Sectional medium-length hole mining method with safety, high efficiency and high recovery rate

Abstract

The invention provides a safe, efficient and high-recovery-rate segmented medium-length hole mining method, and belongs to the field of underground mining. Firstly, presplitting blast holes are formed in rock drilling roadways at the bottoms of stopes, ore bodies at the boundaries of every two adjacent stopes are divided into triangular jambs, and the presplitting blast holes are charged at intervals and subjected to blasting presplitting; separating the top boundary of the triangular jamb from the mining lower boundary of the stope, performing blasting recovery and filling on the triangular jamb, and performing blasting recovery and filling on the normal ore body of the stope. According to the method, the bottom structure of the stope is optimally arranged, ore body mining boundary control is achieved, meanwhile, the stoping sequence is adjusted in a matched mode, ore resources pressed and covered in a triangular pillar area are effectively recycled, construction safety is guaranteed, the situation of mining under a filling body is avoided, and the mining efficiency is improved. And the lean loss index of ore resource recovery is accurately controlled, and the recovery of the triangular jambs and the normal recovery of the stope are orderly linked, so that the efficient production of the stope is realized.

Description

Technical Field

[0001] The invention relates to the technical field of underground mining, and in particular to a segmented medium-deep hole mining method that is safe, efficient and has a high recovery rate. Background Art

[0002] At present, for ore bodies with steep inclination, medium thickness or above or gently inclination, thickness and large mining technology conditions, when the ore rock belongs to medium stability or above lithology conditions, the mining method of segmented medium-deep hole and subsequent filling or segmented rock drilling stage empty field and subsequent filling is generally adopted. The above mining methods have the advantages of low mining and cutting ratio, large production capacity and high safety. However, most medium-deep hole mining sites generally use the bottom structure of the trench to mine, which will cause a V-shaped structure to form at the bottom of the mining site. During the production process, the ore in the bottom structure of the trench cannot be recovered with the normal blasting process of the row, resulting in a part of the ore (triangular ore pillar) left in the trench after the filling of the mining site, resulting in a low recovery rate of ore. The recovery of this triangular ore pillar has always been a major problem that plagues the production of medium-deep hole mining sites in mines.

[0003] A certain prior art discloses a room-and-pillar medium-depth hole filling mining method in which a bottom mining structure is arranged in the original rock. The ore body is divided into chambers and pillars arranged at intervals along the strike direction. The order of mining the chambers and pillars in the panel area is to mine the chambers first and then the pillars. When mining the chambers, backward mining is carried out row by row starting from the second section. After the chambers are mined, the goaf is first filled with cement tailings with a high ash-sand ratio for one section, and then filled and topped with cement tailings with a low ash-sand ratio. When mining the pillars, starting from the first section, the pillars are mined using the same method as the chamber mining. After the pillars are mined, the goaf is filled with cement tailings with a high ash-sand ratio for one section, and then filled and topped with plain tailings. After the mining of the entire ore block is completed, the goaf is recovered using the approach method. Another prior art discloses a bottom structure and recovery method for a medium-deep hole mine with a low mining-to-cut ratio. By optimizing the bottom structure of the medium-deep hole mine, a large triangular ore pillar that is easy to recover is formed in two adjacent mines. A small-section rock drilling tunnel is excavated in the middle of the large triangular ore pillar, and fan-shaped blast holes are drilled upward to form medium-deep holes. Ore is collapsed by micro-difference blasting to achieve the purpose of recovery.

[0004] In the above-mentioned prior art, the recovery of the pillars is carried out in the exposed space of the filling body. During the blasting recovery, the upper filling body may become unstable. In particular, when the quality of the filling body is poor, the safety of the pillar resource recovery cannot be guaranteed. This situation causes the pillar resource recovery rate to be low or even impossible to recover. If the filling body collapses during recovery, the overall depletion rate of the ore will increase, making the comprehensive cost of pillar recovery higher. Summary of the invention

[0005] In view of the technical problems existing in the background art, the present application provides a sectional medium-deep hole mining method that is safe, efficient, and has a high recovery rate, aiming to solve the technical problems in the prior art of medium-deep hole mining methods, where it is difficult to recover the bottom ore pillar safely and efficiently, resulting in a low overall ore recovery rate.

