Stepwise shrinkage stoping with subsequent backfilling method for the upper and lower sublevels of the intermediate pillar

Abstract

The present application provides a stepped ore retention and subsequent filling mining method for the upper and lower disks of the intermediate pillar, belonging to the field of underground mining. During the mining process, the intermediate pillar is used as the stope; the original lower disk haulage roadway is continued, and an upper disk haulage roadway along the strike of the ore body is driven in the hanging wall rock of the ore body. An upper disk mining raise and a lower disk mining raise perpendicular to the strike of the ore body are respectively driven in the hanging wall and footwall rocks, and a stratified connection drift is driven at the same time; an ore-drawing crosscut is driven in the middle of the bottom of the intermediate pillar to connect the upper disk haulage roadway and the lower disk haulage roadway. Using the ore-drawing crosscut as the blasting face, shallow hole blasting is used to drive from the middle of the first layer to both ends respectively to the upper disk and the lower disk; according to the driving method from the middle to both ends, the remaining layers are mined in sequence from bottom to top until the intermediate pillar is mined, and then the remaining intermediate pillars are mined. The present application uses shallow hole blasting and the blasting method from the middle of the stope to both ends to realize the efficient, safe and high recovery rate mining of the intermediate pillar.

Description

Technical Field

[0001] This application relates to the technical field of underground mining, and particularly to a stepwise ore retention and subsequent backfilling mining method for the upper and lower wall raises of the stope pillar. Background Art

[0002] The ore retention method is relatively simple in operation, easy to master and manage, and was a relatively common method for underground mine exploitation in China in the 1990s, especially leading in gold, non-ferrous metal, and chemical mines. The ore retention method generally divides the ore body into ore rooms and stope pillars, mining the ore rooms first and then the stope pillars. However, with the continuous mining of the ore rooms, the stability of the surrounding rock around the ore body is damaged. In order to maintain the stability of the surrounding rock, it is only possible to reluctantly abandon the recovery of the stope pillars and leave them in the ore body for support, resulting in a large number of stope pillars remaining after the mining of the ore rooms, and the ore recovery rate is only 40%-60%, seriously wasting natural mineral resources. In recent years, with the promotion of green mine construction, the filling mining method has gradually replaced the ore retention method due to its characteristics such as operation safety, delaying surface subsidence, high resource recovery rate, low dilution rate, being able to accelerate the consumption of tailings, and reducing the pressure on the tailings pond capacity, and has been widely applied in major mines.

[0003] In order to improve the recovery rate of mine resources and increase the economic benefits of the mine, a filling system was introduced in the later stage for the mined-out areas of the ore bodies mined by the ore retention method in the early stage. On the premise of ensuring surface stability, the remaining stope pillar resources were mined. Currently, the stope pillars are usually mined using medium-deep holes, and the mining process tunnels from the lower wall of the ore body to the upper wall of the ore body, with relatively low mining efficiency and low ore recovery rate, making it difficult to achieve safe and efficient mining of the stope pillars. Summary of the Invention

[0004] In view of the technical problems existing in the background art, this application provides a stepwise ore retention and subsequent backfilling mining method for the upper and lower wall raises of the stope pillar, which uses the shallow hole blasting method and blasts from the middle of the stope to both ends to achieve efficient, safe, and high-recovery mining of the stope pillars.

[0005] In a first aspect, an embodiment of this application provides a stepwise ore retention and subsequent backfilling mining method for the upper and lower wall raises of the stope pillar. In the ore body, stope pillars and filling areas are arranged at intervals along the ore body strike, including the following steps:

[0006] S1. Use the stope pillar as the stope for mining, and the stope width is the width of the stope pillar;

[0007] S2. Follow the original lower wall haulage roadway, drive an upper wall haulage roadway along the ore body strike in the upper wall surrounding rock of the ore body. Both the upper wall haulage roadway and the lower wall haulage roadway are arranged at the bottom of the stope pillar; drive an upper wall mining raise and a lower wall mining raise perpendicular to the ore body strike in the upper and lower wall surrounding rocks of the ore body respectively; drive a stratified connection roadway in each layer to connect different layers with the upper wall mining raise and the lower wall mining raise;

