Stud shallow hole ore breaking two-step shrinkage subsequent filling mining method

Abstract

The invention discloses a double-column shallow hole ore breaking two-step shrinkage subsequent filling mining method, and belongs to the technical field of underground mining. Arranging a cutting project to form a stoping space; the jambs are divided into hanging wall jambs and footwall jambs, the footwall jambs are stoped, and filling is carried out after ore removal; and the hanging side pillar is stoped. According to the scheme, the footwall pillars are firstly stoped and filled to form the supporting body, and the hanging wall pillars are stoped later, so that the exposure of the whole goaf is avoided, and the possibility of surrounding rock instability caused by recovery of the pillars in the tall and large goaf is reduced; the filling bodies replace the pillars to bear the pressure of the top plate, so that the permanent pillar remaining amount is reduced, and the recovery rate is increased; the goaf is closed in time after filling, surrounding rock movement is restrained, and therefore the problem of surface collapse is avoided; and the pillars are divided according to the positions and the rock mass stress, stoping is conducted in sequence, the stress superposition risk of synchronous stoping is reduced, and therefore the high-safety stoping method for the pillars between the ore bodies is provided.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of underground mining, and particularly relates to a two-step pillar mining method for shallow hole ore falling and mining. BACKGROUND

[0002] Metal deposit mining has long been faced with challenges such as poor stability of ore and rock, high risk of surface subsidence, and low resource recovery rate. Although the traditional open stope mining method is suitable for the conditions of stable ore and rock, with the expansion of the mining scale, the exposed area of the mined-out area increases, which easily leads to problems such as ground pressure instability, surface subsidence, and high recovery dilution rate of the ore pillar. Taking the shallow hole mining method as an example, although it has advantages such as small amount of preparation engineering and high flexibility, the long-term non-filling of the mined-out area leads to an increased risk of surrounding rock movement, and the reserved ore pillar is prone to safety accidents due to stress concentration during recovery. In order to control the risk of the mined-out area, the subsequent filling method is gradually popularized, although this method can reduce surface subsidence, the ore room and the ore pillar need to be recovered in steps, which leads to problems such as insufficient strength of the filling body and poor boundary stability during the recovery of the ore pillar, especially when the ore body has a large inclination, the pressure difference between the upper and lower surrounding rocks is significant, and a single ore pillar recovery method easily leads to a rib spalling accident, therefore, a mining method that can safely recover the ore pillar between thin ore bodies is needed. SUMMARY

[0003] In view of the technical problems in the background art, the present application provides a two-step pillar mining method for shallow hole ore falling and mining, comprising: arranging preparation engineering; arranging cutting engineering to form a recovery space; dividing the ore pillar into an upper disc ore pillar and a lower disc ore pillar, recovering the lower disc ore pillar, and filling after ore extraction; recovering the upper disc ore pillar.

[0004] In some embodiments, in the step of dividing the ore pillar into an upper disc ore pillar and a lower disc ore pillar, recovering the lower disc ore pillar, and filling after ore extraction, comprising: recovering the lower disc ore pillar layer by layer from bottom to top, blasting ore in a shallow hole and extracting part of the ore, and leaving part of the ore as a working platform for further mining.

[0005] In some embodiments, in the step of arranging preparation engineering, comprising: leaving a top pillar at the top of the ore pillar, and excavating a top pillar connecting tunnel between the top pillar and the top of the ore body below the top pillar; In the step of dividing the ore pillar into an upper disc ore pillar and a lower disc ore pillar, recovering the lower disc ore pillar, and filling after ore extraction, comprising: recovering the lower disc ore pillar to a position at one-half of the ore pillar elevation, and then entering the mine from a short connecting tunnel in the top pillar connecting tunnel.

[0006] In some embodiments, in the step of dividing the ore pillar into an upper ore pillar and a lower ore pillar, stoping the lower ore pillar, and filling the mined-out area after mining, comprises: stoping the lower ore body to the end, carrying out sectionalized centralized mining, and then filling the empty area.

[0007] In some embodiments, in the step of arranging the preparatory work, comprises: drilling the upper transport roadway along the bottom of the upper ore pillar; In the step of stoping the upper ore pillar, comprises: leaving part of the ore pillar at the bottom of the upper ore pillar near the side of the upper transport roadway as a security pillar.