[0006] The present application provides a sectional medium-deep hole mining method that is safe, efficient, and has a high recovery rate, including the following steps: S1. Divide the ore body to be mined into sections in the height direction, and each section is mined from bottom to top. Each section is divided into several stopes along the strike of the ore body. S2. In any of the above-mentioned sections, before mining each stope, first construct its own drilling roadway at the bottom of the stope, and uniformly arrange pre-splitting blast holes along the strike of the drilling roadway; the pre-splitting blast holes extend obliquely upward from the upper corner of the two side walls of the drilling roadway to the boundary of their respective stopes, and the pre-splitting blast holes divide the ore body at the boundary of adjacent two stopes to form triangular ore pillars. S3. Adopt the method of interval charging along the strike of the drilling roadway for the pre-splitting blast holes in step S2, and conduct blasting pre-splitting to separate the top boundary of the triangular ore pillar from the lower boundary of stope mining, and conduct blasting recovery and filling of the triangular ore pillar. S4. For the stope where the recovery of the triangular ore pillar has been completed, use upward fan-shaped medium-deep holes for blasting stoping and filling, that is, complete the mining and filling of all the ore bodies in the stope. S5. Repeat steps S2 to S4 until all the stopes in the section are mined and filled, and then conduct the mining of other sections from bottom to top until the mining of the entire ore body to be mined is completed.

[0007] As a further improvement of the present invention, in step S2, the included angle between the pre-splitting blast hole and the horizontal plane is 40 degrees to 45 degrees, and the width of the stope is 10 to 20 m.

[0008] As a further improvement of the present invention, the spacing of the pre-splitting blast holes along the strike of the drilling roadway is 1.0 to 1.2 m.

[0009] As a further improvement of the present invention, in step S3, the method for blasting recovery and filling of the triangular ore pillar includes the following steps: SS1. Construct a small-section drilling roadway in the triangular ore pillar, and construct several ore-drawing cross-cuts from the single side wall of the small-section drilling roadway to the drilling roadway of its adjacent stope. SS2. Construct fan-shaped blast holes in the small-section drilling roadway, and the fan-shaped blast holes all extend to the top boundary of the triangular ore pillar. Charge and blast the fan-shaped blast holes, and draw ore through the ore-drawing cross-cuts and the drilling roadway. SS3. After the ore resources in the triangular ore pillar are completely mined, a filling retaining wall is arranged at the connection position between the small-section rock-drilling roadway and the ore-drawing crosscut, and the triangular ore pillar is filled with high-strength filling slurry to complete the blasting recovery and filling of the triangular ore pillar.

[0010] As a further improvement of the present invention, in step S2, within any of the levels, every two adjacent stopes form a mining unit. In the two stopes within the mining unit, there are rock-drilling roadways distributed in mirror symmetry. The distance between the central axes of the rock-drilling roadways in the two stopes is greater than the width of a single stope, so that a large-area triangular ore pillar is formed in the middle of the mining unit after the construction of pre-splitting blast holes.

[0011] As a further improvement of the present invention, in step S2, the diameter of the pre-splitting blast holes is 60 - 80 mm.

[0012] As a further improvement of the present invention, in step S3, when blasting recovery and filling of the triangular ore pillar are carried out, only the large-area triangular ore pillar within the mining unit needs to be blasted and recovered and filled; when the normal ore body in the stope is mined, an ore-drawing access road is constructed from the rock-drilling roadway in the stope to the boundary of the mining unit, and the ore-drawing access road extends to the rock-drilling roadway of the adjacent mining unit to form an ore-drawing channel.

[0013] As a further improvement, when blasting recovery and filling of the large-area triangular ore pillar are carried out, two parallel small-section rock-drilling roadways are constructed in the large-area triangular ore pillar, and the blasting recovery is carried out by combining fan-shaped blast holes and horizontal short holes.

[0014] As a further improvement of the present invention, in step SS1, the included angle between the ore-drawing crosscut and the small-section rock-drilling roadway is 40° - 50°, and the spacing of the ore-drawing crosscut along the trend of the small-section rock-drilling roadway is 10 - 12 m.

