Method for recycling pillar from ore body

Abstract

The method for recycling the jamb from the ore body comprises the following steps that S1, the jamb is divided into a plurality of first chambers and a plurality of second chambers in the first direction, the first chambers and the second chambers are sequentially and alternately arranged in the first direction, and the first direction is perpendicular to the vertical direction; s2, the upper portion of the first chamber is divided into a top protection layer, the lower middle portion of the first chamber is divided into a plurality of first sub-chambers in the vertical direction, and the size of each first sub-chamber in the vertical direction is smaller than or equal to a first preset value; and S3, after filling of the first sub-chambers is completed, the upper portion of the second chamber is divided into a top protection layer, the lower middle portion of the second chamber is divided into a plurality of second sub-chambers in the vertical direction, and the size of each second sub-chamber in the vertical direction is smaller than or equal to a second preset value. The method for recovering the pillars from the ore body has the advantage of high safety.

Description

Technical Field

[0001] The invention relates to the technical field of mining, and in particular to a method for recovering ore pillars from an ore body. Background Art

[0002] The segmented open-pit and subsequent filling mining method divides the ore blocks into chambers and pillars, and it is mined in two steps, first mining the chambers in the first step and then mining the pillars in the second step. The main purpose of reserving a certain thickness of pillars is to support the roof of the mining area, protect the safety of personnel and the integrity of the tunnel, and ensure the stability of the mining area and the stratum. When mining the bottom pillars by the segmented open-pit and subsequent filling mining method, the process is more complicated and cumbersome due to the large number of filling retaining walls. In addition, for complex metal ore bodies with complex mining conditions such as rock crushing and poor stability coefficient, the mining of the pillars is more difficult and more dangerous. Summary of the invention

[0003] The present invention aims to solve one of the technical problems in the related art at least to a certain extent. To this end, an embodiment of the present invention provides a method for recovering ore pillars from an ore body.

[0004] The method for recovering ore pillars from an ore body according to an embodiment of the present invention comprises the following steps:

[0005] S1. Divide the mine pillar into a plurality of first mine rooms and a plurality of second mine rooms along a first direction, wherein the plurality of first mine rooms and the plurality of second mine rooms are alternately arranged in sequence in the first direction, and the first direction is perpendicular to the up-down direction;

[0006] S2, dividing the upper part of the first mine room into a protective roof, dividing the middle and lower part of the first mine room into a plurality of first sub-mine rooms in the vertical direction, wherein the size of each of the first sub-mine rooms in the vertical direction is less than or equal to a first preset value, starting mining and filling from the lowest one of the plurality of first sub-mine rooms of each first mine room, and after mining and filling the lower one of the two adjacent first sub-mine rooms in the vertical direction of each first mine room, mining and filling the upper one of the two adjacent first sub-mine rooms in the vertical direction of each first mine room;

[0007] S3. After the first sub-mine room is filled, the upper part of the second mine room is divided into a protective roof layer, and the middle and lower parts of the second mine room are divided into multiple second sub-mine rooms in the up and down direction, and the size of each second sub-mine room in the up and down direction is less than or equal to a second preset value, and mining and filling are started from the bottommost one of the multiple second sub-mine rooms of each second mine room. After the lower one of the two adjacent second sub-mine rooms in the up and down direction of each second mine room is mined and filled, the upper one of the two adjacent second sub-mine rooms in the up and down direction of each second mine room is mined and filled.

[0008] Therefore, the method for recovering ore pillars from an ore body according to an embodiment of the present invention has the advantage of high safety.

[0009] In some embodiments, the size of each of the first sub-mine chambers and each of the second sub-mine chambers in the vertical direction is less than or equal to 4 meters.

[0010] In some embodiments, the size of the first sub-mining room in the vertical direction is 2 meters or 3 meters;

[0011] The second sub-mining room has a vertical dimension of 2 meters or 3 meters;

[0012] The size of the lower one of the two first sub-mining rooms adjacent in the vertical direction is greater than or equal to the size of the upper one in the vertical direction;

[0013] Of the two second sub-mine rooms adjacent in the vertical direction, the size of the lower one in the vertical direction is greater than or equal to the size of the upper one in the vertical direction.

