Segmented medium-long hole mining method

Abstract

The present application provides a segmented medium-deep hole mining method, which belongs to the field of underground mining. First, pre-splitting blastholes are arranged in the rock drilling tunnel at the bottom of the stope, and the ore body at the boundary of two adjacent stopes is divided into triangular pillars. The pre-splitting blastholes are charged at intervals and pre-splitting blasting is performed to separate the top boundary of the triangular pillar from the mining lower boundary of the stope, and the triangular pillar is blasted for recovery and filling, and then the normal ore body of the stope is blasted for recovery and filling. The present application realizes the control of the mining boundary of the ore body by optimizing the arrangement of the bottom structure of the stope, and at the same time, in conjunction with the adjustment of the recovery sequence, it not only effectively recovers the ore resources covered by the triangular pillar area, but also ensures construction safety, avoids the situation of mining under the filling body, and achieves precise control of the depletion index of the ore resource recovery. The recovery of the triangular pillar and the normal recovery of the stope are connected in an orderly manner, so that the stope achieves efficient production.

Description

Technical Field

[0001] The invention relates to the technical field of underground mining, in particular to a segmented medium-deep hole mining method. 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 is of medium stability or above, the mining method of segmented medium-deep hole followed by backfilling or segmented rock drilling stage open-pit followed by backfilling is generally adopted. The above mining methods have the advantages of low mining-cutting ratio, large production capacity and high safety. However, most medium-deep hole stopes generally use a trench bottom structure for ore extraction, which will result in the formation of a V-shaped structure at the bottom of the stope. During the production process, the ore in the trench bottom structure cannot be recovered through the normal blasting process of the face. As a result, after the stope is filled, a part of the ore (triangular ore pillar) is left in the trench, resulting in a low ore recovery rate. The recovery of this triangular ore pillar has always been a major problem plaguing the production of medium-deep hole stopes in mines.

[0003] A certain prior art discloses a room-and-pillar medium-deep 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, the mining is carried out backwards row by row starting from the second segment. After the chambers are mined, the goaf is first filled with cement tailings with a high ash-sand ratio for one segment, and then filled and topped with cement tailings with a low ash-sand ratio. When mining the pillars, the goaf is mined starting from the first segment 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 segment, and then filled and topped with plain tailings. After the mining of the entire ore block is completed, the ore is recovered using the approach method. Another existing technology discloses a bottom structure and recovery method for a medium-deep hole mine with a low mining-cutting 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 towards the medium-deep hole during construction. The ore is collapsed by micro-difference blasting to achieve the purpose of recovery.

[0004] In the above-mentioned existing technologies, the recovery of pillars is carried out in the exposed space of the filling body. During blasting recovery, the upper filling body may become unstable. Especially 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 overall cost of pillar recovery higher. Summary of the Invention

[0005] In view of the technical problems existing in the background technology, the present application provides a segmented medium-deep hole mining method, which aims to solve the technical problem in the existing medium-deep hole mining method that the bottom pillars are difficult to recover safely and efficiently, resulting in a low overall ore recovery rate.

[0006] The present application provides a segmented medium-deep hole mining method, comprising the following steps:

[0007] S1. Divide the ore body to be mined into middle sections in the height direction, mine each middle section from bottom to top, and divide the middle section into several stopes along the strike of the ore body;

[0008] S2. Before mining in any of the middle sections, each stope shall construct its own rock drilling tunnel at the bottom of the stope, and pre-splitting blastholes shall be evenly arranged along the direction of the rock drilling tunnel; the pre-splitting blastholes shall extend obliquely upward from the upper corners of the two sides of the rock drilling tunnel to the boundary of the respective stope, and the pre-splitting blastholes shall divide the ore body at the boundary of two adjacent stopes into triangular ore pillars;

[0009] S3, the pre-splitting blastholes in step S2 are pre-splitting blasted in an interval charging manner along the direction of the rock drilling tunnel, so that the top boundary of the triangular pillar is separated from the lower boundary of the stope, and the triangular pillar is recovered and filled by blasting;

[0010] S4. For the stope where the triangular pillars have been recovered, blasting and backfilling are carried out using upward fan-shaped medium-long holes, thus completing the mining and backfilling of all ore bodies in the stope;

[0011] S5. Repeat steps S2 to S4 to complete the mining and filling of all the stopes in the middle section, and then mine other middle sections from bottom to top until the mining of the entire ore body to be mined is completed.