[0015] As a further improvement of the present invention, in step S1, before the mining of the ore body to be mined starts, the development and cutting engineering of the ore body is carried out, including the cross-level haulage roadway arranged between each level and along the trend of the ore body, and the ore-pass connecting roadway and the ore-pass shaft perpendicular to the cross-level haulage roadway.

[0016] Beneficial effects: (1) The safe, efficient and high-recovery sectional medium-deep hole mining method of the present application. Before the mining of each sectional stope, pre-splitting blast holes are evenly arranged along the strike in the drilling roadway at the bottom of the stope. The pre-splitting blast holes divide the ore body at the boundary between two adjacent stopes to form triangular ore pillars. The pre-splitting blast holes are blasted by adopting an interval charging method for pre-splitting, so that the top boundary of the triangular ore pillar is separated from the lower boundary of the stope mining, and the triangular ore pillar is blasted, recovered and filled; then the normal ore body in the stope is blasted and mined and filled by using upward fan-shaped medium-deep holes, that is, the mining and filling of all ore bodies in the stope are completed. By optimizing the layout of the bottom structure of the stope, this mining method realizes the control of the boundary of the normal mined ore body in the stope. At the same time, in cooperation with the adjustment of the mining sequence, it not only effectively recovers the ore resources overlying the triangular ore pillar area, but also ensures the construction safety, avoids the situation of mining under the filling body, and accurately controls the dilution and loss indexes of the ore resource recovery. The recovery of the triangular ore pillar and the normal mining of the stope are orderly connected. The comprehensive loss rate of the stope can be controlled at an index level less than 3%, which is greatly reduced compared with the loss rate of the conventional sectional medium-deep hole stope (12% - 15%), enabling the stope to achieve efficient production.

[0017] (2) By setting pre-splitting blast holes and blasting by adopting an interval charging method in the present application, the setting of non-charged empty holes can play an air interval role during blasting, which is beneficial to controlling the blasting effect, reducing the damage to the integrity of the normal ore body, and realizing the accurate control of the recovery boundary of the triangular ore pillar and the lower boundary of the stope mining; it ensures that the ore pillar resources can be completely recovered as designed, will not affect the normal bench blasting of the medium-deep hole stope, can accurately control the ore recovery amount, and reduces the dilution caused by the mining of the triangular ore pillar area in the stope. At the same time, the relevant parameters of the pre-splitting blast holes are limited to control the blasting range and effect, so that the top boundary of the triangular ore pillar is better separated from the lower boundary of the stope mining, and it is beneficial to the subsequent recovery work of the triangular ore pillar, avoiding the waste of ore resources.

[0018] (3) In the present application, a small-section size drilling roadway is constructed in the triangular ore pillar, which provides a compensation space for the small-bench blasting in this area. And an ore-drawing crosscut is set on one side of the small-section size drilling roadway, which improves the ore-drawing efficiency in this area, and the one-side ore-drawing can effectively reduce the mining ratio and the drivage amount, reducing the construction cost.

[0019] 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 implementation manners of the present application. Brief Description of the Drawings

[0020] To more clearly illustrate the technical solutions of this application, the accompanying drawings used in this application will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0021] Figure 1 It is a schematic diagram of the stope structure of the sectional medium-deep hole mining method with high safety, high efficiency and high recovery rate in the embodiments of this application; Figure 2 For Figure 1 the schematic diagram of the stope structure in the II-II direction; Figure 3 For Figure 1 the schematic diagram of the stope structure in the III-III direction; Figure 4 It is a schematic diagram of the bottom structure of the stope and the blasting recovery structure of the triangular ore pillar in an embodiment of this application.

[0022] Explanation of reference numerals: 100, level; 110, stope; 120, drilling roadway; 130, pre-splitting blast hole; 131, empty hole; 140, triangular ore pillar; 141, small-section drilling roadway; 142, ore-drawing crosscut; 143, fan-shaped blast hole; 144, horizontal shallow hole; 150, upward fan-shaped medium-deep hole; 160, large-area triangular ore pillar; 170, level haulage roadway; 180, ore-pass connecting roadway; 190, ore pass; 200, filling body. Specific embodiments

[0023] The embodiments of the technical solutions of this application will be described in detail below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of this application, so they are only examples and cannot be used to limit the protection scope of this application.

