Coal-aluminum green co-mining method

Abstract

The present application relates to the field of coal-aluminum combined mining, and particularly relates to a green coal-aluminum co-mining method. The method is used for mining a coal seam and an underlying bauxite seam, and comprises arranging a longwall coal mining face in the coal seam and a longwall aluminum mining face in the bauxite seam; constructing a gangue storage between a coal seam transport raise and a coal seam transport crosscut, and constructing a gangue storage chamber between an aluminum transport raise and an aluminum seam transport crosscut, the gangue storage being connected to the gangue storage chamber through a chute; using a longwall caving coal mining method to mine the coal mining face, and transporting the generated gangue to the gangue storage; and mining a next coal mining face, at which time a filling mining process is started to mine the aluminum mining face below the previous coal mining face, and gangue, red mud and other solid waste generated in coal-aluminum production are used as filling materials to fill the mined-out area after bauxite mining, so that green mining of coal-aluminum symbiotic resources is realized.

Description

Technical Field

[0001] This invention relates to the field of coal-aluminum co-mining, and more particularly to a green coal-aluminum co-mining method. Background Technology

[0002] Coal-bauxite ore layers are superimposed on coal seams, with the bauxite layer located beneath the coal seam, forming a mineral resource with coal above and aluminum below. The mining of both coal and bauxite seams generates gangue, and the extraction of alumina from bauxite produces industrial solid waste such as red mud. Large quantities of gangue and red mud cannot be fully and effectively utilized, relying instead on large-scale stockpiling, occupying significant land and causing environmental pollution. Simultaneously, the large amount of gangue generated during coal seam excavation and mining is transported back to the surface via transfer conveyors and other machinery, increasing the pressure on mine transportation. Furthermore, during the combined coal and aluminum mining process, the rock strata activities of both coal and aluminum mining affect each other. Maintaining the stability of the surrounding rock during combined mining, preventing fissures from connecting to aquifers, and improving the recovery rate of the bauxite seam are all urgent problems that need to be solved. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention proposes a green co-mining method for coal and aluminum, used for mining coal seams and underlying bauxite seams, comprising the following steps:

[0004] S1: A transport roadway is arranged along the strike in the rock strata between the coal seam and the bauxite seam;

[0005] From the main haulage roadway, a coal seam haulage gate is constructed into the coal seam. From the coal seam haulage gate, a coal seam incline is constructed along the dip of the coal seam. Several longwall mining faces are arranged on both sides of the coal seam incline to form a coal seam mining area. The mining faces on the same side of the coal seam mining area are spaced apart along the dip by leaving protective coal pillars. The coal seam incline includes at least a coal seam haulage incline and a coal seam track incline.

[0006] A bauxite transport gate is constructed from the main transport roadway toward the bauxite layer. From the bauxite transport gate, a bauxite incline is constructed along the dip of the bauxite layer within the bauxite layer. Several longwall bauxite mining faces are arranged on both sides of the bauxite incline to form a bauxite mining area. The bauxite mining faces in the bauxite mining area are usually arranged sequentially along the dip. The bauxite incline includes at least a bauxite transport incline and a bauxite track incline.

[0007] The bauxite mining area is located below the coal seam mining area;

[0008] S2: Construct a gangue bin between the coal seam transport uphill and the coal seam transport gate; construct a gangue storage chamber between the bauxite transport uphill and the bauxite transport gate, the gangue storage chamber including a first gangue storage chamber and a second gangue storage chamber; the gangue bin is connected to the gangue storage chamber via a chute;

[0009] S3: The longwall caving method is used to mine the coal face in the coal seam mining area from top to bottom in an inclined direction; the gangue generated during the mining and tunneling process is transported to the gangue bin and crushed and screened by crusher and screening machine. Large-diameter gangue is discharged from the chute and stored in the first gangue storage chamber, and small-diameter gangue is discharged from the chute and stored in the second gangue storage chamber.

[0010] S4: Proceed to the next coal mining face. At this time, the aluminum mining face below the previous coal mining face will be mined using the backfilling mining process. Along the dip, the mining progress of the aluminum mining face lags behind that of one coal mining face.

[0011] Preferably, in step S1, no pillars are set between the aluminum mining faces on the same side, or only pillars with a small width are left.