[0008] S3. Drive an ore-drawing crosscut in the middle of the bottom of the intermediate pillar to connect the upper-level haulage roadway and the lower-level haulage roadway. Using the ore-drawing crosscut as the blasting face, blast from the middle of the first slice to both ends respectively towards the upper wall surrounding rock and the lower wall surrounding rock in the way of short-hole blasting;

[0009] S4. Recover the remaining slices from bottom to top until the intermediate pillar is completely recovered. The recovery of each slice is blasted from the middle to both ends;

[0010] S5. Repeat steps S1 - S4 until all the intermediate pillars are recovered.

[0011] In the technical solution of the embodiment of the present application, the intermediate pillar is recovered by the short-hole blasting method with a relatively high ore recovery rate. In order to safely and efficiently achieve the recovery, especially for the recovery of unstable rock masses, first, the stope follows the layout form of the ore room stope, so that the lower-level haulage roadway follows the original development project; then drive the upper-level haulage roadway, the upper-level mining raise perpendicular to the ore body strike, the lower-level mining raise, and the slice connection drift. The recovery is carried out by driving from the middle of the stope to both ends, and the caved ore can be transported out from both ends respectively, improving the recovery efficiency and at the same time reducing the operation time of personnel in the stope, further improving the safety of personnel.

[0012] In some embodiments, step S3 further includes driving the upper-level ore-drawing drift and the lower-level ore-drawing drift respectively; the upper-level ore-drawing drift connects the middle of the ore-drawing crosscut with the upper-level haulage roadway, and the lower-level ore-drawing drift connects the middle of the ore-drawing crosscut with the lower-level haulage roadway.

[0013] In this embodiment, by setting the upper-level ore-drawing drift and the lower-level ore-drawing drift, not only the transportation efficiency of the caved ore is improved, but also it is ensured that all the recovered ore in the stope is completely out, ensuring a relatively high recovery rate of the filling mining method.

[0014] In some embodiments, the hole depth of the blast holes blasted by the short-hole blasting method is 2 - 3m, and the hole diameter is 30 - 50mm.

[0015] In this embodiment, by reasonably setting the parameter range of the blast holes, the disturbance to the surrounding rock during the blasting process is reduced, ensuring safety and achieving rapid recovery.

[0016] In some embodiments, during the recovery process, the drilling method is used to master the thickness from the top of the stope of the slice to be recovered to the recovery boundary.

[0017] In this embodiment, through the drilling method, personnel can timely master the situation of the ore body in the un-recovered part above the roof, and make a response plan according to the specific situation of the ore body in the un-recovered part above, ensuring the safety of personnel.

[0018] In some embodiments, when drilling to the stope boundary, a crown pillar is reserved at the top of the stope.

[0019] In this embodiment, the unstable part above is isolated by reserving the crown pillar, preventing the lower stope from being scrapped due to the collapse of the upper waste rock. This can not only ensure the smooth progress of stoping, but also ensure the safety of personnel during the lower stoping when the upper part collapses.

[0020] In some embodiments, the thickness of the crown pillar is 4 - 5m.

[0021] In this embodiment, by setting the thickness of the crown pillar within a reasonable range, the economic benefits of the mine are increased on the premise of ensuring personnel safety.

[0022] In some embodiments, the distance between the upper panel haulage roadway and the boundary of the rib pillar is 5 - 6m.

[0023] In this embodiment, by reasonably setting the distance between the upper panel haulage roadway and the boundary of the rib pillar, when stoping the rib pillar, the disturbance to the upper panel haulage roadway is reduced, and at the same time, the transportation distance of the caved ore is reduced.

[0024] In some embodiments, the height of the bench is 5 - 6m; the height of the ore-drawing crosscut is 3 - 4m.

[0025] In this embodiment, by reasonably controlling the bench height, personnel can safely and efficiently complete the stoping of each bench, and then safely and efficiently complete the stoping of each rib pillar.

[0026] In some embodiments, when backfilling the goaf after the rib pillar stoping is completed, the strength of the filling body at the bottom 5 - 6m and the top 5 - 6m of the goaf is 3 - 5Mpa.