[0024] 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 accompanying drawing descriptions are intended to cover non-exclusive inclusion.

[0025] In the description of the embodiments of this application, technical terms such as "first" and "second" are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity, specific order or primary-secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "multiple" and "several" is more than two, unless otherwise specifically defined.

[0026] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0027] In the description of the embodiments of the present application, the technical 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. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application 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 a limitation on the embodiments of the present application.

[0028] For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances.

[0029] At present, when medium-deep hole mining is carried out in ore bodies with steep inclination, medium thickness or above or gently inclined, thick and large mining technology conditions, most medium-deep hole mining sites generally use the bottom structure of the trench to mine. During the production process, the ore in the bottom structure of the trench cannot be recovered with the normal blasting process of the row, resulting in a part of the ore (triangular pillar) left in the trench after the mining site is filled, resulting in a low recovery rate of ore. The recovery of this triangular pillar has always been a major problem that plagues the production of medium-deep hole mining sites in mines. In the existing technology, the recovery of the pillar is carried out in the exposed space of the filling body. During the blasting recovery, the upper filling body may be unstable. Especially when the filling body is of poor quality, the safety of the pillar resource recovery cannot be guaranteed. This situation causes the pillar resource recovery rate to be low or even impossible to recover. If the filling body collapses during recovery, the overall depletion rate of the ore will increase, making the comprehensive cost of pillar recovery high.

[0030] In order to solve the technical problem in the prior art of medium-deep hole mining methods that it is difficult to recover the bottom ore pillar safely and efficiently, resulting in a low overall ore recovery rate, the present application provides a sectional medium-deep hole mining method that is safe, efficient, and has a high recovery rate. Before the mining of each midsection stope, pre-splitting blast holes are evenly arranged along the trend in the drilling roadway at the bottom of the stope. The pre-splitting blast holes divide the ore body at the boundary between two adjacent stopes to form a triangular ore pillar. The pre-splitting blast holes are blasted by adopting an interval charging method to separate the top boundary of the triangular ore pillar from the lower boundary of the stope mining, and the triangular ore pillar is blasted for recovery and filling. Then, the normal ore body in the stope is blasted and mined and filled by using upward fan-shaped medium-deep holes, that is, the mining and filling of all ore bodies in the stope are completed. By optimizing the layout of the bottom structure of the stope, this mining method realizes the control of the boundary of the normal mining ore body in the stope. At the same time, in cooperation with the adjustment of the mining sequence, it not only effectively recovers the ore resources overlying the triangular ore pillar area, but also ensures construction safety, avoids the situation of mining under the filling body, and accurately controls the dilution and loss indexes of the ore resource recovery. The recovery of the triangular ore pillar and the normal mining of the stope are orderly connected, and the comprehensive loss rate of the stope is greatly reduced, enabling the stope to achieve high-efficiency production.

[0031] For the convenience of description, the following embodiments are described by taking a sectional medium-deep hole mining method that is safe, efficient, and has a high recovery rate in an embodiment of the present application as an example.

[0032] Please refer to Figures 1 to 3 , the embodiment of the present application provides a sectional medium-deep hole mining method that is safe, efficient, and has a high recovery rate, including the following steps: S1. Divide the ore body to be mined into midsections 100 in the height direction, and each midsection 100 is mined from bottom to top. Each midsection is divided into several stopes 110 along the trend of the ore body. S2. In any midsection 100, before the mining of each stope 110, construct their respective drilling roadways 120 at the bottom of the stope 110, and evenly arrange pre-splitting blast holes 130 along the trend in the drilling roadway 120; the pre-splitting blast holes 130 obliquely extend upward from the upper corner of the two side walls of the drilling roadway 120 to the boundary of their respective stopes 110, and the pre-splitting blast holes 130 divide the ore body at the boundary between two adjacent stopes 110 to form a triangular ore pillar 140. S3. Adopt an interval charging method for the pre-splitting blast holes 130 in step S2 along the trend of the drilling roadway 120, that is, empty holes 131 are arranged at intervals in the pre-splitting blast holes 130 for blasting pre-splitting, so that the top boundary of the triangular ore pillar 140 is separated from the lower boundary of the stope 110 mining, and the triangular ore pillar 140 is blasted for recovery and filling. S4. For the stope 110 that has completed the recovery of the triangular ore pillar 140, use upward fan-shaped medium-deep holes 150 for blasting and mining and filling, that is, complete the mining and filling of all ore bodies in the stope 110. S5. Repeat steps S2 - S4 to complete the stoping and backfilling of all the stopes 110 within the middle section 100, and then conduct the mining of other middle sections 100 from bottom to top until the stoping of the entire ore body to be mined is completed.