[0012] Preferably, in step S4, if the distance between the coal seam and the bauxite layer is relatively close, a grouting borehole is drilled on the ground to the coal seam goaf. The tailings produced from the coal washing and beneficiation, as well as the red mud and phosphogypsum produced from the alumina refining of the mined bauxite, are mixed with water in a set ratio at a ground mixing station, and then pumped to the coal seam goaf through the grouting borehole using a ground pumping station.

[0013] Preferably, in step S4, the backfilling mining process of the aluminum mining face is as follows:

[0014] a. A transport tunnel is excavated along the strike from the bauxite transport uphill, and a track tunnel is excavated along the strike from the bauxite track uphill, forming a mining area between the transport tunnel and the track tunnel;

[0015] b. Divide the mining area into several bauxite strips along the strike;

[0016] c. Use the skip mining method to mine bauxite strips. After each bauxite strip is mined, it is immediately backfilled. If the adjacent bauxite strips have already been mined when each bauxite strip is mined, they must be backfilled and the backfill must be stable.

[0017] Preferably, in step a, a protective pillar is left between the mining area and the bauxite track to protect the bauxite track.

[0018] Preferably, in step c, the filling process for each bauxite strip is as follows:

[0019] c1: Construct a sealing wall at the bottom of each mined bauxite strip;

[0020] c2: Large-diameter gangue is transported from the first gangue storage chamber to the track level roadway via a gangue conveyor belt, and then transported by a transfer machine to the bauxite strip after mining.

[0021] c3: Small-diameter gangue is transported from the second gangue storage chamber to the track level roadway via a gangue conveyor belt, and then transported by a transfer machine to the mined bauxite strip.

[0022] Steps c2-c3 are used to form a bottom gangue filling layer in the mined bauxite strip;

[0023] c4: The tailings from the coal washing and beneficiation, along with the red mud and phosphogypsum produced from the alumina refining of the mined bauxite, are transported from the surface to the track level tunnel. They are then mixed with small-diameter gangue transported from the second gangue storage chamber underground, along with water, and stirred in a mixer in the track level tunnel according to a set ratio to form a paste-like filling material. This material is then transported through filling pipelines to the upper part of the bottom gangue filling layer and mixed with the bottom gangue filling layer to form a bauxite strip filling body.

[0024] Preferably, in step c4, the small-diameter gangue has a larger particle size than the tailings, and the small-diameter gangue acts as coarse aggregate.

[0025] Beneficial effects:

[0026] 1. After preliminary crushing and washing of the gangue generated during underground mining, it is stored in the gangue bin to reduce the amount of gangue transported in and out of the mine and reduce the pressure on mine production and transportation.

[0027] 2. The gangue produced from surface washing and the red mud produced from aluminum refining in alumina plants are used as backfill materials to fill the bauxite layer, realizing the reuse of solid waste, reducing backfilling costs, and reducing the environmental damage caused by the accumulation of gangue and red mud on the ground.

[0028] 3. Bauxite mining adopts backfilling mining, and the mining system is rationally designed to achieve green efficiency and extend the service life of the mining area without affecting the normal mining of coal seams. Attached Figure Description

[0029] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof.

[0030] Figure 1 This is a schematic diagram of the overall structure of the coal-aluminum green co-mining roadway layout of the present invention;

[0031] Figure 2 This is a schematic cross-sectional view of the working face arrangement of the coal seam and bauxite layer in the green coal-aluminum co-mining of this invention;

[0032] Figure 3 This is a schematic diagram of the layout of the bauxite layer backfilling mining face in the green coal-aluminum co-mining of this invention;

[0033] Figure 4This is a schematic diagram of the filling tendency of the filling strip in the green co-mining of coal and aluminum in this invention;

[0034] In the attached diagram: 1-Main shaft; 2-Auxiliary shaft; 3-Bottom yard; 4-Main haulage roadway; 5-Coal seam haulage gate; 6-Coal seam incline; 7-Coal mining face; 8-Protective coal pillar; 9-Alumina seam haulage gate; 10-Bauxite incline; 11-Alumina mining face; 12-Gallite bin; 13-Coal bin; 14-Gallite storage chamber; 15-Alumina bin; 16-Pass shaft; 17-Handling level roadway; 18-Track level roadway; 19-Securing pillar; 20-Bauxite strip; 21-Goaf; 22-Sealing wall; 23-Gallite filling layer; 24-Paste filling material; 25-Surface mixing station; 26-Surface pump station; 27-Grouting borehole. Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] like Figure 1-4 As shown, this invention proposes a green co-mining method for coal and aluminum, used for mining coal seams and underlying bauxite seams, comprising the following steps:

