Method for recovering pillar under phosphate ore layer filled with backfill

Abstract

The present application belongs to the field of phosphorite deposit mining technology, and particularly relates to a method for recovering a phosphorite layer bottom pillar under a filling body, which comprises arranging a segmented transport roadway in a sandwich in the top and bottom surface of the bottom pillar to reduce the construction engineering quantity of the rock drilling roadway and the ore roadway; first constructing a filling roadway intersecting on both sides of the segmented transport roadway, filling the filling body roadway with high-strength filling material, and then constructing the segmented transport roadway in the filling roadway, so that the segmented transport roadway is finally topped and bottomed with the sandwich rock, and both sides of the segmented transport roadway are high-strength filling bodies, which greatly improves the strength of the segmented transport roadway and reduces the influence of ore mining. Further, the present application proposes an invention point of leaving a permanent ore pillar in the ore body on one side of the sandwich bottom plate to improve the safety of the segmented transport roadway and the ore room mining; in order to further improve the safety of the ore room mining, the present application first proposes an ore room adopting an eight-character-shaped stope structure.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of phosphate deposit mining, and particularly relates to a method for recovering a bottom pillar of a phosphate layer under a filling body. BACKGROUND

[0002] The Dongdushan phosphate mine area in Daxin, Weng'an is rich in a and b two layers of ore bodies. The ore body has a total length of 190m in strike, a depth of 240m in inclination, and an inclination angle of 55-70 degrees. The average thickness of the a ore body is 28m, and the average thickness of the b ore body is 32m. There is a 5m thick interlayer between the a and b ore bodies, which is not mined during the ore body recovery. The upward sublevel open stope and subsequent filling body mining method is used to recover the 1020 and 1080 middle sections in the mine area. A bottom pillar is left between the two middle sections, and the elevation range of the bottom pillar is 1065-1080. There is a large amount of ore body in the bottom pillar, so the ore body needs to be recovered to reduce resource waste. However, the upper part of the bottom pillar is the filling body after the 1080 middle section is mined, and the lower part of the bottom pillar is the filling body formed after the 1020 middle section is mined. The bonding performance between the filling body and the bottom pillar is poor, and the strength of the filling body is weaker than that of the original ore body. Therefore, how to safely recover the bottom pillar, including the arrangement of the development roadway and the stope form, becomes a difficult problem to be solved. SUMMARY

[0003] In order to solve the above technical problems, the application provides a method for recovering a bottom pillar of a phosphate layer under a filling body, which comprises the following steps:

[0004] S1: arranging an upper sublevel transportation roadway in the interlayer along the strike with the top surface of the bottom pillar as the bottom; and arranging a lower sublevel transportation roadway in the interlayer along the strike with the bottom surface of the bottom pillar as the bottom;

[0005] respectively constructing a filling roadway on the left and right sides of the upper sublevel transportation roadway along the strike; and respectively constructing a filling roadway on the left and right sides of the lower sublevel transportation roadway along the strike;

[0006] S2: filling the filling roadway; and excavating the upper sublevel transportation roadway and the lower sublevel transportation roadway;

[0007] S3: dividing the bottom pillar into one-step ore rooms and two-step ore rooms along the strike; and the height of each ore room is the height of the bottom pillar;

[0008] respectively constructing a drilling roadway on the left and right sides of the upper sublevel transportation roadway at the central position of the top of each ore room; and respectively constructing an ore outlet roadway on the left and right sides of the lower sublevel transportation roadway at the central position of the bottom of each ore room;

[0009] S4: constructing a blasting drill hole from the drilling roadway to the one-step ore room, blasting to form an eight-shaped stope, and then transporting the ore after blasting out of the ore outlet roadway through the lower sublevel transportation roadway; and then filling the one-step ore room through the filling pipeline from the drilling roadway;

[0010] Fan-shaped blasting drilling holes are drilled from the rock drilling roadway to the two-step ore room, and an eight-shaped stope is formed by blasting, and the ore after blasting is transported out from the rock drilling roadway through the lower sublevel transportation roadway; and then the two-step ore room is filled through the filling pipe from the rock drilling roadway.

[0011] Preferably, in step S1, the upper sublevel transportation roadway and the lower sublevel transportation roadway are located in the interlayer as much as possible.

[0012] Preferably, in step S1, the filling roadway intersects with the sublevel transportation roadway, but the left and right filling roadways do not intersect.

[0013] Preferably, in step S2, a filling material with high strength after solidification is used to fill the filling roadway.

