A method for efficient dewatering of a backfill body by means of a drift mining

Abstract

A kind of efficient dehydration method of access type mining filling body, first control filling height, then fill the remaining space, specifically: 1. First, construct filling retaining wall at the connection of stope and vein, place drainage pipe in filling retaining wall, the joint filtration and drainage system of drainage board, support mesh and geotextile is laid from low to high in stope floor, from low to high;Free water first seeps through geotextile, then through support mesh and drainage board to form drainage channel, finally discharged from stope through drainage pipe, waste rock is poured into stope from the upper part of retaining wall by shovel loader, waste rock accumulation body is formed near retaining wall, and then filling is started;2. After the filling body has a certain strength, lay drainage board, support mesh and geotextile from low to high, form drainage channel at the bottom of filling body, lay support mesh and geotextile integrally to form joint filtration and drainage system, extend retaining wall to stope roof, then fill to stope roof, form drainage channel at the bottom of filling body, at the same time, a certain amount of waste rock is accumulated near the lower retaining wall, and the drainage pipe of lower drainage system flows out through the pores in waste rock accumulation body, which has the advantages of ensuring safety and efficient dehydration.

Description

Technical Field

[0001] The invention relates to the technical field of underground mining, and in particular to a method for efficiently dehydrating an entry-type mining filling body. Background Art

[0002] Tailings filling technology not only solves the problem of hazardous waste treatment in mines, but also effectively controls the ground pressure during underground mining, reduces the loss rate of depletion, and improves the ore recovery rate. Therefore, it has become one of the main technical means for underground mining. However, since the average particle size of tailings is generally between 50 and 100 μm, it is difficult to dehydrate and is prone to mixing and slurrying, which causes the following three problems: (1) Excessive free water reduces the strength of the filling body, cannot effectively support the surrounding rock, affects the subsequent mining process, and increases the recovery time; (2) The filling body is prone to collapse when it cannot be effectively dehydrated, and the detached filling body is mixed into the ore pile, which increases the ore depletion rate and increases the cost and difficulty of mineral processing; (3) The filling body is prone to mixing and slurrying during dehydration, affecting the underground production environment and safety operations.

[0003] The above problems are not solved: Chinese patent CN210660207U discloses a method for improving the dehydration technology of the filling body by setting up a special dehydration shaft and connecting it to the lower tunnel, but the patent requires a tunnel at the bottom of the mining area, and it is difficult to set up a special shaft in the mining area; Chinese patent CN105179008A discloses a method for increasing the dehydration of the filling body by laying a water filter pipe in the goaf, but the water filter pipe of this invention requires special fixation and has a limited contact area with the filling body, so its dehydration effect is limited; Chinese patent CN206816297U discloses a method of using waste rock as a filter layer at the bottom of the mining area to promote the dehydration of the filling body, but the waste rock is difficult to lay flat, the cost is high, and the pores are large, which can easily lead to the loss of filling body particles, affect the strength of the filling body, and pollute the underground environment.

[0004] Therefore, in the application of backfill mining technology, especially for the approach-type backfill mining with high turnover requirements, it is of great significance to develop an efficient dehydration method for the backfill body. Summary of the Invention

[0005] The task of the present invention is to overcome the deficiencies of the prior art and provide a method for efficiently dehydrating a filling body by means of an approach type mining method, which can ensure safety and achieve efficient dehydration.

[0006] The task of the present invention is accomplished by the following technical solutions:

[0007] A highly efficient dehydration method for road mining filling bodies. After road mining is completed, the filling height is first controlled to about 1.5m, and then the remaining space is filled. The specific steps and conditions are as follows:

[0008] Step 1: First, build a 1.7m high and 500mm thick filling retaining wall at the junction of the stope and the through-vein. A 700mm long drainage pipe is built into the filling retaining wall, with about 200mm of drainage pipe leaking out. The stope floor is leveled to form a high inside and low outside with a slope of 2-5‰. Then, drainage boards, support meshes and geotextiles are laid from bottom to top to form a combined filtration and drainage system. The boundaries between the geotextiles overlap by 10-20cm, which can prevent fine particles from passing through the geotextiles, avoid "mixing and slurry leakage", reduce the strength of the filling body and pollute the underground environment. Free water first infiltrates through the geotextiles, then drains through the drainage channel formed by the support mesh and drainage boards, and finally discharges the stope through the drainage pipe. After the combined filtration and drainage system is formed, the waste rock is poured into the stope from the upper part of the retaining wall by a scraper. After a waste rock pile about 1.5m high is formed near the retaining wall, filling begins. The filling height is controlled at about 1.5m.

[0009] Step 2: After the filling body has a certain strength, drainage boards, support meshes and geotextiles are laid on it from bottom to top to form a drainage channel at the bottom of the filling body. The drainage boards enter about 1 / 3 of the waste rock area, and the support meshes and geotextiles are laid as a whole to form a joint filtration and drainage system. The retaining wall is extended to the top of the mining area, and then filled to the top of the mining area to form a drainage channel at the bottom of the filling body. At the same time, in order to efficiently discharge the filtered water of the upper filling body, a certain amount of waste rock is piled near the lower retaining wall, which is introduced into the lower drainage system through the pores in the waste rock accumulation body and then efficiently discharged from the drainage pipe.