[0027] In this embodiment, by controlling the strength of the filling body, the overall strength of the filling body is relatively high, maintaining the overall stability of the mine and improving the safety of personnel operations.

[0028] In some embodiments, the width of the stope is 6 - 10m, and the length of the stope is 10 - 12m.

[0029] The above description is only an overview of the technical solution of the present application. In order to be able to understand the technical means of the present application more clearly, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features and advantages of the present application more obvious and understandable, the following specifically gives the specific embodiments of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] To more clearly illustrate the technical solution of this application, the attached drawings used in this application will be briefly introduced below. Obviously, the attached drawings described below are only some embodiments of this application. For those of ordinary skill in the art, without creative efforts, other attached drawings can also be obtained based on these attached drawings.

[0031] Figure 1 It is the front view of the stepped shrinkage stoping with subsequent backfilling mining method for the middle pillar's upper and lower panel raises in the embodiment of this application;

[0032] Figure 2 It is Figure 1 the sectional view taken along II-II;

[0033] Figure 3 It is Figure 1 the sectional view taken along III-III;

[0034] Figure 4 It is Figure 1 the sectional view taken along IV-IV;

[0035] Explanation of reference numerals: 1 - middle pillar; 2 - upper panel haulage drift; 3 - lower panel haulage drift; 4 - upper panel mining raise; ⑤ - lower panel mining raise; 6 - crosscut for level connection; 7 - draw crosscut; <8 - upper wall rock; 9 - lower wall rock; 10 - upper panel ore-drawing drift; 11 - lower panel ore-drawing drift; 12 - blast hole; 13 - caved ore; 14 - ore-waste mixture; 15 - stepped orebody. Specific embodiments

[0036] The embodiments of the technical solution of this application will be described in detail below with reference to the attached drawings. The following embodiments are only used to more clearly illustrate the technical solution of this application, so they are only examples and cannot be used to limit the protection scope of this application.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above attached drawing description are intended to cover non-exclusive inclusion.

[0038] Referring to "embodiment" herein means that the specific features, structures or characteristics described in connection with the embodiment can be included in at least one embodiment of this application. The phrase appears in various positions in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments. Note: There seems to be a mistake in the original text where "⑤" is used instead of "5" in the "Explanation of reference numerals". It has been corrected in the translation.

[0039] In the description of the embodiments of the present application, the orientation or positional relationship indicated by technical terms such as "middle part", "length", "width", "thickness", "top", "bottom", etc. is based on the orientation or positional relationship shown in the drawings. This is only for the convenience of describing the embodiments of the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the embodiments of the present application.

[0040] In order to improve the recovery rate of mine resources and increase the economic benefits of the mine, it is necessary to recover the remaining pillar resources. At present, the recovery efficiency of the pillars is relatively low, and the ore recovery rate is low, making it difficult to achieve the safe and efficient recovery of the pillars.

[0041] To solve the technical problem of being unable to achieve the safe and efficient recovery of the pillars, the present application provides a stepped ore-retaining subsequent filling mining method for the upper and lower stope raises of the pillars. The pillars are recovered by means of short-hole blasting. The lower stope haulage roadway follows the original development project. Then, the upper stope haulage roadway, the upper stope raise perpendicular to the ore body strike, the lower stope raise, and the cross-cut are driven. The recovery is carried out by driving from the middle of the stope to both ends, and the caved ore can be transported out from both ends respectively, improving the recovery efficiency. At the same time, the operation time of personnel in the stope is reduced, further improving the safety of personnel and achieving the efficient, safe, and high-recovery rate recovery of the pillars.

[0042] Please refer to Figure 1 , which is a schematic structural diagram of the stepped ore-retaining subsequent filling mining method for the upper and lower stope raises of the pillars provided for the embodiments of the present application. The goaf left over from the previous mining of the stope has been filled to form a filling area, and the pillar 1 is ready to be recovered. The pillar 1 and the filling area are arranged at intervals along the ore body strike. The recovery process of the pillar 1 includes the following steps:

[0043] S1. Taking the pillar 1 as the stope for recovery, the stope width is the width of the pillar 1.