[0014] Preferably, in step S3, the length of the ore room along the strike is 15-20m.

[0015] Preferably, in step S3, the thickness of each ore room is the entire thickness of the b ore layer on the side of the interlayer roof and part of the thickness of the a ore layer on the side of the interlayer floor, wherein the a ore layer is provided with a right triangle or right trapezoid protective coal pillar next to the left side of the interlayer.

[0016] Preferably, in step S4, for each ore room, the a ore layer and the b ore layer are simultaneously mined and filled, and the mining direction is from the distal end to the interlayer direction.

[0017] Beneficial technical effects: 1. The present application proposes to arrange the sublevel transportation roadway in the interlayer in the top and bottom surface of the bottom pillar for the filling body under the bottom pillar recovery condition between the two thick ore layers, which can greatly reduce the construction engineering quantity of the rock drilling roadway and the ore roadway; and for the weak bonding position of the interlayer where the sublevel transportation roadway is close to or touches the interlayer and the filling body, the present application proposes to first construct the filling roadway intersecting the sublevel transportation roadway on both sides, and then to construct the sublevel transportation roadway in the filling roadway after filling the filling body roadway with high-strength filling material, so that the sublevel transportation roadway is finally provided with the interlayer rock as the top and bottom and the high-strength filling body as the two sides, greatly improving the strength of the sublevel transportation roadway and reducing the influence of the ore mining.

[0018] 2. For the problem of insufficient stability of the sublevel transportation roadway due to the weak strength of the interlayer top and bottom filling body and the influence of the mining of the left and right ore layers on the interlayer strength, the present application proposes to provide a permanent coal pillar in the ore body on one side of the interlayer bottom to improve the safety of the sublevel transportation roadway and the mining of the ore room; and further, in order to improve the safety of the mining of the ore room, the present application first proposes to use an eight-shaped stope structure for each ore room, and the adjacent stope structures are inverted trapezoidal permanent coal pillars. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1This is a schematic cross-sectional view of the bottom pillar along the dip direction of the ore layer in this invention;

[0020] Figure 2 This is a schematic diagram of the inclined profile of the segmented transport roadway in the bottom pillar recovery method of the present invention;

[0021] Figure 3 This is a schematic diagram of the inclined surface of the filling tunnel after filling in the bottom column recovery method of the present invention;

[0022] Figure 4 This is a schematic cross-sectional view of the segmented transport tunnel construction of the bottom pillar recovery method of the present invention;

[0023] Figure 5 A schematic diagram of the dip profile for protecting the pillar in the bottom pillar recovery method of the present invention;

[0024] Figure 6 This is a schematic cross-sectional view of the rock drilling tunnel direction in the bottom pillar recovery method of the present invention;

[0025] Figure 7 This is a schematic cross-sectional view of the stope backfilling direction in the first step of the bottom pillar recovery method of the present invention.

[0026] Figure 8 This is a schematic cross-sectional view of the stope backfilling direction in the second step of the bottom pillar recovery method of the present invention.

[0027] In the diagram, a-ore layer; b-ore layer; interlayer 1; bottom section of the 1080-meter section 2; bottom pillar 3; top section of the 1020-meter section 4; upper section transport roadway 51; lower section transport roadway 52; filling roadway 6; high-strength filling body 7; drilling roadway 8; ore extraction roadway 9; first-stage stope 10; second-stage stope 11; V-shaped stope 12; trapezoidal permanent pillar 13. Detailed Implementation

[0028] The following example uses the bottom column between the 1020 and 1080 sections of the Weng'an Daxin Beidoushan phosphate mine as an illustration, combined with the attached... Figures 1-8 The present invention will be further described below.

[0029] like Figure 1 As shown, the Weng'an Daxin Beidoushan phosphate mine is rich in two ore layers, a and b. The 1020 and 1080 sections were mined using the upward segmented open-pit backfilling mining method. Interlayers (rock layers, not valuable for mining relative to layers a and b) were not mined during the ore body mining. A bottom pillar 3 was left between the two sections, with an elevation range of 1065-1080. The dip angle of the bottom pillar 3 ore body is approximately 60°. Ore body a is 28m thick, ore body b is 32m thick, and there is a 5m thick interlayer 1 between ore bodies a and b.

