Method for recovering bottom column of phosphorite layer under filling body

Abstract

The invention belongs to the field of phosphorite bed mining processes, and particularly relates to a method for recovering a bottom column of a phosphorite layer under a filling body, which comprises the following steps of: arranging a segmented transportation roadway in an interlayer in the top and bottom surfaces of the bottom column to reduce the construction work amount of a drilling roadway and an ore removal roadway; according to the scheme that filling roadways are constructed on the two sides of a segmented transportation roadway in an intersecting mode, filling body roadways are filled with high-strength filling materials, and then the segmented transportation roadway is constructed in the filling roadways, so that the segmented transportation roadway finally takes interlayer rocks as the top and the bottom and takes high-strength filling bodies as the two sides, and the strength of the segmented transportation roadway is greatly improved; and the influence caused by ore mining is reduced. Furthermore, the invention provides an inventive point of reserving a permanent ore pillar in the ore body on one side of the interlayer bottom plate, so that the safety during mining of the segmented transportation roadway and the chamber is improved; in order to further improve the safety during mining of the chambers, the invention provides a splayed stope structure for the chambers for the first time.

Description

Technical Field

[0001] The present invention belongs to the field of phosphorus deposit mining technology, and particularly relates to a method for recovering the bottom pillar of a phosphorus ore layer under a filling body. Background Art

[0002] The Wengan Daxin Beidoushan Phosphorus Mine area is rich in two ore layers, namely ore layer a and ore layer b. The total strike length of the ore body is 190 m, the inclined depth is 240 m, the dip angle of the ore body is 55° - 70°, the average thickness of ore layer a is 28 m, the average thickness of ore layer b is 32 m, and there is a 5-m-thick interlayer between ore layers a and b, which is not mined during ore body mining. The upward sublevel open stoping with subsequent filling method is used to mine the 1020 level and the 1080 level in the mining area. A bottom pillar is left between the two levels, and the elevation range of the bottom pillar is 1065 - 1080. There are a large number of ore bodies in the bottom pillar, so secondary mining is required to reduce resource waste. However, since the upper part of the bottom pillar is the filling body after the mining of the 1080 level, and the lower part of the bottom pillar is the filling body formed by the mining of the 1020 level, 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 layout of the development roadway and the stope form, has become a difficult problem to be solved urgently. Summary of the Invention

[0003] In order to solve the above technical problems, the present invention provides a method for recovering the bottom pillar of a phosphorus ore layer under a filling body, which includes the following steps:

[0004] S1: The upper sublevel haulage roadway is arranged along the strike in the interlayer with the top surface of the bottom pillar as the bottom; the lower sublevel haulage roadway is arranged along the strike in the interlayer with the bottom surface of the bottom pillar as the bottom;

[0005] One filling roadway is constructed on each side along the strike on the left and right of the designed position of the upper sublevel haulage roadway; one filling roadway is constructed on each side of the designed position of the lower sublevel haulage roadway;

[0006] S2: The filling roadways are filled; the upper sublevel haulage roadway and the lower sublevel haulage roadway are excavated;

[0007] S3: The bottom pillar is divided into a first-step stope and a second-step stope at intervals along the strike; the height of each stope is the height of the bottom pillar;

[0008] Drifting headings are constructed from the upper sublevel haulage roadway to the left and right sides respectively at the center of the top of each stope, and ore-drawing headings are constructed from the lower sublevel haulage roadway to the left and right sides respectively at the center of the bottom of each stope;

[0009] S4: Blasting holes are constructed from the drifting headings to the first-step stope for blasting to form an eight-shaped stope, and the blasted ore is transported out through the ore-drawing heading and the lower sublevel haulage roadway; then the first-step stope is filled through the filling pipeline from the drifting heading;

[0010] Fan-shaped blasting holes are constructed from the rock-drilling roadway to the second-step ore chamber, and an eight-shaped stope is formed by blasting. The blasted ore is transported out through the ore-drawing roadway and the lower-section transportation roadway. Then, the second-step ore chamber is filled through the filling pipeline from the rock-drilling roadway.

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

[0012] Preferably, in step S1, there is an intersection between the filling roadway and the sectional transportation roadway, but there is no intersection between the left and right filling roadways.

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

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

[0015] Preferably, in step S3, the thickness of each ore chamber is the entire thickness of the b ore layer on the side of the interlayer roof and a part of the thickness of the a ore layer on the side of the interlayer floor. A right-angled triangle or right-angled trapezoidal protective coal pillar is reserved on the left side of the a ore layer close to the interlayer.