[0010] Compared with the prior art, the present invention has the following advantages or effects:

[0011] (1) A combined filtration and drainage system is set at the bottom of each step, which greatly increases the internal drainage system of the filling body and facilitates the efficient dehydration of the filling body;

[0012] (2) The drainage system can effectively increase the contact area between the filling and the drainage system, and more efficiently discharge the water released during the solidification process of the filling;

[0013] (3) The drainage board, supporting grid and geotextile form a filtration and drainage system. By utilizing the infiltration function of the geotextile, it can prevent the traditional drainage system such as filter pipes from easily "running away the mix and slurry" and polluting the underground environment.

[0014] (4) The water passage formed by the lower "support mesh + drainage board" can effectively drain water, accelerate the improvement of filling body strength, shorten the filling waiting time and mining and filling cycle time, and improve mining production efficiency;

[0015] (5) The two-layer drainage system of the filling body is effectively connected through the internal pores of the waste rock accumulation body, which not only solves the problem of mine waste rock disposal, but also improves the integrity of the drainage system, thereby further improving the dehydration efficiency of the filling body. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of a high-efficiency dehydration method for mining filling bodies according to the present invention.

[0017] Figure 2 yes Figure 1 The method shown is a schematic diagram of the layout of the "drainage board + support mesh + geotextile" combined filtration and drainage system of the stope floor.

[0018] Figure 3 yes Figure 1 Schematic diagram of filling step one of the method shown.

[0019] Figure 4 It's two Figure 1 Schematic diagram of drainage system layout in step 2 of the method shown.

[0020] Figure 5 yes Figure 1 Schematic diagram of filling in step two of the method shown.

[0021] The symbols in the accompanying drawings represent:

[0022] 1. Drainage board 2. Support mesh 3. Geotextile 4. Drain pipe 5. Backfill retaining wall 6. Stope 7. Through-vein 8. Waste rock accumulation 9. Backfill

[0023] The present invention is described in further detail below with reference to the accompanying drawings. DETAILED DESCRIPTION

[0024] like Figure 1-5 As shown in the figure, a method for efficient dehydration of backfill in road mining is used. After the road mining is completed, the backfill height is first controlled to about 1.5m, and then the remaining space is filled. The specific steps and conditions are as follows:

[0025] Step 1: First, a 1.7m high and 500mm thick filling retaining wall (5) is constructed at the connection between the stope (6) and the through-vein (7). A 700mm long drainage pipe (4) is built into the filling retaining wall (5), and the drainage pipe leaks about 200mm. The bottom plate of the mining area is leveled to form a high inside and low outside with a slope of 2 to 5‰; then, drainage boards (1), support meshes (2) and geotextiles (3) are laid from bottom to top to form a combined filtration and drainage system. The boundaries between the geotextiles (3) overlap by 10 to 20 cm, which can prevent fine particles from passing through the geotextiles (3), avoid "running mix and slurry", reduce the strength of the filling body and pollute the underground environment. Free water first infiltrates through the geotextile (3), then drains through the support mesh (2) and drainage boards (1) to form a drainage channel, and finally discharges the mining area (6) through the drainage pipe (4). After the combined filtration and drainage system is formed, the waste rock is poured from the upper part of the retaining wall (5) into the mining area (6). After a waste rock accumulation body (8) of about 1.5 m high is formed near the retaining wall (5), filling begins, and the filling height is controlled at about 1.5 m.

[0026] Step 2: After the filling body (9) has a certain strength, a drainage board (1), a supporting mesh (2) and a geotextile (3) are laid on it from bottom to top to form a drainage channel at the bottom of the filling body, wherein the drainage board (1) enters about 1 / 3 of the waste rock area, and the supporting mesh (2) and the geotextile (3) are laid as a whole to form a combined filtration and drainage system. The retaining wall (5) is extended to the top plate of the mining area, and then the filling is carried out to the top of the mining area (6) to form a drainage channel at the bottom of the filling body. At the same time, in order to efficiently discharge the filtered water of the upper filling body, a certain amount of waste rock is piled near the lower retaining wall, and is introduced into the lower drainage system through the pores in the waste rock accumulation body, and then efficiently discharged from the drainage pipe.

[0027] The process of the present invention may further be:

[0028] The drainage board (1) is a HDPE 30 plastic drainage board.

[0029] The supporting mesh (2) is a 300g / ㎡ plastic supporting mesh.

[0030] The geotextile (3) is a 400g / ㎡ filament geotextile.

[0031] The specification of the drainage pipe (4) is φ150mm.

[0032] The filling retaining wall (5) is a C25 concrete filling retaining wall.