[0012] As a further improvement of the present invention, in step S2, the angle between the pre-splitting blasthole and the horizontal plane is 40 degrees to 45 degrees, and the width of the stope is 10 to 20 m.

[0013] As a further improvement of the present invention, the spacing between the pre-splitting blastholes along the strike of the rock drilling tunnel is 1.0-1.2 m.

[0014] As a further improvement of the present invention, in step S3, the method for blasting, recovering and filling the triangular pillar comprises the following steps:

[0015] 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 in the adjacent stope;

[0016] 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 extracting the ore through the ore-extraction vein and the rock drilling tunnel;

[0017] 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.

[0018] As a further improvement of the present invention, 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 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.

[0019] As a further improvement of the present invention, in step S2, the diameter of the pre-splitting blasthole is 60-80 mm.

[0020] As a further improvement of the present invention, in step S3, when blasting and recovering and filling the triangular pillars, it is only necessary to blast and recover and fill the large-area triangular pillars in the mining unit; when mining the normal ore body in the mining field, an exit route is constructed from the rock drilling tunnel in the mining field to the boundary of the mining unit, and the mine exit route extends to the rock drilling tunnel of the adjacent mining unit to form a mine exit channel.

[0021] As a further improvement of the present invention, when blasting and filling the large-area triangular pillars, two parallel small-section drilling tunnels are constructed in the large-area triangular pillars, and blasting recovery is carried out by combining fan-shaped blast holes with horizontal shallow holes.

[0022] As a further improvement of the present invention, in step SS1, the angle between the ore-producing vein and the small-section drilling tunnel is 40°~50°, and the spacing between the ore-producing vein along the direction of the small-section drilling tunnel is 10~12 m.

[0023] As a further improvement of the present invention, in step S1, before the mining of the ore body to be mined begins, the mining and cutting engineering of the ore body is carried out, including a middle section transport tunnel located between each middle section and along the direction of the ore body, and a chute connecting tunnel and chute shaft perpendicular to the middle section transport tunnel.

[0024] Beneficial effects:

[0025] (1) The segmented medium-deep hole mining method of the present application is to evenly arrange pre-splitting blastholes along the direction of the rock drilling tunnel at the bottom of the stope before mining in each middle stope. The pre-splitting blastholes divide the ore body at the boundary of two adjacent stopes into triangular ore pillars. The pre-splitting blastholes are pre-splitting by blasting with interval charging to separate the top boundary of the triangular ore pillar from the mining lower boundary of the stope, and the triangular ore pillar is recovered and filled by blasting; then, the normal ore body of the stope is blasted and filled by upward fan-shaped medium-deep holes, thus completing the mining and filling of all ore bodies in the stope. This mining method controls the boundaries of the normally mined ore bodies within the stope by optimizing the arrangement of the stope bottom structure. Simultaneously, by adjusting the mining sequence, it not only effectively recovers the ore resources buried in the triangular pillar area, but also ensures construction safety, avoids mining under the filling body, and precisely controls the loss indicators of ore resource recovery. The recovery of the triangular pillars and the normal mining of the stope are connected in an orderly manner, and the comprehensive loss rate of the stope can be controlled at an indicator level of less than 3%, which is significantly lower than the loss rate of conventional segmented medium and deep hole stopes (12%~15%), enabling the stope to achieve efficient production.

