Precious metal mine underground filling structure and filling construction method

Abstract

The invention discloses a precious metal mine underground filling structure and a filling construction method, and relates to the technical field of underground mine mining. The device comprises a filling access road and an adjacent construction access road, a sealing plate wall is arranged at the starting end of the filling access road, a top plate is installed at the top of the sealing plate wall, a filling pipeline is hung at the bottom of the top plate, and an anti-explosion protection layer is arranged on the side, close to the adjacent construction access road, of the filling access road. A conical waste rock pile is stacked in the filling access, and a bottom drainage channel is formed in the conical waste rock pile. According to the method, rapid water filtration of the filling slurry can be achieved, a cementing material is retained and prevented from being lost in the slurry dehydration process, surface layer pulverization and blasting damage caused by the influence of the carbonization effect of the filling body are avoided under the protection of the anti-explosion protection layer, the integrity of the filling body is maintained, the safety of the recovery operation is improved, and the recovery efficiency is improved. And more importantly, the loss and dilution of precious metal ores are obviously reduced.

Description

Technical Field

[0001] The invention relates to the technical field of underground mining, and in particular to an underground filling structure and a filling construction method of a precious metal mine. Background Art

[0002] In modern mining, especially in the mining process of precious metal mines, in order to improve resource recovery rate, ensure the safety and environmental friendliness of mines, underground filling technology has gradually become one of the indispensable technologies in mining engineering. By filling the mine cavity, underground filling technology can not only effectively improve the stability of the ore body and reduce the risk of mine collapse, but also reduce the storage of waste and environmental pollution. Especially in the mining process of precious metal mines, due to the complexity of the ore body and the large changes in ore grade, underground filling technology plays an important role in improving mine production efficiency and extending the life cycle of mines.

[0003] The mining process of precious metal mines such as gold produces a large amount of waste rock and ore dressing tailings. The waste rock is mainly formed during the construction process of underground development and mining and approval engineering. The tailings are mainly solid waste formed during the ore dressing process, and are usually backfilled into the underground goaf as aggregate. The disposal of underground waste rock and ore dressing tailings is an important issue that restricts the high quality and sustainable development of mines. The discharge of tailings into tailings ponds not only occupies the surface area but also poses a huge safety hazard to the surrounding surface. Lifting the waste rock to the surface increases the lifting cost. An economical and effective method is to fill the underground waste rock and ore dressing tailings into the underground goaf as filling aggregates, which is widely used by underground mines. In addition, for the mining of precious metal mines, due to the high economic properties of the ore, shallow hole blasting and selective approach are usually adopted. However, when the side wall of the recovery approach is the filling body, the exposed surface of the filling body is affected by carbonization to form a loose layer on the surface, which causes the loss and depletion of precious metal ore after mixing with the ore.

[0004] The Chinese patent with the authorization announcement number CN221823869U discloses a filling structure and filling equipment for the access road in the goaf of an underground mine, including: a filling layer, a hanger, a mesh and a water filter pipe. The filling layer includes a first filling layer and a second filling layer, the first filling layer is used to fill the bottom of the access road, and the second filling layer is used to fill the space between the first filling layer and the top of the access road. The hanger is arranged in the filling layer, and the hanger extends along the height direction of the access road. The mesh is arranged in the filling layer, the mesh is laid flat, and the mesh is tied to the hanger. The water filter pipe is arranged in the filling layer, and one end of the water filter pipe is arranged outside the filling layer. This prior art uses hangers to increase the filling strength of the access road, which makes underground construction difficult, and the outer surface does not have an explosion-proof effect. During mining, it is affected by the blasting force, resulting in the exposed side of the filling body being damaged and falling off. Summary of the invention

[0005] The purpose of the present invention is to solve the above-mentioned problems and provide an underground filling structure and a filling construction method for a precious metal mine.

[0006] In order to achieve the above-mentioned purpose, the present invention specifically adopts the following technical solutions: The underground filling structure of a precious metal mine comprises a filling access and an adjacent construction access. A closed plate wall is arranged at the starting end of the filling access, a roof is installed on the top of the closed plate wall, a filling pipeline is suspended at the bottom of the roof, the outlet of the filling pipeline is higher than the surface of the filling access, an anti-explosion protection layer is arranged on the side of the filling access close to the adjacent construction access, a conical waste rock pile is stacked inside the filling access, and a bottom drainage channel is formed inside the conical waste rock pile.