[0044] S2. Follow the original lower stope haulage roadway 3 arranged in the lower wall rock 9 and laid along the ore body strike. After the filling body in the filling area of the stope is cured, drive the upper stope haulage roadway 2 along the ore body strike in the upper wall rock 8 of the ore body. Both the upper stope haulage roadway 2 and the lower stope haulage roadway 3 are arranged at the bottom of the pillar 1; drive the upper stope raise 4 and the lower stope raise 5 perpendicular to the ore body strike in the upper wall rock 8 and the lower wall rock 9 of the ore body respectively; drive the cross-cuts 6 in the upper wall rock 8 and the lower wall rock 9 of each level to connect different levels with the upper stope raise 4 and the lower stope raise 5 respectively. Specifically, the inclination angles of the upper stope raise 4 and the lower stope raise 5 are similar to the inclination angle of the pillar 1, and the lengths of the upper stope raise 4 and the lower stope raise 5 extend from the bottom of the pillar 1 to the top of the pillar 1.

[0045] S3. In the middle of the bottom of the intermediate pillar 1, drive an ore-drawing crosscut 7 to connect the upper-level haulage roadway 2 and the lower-level haulage roadway 3. Using the ore-drawing crosscut 7 as the blasting face, and adopting short-hole blasting method, blast from the middle of the first slice to both ends respectively until reaching the upper wall rock 8 and the lower wall rock 9. Use a load-haul-dump (LHD) vehicle to transport some of the caved ore 13 from the ore-drawing crosscut 7 to the surface concentrator through the upper-level haulage roadway 2 and the lower-level haulage roadway 3 respectively.

[0046] S4. Sequentially stop the remaining slices from bottom to top until the intermediate pillar 1 is completely stopped. The stoping of each slice adopts short-hole blasting and drives from the middle of the stope to the upper wall rock 8 and the lower wall rock 9 at both ends respectively. Immediately after ore extraction, backfill the mined-out area. Specifically, during the stoping process, personnel enter the middle of the stope and set blast holes 12 in different directions in the ore body above, so as to drive in two directions towards the upper wall and the lower wall respectively. Specifically, during the stoping of all slices, stop along the strike direction of the ore body until reaching the boundary with the adjacent backfill body, and stop in the direction perpendicular to the strike direction of the ore body and in the vertical direction (i.e., in terms of vertical height) until reaching the boundary with the upper wall rock 8 and the lower wall rock 9. That is, when stopping different slices, determine the stoping range according to the shape of different positions of the intermediate pillar 1, and conduct the maximum degree of stoping for the irregular intermediate pillar 1. Based on the ore reserves left over from the previous stoping of the ore room stope in the mine, step-shaped stoping is adopted at the stope boundary of the intermediate pillar 1 to ensure the maximum degree of ore extraction. When stopping the remaining slices, use a LHD vehicle to transport some of the caved ore 13 from the ore-drawing crosscut 7 to the surface concentrator through the upper-level haulage roadway 2 and the lower-level haulage roadway 3 respectively, and reserve some caved ore 13 in the stope. Personnel stand on the caved ore 13 to complete the further stoping of the upper slice. The proportion of the intermediate pillar 1 in the whole ore body is relatively small. Therefore, even if the intermediate pillar 1 is used as the stope and backfilled after the whole intermediate pillar 1 is completely stopped, it will basically not affect the strength of the whole ore body.

[0047] S5. Repeat steps S1 - S4 until all intermediate pillars 1 are completely stopped.