[0014] In some embodiments, before mining the ore pillar, a main access road is opened on both sides of the ore pillar in the second direction, the main access road extends along the first direction, and any two of the first direction, the second direction and the up-down direction are perpendicular to each other;

[0015] In the step S2, a transverse access is opened from the main access to the first sub-ore chamber to mine the first sub-ore chamber, and then the transverse access in the first sub-ore chamber is filled;

[0016] In the step S3, a transverse approach is opened from the main approach to the second sub-mine chamber to mine the second sub-mine chamber, and then the transverse approach in the second mine chamber is filled.

[0017] In some embodiments, the first direction is the direction of the ore body, and the transverse access road extends along the second direction;

[0018] During the mining process, the transverse approach is excavated according to the third preset slope so that the bottom surface of the transverse approach is a downwardly inclined slope.

[0019] In some embodiments, the bottom height at the inlet of the transverse passage is higher than the bottom height at the outlet, and the inclination of the bottom surface of the transverse passage is greater than or equal to 2% and less than or equal to 3%.

[0020] In some embodiments, when the transverse access road is filled, a filling retaining wall is constructed at the entrance and exit of the transverse access road;

[0021] The filling layers in each transverse passage include a first filling layer and a second filling layer, wherein the first filling layer is located above the corresponding second filling layer, and the compressive strength of the first filling layer is greater than the compressive strength of the second filling layer.

[0022] In some embodiments, the compressive strength of the cementing material used in the first filling layer is greater than or equal to 3 MPa;

[0023] The thickness of the first filling layer in each transverse passage in the vertical direction is greater than or equal to 0.3 meters.

[0024] In some embodiments, a bottom tunnel is opened from the layered connecting tunnel below the mine pillar, and a ventilation filling shaft leading into the mine pillar is constructed from the bottom tunnel;

[0025] Fresh air flows into the mining face from the ramp, the segmented roadway, the layered connecting road and the main access road in sequence, and the polluted air is discharged to the surface through the filling ventilation skylight and the return air shaft;

[0026] During mining, a blasting hole is opened in the ore pillar using a rock drill.

[0027] In some embodiments, the height of the protective covering layer in the vertical direction is greater than or equal to 3 meters. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a front view of a mining pillar of an ore body according to a method for recovering ore pillars in an embodiment of the present invention.

[0029] Figure 2 It is a side view of a mineral pillar mined by a mineral pillar recovery method of an ore body according to an embodiment of the present invention.

[0030] Figure 3 It is a top view of mining a pillar according to the method for recovering a pillar from an ore body according to an embodiment of the present invention.

[0031] Figure 4 It is a top view of the main approach for mining ore pillars in the ore body ore pillar recovery method according to an embodiment of the present invention.

[0032] Figure 5 It is a front view of a transverse approach for mining a pillar according to a method for recovering a pillar from an ore body according to an embodiment of the present invention.

[0033] Figure numerals: 1. first mine room, 101. first sub-mine room, 2. second mine room, 201. second sub-mine room, 3. top protection layer, 4. main access road, 5. horizontal access road, 6. transport tunnel, 7. segmented tunnel, 8. layered connecting road, 9. filling body, 10. ventilation filling skylight, 11. ramp, 12. through-vein tunnel, 13. chute. DETAILED DESCRIPTION

[0034] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0035] The following describes the ore body recovery ore pillar method of the embodiment of the present invention with reference to the accompanying drawings. Figures 1 to 5 As shown, the method for recovering ore pillars from an ore body according to an embodiment of the present invention comprises the following steps:

[0036] S1. Divide the ore pillar into a plurality of first ore chambers 1 and a plurality of second ore chambers 2 along a first direction. The plurality of first ore chambers 1 and the plurality of second ore chambers 2 are alternately arranged in the first direction, and the first direction is perpendicular to the up-down direction. Specifically, the first direction is the direction of the ore body. During mining, the first ore chamber 1 can be mined first, so that the unmined second ore chamber 2 can be used as a supporting column. After the first ore chamber 1 is filled, it can be used as a supporting column, and then the second ore chamber 2 can be mined, thereby improving the safety of mining. The first direction can be a left-right direction, and the left-right direction is shown by the arrow in the figure. For example, a plurality of first ore chambers 1 and a plurality of second ore chambers 2 are alternately arranged in the left-right direction.