[0007] Furthermore, the explosion-proof protective layer is formed by cross-stitching an inner geotextile layer and an outer polypropylene woven bag layer.

[0008] Furthermore, the geotextile is a filament needle-punched non-woven fabric, which is water-permeable, but does not penetrate solid particles below 10 μm, and has a thickness of 5-10 cm.

[0009] Furthermore, the polypropylene woven bag is mixed with a flame retardant and is water-permeable.

[0010] Furthermore, the bottom of the explosion-proof protective layer horizontally extends into the filling passage for a distance greater than 30 cm, and the top of the explosion-proof protective layer horizontally extends into the filling passage for a distance greater than 50 cm.

[0011] Furthermore, a board wall auxiliary support is provided on the outer side of the closed board wall.

[0012] Furthermore, the height of the conical waste rock pile is less than 1m, the size of the waste rock blocks does not exceed 20cm, and the triangular cone formed extends outward at its maximum to the side of the filling road.

[0013] Furthermore, a guide groove is provided at the bottom of the top plate, and the guide groove is designed as a fold line. A deceleration part is provided at the position of the guide groove near the middle of the filling inlet, and the spacing of the deceleration parts is smaller than the spacing of the guide grooves. A support part is provided on the outside of the top plate, and a pipe hole is provided inside the support part, and the filling pipeline passes through the pipe hole. The filling pipeline adopts a flexible pipe, and a support groove is provided on the top of the closed plate wall, and the support part is sealed and inserted in the support groove. A mounting ring is fixedly installed on the outside of the filling pipeline, and a hanging part is fixedly installed on the bottom of the mounting ring, and the hanging part is slidably connected in the guide groove. A guide part is provided between the hanging part and the mounting ring, and arc-shaped spring sheets are provided on both sides of the guide part. A pull rope is fixedly connected to the side of the mounting ring away from the support part, and a rope hole is provided on the top of the top plate, and the pull rope passes through the rope hole. An elastic telescopic part is provided in the middle position of the pull rope, and the elastic telescopic part consists of an outer braided corrugated layer and an inner reset elastic rope.

[0014] The underground filling construction method of precious metal mines includes the following steps: S1. After all the ore is mined out of the access road, an empty area to be filled is formed. The scraper transports the underground waste rock into the empty area to be filled and piles it in the middle of the access road to form a conical waste rock pile. A bottom drainage channel is formed inside the waste rock pile to facilitate rapid drainage of tailings filling slurry. S2. A flexible composite anti-explosion protective layer is set close to the mine wall of the filling access road. The bottom of the unfolded anti-explosion protective layer is pressed under the conical waste rock pile, and the top is fixed on the top plate of the empty area of ​​the filling access road. The tailings filling slurry filling pipeline is hung on the lower surface of the top plate, and a closed plate wall is set up at the starting end of the filling access road; S3. After the preparation work is completed, notify the filling station to start conveying the tailings filling slurry, and convey the tailings filling slurry prepared on the surface to the empty area to be filled underground. The tailings filling slurry continuously infiltrates and fills the gaps in the waste rock pile, and covers the waste rock pile until it fills the entire empty area of ​​the access road. After a certain period of hardening, the inner layer of the anti-explosion protective layer adheres to the filling body to form a whole; S4. When mining adjacent construction approaches, as the approaches continue to advance, the protected filling body and the anti-explosion protective layer are continuously exposed. The anti-explosion protective layer can effectively mitigate the blasting force and avoid surface powdering caused by exposed carbonization.

[0015] Furthermore, the tailings filling slurry comprises solid tailings, solid-phase cementitious material and liquid-phase water, which is stirred and mixed at a filling preparation station to form a relatively homogeneous slurry. The solid-phase cementitious material is made by mixing slag powder, desulfurized gypsum powder, lime powder and admixtures.

[0016] The beneficial effects of the present invention are as follows: 1. The present invention can achieve rapid filtration of filling slurry and retain cementitious materials to avoid loss during the slurry dehydration process. The filling body is protected by the anti-explosion protective layer to avoid surface pulverization and blasting damage caused by carbonization, thereby maintaining the integrity of the filling body and improving the safety of the recovery operation. More importantly, the loss and depletion of precious metal ores are significantly reduced. At the same time, mine waste rock and tailings solid waste are disposed of and utilized on a large scale, which has important safety, economic and environmental benefits.