[0008] In some embodiments, in the step of arranging the preparatory work, comprises: using the existing mining roadway at the bottom of the ore pillar, wherein the upper transport roadway passes through the mining roadway and is not parallel to the mining roadway, and the upper transport roadway is arranged at the end of the mining roadway near the upper ore pillar; In the step of stoping the upper ore pillar, comprises: brushing out the mining roadway on one side of the upper ore pillar, and forming an upper loading chamber.

[0009] In some embodiments, in the step of arranging the preparatory work, comprises: drilling the upper raise along the vertical direction of the ore body on the surface of the upper ore pillar, so that the upper raise is in communication with the bottom mining roadway, and the upper raise is also in communication with the upper-middle section ventilation roadway.

[0010] In some embodiments, in the step of arranging the preparatory work, comprises: drilling the lower raise along the vertical direction of the ore body on the surface of the lower ore pillar, and the lower raise is in communication with the upper raise through the top connecting roadway, wherein the top connecting roadway is arranged at the top of the inter-column ore body.

[0011] In some embodiments, in the step of arranging the preparatory work, comprises: using the existing mining roadway at the bottom of the ore pillar; In the step of dividing the ore pillar into an upper ore pillar and a lower ore pillar, stoping the lower ore pillar, and filling the mined-out area after mining, comprises: brushing out the mining roadway on one side of the lower ore pillar, and forming a lower loading chamber. In the step of stoping the upper ore pillar, comprises: brushing out the mining roadway on one side of the upper ore pillar, and forming an upper loading chamber.

[0012] In some embodiments, after the step of brushing out the mining roadway on one side of the lower ore pillar, and forming a lower loading chamber, the step of dividing the ore pillar into an upper ore pillar and a lower ore pillar, stoping the lower ore pillar, and filling the mined-out area after mining further comprises: Temporary support reinforcement is carried out in the space expanded by the brush.

[0013] The application provides an inter-column shallow hole ore falling two-step ore remaining post-filling mining method, which comprises the following steps: arranging mining preparation engineering; arranging cutting engineering to form a mining space; dividing a mineral column into an upper disc mineral column and a lower disc mineral column, mining the lower disc mineral column, and carrying out filling after ore mining; and mining the upper disc mineral column. In the scheme, the lower disc mineral column is mined first and filling is carried out to form a support body, and the upper disc mineral column is mined later, so that the whole mining space is avoided from being exposed, and the possibility of surrounding rock instability caused by the recovery of the mineral column in the high and large mining space is reduced; the filling body replaces the mineral column to bear the roof pressure, so that the amount of the permanent mineral column is reduced, and the recovery rate is improved; the space is closed in time after filling, and the movement of the surrounding rock is inhibited, so that the problem of surface subsidence is avoided; the mineral column is divided according to the position and rock mass stress, and is mined in sequence, so that the stress superposition risk of synchronous mining is reduced, and the problem of stope collapse caused by uncontrolled ground pressure is avoided, thereby providing a high-safety mineral body inter-column mining method.

[0014] The above description is only a summary of the technical scheme of the application, in order to more clearly understand the technical means of the application, and can be implemented according to the content of the specification, and in order to make the above and other purposes, characteristics and advantages of the application more obvious and easy to understand, the following specific embodiments of the application are described. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical scheme of the application, the drawings used in the application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creating laborious work.

[0016] Figure 1 is a basic step schematic diagram of an inter-column shallow hole ore falling two-step ore remaining post-filling mining method provided by an embodiment of the application; Figure 2 is an optimization step schematic diagram of an inter-column shallow hole ore falling two-step ore remaining post-filling mining method provided by an embodiment of the application about mining in sequence; Figure 3 is a further optimization step schematic diagram of an inter-column shallow hole ore falling two-step ore remaining post-filling mining method provided by an embodiment of the application about mining in sequence and in layers; Figure 4 is a step schematic diagram of an inter-column shallow hole ore falling two-step ore remaining post-filling mining method provided by an embodiment of the application about filling; Figure 5 is an optimization step schematic diagram of an inter-column shallow hole ore falling two-step ore remaining post-filling mining method provided by an embodiment of the application about mining of the upper disc mineral column; Figure 6is a further optimization step schematic diagram of the upper disc pillar recovery of the inter-column shallow hole ore falling two-step ore drawing subsequent filling mining method provided by the embodiment of the present application; Figure 7 is a step schematic diagram of setting the upper disc raise of the inter-column shallow hole ore falling two-step ore drawing subsequent filling mining method provided by the embodiment of the present application; Figure 8 is a step schematic diagram of setting the lower disc raise of the inter-column shallow hole ore falling two-step ore drawing subsequent filling mining method provided by the embodiment of the present application; Figure 9 is a step schematic diagram of expanding the ore drawing roadway of the inter-column shallow hole ore falling two-step ore drawing subsequent filling mining method provided by the embodiment of the present application; Figure 10 is a step schematic diagram of strengthening support of the inter-column shallow hole ore falling two-step ore drawing subsequent filling mining method provided by the embodiment of the present application. DETAILED DESCRIPTION