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

[0017] Beneficial technical effects: 1. For the recovery working condition of the bottom pillar under the filling body with an interlayer between two thick ore layers, the present invention proposes to arrange the sectional transportation roadway in the interlayer between the top and bottom surfaces of the bottom pillar, which can greatly reduce the construction workload of the rock-drilling roadway and the ore-drawing roadway. At the same time, aiming at the problem that the sectional transportation roadway constructed in the interlayer is close to or touches the weak bonding position where the interlayer is connected to the filling body, a scheme is proposed to first construct filling roadways intersecting on both sides of the sectional transportation roadway, and then construct the sectional transportation roadway in the filling roadway after filling the filling body roadway with high-strength filling materials. In this way, the sectional transportation roadway finally has the interlayer rock as the top and bottom and high-strength filling bodies as the two sides, greatly improving the strength of the sectional transportation roadway and reducing the influence brought by ore mining.

[0018] 2. Aiming at the problem that the strength of the filling bodies at the top and bottom of the interlayer is not strong, and the mining of the ore layers on the left and right sides affects the strength of the interlayer, thus resulting in insufficient stability of the sectional transportation roadway, the present invention proposes an invention point of leaving a permanent ore pillar in the ore body on one side of the interlayer floor to improve the safety during the mining of the sectional transportation roadway and the ore chamber. Moreover, further, in order to improve the safety during the mining of the ore chamber, the present invention first proposes to adopt an eight-shaped stope structure for each ore chamber, and an inverted trapezoidal permanent ore pillar is arranged between adjacent stope structures. Description of the Drawings

[0019] Figure 1Schematic diagram of the occurrence profile of the sill pillar along the dip of the orebody in the present invention;

[0020] Figure 2 Schematic diagram of the dip profile of the sill pillar recovery method in the present invention with the sectional haulage roadway arranged;

[0021] Figure 3 Schematic diagram of the dip section after backfilling in the filling roadway of the sill pillar recovery method in the present invention;

[0022] Figure 4 Schematic diagram of the dip profile during the construction of the sectional haulage roadway in the sill pillar recovery method in the present invention;

[0023] Figure 5 Schematic diagram of the dip profile of the protective pillar arrangement in the sill pillar recovery method in the present invention;

[0024] Figure 6 Schematic diagram of the strike profile of the drifter roadway in the sill pillar recovery method in the present invention;

[0025] Figure 7 Schematic diagram of the strike profile of the first-step stope mining and backfilling in the sill pillar recovery method in the present invention;

[0026] Figure 8 Schematic diagram of the strike profile of the second-step stope mining and backfilling in the sill pillar recovery method in the present invention;

[0027] In the figure, a - orebody; b - orebody; interlayer 1, bottom sectional backfill body at the 1080 level 2, sill pillar 3, top sectional backfill body at the 1020 level 4, upper sectional haulage roadway 51, lower sectional haulage roadway 52, filling roadway 6, high-strength backfill body 7, drifter roadway 8, ore-drawing roadway 9, first-step stope 10, second-step stope 11, figure-eight stope 12, trapezoidal permanent pillar 13. Detailed implementation method

[0028] The following takes the sill pillar between the 1020 level and the 1080 level of Wengan Daxin Beidoushan Phosphate Mine as an example, and in combination with the attached Figure 1-8 , the present invention will be further described.

[0029] As Figure 1 shown, the Wengan Daxin Beidoushan Phosphate Mine area is rich in two ore layers, a and b. The upward sublevel open stoping and subsequent filling mining method is used to mine the 1020 level and the 1080 level in the mine area. The interlayer is not mined during the orebody mining (the interlayer is rock and has no mining value compared with the a and b ore layers). A sill pillar 3 is left between the two levels, and the elevation range of the sill pillar 3 is 1065 - 1080. The dip angle of the sill pillar 3 orebody is about 60°. The thickness of the a orebody is 28 m, the thickness of the b orebody is 32 m, and there is a 5-m-thick interlayer 1 between the a and b ore bodies.

[0030] At present, it is necessary to conduct secondary mining on the sill pillar 3 to reduce resource waste. However, since the upper part of the sill pillar 3 is the bottom sectional filling body 2 of the 1080 level and the lower part is the top sectional filling body 4 of the 1020 level, the bonding performance between the filling body 2 and the sill pillar 3 is worse than that of the original rock, and the strength of the filling body 2 is weaker than that of the a and b ore layers. Therefore, how to safely mine the sill pillar 3, including the layout of the development headings and the stope form, has become a difficult problem to be solved urgently.