[0017] 2. The present invention provides a guide groove on the lower surface of the top plate so that the filling pipeline can move in a zigzag shape under the top plate, and evenly grout the inside of the filling inlet. Then, by setting a deceleration part, the filling pipeline moves more slowly in the middle position, so that the slurry stays in the conical waste rock pile for a long time, and the slurry can fully flow into the crushed stone pile, and the grouting is even. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of filling construction of the present invention; Figure 2This is a schematic diagram of the filling access construction of the present invention; Figure 3 It is a schematic diagram of the structure of the explosion-proof protective layer of the present invention; Figure 4 It is a schematic diagram of the top plate installation structure of the present invention; Figure 5 It is a schematic diagram of the top plate and filling pipeline structure of the present invention; Figure 6 It is a schematic diagram of the local structure of the filling pipeline of the present invention; Figure 7 It is a structural schematic diagram of the hanging member of the present invention.

[0019] Figure numerals: 1. conical waste rock pile; 2. bottom drainage channel; 3. explosion-proof protective layer; 4. filling pipeline; 41. mounting ring; 42. hanging part; 43. guide part; 44. arc-shaped spring piece; 45. pull rope; 46. elastic telescopic part; 5. top plate; 51. guide groove; 52. speed reduction part; 53. support part; 61. closed board wall; 62. board wall auxiliary support; 7. adjacent construction access; 8. geotextile; 9. polypropylene woven bag. DETAILED DESCRIPTION

[0020] To make the purpose, technical solution and advantages of the embodiments of the present invention more clear, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0021] like Figure 1-Figure 7 As shown, the underground filling structure of the precious metal mine includes a filling access road and an adjacent construction access road 7. A closed plate wall 61 is arranged at the starting end of the filling access road. A top plate 5 is installed on the top of the closed plate wall 61. A filling pipeline 4 is suspended at the bottom of the top plate 5. The outlet of the filling pipeline 4 is higher than the surface of the filling access road. An anti-explosion protection layer 3 is arranged on the side of the filling access road close to the adjacent construction access road 7. A conical waste rock pile 1 is piled inside the filling access road, and a bottom drainage channel 2 is formed inside the conical waste rock pile 1.

[0022] The invention can not only fully consume the underground waste rock and ore dressing tailings of precious metal mines, but also effectively reduce the loss and dilution of precious metal ores, and has important safety, economic and environmental protection benefits.

[0023] On the basis of the above embodiment, the explosion-proof protective layer 3 is formed by cross-stitching an inner geotextile 8 and an outer polypropylene woven bag 9 .

[0024] The geotextile 8 has good strength and toughness, and can provide a certain bearing capacity and tensile resistance. As the inner layer material, it can provide basic support to prevent the inner materials from loosening or breaking. The polypropylene woven bag 9 has the characteristics of tensile resistance and tear resistance. As the outer layer material, it can enhance the stability of the overall structure and the explosion protection capability. The cross-stitching method combines the inner and outer layers more closely, which can effectively disperse the external pressure and explosion impact force, and avoid the outer layer material from falling off or shifting.

[0025] In the explosion-proof design, the combination of the inner and outer layers can effectively mitigate the shock waves and pressure generated by the explosion. The strength of the geotextile 8 and the tear resistance of the polypropylene woven bag 9 are combined to improve the explosion resistance of the protective layer and reduce the damage to the surrounding environment or personnel caused by the fragments and impact generated by the explosion. The outer layer structure of the polypropylene woven bag 9 has a certain elasticity and can absorb part of the impact force, while the geotextile 8 as the inner layer can resist the explosion pressure, thereby improving the overall explosion-proof effect.

[0026] On the basis of the above embodiment, the geotextile 8 is a filament needle-punched non-woven fabric, which is water-permeable but does not penetrate solid particles below 10 μm, and has a thickness of 5-10 cm.