[0017] The embodiments of the technical scheme of the present application will be described in detail below with reference to the drawings. The following embodiments are only used to more clearly illustrate the technical scheme of the present application, and therefore only serve as examples, and cannot limit the protection scope of the present application.

[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments of the present application, and are not intended to limit the present application; the terms "include" and "have" and any variations thereof in the specification and claims of the present application and the above description of drawings are intended to cover non-exclusive inclusion.

[0019] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly and specifically limited.

[0020] Reference to "an embodiment" herein means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily all refer to the same embodiment, nor is it necessarily independent or alternative to other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0021] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0022] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0023] 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.

[0024] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0025] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0026] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0027] Reference Figure 1The invention discloses a kind of inter-column shallow hole ore falling two-step ore drawing subsequent filling mining method, comprising the following steps: S101, layout mining preparation engineering.It is specific to excavate transport drift, ventilation shaft, ore drawing chute and connecting roadway in ore body, to form the system framework of ore transport, personnel passage and ventilation.Exemplarily, transport drift is arranged in footwall along the strike of ore body, or can be along the existing roadway of stope and partially brush to adapt to the working range of inter-column of ore body;Ventilation shaft penetrates upper and lower levels and connects return air roadway, and ore drawing chute is vertically distributed at the bottom of inter-column of ore body, to ensure that the ore after blasting can fall into transport level by gravity;The purpose of this step is to establish the basic channel network of mining operation, to provide working space and working conditions for subsequent mining operation.

[0028] S102, layout cutting engineering, to form stoping space.It is specific to excavate cutting drift and cutting uphole at the bottom of inter-column of ore body, to form initial free surface by shallow hole blasting.The exemplarily cutting uphole vertically climbs along the center line of inter-column of ore body, with the same height as inter-column of ore body, and cutting drift horizontally connects the bottom space and ore drawing chute;This process is to create enough working space and guide the flow path of caving ore, to release the stress of ore body by directional blasting, to make subsequent ore falling more easily along the weak plane, to reduce blasting energy consumption and improve ore falling efficiency.

[0029] S103, divide ore pillar into upper and lower ore pillars, stoping lower ore pillar, and filling after ore drawing.It is specific to divide inter-column into two categories according to the difference of ore body inclination and surrounding rock stability, exemplarily, lower ore pillar is preferentially stoped by shallow hole drilling and blasting due to its proximity to transport level and smaller ground pressure.YT-28 drill is used for drilling, with hole depth not exceeding 2 meters, and ore is transported to chute by shovel after micro-differential blasting;This step reduces the overall ground pressure risk by stoping in sequence, and avoids plastic deformation of lower ore pillar due to long-term pressure by preferentially stoping stress concentration area, to ensure the safety of subsequent upper ore pillar stoping.

[0030] It should be noted that the up and down here are not limited to the up and down in the positional relationship, but only as a description of the sequence of mining, so the positional relationship between the upper and lower pillars is not fixed, and the setting of two pillars with different forms will also bring different effects. For example, the top surface of the lower pillar is attached to the bottom surface of the upper pillar. At this time, the lower pillar is usually located near the transportation roadway, and the tectonic stress is smaller, and it is more directly affected by the lower mining. Prior recovery can avoid plastic deformation or instability caused by long-term pressure, reducing the risk of sudden ground pressure activity; the upper pillar is close to the surface or overburden, and the ground pressure concentration degree is high. If the upper part is mined first, it may cause roof subsidence or even surface subsidence; and after filling the lower part, the filling body formed can replace the pillars to support the upper part of the surrounding rock, significantly improving the safety of subsequent operations; at the same time, the lower filling body creates a stable operation platform for subsequent upper recovery, avoiding the problem of roadway deformation and ventilation obstruction caused by untreated goaf, and shortening the preparation period of the stope.