[0026] (2) This application sets pre-splitting blastholes and implements blasting in an intermittent charging manner. The setting of empty holes without charging can act as air intervals during blasting, which is conducive to controlling the blasting effect, reducing the damage to the integrity of the normal ore body, and achieving accurate control of the recovery boundary of the triangular pillar and the lower boundary of the stope; ensuring that the pillar resources can be fully recovered as designed, without affecting the normal blasting of the medium and deep hole stope, and can accurately control the amount of ore recovery, reducing the depletion of the stope caused by the recovery of the triangular pillar area. At the same time, the relevant parameters of the pre-splitting blastholes are limited, the blasting range and effect are controlled, so that the top boundary of the triangular pillar is better separated from the lower boundary of the stope, and it is conducive to the subsequent recovery of the triangular pillar, avoiding the waste of ore resources.

[0027] (3) This application constructs a small-section drilling tunnel in the triangular ore pillar, which provides compensation space for small-row blasting in the area, and sets a mining vein on one side of the small-section drilling tunnel, which improves the mining efficiency in the area. The single-sided mining can effectively reduce the mining ratio and the amount of mining work, thereby reducing construction costs.

[0028] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] To more clearly illustrate the technical solution of this application, the following is a brief introduction to the drawings used in this application. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be derived from these drawings without inventive effort.

[0030] Figure 1 Schematic diagram of the stope structure of the segmented medium-deep hole mining method in the embodiment of the present application;

[0031] Figure 2 for Figure 1 Schematic diagram of the stope structure in the middle II-II direction;

[0032] Figure 3 for Figure 1 Schematic diagram of the stope structure in the middle III-III direction;

[0033] Figure 4 This is a schematic diagram of the bottom structure of the stope and the blasting recovery structure of the triangular pillar in a certain embodiment of the present application.

[0034] Explanation of the accompanying reference numerals: 100, middle section; 110, mining area; 120, rock drilling tunnel; 130, pre-splitting blasthole; 131, empty hole; 140, triangular pillar; 141, small-section rock drilling tunnel; 142, ore-exiting vein; 143, fan-shaped blasthole; 144, horizontal shallow hole; 150, upward fan-shaped medium-deep hole; 160, large-area triangular pillar; 170, middle section transport tunnel; 180, ore chute connecting tunnel; 190, ore chute; 200, filling body. DETAILED DESCRIPTION

[0035] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art 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-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0037] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the technical features indicated. In the description of the embodiments of this application, "multiple" and "several" mean more than two, unless otherwise specifically defined.

[0038] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0039] 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., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and 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 device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0040] For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of this application can be understood according to specific circumstances.

[0041] At present, when conducting medium-deep hole mining in ore bodies with steeply inclined medium-thick or slightly inclined thick mining technology conditions, most medium-deep hole mining sites generally use a trench bottom structure for mining. During the production process, the ore in the trench bottom structure cannot be recovered during the normal blasting process of the face, resulting in a portion of ore (triangular pillars) left in the trench after the mining site is filled, resulting in a low ore recovery rate. The recovery of this triangular pillar has always been a major problem that has plagued the production of medium-deep hole mining sites in mines. In the existing technology, 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. 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. Moreover, if the filling body collapses during recovery, the overall depletion rate of the ore will increase, making the comprehensive cost of pillar recovery high.

[0042] In order to solve the technical problem that in the existing medium-deep hole mining method, the bottom pillars are difficult to recover safely and efficiently, resulting in a low overall ore recovery rate, the present application provides a safe, efficient and high-recovery segmented medium-deep hole mining method. Before mining in each middle section, pre-splitting blastholes are evenly arranged along the direction of the rock drilling tunnel at the bottom of the stope. The pre-splitting blastholes divide the ore body at the boundary of two adjacent stopes into triangular pillars. The pre-splitting blastholes are pre-splitting by blasting with interval charging to separate the top boundary of the triangular pillar from the lower boundary of the stope mining, and the triangular pillar is recovered and filled by blasting; then the normal ore body of the stope is blasted and filled using upward fan-shaped medium-deep holes, thereby completing the mining and filling of all ore bodies in the stope. This mining method controls the boundaries of the normally mined ore bodies in the stope by optimizing the arrangement of the stope bottom structure. At the same time, by adjusting the mining sequence, it not only effectively recovers the ore resources covered by the triangular pillar area, but also ensures construction safety, avoids mining under the filling body, and achieves precise control of the depletion indicators of ore resource recovery. The recovery of the triangular pillars and the normal mining of the stope are connected in an orderly manner, and the comprehensive loss rate of the stope is greatly reduced, enabling the stope to achieve efficient production.