[0037] S1: As Figure 1-2 As shown, a main shaft 1 and an auxiliary shaft 2 are arranged, and a bottom yard 3 is set at the bottom of the main shaft 1 and the auxiliary shaft 2; a transport roadway 4 is arranged along the strike and connected to the bottom yard 3; the transport roadway 4 is arranged in the rock strata between the coal seam and the bauxite seam;

[0038] From the main transport roadway 4, construct the coal seam transport gate 5 towards the coal seam. From the coal seam transport gate 5, construct the coal seam incline 6 along the dip of the coal seam within the coal seam. On both sides of the direction of the coal seam incline 6... Figure 1 Several longwall mining faces 7 are arranged on the left and right sides of the coal seam to form a coal seam mining area. Each mining face 7 is arranged along the strike, and the mining faces 7 on the same side are spaced apart along the dip. Protective coal pillars 8 are set between the mining faces on the same side; the coal seam incline 6 includes at least a coal seam transport incline ( Figure 1 (middle left) and coal seam track uphill ( Figure 1 (Middle right); The connection method between the longwall mining face 7 and the coal seam uphill face 6 is well known in the field and will not be described in detail here.

[0039] From the main transport roadway 4, a bauxite transport gate 9 is constructed towards the bauxite layer. From the bauxite transport gate 9, a bauxite incline 10 is constructed along the dip of the bauxite layer within the bauxite layer. Several longwall mining faces 11 are arranged on both sides of the bauxite incline 10. Figure 1 The left and right sides of the middle section form a bauxite mining area. Each bauxite mining face 11 is arranged along the strike, and the bauxite mining faces 11 on the same side are arranged sequentially along the dip. Pillars may not be set between bauxite mining faces on the same side, or they may be arranged as follows. Figure 1 , Figure 3 The diagram shows a narrow pillar; the bauxite uphill section includes at least bauxite transportation uphill. Figure 1 (middle left) and bauxite track uphill ( Figure 1 (Middle right); The connection method between the longwall aluminum mining face 11 and the bauxite uphill 10 is existing technology and will not be described in detail here; This invention... Figure 3 An embodiment is provided.

[0040] The bauxite mining area is located below the coal seam mining area.

[0041] S2: Construct a gangue bin 12 and a coal bin 13 between the coal seam transport uphill and the coal seam transport gate 6. The coal bin 13 is used to store coal transported from the coal seam transport uphill, and the gangue bin 12 is used to store gangue transported from the coal seam transport uphill.

[0042] A coal storage chamber 14 and an aluminum silo 15 are constructed between the bauxite transport uphill and the aluminum layer transport gate 9. The aluminum silo 15 is used to store bauxite transported from the bauxite transport uphill. The coal storage chamber 14 includes a first coal storage chamber and a second coal storage chamber.

[0043] The gangue bin 12 is connected to the gangue storage chamber 14 via a chute 16. The gangue storage chamber 14 is used to store the gangue transported out of the gangue bin 12.

[0044] S3: The coal mining faces 7 in the coal seam mining area are mined sequentially from top to bottom along the dip direction, starting with the uppermost coal mining face 7. Figure 2 The leftmost coal face 7); then the next adjacent coal face 7 is mined. Figure 2 The leftmost coal mining face 7 and the rightmost coal mining face 7); Coal mining face 7 adopts the longwall caving method, and after mining, a goaf 21 is formed;

[0045] The gangue generated during the mining and tunneling process of the coal face 7 will be transported to the gangue bin 12 and crushed and screened using a crusher and a screening machine. Large-diameter gangue will be discharged from the chute 16 and stored in the first gangue storage chamber, while small-diameter gangue will be discharged from the chute 16 and stored in the second gangue storage chamber.

[0046] S4: When the next coal mining face 7 is being mined, the strata above the previous coal mining face 7 are basically stable after the previous coal mining face 7 is mined. The aluminum mining face 11 below the previous coal mining face 7 is mined using the backfilling mining process. That is, along the dip, the mining progress of the aluminum mining face 11 is lagging behind one coal mining face 7. When the nth coal mining face 7 is being mined, the (n-1)th aluminum mining face 11 is being mined at the same time.