[0033] Through the optimized layout of the bottom structure of the stope 110, this mining method realizes the control of the ore body mining boundary. Meanwhile, in coordination with the adjustment of the stoping sequence, it not only effectively recovers the ore resources overlying the triangular ore pillar 140 area, but also ensures construction safety, avoids the situation of mining under the filling body 200, and accurately controls the dilution and loss indexes of ore resource stoping. The recovery of the triangular ore pillar 140 and the normal stoping of the stope 110 are orderly connected. The comprehensive loss rate of the stope 110 can be controlled at an index level of less than 3%, which is greatly reduced compared with the loss rate of the conventional sublevel medium - deep - hole stope (12% - 15%), enabling the stope 110 to achieve high - efficient production.

[0034] It should be noted that in step S4, for the stope 110 where the mining of the triangular ore pillar 140 has been completed, it means that the ore pillars on both sides at the bottom of the stope 110 have been recovered in the form of the triangular ore pillar 140.

[0035] Further, in some embodiments, in step S2, the angle between the pre - split blast holes 130 and the horizontal plane is 40 degrees - 45 degrees, and the width of the stope 110 is 10 - 20 m. The spacing of the pre - split blast holes 130 along the direction of the drilling roadway 120 is 1.0 - 1.2 m.

[0036] In the technical solution of the embodiment of the present application, the pre - split blast holes 130 are blasted in an interval charging manner. The setting of the empty holes 131 without charge can play an air - interval role during blasting, which is beneficial to controlling the blasting effect, reducing the damage to the integrity of the normal ore body, and realizing the accurate control of the recovery boundary of the triangular ore pillar 140 and the lower boundary of the stope 110 mining; ensuring that the ore pillar resources can be fully recovered as designed, without affecting the normal bench blasting of the medium - deep - hole stope, being able to accurately control the ore recovery volume, and reducing the dilution caused by the stoping of the triangular ore pillar area in the stope 110. Limiting the angle between the pre - split blast holes 130 and the horizontal plane, the width of the stope 110, and the spacing of the pre - split blast holes 130 enables the pre - split blast holes 130 to form a triangular ore pillar 140 with a suitable area at the bottom of the stope 110, controlling the blasting range and effect, better separating the top boundary of the triangular ore pillar 140 from the lower boundary of the stope 110 mining, and being beneficial to the subsequent recovery work of the triangular ore pillar 140, avoiding the waste of ore resources.

[0037] Further, in some embodiments, in step S3, the method for blasting recovery and filling of the triangular ore pillar 140 includes the following steps: SS1. Construct a small-section tunneling roadway 141 in the triangular ore pillar 140, and construct several ore-drawing cross-cuts 142 from the single-side wall of the small-section tunneling roadway 141 to the tunneling roadway 120 of its adjacent stope 110. SS2. Construct fan-shaped blast holes 143 in the small-section tunneling roadway 141. The fan-shaped blast holes 143 all extend to the top boundary of the triangular ore pillar 140. Charge and blast the fan-shaped blast holes 143, and draw ore through the ore-drawing cross-cuts 142 and the tunneling roadway 120 connected to the ore-drawing cross-cuts 142. SS3. After the ore resources in the triangular ore pillar 140 are completely mined, arrange a filling retaining wall at the connection position between the small-section tunneling roadway 141 and the ore-drawing cross-cuts 142, and use high-strength filling slurry to fill the triangular ore pillar 140 to complete the blasting recovery and filling of the triangular ore pillar 140.