[0037] S2. The upper part (top) of the first chamber 1 is divided into a protective roof 3, and the middle and lower part of the first chamber 1 is divided into a plurality of first sub-chambers 101 in the vertical direction. The size of each first sub-chamber 101 in the vertical direction is less than or equal to the first preset value, and the mining and filling are started from the one located at the bottom among the plurality of first sub-chambers 101 of each first chamber 1. After the one located at the bottom among the two adjacent first sub-chambers 101 in the vertical direction of each first chamber 1 is mined and filled, the one located at the top among the two adjacent first sub-chambers 101 in the vertical direction of each first chamber 1 is mined and filled. In other words, the first chamber 1 is mined and filled first, and one first sub-chamber 101 is mined and filled each time, and the plurality of first sub-chambers 101 are mined and filled in sequence from bottom to top, and the size of each first sub-chamber 101 in the vertical direction is less than or equal to the first preset value, thereby reducing the stress change caused by the excavation disturbance and ensuring the safety of the pillars during mining. Furthermore, the upper part (top) of the first mining chamber 1 is divided into a protective roof 3 and is not mined, thereby further ensuring the safety of mining.

[0038] S3. After the first sub-mining room 101 is filled, the upper part (top) of the second mining room 2 is divided into a protective roof 3, and the middle and lower part of the second mining room 2 is divided into a plurality of second sub-mining rooms 201 in the vertical direction. The size of each second sub-mining room 201 in the vertical direction is less than or equal to the second preset value, and the mining and filling are started from the bottom one of the plurality of second sub-mining rooms 201 of each second mining room 2. After the bottom one of the two second sub-mining rooms 201 adjacent to each other in the vertical direction of each second mining room 2 is mined and filled, the top one of the two second sub-mining rooms 201 adjacent to each other in the vertical direction of each second mining room 2 is mined and filled. Specifically, after the first sub-mining room 101 is filled and has sufficient strength, the second mining room 2 is mined. Each time a second sub-mining room 201 is mined and filled, multiple second sub-mining rooms 201 are mined and filled in sequence from bottom to top, and the size of each second sub-mining room 201 in the vertical direction is less than or equal to the second preset value, thereby reducing the stress change caused by excavation disturbance and ensuring the safety of the pillar during mining. The upper part (top) of the second mining room 2 is divided into a protective top layer 3 and is not mined, thereby further ensuring the safety of mining.

[0039] According to the method for recovering pillars from an ore body of an embodiment of the present invention, multiple first ore chambers 1 are mined and filled first, and then multiple second ore chambers 2 are mined and filled, so that they can support each other during mining. The upper parts of the first ore chambers 1 and the second ore chambers 2 are not mined and serve as a protective layer 3, and the height of the protective layer 3 in the vertical direction is greater than or equal to 3 meters, so as to improve the safety of mining. When the first ore chamber 1 and the second ore chamber 2 are mined, they are mined upward in sequence for multiple times, and the thickness of each mining is small, so as to reduce the stress changes caused by the excavation disturbance and ensure the safety of the pillars during mining. For example, the height of the protective layer 3 in the vertical direction is 4 meters, and the ore body is a metal ore body.

[0040] Therefore, the method for recovering ore pillars from an ore body according to an embodiment of the present invention has the advantage of high safety.

[0041] like Figure 1 and Figure 2 As shown, in some embodiments, the size of each first sub-mining room 101 and each second sub-mining room 201 in the vertical direction is less than or equal to 4 meters. That is, when the first mining room 1 and the second mining room 2 are mined, the thickness of each upward mining is less than or equal to 4 meters. For example, the size of the first sub-mining room 101 in the vertical direction is 2 meters or 3 meters; the size of the second sub-mining room 201 in the vertical direction is 2 meters or 3 meters.