[0043] For the convenience of description, the following embodiments are described by taking a safe, efficient and high-recovery segmented medium-deep hole mining method according to an embodiment of the present application as an example.

[0044] Please refer to Figures 1 to 3 The present invention provides a safe, efficient and high-recovery segmented medium-deep hole mining method, comprising the following steps:

[0045] S1. Divide the ore body to be mined into middle sections 100 in the height direction, mine each middle section 100 from bottom to top, and divide the middle section into several stopes 110 along the strike of the ore body;

[0046] S2. Within any middle section 100, before mining each stope 110, a respective rock drilling tunnel 120 is constructed at the bottom of the stope 110, and pre-splitting blastholes 130 are evenly arranged along the strike of the rock drilling tunnel 120. The pre-splitting blastholes 130 extend obliquely upward from the upper corners of the walls of the rock drilling tunnel 120 on both sides to the boundary of the respective stope 110. The pre-splitting blastholes 130 divide the ore body at the boundary between two adjacent stopes 110 into triangular ore pillars 140.

[0047] S3, the pre-splitting blastholes 130 in step S2 are charged at intervals along the direction of the rock drilling tunnel 120, i.e., empty holes 131 are arranged at intervals in the pre-splitting blastholes 130, and blasting pre-splitting is performed to separate the top boundary of the triangular pillar 140 from the mining lower boundary of the stope 110, and the triangular pillar 140 is blasted and recovered and filled;

[0048] S4. Blast mining and backfilling are performed in the stope 110 where the triangular pillars 140 have been recovered, using upward fan-shaped medium-long holes 150, thereby completing the mining and backfilling of all ore bodies in the stope 110.

[0049] S5. Repeat steps S2 to S4 to complete the mining and filling of all the stopes 110 in the middle section 100, and then mine other middle sections 100 from bottom to top until the mining of the entire ore body to be mined is completed.

[0050] This mining method achieves control over the mining boundary of the ore body by optimizing the bottom structure of the stope 110. At the same time, by adjusting the mining sequence, it not only effectively recovers the ore resources covered by the triangular pillar 140 area, but also ensures construction safety, avoids mining under the backfill body 200, and achieves precise control over the depletion and loss indicators of ore resource recovery. The recovery of the triangular pillar 140 and the normal mining of the stope 110 are connected in an orderly manner. The comprehensive loss rate of the stope 110 can be controlled at an indicator level of less than 3%, which is greatly lower than the loss rate of conventional segmented medium and long hole stopes (12%~15%), enabling the stope 110 to achieve efficient production.

[0051] It should be noted that in step S4 , the stope 110 that has completed the mining of the triangular pillars 140 has obtained a situation in which the pillars on both sides of the bottom of the stope 110 are recovered in the form of triangular pillars 140 .

[0052] Furthermore, in some embodiments, in step S2, the angle between the pre-splitting blastholes 130 and the horizontal plane is 40-45 degrees, the width of the stope 110 is 10-20 m, and the spacing between the pre-splitting blastholes 130 along the strike of the rock drilling tunnel 120 is 1.0-1.2 m.

