Structural layout of end-sand-releasing mining site to improve filling and top connection rate

Abstract

The present invention discloses a structural arrangement method for improving the filling connection rate of a sand-released stope at the end, wherein a stope (1) is arranged every 40 to 80 meters along the direction of the ore body, and a spacer (2) is left between two adjacent stopes (1); a filling inclined shaft (3) is arranged in the spacer (2), a filling main pipe (4) is hung on the top plate of the tunnel of the filling inclined shaft (3), a filling connection tunnel (5) is dug from the filling inclined shaft (3) close to the top area of ​​the stope (1) to the stope (1), and a filling branch pipe (6) is placed in the stope (1) to connect the filling branch pipe (6) to the stope (1). ) is connected to the mining area (1); blast holes are drilled in the mining areas of each sub-area in the rock drilling tunnel, and a stepped sand release trough is formed at the top of the mining area (1) by deepening the depth of the blast holes in each area. The sand release point at the end of the rock drilling tunnel is blasted backward, and the ore falls into the rock drilling tunnel and is transported to the chute by a shovel loader for unloading; after the mining of the mining area is completed, the empty area is filled in batches, and the filling connection rate can reach 100%, ensuring the filling effect, effectively controlling the ground pressure activity, and ensuring the safety during the mining process.

Description

Technical Field

[0001] The present invention belongs to the technical field of underground mine filling and mining, and specifically relates to a mining structure layout method for improving the filling and top connection of underground mines. The present invention is particularly suitable for use in mines that adopt an end sand release scheme in filling mining, and can be widely used in underground mining of non-coal solid mines such as ferrous, non-ferrous, and chemical industries. Background Art

[0002] With the continuous exploitation of underground mineral resources, a large number of goafs have been left behind. The goafs are widely distributed, highly concealed, poorly regular, and have large changes in spatial morphology. The roof collapse is difficult to predict, which is a major safety hazard in mines and has caused many mine safety accidents.

[0003] With the advancement of mining technology and the requirements of ecological and environmental protection, backfill mining has become the preferred method for the development and utilization of non-ferrous, ferrous, chemical, gold and other mines. On February 8, 2022, the State Administration of Mine Safety issued a notice on "Guiding Opinions on Strengthening Safety Production in Non-coal Mines", which clearly stated that "newly built metal and non-metal underground mines should adopt backfill mining methods, and those that cannot be adopted must be strictly demonstrated." The biggest advantage of backfill mining is that it can adapt to the mining of various complex and changeable ore bodies with poor surrounding rock conditions, can maximize the recovery rate of mining ore and reduce the depletion rate, and can effectively control ground pressure activities to ensure safe production, while maximizing the protection of the surface environment.

[0004] Based on the filling situation of mines at home and abroad, and considering safety factors, the filling tunnels and sand release pipelines are generally not arranged directly above the goaf, but are mostly arranged in the pillars at one end of the mining area, and the end sand release scheme is adopted. Due to the following main factors, the phenomenon of filling without top connection is common and has never been well solved:

[0005] (1) Consolidation and sedimentation of filling slurry. On the one hand, after the filling slurry fills the empty space, the solid particles gradually sink due to the stratification and segregation of the slurry, forcing most of the water to separate on the surface of the filling body and be removed by runoff, forming a space between the surface of the filling body and the top plate. On the other hand, after the gravity water in the gaps between the solid particles is removed by infiltration, the filling body will also settle. The shrinkage rate of the filling body due to the dehydration and consolidation of the slurry is 5% to 22%.

[0006] (2) Gravity slope of filling slurry. During the flow of filling slurry in the mining area, the aggregate in the filling slurry settles, and a gravity slope will be formed from the sand outlet of the filling pipe at one end to the other end of the mining area. The worse the fluidity of the filling slurry, the greater the slope. When one end of the sand outlet of the filling pipe is connected to the top, the other end of the mining area cannot be completely connected to the top due to the influence of the gravity slope. Taking the slurry concentration of 60-68% as an example, its gravity slope is usually between 4% and 8%. If the length of the filling mining area is 50m, when one end of the sand outlet is completely connected to the top, there is still 2-4m of space at the other end that is not connected to the top.

[0007] (3) The filling slurry concentration is too low and the water filtration speed is slow. Too low slurry concentration can easily lead to segregation and stratification of the filling material, increasing the natural slope angle. At the same time, a large amount of accumulated water is difficult to be discharged in time, occupying the filling space and hindering the filling connection.

[0008] In addition, the discharge of water from the filling pipe, irregularities in the roof of the mine and human factors will affect the filling and top connection effect of the mine. Since the filling and top connection of the mine is directly related to the quality of the filling body and the production safety of the mine, if the filling and top connection is not good, it will cause the filling body or surrounding rock to fall.