[0027] Filament needle-punched nonwoven fabrics have excellent water permeability, allowing water to pass freely while effectively avoiding water accumulation or seepage problems. For applications that require drainage or soil stabilization (such as foundation pits, drainage systems, etc.), water permeability is a key feature that helps maintain the stability of the structure and avoid the pressure caused by water accumulation. This geotextile can effectively prevent solid particles below 10μm from passing through, which is very important for underground mining engineering applications. Preventing fine particles from entering the system can maintain the stability of the soil or materials, and avoid particles clogging the drainage system or causing structural failure; filament needle-punched nonwoven fabrics can make the fibers tightly connected through the needle-punching process, giving the geotextile higher tensile strength and wear resistance, which means that the geotextile is stronger when subjected to external forces, not easy to break, and can be used stably for a long time.

[0028] Furthermore, the outer polypropylene woven bag 9 is mixed with flame retardant and is water-permeable and has high temperature resistant and flame retardant properties.

[0029] On the basis of the above embodiment, the anti-explosion protection layer 3 may further include: the bottom of the anti-explosion protection layer 3 may extend horizontally into the filling passage by more than 30 cm, and the top of the anti-explosion protection layer 3 may extend horizontally into the filling passage by more than 50 cm.

[0030] Through the extended design, it is possible to effectively prevent the explosion wave from bypassing the edge of the explosion-proof protective layer 3 and directly affecting the target in the protection area, especially the edge area or the part susceptible to the explosion wave. The extended filling area can block and disperse the explosion energy bypassing the edge to ensure comprehensive protection.

[0031] On the basis of the above embodiment, it also includes that a panel wall auxiliary support 62 is provided on the outer side of the closed panel wall 61 to increase the support strength of the closed panel wall 61.

[0032] Furthermore, the height of the conical waste rock pile 1 is less than 1m, the size of the waste rock blocks does not exceed 20cm, and the formed triangular cone extends outward to the side of the filling road at the maximum, with good stacking effect and convenient for subsequent grouting.

[0033] On the basis of the above embodiment, the top plate 5 is further provided with a guide groove 51 at the bottom, the guide groove 51 is designed as a broken line, a deceleration portion 52 is provided at the position of the guide groove 51 near the middle of the filling inlet, the spacing of the deceleration portion 52 is smaller than the spacing of the guide groove 51, a support portion 53 is provided on the outside of the top plate 5, a pipe hole is provided inside the support portion 53, the filling pipeline 4 passes through the pipe hole, the filling pipeline 4 adopts a flexible pipeline, a support groove is provided on the top of the closed plate wall 61, the support portion 53 is sealed and plugged into the support groove, and the outside of the filling pipeline 4 is fixedly installed with A mounting ring 41 is provided, and a hanging part 42 is fixedly installed at the bottom of the mounting ring 41. The hanging part 42 is slidably connected in the guide groove 51. A guide part 43 is provided between the hanging part 42 and the mounting ring 41. Arc-shaped spring pieces 44 are provided on both sides of the guide part 43. A pull rope 45 is fixedly connected to the side of the mounting ring 41 away from the support part 53. A rope hole is provided at the top of the top plate 5. The pull rope 45 passes through the rope hole. An elastic telescopic part 46 is provided in the middle position of the pull rope 45. The elastic telescopic part 46 consists of an outer woven corrugated layer and an inner reset elastic rope.

[0034] Due to the long length of the filling route, the fixed grouting of the filling pipeline 4 is not only uneven, but also requires a long grouting time, and it is difficult to manually enter the auxiliary operation underground in the mine. Therefore, through the arrangement of this embodiment, when grouting, first pull the pull rope 45, and the pull rope 45 drives the filling pipeline 4 outlet to move through the mounting ring 41, and under the guidance of the hanging part 42 and the guide groove 51, the movement trajectory of the filling pipeline 4 outlet is a broken line, so that the filling pipeline 4 outlet can sweep to every corner of the filling route to ensure uniform filling. When the filling pipeline 4 outlet moves to the end of the filling route, the filling pipeline 4 is pulled in the opposite direction. Therefore, by repeatedly pulling the pull rope 45 and the filling pipeline 4, the slurry can be evenly filled in the filling route in layers, and the filling is uniform.