[0030] It is necessary to re-mine the bottom pillar 3 to reduce resource waste. However, since the bottom pillar 3 is topped by the bottom section filling body 2 of the 1080 mid-section and bottomed by the top section filling body 4 of the 1020 mid-section, the bonding performance between the filling body 2 and the bottom pillar 3 is relatively poor compared to the original rock, and the strength of the filling body 2 is weaker than that of the a and b ore layers, how to safely mine the bottom pillar 3, including the layout of the preparatory roadway and the stope form, has become an urgent problem to be solved.

[0031] To address the above problems, this invention proposes a method for recovering the bottom column of a phosphate rock layer under a filling body, comprising the following steps:

[0032] S1: As Figure 2 As shown, the upper segmented transport tunnel 51 is arranged along the direction within the interlayer 1 with the top surface of the bottom pillar 3 as the base; the lower segmented transport tunnel 52 is arranged along the direction within the interlayer 1 with the bottom surface of the bottom pillar 3 as the base, so that the upper segmented transport tunnel 51 and the lower segmented transport tunnel 52 are located within the interlayer 1 as much as possible; the upper segmented transport tunnel 51 and the lower segmented transport tunnel 52 have rectangular cross sections with dimensions of 4m×4m; the upper segmented transport tunnel 51 and the lower segmented transport tunnel 52 function as the segmented transport tunnel (or the middle section transport tunnel) when the middle section is mined in segments. The upper and lower of the upper segmented transport tunnel 51 and the lower segmented transport tunnel 52 do not refer to the upper segment or the lower segment, but rather to the segmented transport being located above or below the bottom pillar 3;

[0033] A filling tunnel 6 is constructed on both sides of the designed location of the upper segment transport tunnel 51 along its direction. The filling tunnel 6 intersects with the upper segment transport tunnel 51, but the two filling tunnels 6 do not intersect. A filling tunnel 6 is constructed on both sides of the designed location of the lower segment transport tunnel 52. The filling tunnel 6 intersects with the lower segment transport tunnel 52, but the two filling tunnels 6 do not intersect. The cross-section of the filling tunnel 6 is rectangular. In this embodiment, the dimensions of the left filling tunnel 6 are 2.6m × 4m, and the dimensions of the right filling tunnel 6 are 3.0m × 4m.

[0034] S2: As Figure 3 As shown, the filling tunnel 6 is filled with a filling material with high strength after solidification, and a high-strength filling body 7 is formed after filling.

[0035] like Figure 4 As shown, the upper segment transport tunnel 51 and the lower segment transport tunnel 52 are excavated according to their designed positions. At this time, a portion of the high-strength filling material 7 will be excavated.

[0036] This invention addresses the issue of recovering bottom pillars in filling bodies with interlayers between thick, double-layered ore formations. It proposes arranging segmented haulage roadways within the interlayers on the top and bottom surfaces of the bottom pillars. This significantly reduces the construction workload of drilling and ore extraction roadways. Furthermore, considering the weak bonding between the interlayer and the filling body at locations where the segmented haulage roadways are close to or touch, the invention proposes first constructing filling roadways on both sides of the intersecting segmented haulage roadways. Then, the filling body roadways are filled with high-strength filling material before the segmented haulage roadways are constructed within them. This ensures that the segmented haulage roadways ultimately have the interlayered rock as their top and bottom, and the high-strength filling body as their two sides, greatly improving the strength of the segmented haulage roadways and reducing their susceptibility to ore mining disturbances.

[0037] S3: As Figures 5-6 As shown, the bottom pillar 3 is divided into a first-step stope 10 and a second-step stope 11 along the strike. The first-step stope 10 is the odd-numbered stope along the strike, and the second-step stope 11 is the even-numbered stope along the strike. The height of each stope is the height of the bottom pillar 3. The length along the strike is 15-20m, and the thickness is the entire thickness of the b-layer located on the top plate of the interlayer and a part of the thickness of the a-layer located on the bottom plate of the interlayer. A right-angled triangle or right-angled trapezoidal protective coal pillar 14 is left on the left side of the a-layer, which is close to the interlayer 1. The hypotenuse of the right-angled triangle or right-angled trapezoid is the bottom surface of the interlayer 1.

[0038] At the top center of each stope, rock drilling tunnels 8 are constructed from the upper segment transport tunnel 51 to the left and right sides respectively; at the bottom center of each stope, ore extraction tunnels 9 are constructed from the lower segment transport tunnel 52 to the left and right sides respectively.

[0039] S4: As Figures 6-8 As shown, a fan-shaped blasting borehole is drilled from the rock-drilling roadway 8 to the first-stage stope 10. The blasting forms a figure-eight shaped stope 12. The blasted ore is transported out from the ore extraction roadway 9 through the lower sub-section transport roadway 52. ​​Then, the first-stage stope 10 is filled through the rock-drilling roadway 8 via the filling pipeline.