[0047] If the distance between the coal seam and the bauxite layer is close, the mining of the bauxite layer will affect the stabilized coal seam goaf 21. To address this, grouting boreholes 27 can be drilled on the ground to the coal seam goaf 21. The tailings from the coal washing and beneficiation, as well as the red mud and phosphogypsum produced from the alumina refining of the mined bauxite, can be mixed with water in a set ratio at a ground mixing station 25. Then, the mixture can be pumped to the coal seam goaf 21 through the grouting boreholes 27 using a ground pumping station 26.

[0048] The backfilling mining process of the aluminum mining face 11 is as follows:

[0049] a. such as Figure 1 , Figure 3 As shown, a transport level 17 is excavated along the strike from the bauxite transport uphill, and a track level 18 is excavated along the strike from the bauxite track uphill. A mining area is formed between the transport level 17 and the track level 18. A protective pillar 19 is left between the mining area and the bauxite track uphill to protect the bauxite uphill 10.

[0050] b. Divide the mining area into several bauxite strips 20 along the strike, and number them sequentially as 1#, 2#, 3#... The length of each bauxite strip 20 is the width of the mining area, that is, the distance between the transport level 17 and the track level 18. Each bauxite strip 20 is about 5m wide.

[0051] c. Use a skip-mining method to recover bauxite strips 20, immediately backfilling each bauxite strip 20 after it is mined; for example, skip-mining one bauxite strip 20 at a time: first, mine the odd-numbered bauxite strips 20 sequentially, backfilling each one immediately after it is mined, then mine the even-numbered bauxite strips 20 sequentially, backfilling each one immediately after it is mined. If an adjacent bauxite strip 20 has already been mined while a particular bauxite strip 20 is being mined, it must be completely backfilled and the backfill must be stable; alternatively, each time... Two bauxite strips 20 are mined in a skip-mining manner: First, the 3m-2 bauxite strip 20 is mined in sequence, and each bauxite strip 20 is immediately backfilled after mining. Then, the 3m-1 bauxite strip 20 is mined in sequence, and each bauxite strip 20 is immediately backfilled after mining. Then, the 3m bauxite strip 20 is mined in sequence, and each bauxite strip 20 is immediately backfilled after mining. m≥1. If an adjacent bauxite strip 20 has already been mined when each bauxite strip 20 is being mined, it must be backfilled and the backfill must be stable.

[0052] like Figure 3-4 As shown, the filling process for each bauxite strip is as follows:

[0053] c1: Construct a sealing wall 22 at the lower part of each mined bauxite strip 20 (i.e., near the transport tunnel side) to seal the lower part of the mined bauxite strip 20.

[0054] c2: Large-diameter gangue is transported from the first gangue storage chamber to the track level roadway 18 via a gangue conveyor belt, and then transported by a transfer machine to the mined bauxite strip 20.

[0055] c3: Small-diameter gangue is transported from the second gangue storage chamber to the track level roadway 18 via a gangue conveyor belt, and then transported by a transfer machine to the mined bauxite strip 20.

[0056] Through steps c2-c3, a bottom gangue filling layer 23 is formed in the mined bauxite strip 20. The gangue filling layer 23 contains alternating large-diameter and small-diameter crushed stones to improve the compactness of the gangue filling layer 23; or large-diameter gangue and small-diameter gangue can be transported to the mined bauxite strip 20 at the same time according to a set ratio.

[0057] c4: The tailings from the coal washing and beneficiation, along with the red mud and phosphogypsum produced from the alumina refining of the mined bauxite, are transported from the surface to track level tunnel 18. They are then mixed with small-diameter gangue transported from the second gangue storage chamber underground to track level tunnel 18, along with water, and stirred in a mixer in track level tunnel 18 according to a set ratio to form a paste filling material 24. This paste is then transported through filling pipelines to the upper part of the bottom gangue filling layer 23, where it mixes with the bottom gangue filling layer 23 to form a bauxite strip filling body. The small-diameter gangue has a larger particle size than the tailings and acts as coarse aggregate.