[0031] For example, the side boundary of the lower pillar is attached to the side boundary of the upper pillar. At this time, the spatial relationship between the lower pillar and the upper pillar is relatively left or relatively right, wherein the lower pillar is the weak side of the structure, and the upper pillar is the stable side of the surrounding rock. The upper and lower parts are separately excavated to avoid cross disturbance. When mining, the lower pillar on the weak side of the structure is preferentially mined, thereby preferentially mining the high-stress pillar and reducing the disturbance of the subsequent rock mass. After the lower pillar is mined, the lower pillar is filled to form a support body, and then the upper pillar is mined. The filling body is used to constrain the roof displacement and reduce the disturbance to the rock mass.

[0032] S104, mining the upper pillar. Specifically, after the lower pillar region filling body reaches the designed strength, the same shallow hole mining technology is used to mine the upper pillar. Part of the retaining pillar is reserved to isolate the filling body during mining. After blasting, the ore removal process is consistent with the lower part; this step uses the rigid support formed by the filling body to replace the function of the pillar, controls the movement of the upper surrounding rock through the filling body, avoids roof collapse and surface subsidence, and reduces the exposed area of the goaf through step-by-step mining, thereby optimizing the ground pressure distribution.

[0033] Subsequent filling is carried out throughout the whole process of pillar mining. After each pillar is mined, full-tailings cemented filling is used to avoid the instability of the surrounding rock caused by long-term exposure of the goaf. For example, the bottom 5m filling layer has a cement-sand ratio of 1:4 (cement: tailings), and the upper part has a cement-sand ratio of 1:6, with a slurry concentration of 63-65%, ensuring that the 28-day strength is ≥2.5 MPa. The filling is implemented in multiple layers, with each layer being 1.5-2 meters. The front layer is coagulated before the back layer is stacked to fill the upper layer until the top is reached.

[0034] Traditional open stope method (such as ordinary room and pillar method) is prone to cause roof instability, surface subsidence and resource loss caused by stress concentration of the pillar due to the failure to timely process the mined-out area. In the present scheme, the lower-pillar is mined first and filled to form a support body, and the upper-pillar is mined later, avoiding the exposure of the overall mined-out area, thereby reducing the possibility of surrounding rock instability caused by pillar recovery in high and large mined-out area; the filling body replaces the pillar to bear the roof pressure, thereby reducing the amount of permanent pillar and improving the recovery rate; the mined-out area is closed in time after filling, thereby inhibiting the movement of surrounding rock and avoiding surface subsidence; the pillars are divided according to the position and rock mass stress and mined in sequence, thereby reducing the stress superposition risk of synchronous mining and avoiding the problem of stope collapse caused by uncontrolled ground pressure.

[0035] In some embodiments, referring to Figure 2 In S103, the pillars are divided into upper-pillar and lower-pillar, the lower-pillar is mined, and in the process of filling after mining, it includes: S1031, the lower-pillar is mined layer by layer from bottom to top, and part of the ore is blasted and mined in shallow holes, and part of the ore is left as a working platform for subsequent mining. Specifically, in this step, the lower-pillar is mined layer by layer from bottom to top, which means that the mining sequence is from the bottom of the ore body to the top of the ore body layer by layer, and the layer height is determined according to the stability of the ore rock and the performance of the rock drilling equipment. Through this layering method, the stage control of ground pressure is realized, thereby avoiding the collapse risk caused by large-area exposure of the roof; the shallow hole blasting method is a blasting technology that realizes rock breaking by drilling and charging and controlling blasting energy, and the holes are arranged in a horizontal or upward parallel manner, and the ore is blasted by using the micro-difference blasting technology, which can accurately control the ore boundary, reduce the damage to the surrounding rock of the upper and lower pillars, and reduce the ore dilution rate; part of the ore is blasted and mined, thereby retaining the remaining ore as a working platform for subsequent mining, so that personnel can safely perform rock drilling, supporting and other operations on the ore pile, and the temporary support of the surrounding rock is formed by temporarily retaining the ore, thereby inhibiting the ground pressure, and the stability of the working face is also ensured, thereby avoiding the exposure of the open stope. By layering mining, the exposure area is limited to reduce the risk of caving; by using the fine parameters of shallow hole blasting, the production of large blocks is reduced, and the ore mining efficiency is improved; the dynamic support system formed by local ore mining and ore retention ensures the safety of the operation, does not need to erect an artificial platform, significantly reduces the supporting cost and time consumption, and solves the problems of roof instability and large block retention in the mining of steeply inclined ore body.