[0038] In the technical solution of the embodiment of the present application, constructing a small-section tunneling roadway 141 in the triangular ore pillar 140 provides a compensation space for small-bench blasting in this area. And arranging the ore-drawing cross-cuts 142 on the single side of the small-section tunneling roadway 141 improves the ore-drawing efficiency in this area, and the single-side ore-drawing can effectively reduce the mining ratio and the development and preparation work amount, and reduce the construction cost; setting the fan-shaped blast holes 143 extending to the top boundary of the triangular ore pillar 140 avoids structural damage to the tunneling roadway 120 during the blasting recovery of the triangular ore pillar 140, affecting the subsequent mining of the normal ore body in the stope 110.

[0039] Further, in some embodiments, in step SS1, the included angle between the ore-drawing cross-cuts 142 and the small-section tunneling roadway 141 is 40° - 50°, and the spacing of the ore-drawing cross-cuts 142 along the trend of the small-section tunneling roadway 141 is 10 - 12 m.

[0040] Please refer to Figure 4 As shown, in some embodiments, in step S2, within any level 100, every two adjacent stopes 110 form a mining unit. The tunneling roadways 120 provided in the two stopes 110 within the mining unit are distributed in mirror symmetry. The distance between the central axes of the tunneling roadways 120 of the two stopes 110 is greater than the width of a single stope 110, so that a large-area triangular ore pillar 160 is formed in the middle of the mining unit after the construction of the pre-splitting blast holes 130. In step S3, when blasting recovery and filling the triangular ore pillar 140, only the large-area triangular ore pillar 160 within the mining unit needs to be blasted and recovered and filled; when mining the normal ore body in the stope 110, draw-ore headings are constructed from the tunneling roadway 120 in the stope 110 to the boundary of the mining unit, and the draw-ore headings extend to the tunneling roadway 120 of the adjacent mining unit to form a draw-ore channel.

[0041] In the technical solution of the embodiment of the present application, by designing the drilling roadway 120 of the stope 110 in the stoping unit near the boundary of the stope 110, it helps to reduce the number of triangular ore pillars 140 to be recovered, and the drilling depth of the blasting construction during the recovery of the triangular ore pillar 140 is relatively shallow. Rock drilling equipment with a smaller specification model can be used, and the corresponding development and cutting engineering can also adopt a small cross-sectional size, reducing the construction time of the development engineering and saving the construction cost of the development engineering.

[0042] Further, in some embodiments, when blasting and filling a large-area triangular ore pillar 160, two parallel small cross-sectional size drilling roadways 141 are constructed in the large-area triangular ore pillar 160, and the blasting recovery is carried out by combining fan-shaped blast holes 143 and horizontal shallow holes 144.

[0043] In the technical solution of the embodiment of the present application, two parallel small cross-sectional size drilling roadways 141 are constructed in the large-area triangular ore pillar 160, which is convenient for evenly distributing blast holes within the range of the large-area triangular ore pillar 160 and recovering the large-area triangular ore pillar 160 as completely as possible.

[0044] Further, in some embodiments, in step S2, the diameter of the presplitting blast holes 130 is 60 - 80 mm. In step S1, before the stoping of the ore body to be mined begins, the development and cutting engineering of the ore body is carried out, including the cross-cut haulage roadway 170 arranged between each level 100 and along the ore body strike, and the ore pass connecting roadway 180 and ore pass 190 perpendicular to the cross-cut haulage roadway 170.

[0045] Specific embodiments are listed below. It should be noted that the embodiments described below are exemplary and are only used to explain the present application and should not be construed as a limitation of the present application. For those not specified in the embodiments regarding specific technologies or conditions, they are carried out according to the technologies or conditions described in the literature in the field, and those skilled in the art can make adaptive adjustments according to the actual stope working conditions.