[0058] The above description of the disclosed embodiments is presented in a progressive manner to enable those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A green co-mining method for coal and aluminum, used for mining coal seams and underlying bauxite seams, characterized in that, Includes the following steps: S1: A transport roadway is arranged along the strike in the rock strata between the coal seam and the bauxite seam; From the main haulage roadway, a coal seam haulage gate is constructed into the coal seam. From the coal seam haulage gate, a coal seam incline is constructed along the dip of the coal seam. Several longwall mining faces are arranged on both sides of the coal seam incline to form a coal seam mining area. Coal seam mining faces on the same side of the coal seam mining area are spaced apart along the dip by leaving protective coal pillars. The coal seam incline includes at least a coal seam haulage incline and a coal seam track incline. A bauxite transport gate is constructed from the main transport roadway toward the bauxite layer. From the bauxite transport gate, a bauxite uphill is constructed along the dip of the bauxite layer within the bauxite layer. Several longwall bauxite mining faces are arranged on both sides of the bauxite uphill, forming a bauxite mining area. The bauxite mining faces on the same side of the bauxite mining area are arranged sequentially along the dip. The bauxite uphill includes at least a bauxite transport uphill and a bauxite track uphill. The bauxite mining area is located below the coal seam mining area; S2: Construct a gangue bin between the coal seam transport uphill and the coal seam transport gate; construct a gangue storage chamber between the bauxite transport uphill and the bauxite transport gate, the gangue storage chamber including a first gangue storage chamber and a second gangue storage chamber; the gangue bin is connected to the gangue storage chamber via a chute; S3: The longwall caving method is used to mine the coal face in the coal seam mining area from top to bottom in an inclined direction; the gangue generated during the mining and tunneling process is transported to the gangue bin and crushed and screened by crusher and screening machine. Large-diameter gangue is discharged from the chute and stored in the first gangue storage chamber, and small-diameter gangue is discharged from the chute and stored in the second gangue storage chamber. S4: Proceed to the next coal mining face. At this time, the aluminum mining face below the previous coal mining face will be mined using the backfilling mining process. Along the dip, the mining progress of the aluminum mining face lags behind that of one coal mining face. The backfilling mining process of the aluminum mining face is as follows: a. A transport tunnel is excavated along the strike from the bauxite transport uphill, and a track tunnel is excavated along the strike from the bauxite track uphill, forming a mining area between the transport tunnel and the track tunnel; b. Divide the mining area into several bauxite strips along the strike; c. Use the skip mining method to mine bauxite strips. After each bauxite strip is mined, it is immediately backfilled. If the adjacent bauxite strips have already been mined when each bauxite strip is mined, they must be backfilled and the backfill must be stable.

2. The green co-mining method for coal and aluminum according to claim 1, characterized in that, In step S1, no pillars are set between aluminum mining faces on the same side, or only pillars with a small width are left.

3. The green co-mining method for coal and aluminum according to claim 1, characterized in that, In step S4, if the distance between the coal seam and the bauxite layer is close, a grouting borehole is drilled on the ground to the coal seam goaf. The tailings produced from the coal washing and beneficiation, as well as the red mud and phosphogypsum produced from the alumina refining of the mined bauxite, are mixed with water in a set ratio at a ground mixing station, and then pumped to the coal seam goaf through the grouting borehole using a ground pumping station.

4. The green co-mining method for coal and aluminum according to claim 1, characterized in that, In step a, a protective pillar is left between the mining area and the bauxite track to protect the bauxite uphill.

5. The green co-mining method for coal and aluminum according to claim 1 or 4, characterized in that, In step c, the filling process for each bauxite strip is as follows: c1: Construct a sealing wall at the bottom of each mined bauxite strip; c2: Large-diameter gangue is transported from the first gangue storage chamber to the track level roadway via a gangue conveyor belt, and then transported by a transfer machine to the bauxite strip after mining. c3: Small-diameter gangue is transported from the second gangue storage chamber to the track level roadway via a gangue conveyor belt, and then transported by a transfer machine to the mined bauxite strip. Steps c2-c3 are used to form a bottom gangue filling layer in the mined bauxite strip; c4: The tailings from the coal washing and beneficiation, along with the red mud and phosphogypsum produced from the alumina refining of the mined bauxite, are transported from the surface to the track level tunnel. They are then mixed with small-diameter gangue transported from the second gangue storage chamber underground, along with water, and stirred in a mixer in the track level tunnel according to a set ratio to form a paste-like filling material. This material is then transported through filling pipelines to the upper part of the bottom gangue filling layer and mixed with the bottom gangue filling layer to form a bauxite strip filling body.

6. The green co-mining method for coal and aluminum according to claim 5, characterized in that, In step c4, the small-diameter gangue has a larger particle size than the tailings, and the small-diameter gangue acts as coarse aggregate.

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