[0036] In some embodiments, referring to Figure 3In S101, the arrangement of the preparation engineering includes: S1011, leaving a top pillar on the top of the ore pillar, and excavating a top pillar connecting passage between the top of the ore pillar and the top of the ore body below the top pillar; in S103, the ore pillar is divided into an upper disc ore pillar and a lower disc ore pillar, the lower disc ore pillar is mined, and in the filling after the ore is mined, S1032, the lower disc ore pillar is mined to one half of the ore pillar elevation, and personnel enter the mine from the short connecting passage in the top pillar connecting passage. Specifically, the top pillar refers to the structural layer of the ore body reserved on the top of the ore pillar, and its core role is to support the overburden pressure through its bearing capacity, avoid the premature collapse of the roof of the mined-out area, and thus maintain the overall stability of the stope, especially for the ore body with medium stability of the ore rock or local broken zone; the top pillar connecting passage is a horizontal tunnel excavated between the top of the ore pillar and the top of the ore body below, which provides a permanent passage for personnel passage, equipment transportation and ventilation path, and optimizes the airflow distribution inside the stope through its horizontal connectivity, and reduces the ventilation dead angle; when the height of the sublevel mining exceeds the safety range of the conventional operation (i.e. one half of the ore pillar elevation), personnel enter the mine by drilling a short connecting passage, wherein the short connecting passage is a vertical or inclined passage temporarily drilled from the bottom plate of the top pillar connecting passage, which directly penetrates the working face of the high sublevel stope, so that the operating personnel can safely reach the operating point without climbing from the bottom of the ore pile, reducing the risk of falling from a high altitude; the drilling uses shallow hole blasting combined with light drilling equipment (such as YT-28 drill), to ensure the flexibility and timeliness of construction. The top pillar as a permanent support structure limits the exposed area of the roof of the mined-out area within the safety threshold, and inhibits the risk of deformation of the surrounding rock; the top pillar connecting passage builds a stable three-dimensional channel network, providing a spatial reference for the drilling of the short connecting passage; and the short connecting passage as a dynamic access point avoids the hidden danger of personnel climbing the ore pile, which not only avoids the high cost of additional temporary platform erection, but also guarantees the process requirement of flexible adjustment of the sublevel height, thereby solving the problem of safe entry and exit of personnel in high-altitude operation in the sublevel mining of steeply inclined ore body.

[0037] In some embodiments, reference is made to Figure 4In S103, the pillar is divided into upper disc pillar and lower disc pillar, the lower disc pillar is mined, and in the filling after the mining, it comprises: S1033, mining the lower disc ore body to the end, and then filling the empty area. Specifically, the segmented concentrated mining refers to that after the completion of the full layer mining of the lower disc pillar, the ore remaining in the stope is not retained as a working platform, but is transported out in one time through a shovel truck or a vibrating ore-drawing machine, and the amount of mining can reach 70%-80% of the total caving ore amount, thereby shortening the mining period, reducing the energy consumption of the equipment frequently entering and leaving the stope, and leaving a working space for the filling of the empty area. The empty area is filled with full tailings cemented filling immediately after the concentrated mining, and the filling slurry concentration is controlled at 63-65%, the bottom 5m height adopts high-strength ratio of 1:4, and the upper part adopts ordinary ratio of 1:6, which can inhibit the displacement of the upper disc surrounding rock through the high-strength filling body at the bottom, and form a uniform support through the upper filling body, thereby creating stable boundary conditions for the subsequent mining of the upper disc pillar.

[0038] The ore retained in the layer mining stage provides temporary support, but long-term retention increases the risk of surrounding rock creep. The segmented concentrated mining quickly empties the stope, shortens the roof exposure time, and reduces the probability of ground pressure appearance. The filling operation follows immediately, uses the high-strength filling body at the bottom to resist the lateral pressure of the upper disc surrounding rock, and controls the roof subsidence amount through the continuous support surface formed by the upper filling body, thereby avoiding the interference of the empty area collapse on the mining of the upper disc pillar. The scheme realizes the improvement of the mining efficiency and the reduction of the interruption problem in the connection between mining and filling caused by the delay of the filling period under the premise of ensuring the safety of mining.