[0046] Embodiment 1 This embodiment provides a sublevel medium-deep hole mining method that is safe, efficient, and has a high recovery rate, and is applied to the actual situation of an ore body under the technical conditions of gently inclined thick ore bodies, including the following steps: S1. Divide the ore body to be mined into levels in the height direction. The height of each level is 27 m, and each level is mined from bottom to top. The ore body within each level is divided into several stopes along the ore body strike, and the width of each stope is 15 m; before the stoping of the ore body to be mined begins, the development and cutting engineering of the ore body is carried out, including the cross-cut haulage roadway arranged between each level and along the ore body strike, and the ore pass connecting roadway and ore pass perpendicular to the cross-cut haulage roadway; S2. In any middle section, before the mining of each stope, construct their respective drilling headings at the bottom of the stope, and evenly arrange pre-splitting blast holes along the heading direction of the drilling heading; the pre-splitting blast holes extend obliquely upward from the upper side corners of both sidewalls of the drilling heading to the boundaries of their respective stopes, and the pre-splitting blast holes divide the ore body at the boundaries of adjacent two stopes to form triangular ore pillars. Among them, the angle between the pre-splitting blast holes and the horizontal plane is 40°, the spacing of the pre-splitting blast holes along the heading direction of the drilling heading is 1.0 m, and the diameter of the pre-splitting blast holes is 60 mm. S3. Adopt the method of interval charging for the pre-splitting blast holes in step S2 along the heading direction of the drilling heading to carry out blasting pre-splitting, so that the top boundary of the triangular ore pillar is separated from the lower boundary of the stope mining, and carry out blasting recovery and filling of the triangular ore pillar; among them, the method of blasting recovery and filling of the triangular ore pillar includes the following steps: SS1. Construct a small-section drilling heading in the triangular ore pillar, and construct several ore-drawing cross-cuts from the single sidewall of the small-section drilling heading to the drilling heading of its adjacent stope; the angle between the ore-drawing cross-cuts and the small-section drilling heading is 45°, and the spacing of the ore-drawing cross-cuts along the heading direction of the small-section drilling heading is 10 m. SS2. Construct fan-shaped blast holes in the small-section drilling heading, and the fan-shaped blast holes all extend to the top boundary of the triangular ore pillar, carry out charging and blasting for the fan-shaped blast holes, and carry out ore drawing through the ore-drawing cross-cuts and the drilling headings connected with the ore-drawing cross-cuts. SS3. After the ore resources in the triangular ore pillar are completely mined, arrange a filling retaining wall at the connection position between the small-section drilling heading and the ore-drawing cross-cuts, and use high-strength filling slurry to carry out filling treatment for the triangular ore pillar 140 to complete the blasting recovery and filling of the triangular ore pillar. S4. Carry out blasting mining and filling for the stope that has completed the recovery of the triangular ore pillar by using upward fan-shaped medium-deep holes, that is, complete the mining and filling of all ore bodies in the stope. S5. Repeat steps S2~S4 to complete the mining and filling of all stopes in the middle section, and then carry out the mining of other middle sections from bottom to top until the mining of the entire ore body to be mined is completed.

[0047] Through the actual verification of Example 1, this mining method not only effectively recovers the ore resources overlying the triangular ore pillar area, but also ensures construction safety, avoids the situation of mining under the filling body, and accurately controls the dilution and loss indexes of ore resource mining. The recovery of the triangular ore pillar and the normal mining of the stope are orderly connected. The comprehensive loss rate of the stope can be controlled at an index level of less than 3%, which is greatly reduced compared with the loss rate of the conventional sublevel medium-deep hole stope (12%~15%), making the stope achieve high-efficiency production.

[0048] It should be noted that this application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and embodiments with the same structure in essence as the technical idea and achieving the same effects within the scope of the technical solution of this application are all included in the technical scope of this application. In addition, within the scope of not departing from the gist of this application, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways constructed by combining some of the constituent elements in the embodiments are also included in the scope of this application.

Claims

1. A safe, efficient and high recovery segmented medium-deep hole mining method, characterized in that: The following steps are involved: S1. Divide the ore body to be mined into middle sections in the height direction, and mine each middle section from bottom to top. The middle section is divided into several stopes along the direction of the ore body; S2. In any of the middle sections, before mining, each stope shall construct its own rock drilling tunnel at the bottom of the stope, and evenly arrange pre-splitting blastholes along the direction of the rock drilling tunnel; the pre-splitting blastholes extend obliquely upward from the upper corners of both sides of the rock drilling tunnel to the boundaries of the respective stopes, and the pre-splitting blastholes divide the ore bodies at the boundaries of two adjacent stopes into triangular ore pillars; S3, the pre-splitting blastholes of step S2 are charged at intervals along the direction of the rock drilling tunnel to perform blasting pre-splitting, so that the top boundary of the triangular pillar is separated from the lower boundary of the stope mining, and the triangular pillar is blasted and recovered and filled; S4. For the stope where the triangular pillars have been recovered, blasting and backfilling are carried out using upward fan-shaped medium-deep holes, that is, the mining and backfilling of all ore bodies in the stope are completed; S5. Repeat steps S2 to S4 to complete the mining and filling of all the mining areas in the middle section, and then carry out mining of other middle sections from bottom to top until the mining of the entire ore body to be mined is completed.