[0042] like Figure 1As shown, (each first mining room 1) the size of the lower one of the two adjacent first sub-mining rooms 101 in the vertical direction is greater than or equal to the size of the upper one in the vertical direction. (each second mining room 2) the size of the lower one of the two adjacent second sub-mining rooms 201 in the vertical direction is greater than or equal to the size of the upper one in the vertical direction. For example, the thickness of the first sub-mining room 101 located at the bottom of each first mining room 1 is 3 meters, and the thickness of the other first sub-mining rooms 101 of each first mining room 1 is 2 meters. The thickness of the second sub-mining room 201 located at the bottom of each second mining room 2 is 3 meters, and the thickness of the other second sub-mining rooms 201 of each second mining room 2 is 2 meters.

[0043] like Figure 4 As shown, in some embodiments, before mining the pillar, a main access 4 is opened on both sides of the second direction of the pillar, the main access 4 extends along the first direction, and any two of the first direction, the second direction and the up-down direction are perpendicular to each other. Specifically, the main access 4 is a passage opened to facilitate mining the pillar, the extension direction of the main access 4 is consistent with the length direction of the pillar 2, and the second direction is the width direction of the pillar. For example, the main access 4 is opened on both sides of the left-right direction of the pillar, and the main access 4 extends along the front-back direction.

[0044] In step S2, a transverse access 5 is opened from the main access 4 to the first sub-mining room 101 to mine the first sub-mining room 101, and then the transverse access 5 in the first mining room 1 is filled. In step S3, a transverse access 5 is opened from the main access 4 to the second sub-mining room 201 to mine the second sub-mining room 201, and then the transverse access 5 in the second mining room 2 is filled.

[0045] Specifically, the transverse road 5 extends along the second direction, and the extension direction of the transverse road 5 is (substantially) perpendicular to the extension direction of the main road 4. The transverse road 5 is opened in the ore pillar, that is, the passage formed after mining. The transverse road 5 is formed in the first sub-mine room 101 to complete mining, and then the transverse road 5 is filled, so that the first sub-mine room 101 can be mined and filled.

[0046] In some embodiments, during the mining process, the transverse road 5 is excavated according to the third preset slope so that the bottom surface of the transverse road 5 is a downwardly inclined surface. Specifically, the bottom surface height at the entrance of the transverse road 5 is higher than the bottom surface height at the exit, and the inclination of the bottom surface of the transverse road 5 is greater than or equal to 2% and less than or equal to 3%. It is ensured that the top is fully closed during filling, which is convenient for the recovery of the next stope of the transverse road 5.

[0047] During mining, a rock drill is used to open blasting holes in the ore pillars. Specifically, the rock drilling and blasting project uses a rock drilling trolley to drill blasting holes. During blasting, a compound micro-difference detonation method is used. Each blasting hole uses an electronic detonator to detonate in the hole. Micro-difference blasting is used within and between rows, and blasting is timed. The recovered ore is taken out of the mine by an electric scraper. After the blasting is completed, prying and support operations are carried out. When entering the work site, the top plate and the side are first pried manually, and anchor net support is used. The support operation is mainly anchor net support, and rock drilling uses a rock drilling trolley to construct drilling holes. When hanging the anchor net, first insert the anchor rod into the drill hole and grout it. After the anchor rod forms a certain anchoring force, the upper mesh passes through the anchor rod and sticks to the rock, and then the support plate is put into the anchor rod to press the mesh. The wall thickness of the filling retaining wall is 2m. The skeleton layer of the filling retaining wall is constructed with two rows of round steel at a distance of 0.5m at the bottom and 0.5m at the two sides, reaching a depth of 0.5m to the bedrock. Two rows of steel mesh are tied on the wall and welded to the round steel to ensure the strength of the wall.

[0048] In some embodiments, the hole depth of the blasting drilling position is 3m, and the penetration of each shot is 3m. The blasting adopts micro-difference blasting. The explosive is the main explosive, and the detonating charge is made of a φ32mm diameter drug roll and an electronic detonator.

[0049] In some embodiments, when the cross-entry road 5 is filled, a filling retaining wall is constructed at the entrance and exit of the cross-entry road 5. Specifically, a filling retaining wall is constructed at the entrance and exit of the cross-entry road 5 before the stope is filled. The retaining wall is constructed of materials such as anchor rods, steel mesh, rough stone, and high-pressure aerated bricks. After the wall is tightly pressed and compacted, and the filling retaining wall reaches the designed strength, the stope filling operation begins.