[0039] In some embodiments, referring to Figure 5 In S101, the preparation of the mining is arranged, comprising: S1012, excavating an upper disc transportation roadway along the bottom of the upper disc of the ore body; in S104, mining the upper disc pillar, comprising: S1041, leaving part of the pillar near the upper disc transportation roadway at the bottom of the upper disc pillar as a security pillar. Specifically, the upper disc transportation roadway is a horizontal transportation channel excavated along the boundary of the upper disc surrounding rock, which directly connects the upper disc pillar stope and the main transportation system, shortens the ore transfer distance, and optimizes the ventilation path, and is especially suitable for the independent mining stage of the upper disc pillar in the steeply inclined ore body. The security pillar refers to the unmined ore body retained in the area adjacent to the upper disc transportation roadway at the bottom of the upper disc pillar, which resists the lateral pressure of the upper disc surrounding rock through its high-strength rock structure, avoids the roof collapse or side wall convergence deformation of the transportation roadway due to mining stress concentration, and thereby ensures the long-term stability of the transportation channel.

[0040] The upper disc transportation roadway passes through the upper disc boundary of the ore body directly, shortens the ore transportation path, and reduces the energy consumption of the trackless equipment operation; the safety pillar suppresses the displacement of the upper disc surrounding rock within a safety threshold by forming a rigid support body, and blocks the transmission path of the goaf pressure to the upper disc transportation roadway, which not only avoids the production loss caused by the maintenance of the roadway in the traditional method, but also ensures the continuity of the parallel operation of the upper disc pillar stoping and the ore transportation, thereby further improving the comprehensive efficiency of the stope.

[0041] In some embodiments, referring to Figure 6 In S101, arranging the preparatory work, comprising: S1013, using the existing out-of-mine roadway at the bottom of the pillar, wherein the upper disc transportation roadway passes through the out-of-mine roadway and is not parallel to the out-of-mine roadway, and the upper disc transportation roadway is arranged at one end of the out-of-mine roadway close to the upper disc pillar; in S104, stoping the upper disc pillar, comprising: S1042, expanding the out-of-mine roadway on one side of the upper disc pillar and forming an upper disc loading chamber. Specifically, using the existing out-of-mine roadway at the bottom of the pillar means directly using the ore transportation channel developed during the stoping of the lower disc pillar, avoiding repeated excavation of new roadways, thereby reducing the amount of preparatory work, and preserving the stress balance state of the surrounding rock of the original roadway; and the upper disc transportation roadway passing through the out-of-mine roadway and not being parallel to the out-of-mine roadway requires the upper disc transportation roadway to pass through the out-of-mine roadway at an oblique angle or vertically, eliminating the planar conflict of the transportation path through non-parallel intersection layout, avoiding equipment traffic interference, and using the natural support structure formed at the intersection to enhance the stability of the roadway roof. When stoping the upper disc pillar, expanding the out-of-mine roadway on one side of the upper disc pillar is to widen the side slope of the out-of-mine roadway close to the upper disc pillar through shallow hole blasting, forming an upper disc loading chamber. The upper disc loading chamber is a rectangular ore loading space constructed at the end of the expanded out-of-mine roadway, which realizes concentrated loading and rapid transfer of ore through the installation of a vibrating ore-drawing machine or a shovel loader loading point.

[0042] In some embodiments, referring to Figure 7 In S101, arranging the preparatory work, comprising: S1014, opening the upper disc raise on the surface of the upper disc pillar along the vertical direction of the ore body, so that it is communicated with the bottom out-of-mine roadway, and the upper disc raise is also communicated with the upper-middle section ventilation roadway. Specifically, the upper disc raise is a shaft developed along the vertical direction of the upper disc pillar, and its core role is to build a vertical or inclined downward channel that is attached to the side surface of the upper disc pillar, directly connecting the bottom out-of-mine roadway and the upper-middle section ventilation roadway, and forming independent ventilation and material transportation paths. Through this vertical through design, fresh air flow can enter the raise from the bottom out-of-mine roadway, go up to the stope working face, and then carry the dirty air into the upper-middle section ventilation roadway, and finally be discharged to the ground by the return air system, thereby realizing the ventilation circulation of going down and going up in the steeply inclined ore body stoping, shortening the dust and harmful gas of blasting, and improving the safety of the working environment.

[0043] In some embodiments, referring to Figure 8In S101, the arrangement of the mining preparation engineering comprises: S1015, excavating a lower disc raise along the vertical direction of the ore body on the surface of the lower disc pillar, and the lower disc raise is communicated with the upper disc raise through a top connecting lane, wherein the top connecting lane is arranged at the top of the inter-pillar ore body. Specifically, the lower disc raise is a shaft excavated along the vertical direction of the lower disc pillar, and its core role is to cooperatively build a double-channel system penetrating the pillar with the upper disc raise, and to form a closed ventilation and transportation loop through the top connecting lane, so that the annular ventilation path of the lower disc air inlet and the upper disc air outlet is realized in the stoping of the steeply inclined ore body: the fresh air flow enters from the lower disc raise, is horizontally guided to the upper disc raise through the top connecting lane, and is finally discharged by the air return system, so that the ventilation dead angle is avoided in the stope, the retention time of the contaminated air is further compressed, and the safety of the working environment is improved.