[0040] A fan-shaped blasting borehole is drilled from the self-drilling roadway 8 to the second-stage stope 11, forming a figure-eight shaped stope 12. The blasted ore is transported out from the ore extraction roadway 9 through the lower sub-section transport roadway 52. ​​Then, the second-stage stope 11 is filled through the self-drilling roadway 8 via the filling pipeline. An inverted trapezoidal permanent pillar 13 is formed between the stopes of adjacent stops or between the filling bodies and is not mined.

[0041] For each mineral stope, it is preferable to mine and fill both mineral layer a and mineral layer b simultaneously, with the mining direction being opposite from the far end towards the interlayer.

[0042] The present application is aimed at the back pillar recovery condition of the filling body under the double thick large ore layer with the interlayer, proposes to arrange the sublevel transportation roadway in the interlayer in the top and bottom surface of the back pillar, so that the construction engineering quantity of the rock drilling roadway and the ore drawing roadway can be greatly reduced; aiming at the problem that the strength of the interlayer top and bottom filling body is not strong, the left and right sides of the ore layer mining have influence on the strength of the interlayer, and further causes the insufficient stability of the sublevel transportation roadway, the present application proposes the invention point of leaving the permanent ore pillar in the ore body on one side of the interlayer bottom plate, so as to improve the safety of the sublevel transportation roadway and the ore room mining; and further, in order to improve the safety of the ore room mining, the present application proposes to adopt the eight-shaped stope structure for each ore room, and the adjacent stope structures are the inverted trapezoidal permanent ore pillars.

[0043] The present application is not limited to the above-mentioned best mode, and anyone can derive other various forms of methods under the inspiration of the present application, as long as the technical solutions are the same or similar to the present application, which falls within the protection scope of the present application.

Claims

1. A method for pillar recovery under the phosphate ore layer of the filling body, characterized in that, It comprises the following steps: S1: arranging an upper sub-transport roadway in the interlayer along the strike with the floor of the pillar as the bottom, and arranging a lower sub-transport roadway in the interlayer along the strike with the bottom of the pillar as the bottom; a filling roadway is constructed on the left and right sides of the upper sub-transport roadway along the strike, and a filling roadway is constructed on the left and right sides of the lower sub-transport roadway along the strike; the filling roadway intersects with the sub-transport roadway, but the left and right filling roadways do not intersect with each other; S2: filling the filling roadway, and excavating the upper and lower sub-transport roadways; S3: dividing the pillar into one-step rooms and two-step rooms along the strike; the height of each room is the height of the pillar, and the thickness of each room is the entire thickness of the b coal seam on the side of the interlayer roof and a part of the thickness of the a coal seam on the side of the interlayer floor, wherein the a coal seam is provided with a right-angled triangular or right-angled trapezoidal protective coal pillar on the left side close to the interlayer; rock drilling roadways are constructed on the top of each room from the upper sub-transport roadway to the left and right sides, and ore extraction roadways are constructed on the bottom of each room from the lower sub-transport roadway to the left and right sides; the thickness of each room is the entire thickness of the b coal seam on the side of the interlayer roof and a part of the thickness of the a coal seam on the side of the interlayer floor, wherein the a coal seam is provided with a right-angled triangular or right-angled trapezoidal protective coal pillar on the left side close to the interlayer; S4: constructing blasting boreholes from the rock drilling roadway to the one-step room to form an eight-shaped stope, and the blasted ore is transported out through the ore extraction roadway and the lower sub-transport roadway; then the one-step room is filled through the filling pipe from the rock drilling roadway; fan-shaped blasting boreholes are constructed from the rock drilling roadway to the two-step room to form an eight-shaped stope, and the blasted ore is transported out through the ore extraction roadway and the lower sub-transport roadway; then the two-step room is filled through the filling pipe from the rock drilling roadway.

2. The method of pillar recovery of the underlying phosphate ore layer of the fill according to claim 1, characterized in that, In step S2, a filling material with high strength after solidification is used to fill the filling roadway.

3. The method of claim 1, wherein the method is characterized by, In step S3, the length of the room along the strike is 15-20 m.

4. The method of claim 1, wherein the method is characterized by, In step S4, the a coal seam and the b coal seam are simultaneously mined and filled for each room, and the mining direction is from the far end to the interlayer.

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