[0033] Example

[0034] After the end of the road mining, the filling process is divided into two steps. The first step is to control the filling height at about 1.5m, and the second step is to fill the remaining space. The details are as follows: First, a 1.7m high and 500mm thick C25 concrete retaining wall (5) is built at the connection between the mining area and the vein (7). A 700mm long φ150 drainage pipe (4) is built into the retaining wall, and the drainage pipe leaks about 200mm. The mining site floor is leveled to form an inner high and outer low with a slope of 2-5‰, and then HDPE 30 plastic drainage board (1) is laid. After the laying is completed, 300g / ㎡ plastic support mesh (2) and 400g / ㎡ filament geotextile (3) are laid on the upper part of the HDPE 30 drainage board (1). The geotextiles (3) are overlapped by 10-20cm to prevent muddy water from passing through the geotextile (3) and clogging the water filtration system, resulting in poor drainage and reduced water filtration. The HDPE 30 plastic drainage board is combined with the 300g / ㎡ plastic support mesh (2) and the 400g / ㎡ filament geotextile (3) to form a "drainage board + support mesh + geotextile" combined filtration and drainage system. After the geotextile (3) is infiltrated, the 300g / ㎡ plastic support mesh (2) and HDPE The drainage channel formed by the 30 plastic drainage board (1) is used for efficient drainage, and then the water is discharged from the stope (6) through the φ150 drainage pipe (4). Figure 2 As shown in the figure, after the combined filtration and drainage system of "drainage board + support mesh + geotextile" is formed on the stope floor, the waste rock is poured from the upper part of the C25 concrete retaining wall (5) into the stope using a scraper, forming a waste rock accumulation body (8) about 1.5m high near the C25 concrete retaining wall (5), and then filling begins, with the filling height controlled at about 1.5m, as shown in the figure. Figure 3 As shown. After the filling body (9) has a certain strength, the drainage board (1), the support mesh (2), and the geotextile (3) are laid on the upper part in steps, wherein the drainage board (1) only needs to enter the waste rock area for about 1 / 3, and the support mesh (2) and the geotextile (3) are laid as a whole, and the steps are as described above. Figure 4 As shown in FIG, after forming the combined filtration and drainage system of "drainage board + support mesh + geotextile", the C25 concrete retaining wall (5) is extended to the top plate of the stope, and then filled to the top of the stope (6), as shown in FIG. Figure 5 shown.

[0035] As described above, the present invention can be better implemented. The above embodiments are only the best implementation methods of the present invention, but the implementation methods of the present invention are not limited to the above embodiments. Other changes, modifications, replacements, combinations, and simplifications made without departing from the spirit and principles of the present invention should be considered equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A high-efficiency dehydration method for mining filling bodies, characterized in that After the road mining is completed, the filling height is controlled to about 1.5m, and then the remaining space is filled. The specific steps and conditions are as follows: The first step: first, a 1.7m high and 500mm thick filling retaining wall (5) is constructed at the junction of the stope (6) and the through-vein (7), a drainage pipe (4) is built into the filling retaining wall (5), and the stope ground is leveled to form a stope floor with a high inside and a low outside and a slope of 2 to 5‰; then, drainage boards (1), supporting meshes (2) and geotextiles (3) are laid from bottom to top to form a combined filtration and drainage system. Free water first infiltrates through the geotextile (3), and then drains through the drainage channel formed by the supporting mesh (2) and the drainage board (1), and finally is discharged from the stope (6) through the drainage pipe (4). After the combined filtration and drainage system is formed, waste rock is poured from the upper part of the retaining wall (5) into the stope (6) by a scraper, and a waste rock accumulation body (8) of about 1.5m high is formed near the retaining wall (5) and then filling is started. The height of the filling body (9) is controlled to be about 1.5m; Step 2: After the filling body (9) has a certain strength, the drainage board (1), the support mesh (2) and the geotextile (3) are laid on the upper layer from bottom to top to form a combined filtration and drainage system, and a drainage channel is formed at the bottom of the filling body (9), wherein the drainage board (1) enters about 1 / 3 of the waste rock area, and the support mesh (2) and the geotextile (3) are laid as a whole. After the combined filtration and drainage system is formed, the retaining wall (5) is extended to the top plate of the mining area, and then the filling is carried out to the top of the mining area (6), and a drainage channel is formed at the bottom of the filling body. At the same time, in order to efficiently discharge the filtered water of the upper filling body, a certain amount of waste rock is piled near the lower retaining wall, and is introduced into the lower drainage system through the pores in the waste rock accumulation body, and then efficiently discharged from the drainage pipe.

2. The method according to claim 1, wherein The boundaries between the geotextiles (3) overlap by 10 to 20 cm, which can prevent fine particles from passing through the geotextiles (3), avoiding "running of mix and slurry", reducing the strength of the filling body and polluting the underground environment.

3. The method according to claim 1, wherein The drainage board (1) is a HDPE 30 plastic board.

4. The method according to claim 1, wherein The supporting mesh (2) is a 300g / ㎡ plastic mesh.

5. The method according to claim 1, wherein The geotextile (3) is a 400g / ㎡ filament geotextile.

6. The method according to claim 1, wherein The specification of the drainage pipe (4) is φ150mm, 700mm long, and has an external leakage of about 200mm.

7. The method according to claim 1, wherein The filling retaining wall (5) is a C25 concrete filling wall.

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