[0044] In the stoping process, the structure solves the problem of long-distance ore block ventilation efficiency decay through spatial symmetry layout: the traditional single raise ventilation mode is prone to air flow short circuit due to increased wind resistance when the ore block is too long, and the parallel design of the lower disc raise and the upper disc raise in the scheme divides the ventilation path into independent air inlet and air return branches, reduces the wind pressure loss, and utilizes the natural pressure difference formed by the ore body inclination to enhance the stability of the air flow. At the same time, the top connecting lane as a horizontal connecting channel not only optimizes the air flow distribution, but also provides a shortcut for equipment transfer: the rock drilling equipment can be lifted to the connecting lane through the lower disc raise, then horizontally transported to the upper disc stope, or enter the bottom ore pass through the upper disc stope in the same path, avoiding the inefficient path of the traditional method which needs to detour the stage lane, thereby shortening the material transfer time.

[0045] In some embodiments, with reference to Figure 9 In S101, the arrangement of the mining preparation engineering comprises: S1016, using the existing ore pass at the bottom of the pillar; in S103, the pillar is divided into an upper disc pillar and a lower disc pillar, the lower disc pillar is stoped, and in the filling after ore extraction, S1034, the lower disc ore pass on one side of the lower disc pillar is expanded and brushed, and a lower disc loading chamber is formed; in S104, the upper disc pillar is stoped, and S1042, the upper disc ore pass on one side of the upper disc pillar is expanded and brushed, and an upper disc loading chamber is formed.

[0046] Specifically, using the existing ore pass at the bottom of the pillar means directly using the ore transportation channel developed during the stoping stage of the lower disc pillar, avoiding repeated excavation of new lanes, thereby reducing the amount of mining preparation engineering, and preserving the stress balance state of the surrounding rock of the original lane.

[0047] When the lower-pillar is mined, the out-of-mine roadway on the side of the expanded lower-pillar is widened by shallow-hole blasting to widen the side of the out-of-mine roadway close to the lower-pillar, thereby forming a lower-pillar loading chamber. The lower-pillar loading chamber is a rectangular ore loading space formed at the end of the out-of-mine roadway after the expansion, and the concentrated loading and rapid transfer of the lower-pillar ore is realized by installing a vibrating ore-drawing machine or a shovel loader loading point. Similarly, when the upper-pillar is mined, the out-of-mine roadway on the side of the expanded upper-pillar is formed into an upper-pillar loading chamber using the same technical principle, but the positions of the two chambers must be staggered to avoid the intersection of the transport paths.

[0048] The multiplexed out-of-mine roadway reduces the scope of disturbance of the surrounding rock by reducing the excavation of new roadways, and maintains the stress bearing continuity of the safety pillar. The symmetrical arrangement of the lower-pillar and upper-pillar loading chambers realizes the independent transfer of the lower-pillar and upper-pillar ores through a double-channel transfer mechanism, avoids the cross interference problem of traditional single-lane transportation, improves the ore transfer efficiency, and solves the problems of ore transfer path conflict and low ore loading efficiency in double-pillar mining.

[0049] In some embodiments, with reference to Figure 10 After S1034, the out-of-mine roadway on the side of the expanded lower-pillar is expanded, and a lower-pillar loading chamber is formed, the lower-pillar and the upper-pillar are separated, the lower-pillar is mined, and the filling after mining further includes: S1035, temporary support reinforcement is performed in the expanded space. Specifically, the temporary support reinforcement refers to the immediate reinforcement of the chamber roof and side wall formed by expansion using anchor rods combined with metal nets or collapsible supports. The core function is to inhibit the expansion of the loose circle caused by the stress release of the surrounding rock after expansion, to avoid chamber spalling or roof caving, and to ensure the safety of ore loading operations.

[0050] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto. Any modification, equivalent replacement and improvement made by any person skilled in the art within the technical scope disclosed by the present application, as long as it is within the spirit and principles of the present application, shall be covered within the protection scope of the present application.