[0031] In view of the above problems, the present invention proposes a method for recovering the phosphorite sill pillar under the filling body, which includes the following steps:

[0032] S1: As Figure 2 shown, taking the top surface of the sill pillar 3 as the bottom, the upper sectional haulage roadway 51 is arranged along the strike in the interlayer 1; taking the bottom surface of the sill pillar 3 as the bottom, the lower sectional haulage roadway 52 is arranged along the strike in the interlayer 1, and the upper sectional haulage roadway 51 and the lower sectional haulage roadway 52 are located in the interlayer 1 as much as possible; the upper sectional haulage roadway 51 and the lower sectional haulage roadway 52 have a rectangular cross-section with a size of 4m×4m; the functions of the upper sectional haulage roadway 51 and the lower sectional haulage roadway 52 are the same as those of the sectional haulage roadway (or the level haulage roadway) during the sectional mining of the level. The upper and lower of the upper sectional haulage roadway 51 and the lower sectional haulage roadway 52 do not refer to the upper section or the lower section, but refer to the sectional haulage being located above or below the sill pillar 3;

[0033] On the left and right sides of the designed position of the upper sectional haulage roadway 51, a filling roadway 6 is respectively constructed along the strike. The filling roadway 6 intersects with the upper sectional haulage roadway 51, but the two filling roadways 6 do not intersect; on the left and right sides of the designed position of the lower sectional haulage roadway 52, a filling roadway 6 is respectively constructed. The filling roadway 6 intersects with the lower sectional haulage roadway 52, but the two filling roadways 6 do not intersect; the cross-section of the filling roadway 6 is rectangular. In this embodiment, the size of the left filling roadway 6 is 2.6m×4m, and the size of the right filling roadway 6 is 3.0m×4m;

[0034] S2: As Figure 3 shown, the filling roadway 6 is filled with a filling material with a relatively high strength after solidification to form a high-strength filling body 7;

[0035] As Figure 4 shown, the upper sectional haulage roadway 51 and the lower sectional haulage roadway 52 are excavated according to the designed positions of the upper sectional haulage roadway 51 and the lower sectional haulage roadway 52. At this time, a part of the high-strength filling body 7 will be excavated;

[0036] In view of the recovery working condition of the bottom pillar under the filling body with an interlayer existing between two thick ore bodies, the present invention proposes to arrange the sectional haulage roadway in the interlayer between the top and bottom surfaces of the bottom pillar, which can greatly reduce the construction workload of the drilling roadway and the ore-drawing roadway. At the same time, aiming at the weak bonding position where the sectional haulage roadway constructed in the interlayer is close to or touches the connection between the interlayer and the filling body, a scheme is proposed to first construct the filling roadway at the intersection on both sides of the sectional haulage roadway, and then construct the sectional haulage roadway in the filling roadway after filling the filling body roadway with high-strength filling materials. In this way, the sectional haulage roadway finally has the interlayer rock as the top and bottom and the high-strength filling body as the two sides, greatly improving the strength of the sectional haulage roadway and reducing the influence brought by ore mining.

[0037] S3: As Figure 5-6 shown, the bottom pillar 3 is divided into the first-step ore chamber 10 and the second-step ore chamber 11 at intervals along the strike. The first-step ore chamber 10 is the odd-numbered ore chamber along the strike, and the second-step ore chamber 11 is the even-numbered ore chamber along the strike. The height of each ore chamber is the height of the bottom pillar 3, the length along the strike is 15 - 20 m, and the thickness is the entire thickness of the b ore body on the side of the interlayer roof and a part of the thickness of the a ore body on the side of the interlayer floor. Among them, a right-angled triangle or right-angled trapezoidal protective coal pillar 14 is reserved on the left side of the a ore body close to the interlayer 1, and the hypotenuse of the right-angled triangle or right-angled trapezoid is the bottom surface of the interlayer 1.

[0038] At the central position at the top of each ore chamber, the drilling roadway 8 is constructed separately from the upper sectional haulage roadway 51 to the left and right sides. At the central position at the bottom of each ore chamber, the ore-drawing roadway 9 is constructed separately from the lower sectional haulage roadway 52 to the left and right sides.

[0039] S4: As Figure 6-8 shown, fan-shaped blasting holes are constructed from the drilling roadway 8 to the first-step ore chamber 10 to form an eight-shaped stope 12 by blasting. The blasted ore is transported out through the ore-drawing roadway 9 and the lower sectional haulage roadway 52. Then, the first-step ore chamber 10 is filled through the filling pipeline from the drilling roadway 8.

[0040] Fan-shaped blasting holes are constructed from the drilling roadway 8 to the second-step ore chamber 11 to form an eight-shaped stope 12 by blasting. The blasted ore is transported out through the ore-drawing roadway 9 and the lower sectional haulage roadway 52. Then, the second-step ore chamber 11 is filled through the filling pipeline from the drilling roadway 8. An inverted trapezoidal permanent ore pillar 13 is not mined between the stopes or filling bodies of adjacent ore chambers.