2. The safe, efficient and high recovery rate segmented medium-deep hole mining method according to claim 1 is characterized in that: In step S2, the angle between the pre-splitting blasthole and the horizontal plane is 40 to 45 degrees, and the width of the stope is 10 to 20 m.

3. The safe, efficient and high recovery rate segmented medium-deep hole mining method according to claim 2 is characterized in that: The spacing between the pre-splitting blastholes along the direction of the rock drilling tunnel is 1.0-1.2 m.

4. The safe, efficient and high recovery rate segmented medium-deep hole mining method according to claim 1 is characterized in that: In step S3, the triangular pillar blasting recovery and filling method comprises the following steps: SS1. constructing a small-section rock drilling tunnel in the triangular ore pillar, and constructing several ore-exiting through veins on one side of the small-section rock drilling tunnel toward the rock drilling tunnel of the adjacent mining area; SS2, constructing fan-shaped blastholes in the small-section rock drilling tunnel, wherein the fan-shaped blastholes all extend to the top boundary of the triangular ore pillar, charging and blasting the fan-shaped blastholes, and mining is carried out through the mining vein and the rock drilling tunnel; SS3. After the ore resources in the triangular pillar are mined, a filling retaining wall is arranged at the connecting position between the small-section drilling tunnel and the ore-exiting vein, and the triangular pillar is filled with high-strength filling slurry to complete the blasting recovery and filling of the triangular pillar.

5. The safe, efficient and high recovery rate segmented medium-deep hole mining method according to claim 1 is characterized in that: In step S2, in any of the middle sections, every two adjacent mining areas form a mining unit, and the two mining areas in the mining unit are provided with rock drilling tunnels that are distributed in a mirror-symmetrical manner. The distance between the central axes of the rock drilling tunnels of the two mining areas is greater than the width of a single mining area, so that a large-area triangular ore pillar is formed in the middle of the mining unit after the construction of the pre-splitting blasthole.

6. The safe, efficient and high recovery rate segmented medium-deep hole mining method according to claim 3 is characterized in that: In step S2, the diameter of the pre-splitting blasthole is 60-80 mm.

7. The safe, efficient and high recovery rate segmented medium-deep hole mining method according to claim 5 is characterized in that: In step S3, when blasting and recovering the triangular pillars and filling them, it is only necessary to blast and recover the large-area triangular pillars in the mining unit and fill them; when mining the normal ore body in the mining area, an exit route is constructed from the rock drilling tunnel in the mining area to the boundary of the mining unit, and the exit route extends to the rock drilling tunnel of the adjacent mining unit to form an exit channel.

8. The safe, efficient and high recovery rate segmented medium-deep hole mining method according to claim 7 is characterized in that: When blasting and recovering and filling the large-area triangular pillars, two parallel small-section drilling tunnels are constructed in the large-area triangular pillars, and blasting and recovery are carried out by combining fan-shaped blast holes with horizontal shallow holes.

9. The safe, efficient and high recovery rate segmented medium-deep hole mining method according to claim 4 is characterized in that: In step SS1, the angle between the ore-exiting vein and the small-section rock drilling tunnel is 40°-50°, and the spacing between the ore-exiting vein along the direction of the small-section rock drilling tunnel is 10-12 m.

10. The safe, efficient and high recovery rate segmented medium-deep hole mining method according to claim 1 is characterized in that: In step S1, before the mining of the ore body to be mined begins, the ore body is cut and cut, including a middle section transport tunnel located between the middle sections and along the direction of the ore body, and a chute connecting tunnel and a chute shaft perpendicular to the middle section transport tunnel.

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