (11) as a support pillar, sections 1 and 3 (11) are mined simultaneously from the backfill trench (5) and the bottom of the delayed mine pit (12). The mined coal is transported out through the connecting bridge (7) and the delayed mine (2) transportation channels respectively. After sections 1 and 3 (11) are mined, the open-pit stripping material is filled in the sections (11). During the filling of sections 1 and 3 (11), sections 5 and 7 (11) are mined and filled in the same way, using section 6 (11) as a support pillar. After sections 1 and 3 (11) are filled, sections 2 and 4 (11) are mined and filled in the same way, using section 3 (11) as a support pillar. This process continues until all sections (11) are mined. Detour for soil removal: During the above steps, the mining and internal dumping of the advanced mine (1) and the lagging mine (2) continue to advance. The stripping material of the lagging mine (2) is first transported through the connecting bridge (7) and then through the internal dumping site (4) of the advanced mine to the internal dumping site (9) of the lagging mine for disposal. During this process, when a certain section (11) is mined out, the stripping material can be backfilled into the corresponding section (11). Residual coal recovery: Before the first step of coal recovery under the boundary end wall (8) within the range is about to be completed, follow the above steps and proceed along the open-pit mine advance direction (10) to start the next cycle of retaining ditches along the side wall, building connecting bridges and treating steep slopes; Before alternating coal mining with support pillars in the next cycle, the coal under the connecting bridge (7) in the previous cycle is divided into 2-3 sections. The remaining coal is mined from the bottom of the lagging mine pit (12). After the residual coal is recovered, the alternating coal mining with support pillars, bypass soil removal and residual coal recovery steps are carried out in the next cycle. This process is repeated to achieve continuous step-by-step mining of the coal under pressure at the junction of adjacent asynchronous open-pit mines in the same direction.

2. The method for mining coal at the boundary of adjacent asynchronous open-pit mines in the same direction according to claim 1, characterized in that, The reserved width B in the step of leaving a trench along the side is greater than 50m.

3. The method for mining coal at the boundary of adjacent asynchronous open-pit mines in the same direction according to claim 1, characterized in that, The step distance in the construction of the connecting bridge is less than 50m.

4. The method for mining coal at the boundary of adjacent asynchronous open-pit mines in the same direction according to claim 1, characterized in that, The width of the section (11) is 20-30m.

5. The method for mining coal at the boundary of adjacent asynchronous open-pit mines in the same direction according to claim 4, characterized in that, The boundary between the two mines (3) divides the section (11) into two equal parts.

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