[0050] The filling layer in each transverse access road 5 includes a first filling layer and a second filling layer, the first filling layer is located above the corresponding second filling layer, and the compressive strength of the first filling layer is greater than the compressive strength of the second filling layer. Specifically, each access road is filled in two layers after stratified mining. The second filling layer is filled with full tailings cementation (with a lime-sand ratio of 1:7), and the first filling layer is a stratified filling surface, which is filled with full tailings cementation with a strength of not less than 3MPa, in order to facilitate the operation of the scraper.

[0051] In some embodiments, the compressive strength of the adhesive material used in the first filling layer is greater than or equal to 3 MPa. The thickness of the first filling layer in each transverse passage 5 in the vertical direction is greater than or equal to 0.3 meters. For example, the compressive strength of the adhesive material used in the first filling layer is 4 MPa. The thickness of the first filling layer in each transverse passage 5 in the vertical direction is 0.5 meters.

[0052] In some embodiments, a bottom tunnel is opened from the layered connecting road 8 below the mine pillar, and a ventilation filling skylight 10 is constructed from the bottom tunnel to the mine pillar. Fresh air flows into the mining operation face from the ramp 11, the segmented tunnel 7, the layered connecting road 8 and the main access road 4 in sequence, and the polluted air is discharged to the surface through the filling ventilation skylight and the return air shaft. Specifically, the mining project started when the ore body is mined includes the vein tunnel 12, the ramp 11, the segmented tunnel 7, the layered connecting road 8 and the chute 13. The main access road 4, the layered connecting road 8, the segmented tunnel 7 and the chute 13 are connected in sequence, and the mined ore can be transported from the chute 13 to the transport tunnel 6. The transport tunnel 6 can be connected through the vein tunnel 12, and the vein tunnel 12 can be connected through the ramp 11. Specifically, in order to speed up the discharge of blasting smoke, the mining field adopts local fans to strengthen the ventilation of the mining field, adopts through-flow ventilation, and adopts local fans for ventilation when working alone.

[0053] In a specific embodiment, the total height of the reserved bottom column is 8m, the mining height is 5m by the upward horizontal layered approach method, and the reserved height of the protective roof 3 is 3m. The construction of the mining approach follows the principle of constructing the main approach 4 first and then the transverse approach 5. After the transverse approach 5 of each sub-mine room is mined, cementation and filling are carried out to form the roof. During the mining of the transverse approach 5, it is necessary to excavate at a slope of 2% to 3% to ensure that the roof is fully formed during filling, so as to facilitate the mining of the next step of the transverse approach 5 mining area. The transverse approach 5 of the next step mining area can only be mined after the strength of the adjacent filling body reaches the requirement. After each layer is mined, the ore is unloaded and then filled. After the strength of the filling body reaches the requirement, the next cycle of work can be entered. The cross-sectional specifications of the main approach 4 are 4.0m×3.5m, and the cross-sectional specifications of the transverse approach 5 are 3.2m×3.0m.

[0054] For the first and second chambers 1 and 2, the upward horizontal access filling method is used to recover the pillars layer by layer from bottom to top. The mining height of the stope is 5m, the height of the sub-mine chamber below is 3m, and the height of the sub-mine chamber above is 2m. The mining operation advances upward with the working face, filling the goaf layer by layer, and leaving a working space for continued mining. After the mining and filling are completed, the main access road 4 is pressed 3m uphill, and the 2m high bottom pillar of the sub-mine chamber above is mined. After each layer is mined, the ore is unloaded and filled. When the filling body strength meets the requirements, the next cycle of work can be entered.

[0055] In the description of the present invention, it is to be understood that the 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 orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention 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 limiting the present invention.