[0035] At the same time, since there is a conical waste rock pile 1 in the middle of the filling access road, more slurry is needed in the middle position, and the slurry needs to stay for a long time before it can be fully filled into the conical waste rock pile 1. Therefore, through the setting of the deceleration part 52, when the hanging member 42 moves to the deceleration part 52, the arc-shaped spring piece 44 on the guide member 43 is squeezed by the deceleration part 52, and the friction between the two increases. At this time, the friction force is greater than the elastic force of the elastic telescopic part 46, and the elastic telescopic part 46 is stretched. At this time, the outlet of the filling pipeline 4 is suspended just above the conical waste rock pile 1. When the elastic telescopic part 46 is fully stretched, the guide member 43 is pulled out of the deceleration part 52, and the arc-shaped spring piece 44 is restored. Under the action of the elastic force of the elastic telescopic part 46, the hanging member 42 will quickly slide in the guide groove 51 to the roadside close to the filling access road, and the outlet of the filling pipeline 4 will sweep quickly, less slurry is required at the edge, and the slurry is swept in evenly, so it can be ensured that each layer of slurry can be completely filled into the conical waste rock pile 1.

[0036] Therefore, by adopting the arrangement of this embodiment, a simple structure can be suitable for grouting of underground filling access roads in precious metal mines, with high grouting efficiency and uniform grouting.

[0037] The underground filling construction method of precious metal mines includes the following steps: S1. After all the ore in the access road is mined, an empty area of ​​the access road to be filled is formed. The scraper transports the underground waste rock into the empty area of ​​the access road to be filled, and piles it in the middle of the access road to be filled to form a conical waste rock pile 1, and a bottom drainage channel 2 is formed inside the waste rock pile to facilitate rapid drainage of tailings filling slurry; S2, a flexible composite structure explosion-proof protective layer 3 is set close to the mine wall of the filling access road. The bottom of the unfolded explosion-proof protective layer 3 is pressed under the conical waste rock pile 1, and the top is fixed on the top plate 5 of the empty area of ​​the filling access road. The tailings filling slurry filling pipeline 4 is hung on the lower surface of the top plate 5, and a closed plate wall 61 is set up at the starting end of the filling access road; S3. After the preparation work is completed, notify the filling station to start conveying the tailings filling slurry, and convey the tailings filling slurry prepared on the surface to the empty area to be filled underground. The tailings filling slurry continuously infiltrates and fills the gaps in the waste rock pile, and covers the waste rock pile until it fills the entire empty area of ​​the access road. After a certain period of hardening, the inner layer geotextile 8 of the anti-explosion protective layer 3 adheres to the filling body to form a whole; S4. When mining the adjacent construction approach 7, as the approach continues to advance forward, the protected filling body together with the anti-explosion protection layer 3 is continuously exposed. The anti-explosion protection layer 3 can effectively mitigate the blasting force and avoid surface pulverization caused by exposed carbonization.

[0038] On the basis of the above embodiment, the tailings filling slurry comprises solid tailings, solid phase cementitious material and liquid phase water, and is a relatively homogeneous slurry formed by stirring and mixing at a filling preparation station, wherein the solid phase cementitious material is made by mixing slag powder, desulfurized gypsum powder, lime powder and an admixture, the slump of the tailings filling slurry is not less than 25 cm, and the specific surface area of ​​the slag powder is not less than 450 m 2 / kg.

[0039] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one 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 present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An underground filling structure for a precious metal mine, comprising a filling approach and an adjacent construction approach (7), characterized in that: A closed plate wall (61) is provided at the starting end of the filling access road, a top plate (5) is installed on the top of the closed plate wall (61), a filling pipeline (4) is suspended at the bottom of the top plate (5), the outlet of the filling pipeline (4) is higher than the filling access road surface, an anti-explosion protection layer (3) is provided on the side of the filling access road close to the adjacent construction access road (7), a conical waste rock pile (1) is piled inside the filling access road, and a bottom drainage channel (2) is formed inside the conical waste rock pile (1).

2. The underground filling structure of a precious metal mine according to claim 1 is characterized in that: The explosion-proof protective layer (3) is formed by cross-stitching an inner geotextile (8) and an outer polypropylene woven bag (9).

3. The underground filling structure of a precious metal mine according to claim 2 is characterized in that: The geotextile (8) is a filament needle-punched non-woven fabric that is water-permeable but impermeable to solid particles below 10 μm, and has a thickness of 5-10 cm.