[0048] In the embodiment of the present application, in step S1, the stope follows the layout form of the ore room stope, so that some of the cutting works that have been developed during the stoping of the ore room stope can be followed, reducing the cutting work amount during the stoping process and improving the stoping efficiency. In step S2, the lower drift 3 follows the original development work, reducing the development and cutting work. The upper drift 2 is driven in the upper wall rock 8, and at the same time, the upper wall mining raise 4 and the lower wall mining raise 5 perpendicular to the ore body strike are respectively driven in the upper wall rock 8 and the lower wall rock 9. The setting of the two drifts (i.e., the upper drift 2 and the lower drift 3) and the two mining raises (i.e., the upper wall mining raise 4 and the lower wall mining raise 5) provides guarantee for the stope to be stoped from the middle to both ends. The upper wall mining raise 4 and the lower wall mining raise 5 are set in the upper wall rock 8 and the lower wall rock 9 instead of in the intermediate pillar 1, which can ensure the maximum stoping of the ore body; the upper wall mining raise 4 and the lower wall mining raise 5 are arranged perpendicular to the ore body strike, which can make the crosscut 6 of each layer communicate with the upper wall mining raise 4 and the lower wall mining raise 5 through a small amount of cutting work, ensuring the smooth mining of the intermediate pillar 1. In step S3, first, an ore-drawing crosscut 7 is driven in the middle of the bottom of the intermediate pillar 1 to connect the upper drift 2 and the lower drift 3. The inside of the stope is connected through the upper wall mining raise 4, the upper drift 2, the ore-drawing crosscut 7, the lower drift 3, the lower wall mining raise 5 and the crosscut 6, which is convenient for personnel to enter the stope for stoping operations and ensures the safety of personnel during stoping in the stope, especially for the recovery of the intermediate pillar 1 in some old mines; at the same time, a ventilation system is formed to provide fresh air flow during the stoping process; then, the stoping is carried out in the way of driving from the middle to both ends, improving the stoping efficiency. In step S4, then, the intermediate pillar 1 is efficiently and safely stoped in the way of from the middle to both ends. After the stoping is completed, the mined-out area is filled in time to maintain the stability of the surrounding rock. Compared with medium-deep hole blasting, the short-hole blasting in the present application has less disturbance to the surrounding rock, especially the unstable surrounding rock, during the driving process, and even if personnel are stoping the ore body in the stope, it can be relatively safe. And the short-hole stoping can recover as much ore of the intermediate pillar 1 as possible compared with the medium-deep hole stoping, making the ore recovery rate higher and increasing the economic benefits of the mine; on the basis of adopting short-hole stoping, in the stoping process of the present application, the intermediate pillar 1 is stoped in the way of driving from the middle to both ends, with high stoping efficiency, reducing the operation time of personnel in the stope and further improving the safety of personnel. In addition, the upper drift 2, the lower drift 3, the upper wall mining raise 4 and the lower wall mining raise 5 are set at the same time, which is convenient for personnel to withdraw from different channels in case of emergencies, further improving the safety. In actual stoping, if the surrounding rock with relatively poor stability is encountered, the support project can be set in advance to improve the stability.

[0049] Further, in the embodiment of the present application, as Figure 3As shown, step S3 further includes driving the upper - panel ore - drawing roadway 10 and the lower - panel ore - drawing roadway 11 respectively. The upper - panel ore - drawing roadway 10 connects the middle part of the ore - drawing cross - cut 7 with the upper - panel transportation roadway 2, and the lower - panel ore - drawing roadway 11 connects the middle part of the ore - drawing cross - cut 7 with the lower - panel transportation roadway 3. Specifically, the upper - panel ore - drawing roadway 10 is driven obliquely towards the middle part of the ore - drawing cross - cut 7 in the upper - panel transportation roadway 2, and the upper - panel ore - drawing roadway 10 penetrates the filling body adjacent to the stull 1. The lower - panel ore - drawing roadway 11 is driven obliquely towards the middle part of the ore - drawing cross - cut 7 in the lower - panel transportation roadway 3, and the lower - panel ore - drawing roadway 11 penetrates the filling body adjacent to the stull 1.

[0050] In this embodiment, the caved ore 13 is respectively shoveled into ore cars or string cars through the upper - panel ore - drawing roadway 10, the lower - panel ore - drawing roadway 11 and the ore - drawing cross - cut 7, and transported to the surface concentrator through the original inclined shaft. By setting the upper - panel ore - drawing roadway 10 and the lower - panel ore - drawing roadway 11, more transportation channels are provided for the caved ore 13 to be drawn out, which not only improves the transportation efficiency, but also the multiple transportation channels cooperate to prevent the caved ore 13 from being left in the stope, ensuring that all the mined - out ore in the stope is drawn out and guaranteeing a high recovery rate of the cut - and - fill mining method. In addition, the upper - panel ore - drawing roadway 10 and the lower - panel ore - drawing roadway 11 can further enrich the channels in the stope and optimize the air - return system.