[0053] In the technical solution of the embodiment of the present application, pre-splitting blastholes 130 are blasted using an interval charging method. The provision of uncharged empty holes 131 can act as air intervals during blasting, which is beneficial for controlling the blasting effect, reducing damage to the integrity of the normal ore body, and achieving accurate control of the recovery boundary of the triangular pillar 140 and the lower mining boundary of the stope 110. This ensures that the pillar resources can be fully recovered as designed, without affecting the normal blasting of the medium- and long-hole stope, and can accurately control the ore recovery volume, reducing the dilution of the stope 110 caused by the recovery of the triangular pillar area. By limiting the angle between the pre-splitting blastholes 130 and the horizontal plane, the width of the stope 110, and the spacing between the pre-splitting blastholes 130, the pre-splitting blastholes 130 can form triangular pillars 140 of appropriate area at the bottom of the stope 110, controlling the blasting range and effect, and better separating the top boundary of the triangular pillar 140 from the lower mining boundary of the stope 110. This facilitates the subsequent recovery of the triangular pillar 140 and avoids waste of ore resources.

[0054] Furthermore, in some embodiments, in step S3, the method for blasting, recovering, and filling the triangular pillar 140 includes the following steps:

[0055] SS1: construct a small-section rock drilling tunnel 141 in the triangular ore pillar 140, and construct several ore-exiting through veins 142 on one side of the small-section rock drilling tunnel 141 toward the rock drilling tunnel 120 in the adjacent stope 110;

[0056] SS2. Construct fan-shaped blastholes 143 in the small-section rock drilling tunnel 141. Each fan-shaped blasthole 143 extends to the top boundary of the triangular ore pillar 140. Charge and blast the fan-shaped blastholes 143, and extract ore from the ore-extracting vein 142 and the rock drilling tunnel 120 connected to the ore-extracting vein 142.

[0057] SS3. After the ore resources in the triangular pillar 140 are mined, a filling retaining wall is arranged at the connection position between the small-section drilling tunnel 141 and the ore-exiting vein 142. The triangular pillar 140 is filled with high-strength filling slurry to complete the blasting recovery and filling of the triangular pillar 140.

[0058] In the technical solution of the embodiment of the present application, a small-section drilling tunnel 141 is constructed in the triangular pillar 140 to provide compensation space for small-row blasting in the area, and a mining vein 142 is set on one side of the small-section drilling tunnel 141 to improve the mining efficiency in the area, and the one-sided mining can effectively reduce the mining ratio and the amount of mining engineering, thereby reducing construction costs; a fan-shaped blast hole 143 extending to the top boundary of the triangular pillar 140 is set to avoid structural damage to the drilling tunnel 120 during blasting recovery of the triangular pillar 140, thereby affecting the subsequent mining of normal ore bodies in the mining field 110.

[0059] Furthermore, in some embodiments, in step SS1, the angle between the ore-producing vein 142 and the small-section drilling tunnel 141 is 40°~50°, and the spacing between the ore-producing vein 142 along the direction of the small-section drilling tunnel 141 is 10~12 m.

[0060] See also Figure 4As shown, in some embodiments, in step S2, within any middle section 100, every two adjacent stopes 110 form a mining unit. Within the two stopes 110 within the mining unit, rock drilling tunnels 120 are provided that are distributed in a mirror-symmetrical manner. The distance between the central axes of the rock drilling tunnels 120 of the two stopes 110 is greater than the width of a single stope 110, so that after the pre-splitting blastholes 130 are constructed, a large triangular ore pillar 160 is formed in the center of the mining unit. In step S3, when blasting and backfilling the triangular ore pillar 140, only the large triangular ore pillar 160 within the mining unit needs to be blasted and backfilled. When mining the normal ore body within the stope 110, an exit route is constructed from the rock drilling tunnel 120 within the stope 110 toward the boundary of the mining unit. The exit route extends to the rock drilling tunnel 120 of the adjacent mining unit to form an exit channel.

[0061] In the technical solution of the embodiment of the present application, by designing the drilling tunnel 120 of the mining area 110 in the mining unit close to the boundary position of the mining area 110, it helps to reduce the number of triangular pillars 140 that need to be recovered, and the drilling depth of the blasting construction when the triangular pillars 140 are recovered is shallow, so smaller drilling equipment can be used, and the corresponding mining and cutting projects can also adopt small cross-sectional dimensions, which reduces the construction time of the mining project and saves the construction cost of the mining project.