[0041] Among them, for each ore chamber, it is preferably to simultaneously mine and fill the a ore body and the b ore body, and the mining direction is to construct from the far end to the interlayer direction in an opposite manner.

[0042] In view of the recovery working condition of the bottom pillar under the filling body with an interlayer existing between two thick ore bodies, the present invention proposes to arrange the sectional haulage roadway in the interlayer between the top and bottom surfaces of the bottom pillar, which can greatly reduce the construction workload of the drilling roadway and the ore-drawing roadway. Aiming at the problem that the strength of the filling body on the top and bottom of the interlayer is not strong, and the mining of the ore bodies on the left and right sides affects the strength of the interlayer, thus resulting in insufficient stability of the sectional haulage roadway, the present invention proposes an inventive point of leaving a permanent ore pillar in the ore body on one side of the interlayer floor to improve the safety during the mining of the sectional haulage roadway and the ore room. Furthermore, in order to improve the safety during the mining of the ore room, the present invention proposes to adopt an eight-shaped stope structure for each ore room, and a reverse trapezoidal permanent ore pillar is arranged between adjacent stope structures.

[0043] The present invention is not limited to the above best implementation mode. Any person can obtain various other forms of methods under the inspiration of the present invention. However, any technical solution that is the same as or similar to the present application falls within the protection scope of the present invention.

Claims

1. A method for recovering the bottom column of a phosphate ore layer under a filling body, characterized in that: The steps include: S1: The upper segmented transport lane is arranged along the direction in the mezzanine with the top surface of the bottom column as the bottom; the lower segmented transport lane is arranged along the direction in the mezzanine with the bottom surface of the bottom column as the bottom; A filling tunnel is constructed on both sides of the design position of the upper segment transport tunnel along the strike direction; a filling tunnel is constructed on both sides of the design position of the lower segment transport tunnel; S2: Fill the filling tunnel; excavate the upper and lower segment transport tunnels; S3: Divide the bottom pillar interval into a one-step mine room and a two-step mine room along the strike; the height of each mine room is the height of the bottom pillar, and the thickness is the entire thickness of the b ore layer on the interlayer roof side and a part of the thickness of the a ore layer on the interlayer floor side, wherein a right-angled triangle or right-angled trapezoidal protective coal pillar is left on the left side of the interlayer; At the center of the top of each mine room, a rock drilling tunnel is constructed from the upper section transport tunnel to the left and right sides respectively, and at the center of the bottom of each mine room, a mine exit tunnel is constructed from the lower section transport tunnel to the left and right sides respectively; S4: Drill holes are constructed from the rock drilling tunnel to the first step mine room, and the blasting forms an eight-shaped stope. The ore after blasting is transported out from the mine roadway through the lower stage transportation roadway; then the first step mine room is filled from the rock drilling tunnel through the filling pipeline; Fan-shaped blasting holes are constructed from the rock drilling tunnel to the second-step mine room, and an eight-shaped mining area is formed by blasting. The ore after blasting is transported out from the mine tunnel through the lower segmented transport tunnel; then the second-step mine room is filled from the rock drilling tunnel through the filling pipeline.

2. The method for recovering the bottom pillar of the phosphate ore layer under the filling body according to claim 1, characterized in that: In step S1, the filling lane and the segmented transport lane intersect, but the left and right filling lanes do not intersect.

3. The method for recovering the bottom pillar of the phosphate ore layer under the filling body according to claim 1, characterized in that: In step S1, the filling lane and the segmented transport lane intersect.

4. The method for recovering the bottom pillar of the phosphate ore layer under the filling body according to claim 1, characterized in that: In step S2, the filling tunnel is filled with a filling material having a relatively high strength after solidification.

5. The method for recovering the bottom pillar of the phosphate ore layer under the filling body according to claim 1, characterized in that: In step S3, the length of the mine room along the strike is 15-20m.

6. The method for recovering the bottom pillar of the phosphate ore layer under the filling body according to claim 1, characterized in that: In step S3, the thickness of each mine room is the entire thickness of the b ore layer on the interlayer roof side and a part of the thickness of the a ore layer on the interlayer floor side, wherein a right-angled triangle or right-angled trapezoidal protective coal pillar is left on the left side of the interlayer.

7. The method for recovering the bottom pillar of the phosphate ore layer under the filling body according to claim 1, characterized in that: In step S4, for each mine chamber, the a ore layer and the b ore layer are mined and filled at the same time, and the mining direction is from the far end to the interlayer.

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