[0051] Further, in the embodiment of the present application, the hole depth of the blast hole 12 is 2 - 3m, the hole diameter is 30 - 50mm, and preferably 40mm.

[0052] In this embodiment, by reasonably setting the parameter range of the blast hole 12, the disturbance to the surrounding rock during the blasting process is reduced to ensure safety. On this basis, the depth of the blast hole 12 is made as deep as possible to achieve rapid stoping, reduce the operation time of personnel in the ore body, and further ensure safety, that is, to make the stoping process proceed smoothly, safely and efficiently.

[0053] Further, in the embodiment of the present application, during the stoping process, the thickness from the top of the stope of the layer to be stoped to the stoping boundary is mastered by means of drilling. Specifically, when the stope is stoped to a certain layer, if the upper stope collapses, it is regarded as reaching the stope boundary at this time. If the drilling method is not adopted to timely understand the specific situation of the upper stope, it will pose a great threat to the safety of mining personnel. Therefore, the drilling method should be adopted to timely master the thickness from the top of the stope to the stoping boundary. During the stoping process of the stull 1, after stoping to a certain height, the roof of the layer to be stoped is penetrated by means of drilling, so that personnel can timely master the ore - body situation of the un - stoped part above the roof to ensure personnel safety. In order to further improve safety, the drilling method can be adopted to master the ore - body situation of the un - stoped part above the roof when mining each layer.

[0054] In this embodiment, during the stoping process, by means of drilling, personnel can timely understand the ore body situation of the unmined part above the roof, and make corresponding solutions according to the specific situation of the ore body in the unmined part above, so as to ensure the safety of personnel.

[0055] Furthermore, in the embodiment of the present application, when drilling reaches the stope boundary, a crown pillar is reserved at the top of the stope. Specifically, when it is found after drilling that the unmined part above the roof of the stope to be mined is still an ore body, the stoping operation continues; when it is found after drilling that the unmined part above the roof of the stope to be mined is surrounding rock or a loose mixture of ore and waste rock 14, at this time, when it is considered to reach the mining boundary, a crown pillar is reserved at the top of the stope. In the actual stoping process, due to the too long retention time of the goaf in the stope of the shrinkage stoping method, the stope collapses, and after backfilling, some of the intermediate pillars 1 do not correspond up and down in the stope (that is, during the previous stoping process of the stope, the stope is divided into different levels from top to bottom, and the level height is 40-60m, and the intermediate pillar 1 does not correspond at the position where the upper and lower levels of the stope are in contact), or if the previous prospecting of the mine is not in place, resulting in disordered stoping of the previous stope of the stope, at this time, during the stoping process of the intermediate pillar 1, the boundaries of the upper and lower wall ore bodies are different, the stope does not correspond up and down, and when mining reaches the top of each intermediate pillar 1 or the position where the intermediate pillar 1 does not correspond up and down, the unmined part above is surrounding rock or an unstable mixture of ore and waste rock 14, then a crown pillar needs to be reserved. At the same time, in order to recover as much ore as possible, according to the specific situation at the stope boundary, the stoping is carried out in a stepped manner to form a stepped ore layer 15, and the reserved crown pillar is also stepped at this time.

[0056] In this embodiment, when reaching the stope boundary, the unstable part above is isolated by reserving a crown pillar to prevent the collapse of the upper waste rock from causing the scrapping of the lower stope, which can not only ensure the smooth progress of stoping, but also ensure the safety of personnel during the lower stoping when the upper part collapses. In addition, the short-hole stoping and stepped stoping of the present application can further ensure the safety of personnel.

[0057] Furthermore, in the embodiment of the present application, the thickness of the crown pillar is 4-5m. Specifically, the thickness of the crown pillar is determined according to the depth of the exploration hole during the drilling process.

[0058] In this embodiment, the thickness of the crown pillar is set within a reasonable range. On the premise of ensuring the safety of personnel, the thickness of the crown pillar is reduced as much as possible, the intermediate pillar 1 is mined to the greatest extent, the recovery rate is increased, and the economic benefits of the mine are increased.