[0062] Furthermore, in some embodiments, when blasting recovery and filling are performed on the large-area triangular pillar 160, two parallel small-section drilling tunnels 141 are constructed in the large-area triangular pillar 160, and blasting recovery is performed by combining fan-shaped blast holes 143 with horizontal shallow holes 144.

[0063] In the technical solution of the embodiment of the present application, two parallel small-section drilling tunnels 141 are constructed in the large-area triangular ore pillar 160, so as to evenly distribute blastholes within the range of the large-area triangular ore pillar 160 and recover the large-area triangular ore pillar 160 as completely as possible.

[0064] Furthermore, in some embodiments, in step S2, the diameter of the pre-splitting blasthole 130 is 60-80 mm. In step S1, before the ore body to be mined begins to be mined, the ore body is mined and cut, including a middle section transport tunnel 170 located between the middle sections 100 and along the direction of the ore body, and a chute connecting tunnel 180 and a chute shaft 190 perpendicular to the middle section transport tunnel 170.

[0065] Specific examples are listed below. It should be noted that the examples described below are illustrative and intended only to explain this application, and are not to be construed as limiting this application. Where specific techniques or conditions are not specified in the examples, they are to be followed in accordance with those described in relevant literature in the field, and those skilled in the art may adapt them to actual stope conditions.

[0066] Example 1

[0067] This embodiment provides a safe, efficient, and high-recovery segmented medium-deep hole mining method, which is practically applied to a gently inclined, thick, and large ore body with mining technology conditions, including the following steps:

[0068] S1. The ore body to be mined is divided into middle sections in the vertical direction. The middle section is 27 m high and mined from bottom to top. The middle section is divided into several stopes along the strike of the ore body. The stopes are 15 m wide. Before mining begins, the ore body is cut and prepared. This includes middle transport lanes located between the middle sections and along the strike of the ore body, as well as connecting chute lanes and chute shafts perpendicular to the middle transport lanes.

[0069] S2. Within any middle section, before mining, each stope shall first construct its own rock drilling tunnel at the bottom of the stope, and evenly arrange pre-splitting blastholes along the strike of the rock drilling tunnel. The pre-splitting blastholes extend obliquely upward from the upper corners of the two sides of the rock drilling tunnel to the boundaries of each stope. The pre-splitting blastholes divide the ore body at the boundary between two adjacent stopes into triangular ore pillars.

[0070] The angle between the pre-splitting holes and the horizontal plane is 40°, the spacing between the pre-splitting holes along the strike of the rock drilling tunnel is 1.0 m, and the diameter of the pre-splitting holes is 60 mm.

[0071] S3. The pre-splitting blastholes in step S2 are pre-splitting blasted in an interval-charging manner along the direction of the rock drilling tunnel, so that the top boundary of the triangular pillar is separated from the lower boundary of the stope, and the triangular pillar is recovered and filled by blasting. The method for blasting and filling the triangular pillar comprises the following steps:

[0072] SS1. Construct a small-section rock tunnel in the triangular ore pillar. Construct several ore-exiting veins on one side of the small-section rock tunnel toward the adjacent stope rock tunnel. The angle between the ore-exiting vein and the small-section rock tunnel is 45°, and the ore-exiting veins are spaced 10 meters apart along the strike of the small-section rock tunnel.

[0073] SS2: Construct fan-shaped blastholes in small-section rock tunnels, extending them to the top boundary of the triangular pillars. Charge and blast the fan-shaped blastholes, and extract the ore from the ore-exiting vein and the rock tunnel connected to the ore-exiting vein.

[0074] SS3. After the ore resources in the triangular pillar are mined, a filling retaining wall is arranged at the connection position between the small-section rock drilling tunnel and the ore-exiting vein. The triangular pillar 140 is filled with high-strength filling slurry to complete the blasting recovery and filling of the triangular pillar.