[0009] Therefore, how to improve the filling and top connection rate of the mining area, especially to improve the filling and top connection rate of the mining area with sand release at the end, is a problem that mines using the filling method are facing and need to be solved urgently. Summary of the invention

[0010] The purpose of the present invention is to address the technical problems in the prior art such as poor filling connection rate, low filling top rate, low filling body quality and impact on mine production safety. In view of the characteristics of a mine filled with end sand release, a structural layout method is provided which has a high filling connection rate, can effectively control ground pressure activities and ensure the safety of mining production by providing an end-sand release mine structure to improve the filling connection rate.

[0011] To achieve the above-mentioned purpose of the present invention, the structural arrangement mode of the end sand-released mining field of the present invention improves the filling connection rate, arranges a mining field every 40 to 80 meters along the direction of the ore body, arranges 3 to 5 sub-areas in each mining field, and leaves spacers between two adjacent mining fields. The characteristics are: rock drilling tunnels, ore-exit tunnels, and ore-loading access roads are arranged in the lower part of the mining field, the rock drilling tunnels and ore-loading access roads are arranged along the direction of the ore body, and the rock drilling tunnels and ore-loading access roads are connected through the ore-exit tunnels; filling inclined shafts are arranged in the spacers where the ore body roofs at both ends of the mining field are relatively high, the filling main pipe is hung on the tunnel roof of the filling inclined shaft, and a filling communication tunnel is dug from the filling inclined shaft close to the top area of ​​the mining field to the mining field, and the filling branch pipe is connected to the mining field; in the rock drilling tunnel Blast holes are drilled in the tunnel to the mining areas of each zone, and a stepped sand trough is formed on the top of the mining area by deepening the depth of the blast holes zone by zone. The height of the sand trough in each zone is determined according to the different distances between the filling area of ​​the void and the end sand release point and the gravity slope of the filling slurry to ensure that the average slope of the roof of the void is greater than or equal to the gravity slope of the filling slurry to meet the requirements of natural top connection; with the cutting space at the other end of the sand release point at the end of the mining area as the free surface, backward blasting is carried out in the rock drilling tunnel toward the end sand release point, and a shovel loader is used to transport the collapsed ore through the mine exit tunnel and the loading access road to the chute for unloading; after the mining of the mining area is completed, the passage at the bottom of the void is closed, and the void is filled in batches through the filling main pipe and the filling branch pipe.

[0012] The height of the mining area is generally 10 to 100 meters, depending on the thickness and inclination of the ore body, and the width of the pillars is 10 to 20 meters. The slope of the filling inclined shaft is basically consistent with the inclination of the ore body, and the maximum deviation between the slope of the filling inclined shaft and the inclination of the ore body is ≤10%. For example, if the inclination of the ore body is 40°, the slope of the filling inclined shaft is between 36° and 44°. The bottom plate of the filling inclined shaft is 1 to 2 meters higher than the contact zone of the ore body roof.

[0013] Depending on the distance between the empty area filling area and the end sand release point, the farther away from the end sand release point, the smaller the height of the sand release trough above the ore body roof contact zone, until the height of the sand release trough is equal to the ore body roof contact zone.

[0014] In most cases, the mining area can be divided into three zones along the ore body strike: Zone I, Zone II and Zone III. Zone I, Zone II and Zone III are located from far to near the end sand release point. The self-flow slope of the filling slurry is usually between 4% and 8%. The height of the sand release trough in Zone I is equal to the contact zone of the ore body roof, the sand release trough in Zone II is 1.2 to 2.4 meters higher than the contact zone of the ore rock roof; the sand release trough in Zone III is 2.4 to 4.0 meters higher than the contact zone of the ore body roof. If the ore grade of the ore body roof area in Zone I is low, the height of the sand release trough can be lower than the contact zone of the ore body roof, and the height of the sand release trough in Zone II and Zone III can be adjusted accordingly; in addition, the height difference of the sand release trough in each zone can also be smoothly transitioned by controlling the depth of the blasthole.

[0015] The structural arrangement method of the end sand-released mining field of the present invention for improving the filling and top connection rate adopts the above technical scheme, which has the following positive effects:

[0016] 1) The sand release slot is formed by deepening the blastholes. The blastholes in a single stope are increased by 50 to 120 meters, and the cost per ton of ore is increased by less than 0.07 yuan. This controls the filling cost, improves the filling efficiency, and ensures the safety of the operation;

[0017] 2) Use small-section sand troughs, with over-excavation of 260 to 550 m for a single stope 3 , resulting in an increase in the dilution rate. According to statistics, the increase in the dilution rate is less than 1.5%. In addition, the mixed waste rock and other waste rocks produced by dilution are pre-selected as building stones to offset their corresponding costs.

[0018] 3) A stepped sand trough scheme is adopted, and the average slope of the roof of the empty area is greater than the self-flow slope of the slurry. The mining site adopts a phased filling method, and the filling rate can reach 100%, which is more than 10% higher than the traditional filling scheme, effectively controlling the ground pressure activity and ensuring safety during the mining process. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The front view of the structural arrangement for improving the filling and top connection rate of the end sand-releasing mining area of ​​the present invention.