[0059] Furthermore, in the embodiment of the present application, the distance between the upper wall haulage roadway 2 and the boundary of the intermediate pillar 1 is 5-6m.

[0060] In this embodiment, by reasonably setting the distance between the upper panel haulage roadway 2 and the boundary of the stull 1, the upper panel haulage roadway 2 is at an appropriate distance from the boundary of the stull 1. When mining the stull 1, the disturbance to the upper panel haulage roadway 2 is reduced, making the upper panel haulage roadway 2 safe and stable. On this basis, the upper panel haulage roadway 2 is made as close as possible to the stull 1, thereby reducing the transportation distance of the caved ore 13.

[0061] Further, in the embodiment of the present application, the height of each slice is 5 - 6 m, and the height of the ore-drawing crosscut 7 is 3 - 4 m, preferably 3 m. Specifically, when mining the first slice of each stull 1, first drive an ore-drawing crosscut 7 in the middle of the bottom of the stull 1 to connect the upper panel haulage roadway 2 and the lower panel haulage roadway 3. Then, according to the height of the ore-drawing crosscut 7, using the ore-drawing crosscut 7 as the blasting face, and by means of short-hole blasting, blast from the middle of the first slice to both ends to the upper wall rock 8 and the lower wall rock 9 respectively. When a draw layer is formed, continuously backfill upward by short-hole roof caving, and use a leg-mounted rock drill to drill blast holes 12 for blasting during the backfilling process.

[0062] In this embodiment, by reasonably controlling the slice height, the personnel can safely and efficiently complete the mining of each slice, and then realize the safe and efficient mining of each stull 1.

[0063] Further, in the embodiment of the present application, when filling the goaf after the stull 1 is mined, the strength of the filling body at the bottom 5 - 6 m and the top 5 - 6 m of the goaf is 3 - 5 Mpa, preferably 3 Mpa. Specifically, immediately fill after the ore of each stull 1 is mined, ensure that the strength of the filling body at the bottom 5 - 6 m and the top 5 - 6 m of the goaf reaches 3 Mpa in 28 days, and the strength of the filling body in the middle part only needs to meet the self-supporting requirement.

[0064] In this embodiment, by controlling the strength of the filling body at the bottom 5 - 6 m and the top 5 - 6 m of the goaf, the overall strength of the filling body is relatively high, maintaining the overall stability of the mine and improving the safety of personnel operation. At the same time, control the strength of the filling body in the middle part to meet the self-supporting requirement, ensuring the rapid completion of the filling process while playing a supporting role.

[0065] Further, in the embodiment of the present application, the width of the stull 1 is 6 - 10 m, that is, the width of the stope is 6 - 10 m, and the length of the stope, i.e., the thickness of the ore body, is 10 - 12 m. Specifically, the width of the stope is usually 6 - 8 m. When the previous exploration of the mine is not in place, resulting in disordered mining of the previous ore room stope and inconsistent boundaries of the upper and lower wall ore bodies, the width of some positions of the stope reaches 10 m, thus forming a stepped stope.

[0066] Please refer to Figures 1 to 4, according to one or more embodiments of the present application, the present application adopts the short-hole blasting method, which causes little disturbance to the surrounding rock, especially the unstable surrounding rock, during the tunneling process. Even when personnel are mining the ore body in the stope, it can be relatively safe. Moreover, compared with medium-deep hole mining, short-hole mining can recover as much ore as possible from the intermediate pillar 1, resulting in a higher ore recovery rate and increased economic benefits for the mine. On the basis of adopting short-hole mining, during the mining process of the present application, the original footwall haulage roadway 3 is continued to be used, and the hanging wall haulage roadway 2 is driven in the hanging wall rock 8. At the same time, the hanging wall mining raise 4 and the footwall mining raise 5 perpendicular to the ore body strike are respectively driven in the hanging wall rock 8 and the footwall rock 9. The intermediate pillar 1 is mined by driving from the middle to both ends, with high mining efficiency, reducing the operation time of personnel in the stope and further improving the safety of personnel.