[0056] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0057] In the present invention, unless otherwise clearly specified and limited, the terms "according to", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or can communicate with each other; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0058] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0059] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0060] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A method for recovering ore pillars from an ore body, characterized in that: The following steps are involved: S1. Divide the mine pillar into a plurality of first mine rooms and a plurality of second mine rooms along a first direction, wherein the plurality of first mine rooms and the plurality of second mine rooms are alternately arranged in sequence in the first direction, and the first direction is perpendicular to the up-down direction; S2, dividing the upper part of the first mine room into a protective roof, dividing the middle and lower part of the first mine room into a plurality of first sub-mine rooms in the vertical direction, wherein the size of each of the first sub-mine rooms in the vertical direction is less than or equal to a first preset value, starting mining and filling from the lowest one of the plurality of first sub-mine rooms of each first mine room, and after mining and filling the lower one of the two adjacent first sub-mine rooms in the vertical direction of each first mine room, mining and filling the upper one of the two adjacent first sub-mine rooms in the vertical direction of each first mine room; S3. After the first sub-mine room is filled, the upper part of the second mine room is divided into a protective roof layer, and the middle and lower parts of the second mine room are divided into multiple second sub-mine rooms in the up and down direction, and the size of each second sub-mine room in the up and down direction is less than or equal to a second preset value, and mining and filling are started from the bottommost one of the multiple second sub-mine rooms of each second mine room. After the lower one of the two adjacent second sub-mine rooms in the up and down direction of each second mine room is mined and filled, the upper one of the two adjacent second sub-mine rooms in the up and down direction of each second mine room is mined and filled.

2. The method for recovering ore pillars from an ore body according to claim 1, characterized in that: The size of each of the first sub-mine chambers and each of the second sub-mine chambers in the vertical direction is less than or equal to 4 meters.

3. The method for recovering ore pillars from an ore body according to claim 2, characterized in that: The size of the first sub-mining room in the vertical direction is 2 meters or 3 meters; The second sub-mining room has a vertical dimension of 2 meters or 3 meters; The size of the lower one of the two adjacent first sub-mining rooms in the vertical direction is greater than or equal to the size of the upper one in the vertical direction; Of the two second sub-mine rooms adjacent in the vertical direction, the size of the lower one in the vertical direction is greater than or equal to the size of the upper one in the vertical direction.

4. The method for recovering ore pillars from an ore body according to claim 1, characterized in that: Before mining the ore pillar, a main access road is opened on both sides of the ore pillar in the second direction, the main access road extends along the first direction, and any two of the first direction, the second direction and the up-down direction are perpendicular to each other; In the step S2, a transverse access is opened from the main access to the first sub-ore chamber to mine the first sub-ore chamber, and then the transverse access in the first sub-ore chamber is filled; In the step S3, a transverse approach is opened from the main approach to the second sub-mine chamber to mine the second sub-mine chamber, and then the transverse approach in the second mine chamber is filled.

5. The method for recovering ore pillars from an ore body according to claim 4, characterized in that: The first direction is the direction of the ore body, and the transverse access road extends along the second direction; During the mining process, the transverse approach is excavated according to the third preset slope so that the bottom surface of the transverse approach is a downwardly inclined slope.

6. The method for recovering ore pillars from an ore body according to claim 5, characterized in that: The bottom height at the inlet of the transverse passage is higher than the bottom height at the outlet, and the inclination of the bottom surface of the transverse passage is greater than or equal to 2% and less than or equal to 3%.

7. The method for recovering ore pillars from an ore body according to claim 5, characterized in that: When filling the cross-entry road, a filling retaining wall is constructed at the entrance and exit of the cross-entry road; The filling layers in each transverse passage include a first filling layer and a second filling layer, wherein the first filling layer is located above the corresponding second filling layer, and the compressive strength of the first filling layer is greater than the compressive strength of the second filling layer.

8. The method for recovering ore pillars from an ore body according to claim 7, characterized in that: The compressive strength of the bonding material used in the first filling layer is greater than or equal to 3MPa; The thickness of the first filling layer in each transverse passage in the vertical direction is greater than or equal to 0.3 meters.

9. The method for recovering ore pillars from an ore body according to claim 5, characterized in that: A bottom tunnel is opened from the layered connecting road below the mine pillar, and a ventilation filling skylight leading into the mine pillar is constructed from the bottom tunnel; Fresh air flows into the mining face from the ramp, the segmented roadway, the layered connecting road and the main access road in sequence, and the polluted air is discharged to the surface through the filling ventilation skylight and the return air shaft; During mining, a blasting hole is opened in the ore pillar using a rock drill.

10. The method for recovering ore pillars from an ore body according to any one of claims 1 to 9, characterized in that: The height of the protective layer in the vertical direction is greater than or equal to 3 meters.

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