4. The underground filling structure of a precious metal mine according to claim 3 is characterized in that: The polypropylene woven bag (9) is mixed with a flame retardant and is water-permeable.

5. The underground filling structure of a precious metal mine according to claim 4, characterized in that: The bottom of the explosion-proof protective layer (3) extends horizontally into the filling passage for a distance greater than 30 cm, and the top extends horizontally into the filling passage for a distance greater than 50 cm.

6. The underground filling structure of a precious metal mine according to claim 5, characterized in that: The outer side of the closed board wall (61) is provided with a board wall auxiliary support (62).

7. The underground filling structure of a precious metal mine according to claim 6, characterized in that: The cone-shaped waste rock pile (1) has a height of less than 1 m, a waste rock block size of no more than 20 cm, and the formed triangular cone extends outwards to the maximum extent of the side wall of the filling entrance road.

8. The underground filling structure of a precious metal mine according to claim 7, characterized in that: A guide groove (51) is provided at the bottom of the top plate (5), and the guide groove (51) is designed as a broken line. A deceleration portion (52) is provided at a portion of the guide groove (51) close to the middle of the filling inlet, and the spacing of the deceleration portion (52) is smaller than the spacing of the guide groove (51). A support portion (53) is provided on the outside of the top plate (5), and a pipe hole is provided inside the support portion (53), and the filling pipeline (4) passes through the pipe hole. The filling pipeline (4) adopts a flexible pipeline. A support groove is provided on the top of the closed plate wall (61), and the support portion (53) is sealed and plugged into the support groove. A mounting ring (41) is fixedly installed on the outside of the filling pipeline (4). A hanging member (42) is fixedly mounted on the bottom of the mounting ring (41), and the hanging member (42) is slidably connected in the guide groove (51). A guide member (43) is provided between the hanging member (42) and the mounting ring (41), and arc-shaped spring sheets (44) are provided on both sides of the guide member (43). A pull rope (45) is fixedly connected to the side of the mounting ring (41) away from the support portion (53). A rope hole is provided at the top of the top plate (5), and the pull rope (45) passes through the rope hole. An elastic telescopic portion (46) is provided in the middle of the pull rope (45), and the elastic telescopic portion (46) is composed of an outer braided corrugated layer and an inner reset elastic rope.

9. A method for underground filling construction in a precious metal mine, using the underground filling structure of a precious metal mine as claimed in any one of claims 1 to 8, characterized in that: The following steps are involved: S1. After all the ore in the access road is mined, an empty area of ​​the access road to be filled is formed. The scraper transports the underground waste rock into the empty area of ​​the access road to be filled and piles it in the middle of the access road to be filled to form a conical waste rock pile (1). A bottom drainage channel (2) is formed inside the waste rock pile to facilitate rapid drainage of the tailings filling slurry. S2, a flexible composite structure explosion-proof protective layer (3) is arranged close to the mine wall of the filling access road, the bottom of the unfolded explosion-proof protective layer (3) is pressed under the conical waste rock pile (1), and the top is fixed on the top plate (5) of the empty area of ​​the filling access road, the tailings filling slurry filling pipeline (4) is hung on the lower surface of the top plate (5), and a closed plate wall (61) is erected at the starting end of the filling access road; S3. After the preparation work is completed, the filling station is notified to start conveying the tailings filling slurry, and the tailings filling slurry prepared on the surface is conveyed to the empty area to be filled underground. The tailings filling slurry continuously infiltrates and fills the gaps in the waste rock pile, and covers the waste rock pile until it fills the entire empty area of ​​the access road. After a certain period of hardening, the inner layer of the anti-blast protective layer (3) is adhered to the filling body to form a whole; S4. When mining the adjacent construction access road (7), as the access road continues to advance, the protected filling body together with the anti-explosion protection layer (3) is continuously exposed. The anti-explosion protection layer (3) can effectively mitigate the blasting force and avoid surface powdering caused by exposure carbonization.

10. The underground filling construction method of a precious metal mine according to claim 9, characterized in that: The tailings filling slurry comprises solid tailings, solid-phase cementitious materials and liquid-phase water, and is a relatively homogeneous slurry formed by stirring and mixing at a filling preparation station. The solid-phase cementitious materials are made by mixing slag powder, desulfurized gypsum powder, lime powder and admixtures.

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