[0051] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and embodiments having the same technical idea and playing the same role and effect within the technical solution range of the present application are all included in the technical range of the present application. In addition, within the scope of the main idea of the present application, various modifications, combinations of part of the components in the embodiments to construct other ways that can be thought of by those skilled in the art are also included in the scope of the present application.

Claims

1. A two-step mining method of pillar-shallow hole ore dropping followed by filling, characterized in that: include: Arrange mining and approval projects; Arrange cutting works to form mining space; The ore pillars are divided into upper wall ore pillars and lower wall ore pillars, and the lower wall ore pillars are mined and backfilled after the ore is mined; Mining the hanging wall ore pillar.

2. The two-step pillar-shallow hole mining method according to claim 1, wherein the ore is retained and then filled. The process of dividing the ore pillars into upper ore pillars and lower ore pillars, mining the lower ore pillars, and filling the ore after mining comprises: The lower wall pillars are mined in layers from bottom to top, and shallow hole blasting is used to drop the ore and remove part of the ore, leaving part of the ore as a working platform for further mining.

3. The two-step pillar-shallow-hole ore-dropping and subsequent filling mining method according to claim 2 is characterized in that: The above arrangement and approval engineering includes: A top pillar is left at the top of the ore pillar, and a top pillar connecting road is dug between the bottom of the top pillar and the top of the ore body; The process of dividing the ore pillars into upper ore pillars and lower ore pillars, mining the lower ore pillars, and filling the ore after mining comprises: When mining the lower pillar to the point where the elevation is half of the pillar, personnel enter the mine through a short connecting tunnel drilled from the top pillar connecting tunnel.

4. The two-step pillar-shallow hole mining method according to claim 3, wherein: The process of dividing the ore pillars into upper ore pillars and lower ore pillars, mining the lower ore pillars, and filling the ore after mining comprises: After the lower plate ore body is mined to completion, the ore is extracted in sections and concentrated, and then the empty areas are filled.

5. The two-step pillar-shallow-hole ore-dropping and subsequent filling mining method according to claim 1 is characterized in that: The above arrangement and approval engineering includes: Excavate the hanging wall transportation tunnel along the bottom of the ore body hanging wall; The mining upper wall pillar includes: At the bottom of the upper wall pillar, part of the pillar is left unmined near the upper wall transport tunnel as a safety pillar.

6. The two-step pillar-shallow-hole ore-dropping and subsequent backfilling mining method according to claim 5 is characterized in that: The above arrangement and approval engineering includes: The existing mine exit tunnel at the bottom of the pillar is used, where the upper wall transport tunnel passes through the mine exit tunnel and is not parallel to the mine exit tunnel, and the upper wall transport tunnel is set at the end of the mine exit tunnel close to the upper wall pillar; The mining upper wall pillar includes: Expand the mine tunnel on one side of the upper wall pillar and form an upper wall loading chamber.

7. The two-step pillar-shallow hole mining method according to claim 1, characterized in that: The above arrangement and approval engineering includes: An upper wall shaft is excavated on the surface of the upper wall pillar in the vertical direction of the ore body to connect it with the bottom mining tunnel. At the same time, the upper wall shaft is also connected with the upper and middle ventilation tunnels.

8. The two-step pillar-shallow-hole ore-dropping and subsequent backfilling mining method according to claim 2 is characterized in that: The above arrangement and approval engineering includes: A footwall shaft is excavated on the surface of the footwall pillar in the vertical direction of the ore body. The footwall shaft and the upper wall shaft are connected by a top connecting tunnel, wherein the top connecting tunnel is set at the top of the intermediate pillar ore body.

9. The two-step pillar-shallow hole mining method of claim 1, wherein: The above arrangement and approval engineering includes: Use the existing mine tunnel at the bottom of the pillar; The process of dividing the pillars into upper and lower pillars, mining the lower pillars, and filling the ore after mining includes: Expand the mine tunnel on one side of the footwall pillar and form a footwall loading chamber; The mining upper wall pillar includes: Expand the mine tunnel on one side of the upper wall pillar and form an upper wall loading chamber.

10. The two-step pillar-shallow-hole ore-dropping and subsequent backfilling mining method according to claim 9 is characterized in that: After the expansion and brushing of the side of the footwall pillar to form a mine tunnel and a footwall loading chamber, the step of dividing the pillar into an upper wall pillar and a lower wall pillar, mining the lower wall pillar, and filling the mine after the ore is extracted further comprises: Carry out temporary support reinforcement in the expanded space.

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