[0075] S4. For the stope where the triangular pillars have been recovered, blasting and backfilling are carried out using upward fan-shaped medium-long holes, thus completing the mining and backfilling of all ore bodies in the stope;

[0076] S5. Repeat steps S2 to S4 to complete the mining and filling of all the stopes in the middle section, and then mine other middle sections from bottom to top until the mining of the entire ore body to be mined is completed.

[0077] After actual verification of Example 1, the mining method not only effectively recovered the ore resources covered by the triangular pillar area, but also ensured construction safety, avoided mining under the filling body, and achieved precise control of the depletion and loss indicators of ore resource recovery. The recovery of the triangular pillars and the normal recovery of the stope were connected in an orderly manner. The comprehensive loss rate of the stope can be controlled at an indicator level of less than 3%, which is greatly lower than the loss rate of the conventional segmented medium and deep hole stope (12%~15%), enabling the stope to achieve efficient production.

[0078] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are merely examples, and any embodiments having substantially the same structure and effect as the technical concept within the scope of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the present application, any other embodiments that can be conceived by those skilled in the art and that combine some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A 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, mine each middle section from bottom to top, and divide the middle section into several stopes along the strike of the ore body; S2. Before mining in any of the middle sections, each stope shall construct its own rock drilling tunnel at the bottom of the stope, and pre-splitting blastholes shall be evenly arranged along the direction of the rock drilling tunnel; the pre-splitting blastholes shall extend obliquely upward from the upper corners of the two sides of the rock drilling tunnel to the boundary of the respective stope, and the pre-splitting blastholes shall divide the ore body at the boundary of two adjacent stopes into triangular ore pillars; S3, the pre-splitting blastholes in step S2 are pre-splitting blasted in an interval charging manner along the direction of the rock drilling tunnel, so that the top boundary of the triangular pillar is separated from the lower boundary of the stope, and the triangular pillar is recovered and filled by blasting; S4. For the stope where the triangular pillars have been recovered, blasting and backfilling are carried out using upward fan-shaped medium-long holes, thus completing the mining and backfilling of all ore bodies in the stope; S5, repeating steps S2 to S4, completing the mining and filling of all the stopes in the middle section, and then mining other middle sections from bottom to top until the mining of the entire ore body to be mined is completed; In step S2, within any of the middle sections, every two adjacent stopes form a mining unit, wherein the two stopes within the mining unit are provided with rock drilling tunnels distributed in a mirror-symmetrical manner, and the distance between the central axes of the rock drilling tunnels of the two stopes is greater than the width of a single stope, so that a large triangular ore pillar is formed in the middle of the mining unit after the pre-splitting blasthole is constructed; In step S3, when blasting and recovering the triangular pillars and filling them, only the large-area triangular pillars in the mining unit need to be blasted and recovered and filled; when mining the normal ore body in the stope, an exit road is constructed from the rock drilling tunnel in the stope to the boundary of the mining unit, and the exit road extends to the rock drilling tunnel of the adjacent mining unit to form an exit channel; 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.

2. The segmented medium-long hole mining method according to claim 1, 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 segmented medium-long hole mining method according to claim 2, characterized in that: The spacing between the pre-splitting blastholes along the strike of the rock drilling tunnel is 1.0-1.2 m.

4. The segmented medium-long hole mining method according to claim 1, characterized in that: In step S3, the triangular pillar blasting recovery and filling method includes 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 in the adjacent stope; 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 extracting the ore through the ore-extraction 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 segmented medium-long hole mining method according to claim 3, characterized in that: In step S2, the diameter of the pre-splitting blasthole is 60-80 mm.

6. The segmented medium-long hole mining method according to claim 4, characterized in that: In step SS1, the angle between the ore-producing vein and the small-section rock drilling tunnel is 40° to 50°, and the spacing between the ore-producing vein along the strike of the small-section rock drilling tunnel is 10 to 12 m.

7. The segmented medium-long hole mining method according to claim 1, characterized in that: In step S1, before the mining of the ore body to be mined begins, the ore body is mined 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 chute shaft perpendicular to the middle section transport tunnel.

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