[0067] It should be noted that the present application is not limited to the above embodiments. The above embodiments are only examples, and embodiments with the same structure and the same effect as the technical idea within the technical solution scope of the present application are included in the technical scope of the present application. In addition, within the scope of not departing from the gist of the present application, various deformations that can be thought of by those skilled in the art are applied to the embodiments, and other ways constructed by combining some constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A stepwise shrinkage stoping and subsequent backfilling mining method for the upper and lower sublevels of the intermediate pillar. Intermediate pillars and filling areas are arranged at intervals along the strike of the ore body in the ore body. It is characterized in that It includes the following steps: S1. Taking the intermediate pillar as the stope for mining, with the stope width being the width of the intermediate pillar; S2. Continuing to use the original lower drift, driving an upper drift along the orebody strike in the hanging wall rock of the orebody. Both the upper drift and the lower drift are arranged at the bottom of the intermediate pillar; driving an upper mining raise and a lower mining raise perpendicular to the orebody strike in the hanging wall and footwall rocks of the orebody respectively; driving crosscuts in each level to connect different levels with the upper mining raise and the lower mining raise; S3. Driving an ore-drawing crosscut in the middle at the bottom of the intermediate pillar to connect the upper drift and the lower drift, taking the ore-drawing crosscut as the blasting face, and blasting from the middle of the first level to both ends respectively to the hanging wall rock and the footwall rock in the shallow-hole blasting method; S4. Sequentially mining the remaining levels from bottom to top until the intermediate pillar is mined out. The mining of each level is blasted from the middle to both ends, and the mined-out area is backfilled after ore extraction; S5. Repeating steps S1 - S4 until all the intermediate pillars are mined out.

2. The stepped shrinkage stoping with subsequent backfilling mining method for the upper and lower sublevels of the intermediate pillars according to claim 1, characterized in that, Step S3 further includes driving an upper-ore-drawing drift and a lower-ore-drawing drift respectively; the upper-ore-drawing drift connects the middle of the ore-drawing crosscut with the upper drift, and the lower-ore-drawing drift connects the middle of the ore-drawing crosscut with the lower drift.

3. The overhand cut-and-fill stoping method with stepped ore retention and subsequent filling for the upper and lower hanging walls of the intermediate pillars according to claim 1, characterized in that The hole depth of the blast holes blasted by the shallow-hole blasting method is 2 - 3 m, and the hole diameter is 30 - 50 mm.

4. The stepped shrinkage open stoping with subsequent filling mining method for the upper and lower disks of the intermediate pillars according to claim 1, characterized in that During the mining process, the thickness from the top of the stope of the level to be mined to the mining boundary is mastered by drilling.

5. The stepped shrinkage stoping and subsequent backfilling mining method for the upper and lower wall raises of the intermediate pillar according to claim 4, characterized in that, When drilling reaches the mining boundary, a crown pillar is reserved at the top of the stope.

6. The stepped shrinkage stoping and subsequent backfilling mining method for the upper and lower panels of the intermediate pillars according to claim 5, wherein, The thickness of the crown pillar is 4 - 5 m.

7. The breast stoping and subsequent backfilling mining method with stepped ore retention in the upper and lower sublevels of the intermediate pillar according to claim 1, characterized in that, The distance between the upper drift and the boundary of the intermediate pillar is 5 - 6 m.

8. The stepped breast stoping and subsequent backfilling mining method for the upper and lower wall raises of the intermediate pillar according to claim 1, characterized in that, The height of each level is 5 - 6 m; the height of the ore-drawing crosscut is 3 - ④ m.

9. The stepwise shrinkage stoping and subsequent backfilling mining method for the upper and lower hanging walls of the intermediate pillar according to claim 1, wherein, When the intermediate pillar is mined out and the mined-out area is backfilled, the strength of the backfill body at the bottom 5 - 6 m and the top 5 - 6 m of the mined-out area is 3 - 5 Mpa.

10. The stepped shrinkage stoping with subsequent filling mining method for the upper and lower disks of the intermediate pillar according to claim 1, characterized in that, The stope width is 6 - 10 m, and the stope length is 10 - 12 m.

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