[0020] Figure 2 for Figure 1 Side profile of middle zone I;

[0021] Figure 3 for Figure 1 Side profile of middle zone II;

[0022] Figure 4 for Figure 1 Side profile of middle zone III;

[0023] Figure 5 for Figure 1 Side profile of middle zone IV.

[0024] The accompanying drawings are marked as follows: 1-mining area; 2-pillar; 3-filling inclined shaft; 4-filling main pipe; 5-filling connecting tunnel; 6-filling branch pipe; 7-rock drilling tunnel; 8-blast hole; 9-sand trough; 10-mine exit tunnel; 11-ore loading access road. DETAILED DESCRIPTION

[0025] To better describe the present invention, the structural arrangement of the end sand release mining site for improving the filling and top connection rate of the present invention is further described in detail below with reference to the accompanying drawings.

[0026] Depend on Figure 1 The front view of the structural arrangement of the end sand-releasing mining field of the present invention to improve the filling and top connection rate is shown in combination with Figure 2 , Figure 3 , Figure 4 , Figure 5 It can be seen that the structural arrangement mode of the end-sanding stope of the present invention improves the filling connection rate, a stope 1 is arranged every 40 to 80 m along the direction of the ore body, 3 to 5 sub-zones are arranged in each stope 1, and a spacer 2 is left between two adjacent stopes 1; a rock drilling tunnel 7, a mine-discharging tunnel 10, and a loading access 11 are arranged at the lower part of the stope 1, and the rock drilling tunnel 7 and the loading access 11 are arranged along the direction of the ore body, and the rock drilling tunnel 7 and the loading access 11 are connected through the mine-discharging tunnel 10; a filling inclined shaft 3 is arranged in the spacer 2 where the ore body roof at both ends of the stope 1 is relatively high, and a filling main pipe 4 is hung on the tunnel roof of the filling inclined shaft 3, and a filling connection tunnel 5 is dug from the filling inclined shaft 3 close to the top area of ​​the stope 1 to the stope 1, and a filling branch pipe 6 is connected to the stope 1; blast holes 8 are drilled in the rock drilling tunnel 7 to the stopes of each sub-zone, and through each zone, a filling connection tunnel 5 is dug to the stope 1. The method of deepening the depth of the blasthole 8 forms a stepped sand release trough 9 at the top of the stope 1. Taking the stope 1 with a length of 45m as an example, a partition is formed every 15m in the stope 1, so that the stope 1 is divided into three partitions along the direction of the ore body, namely, zone I, zone II and zone III. Zone I, zone II and zone III are located from far to near to the end sand release point. Zone III is 0 to 15m away from the end sand release point, zone II is 15 to 30m away from the end sand release point, and the rest is zone I. Taking the cutting space at the other end of the sand release point at the end of the stope as the free surface, backward blasting is carried out in the rock drilling tunnel 7 toward the end sand release point, and the collapsed ore is transported to the chute through the mine exit tunnel 10 and the loading access road 11 by a shovel loader to unload the ore. After the stope is mined, the passage at the lower part of the empty area is closed, and the empty area is filled in batches through the filling main pipe 4 and the filling branch pipe 5 to ensure the filling effect.

[0027] The farther from the end sand release point, the lower the height of the sand release trough 9 above the ore body roof contact zone, until the height of the sand release trough 9 is equal to the ore body roof contact zone. Referring to the gravity slope of the filling slurry, which is usually between 4% and 8%, take the length of the stope 1 of 45m as an example, and divide the stope 1 into 3 zones, in zone I, which is 30 to 45m away from the sand release point, the height of the sand release trough 9 is equal to the ore body roof contact zone; in zone II, which is 15 to 30m away from the sand release point, the sand release trough 9 is 1.2 to 2.4m higher than the ore body roof contact zone, and in zone III, which is 0 to 15m away from the sand release point, the sand release trough 9 is 2.4 to 4.0m higher than the ore body roof contact zone.

[0028] The stope 1 is 40 to 80 m long, each partition in the stope 1 is generally 13 to 18 m long, the pillars 2 are 10 to 20 m wide, and the stope height varies from 10 to 100 m depending on the thickness and inclination of the ore body.

[0029] The present invention adopts a stepped sand trough solution. According to the different distances between the filling area and the sand release point, combined with the gravity slope of the filling slurry, sand troughs of different heights are set through the depth of the blasthole, so that the average slope of the roof of the empty area is greater than or equal to the gravity slope of the slurry, so as to meet the requirements of natural top connection, solve the problem of top connection in the mining field, control the ground pressure activity, and ensure the safety of mining production. At the same time, the sand trough with a small cross-section is formed by deepening the blasthole, which effectively controls the filling cost and ore depletion rate.

[0030] The method of the present invention has been industrially tested in backfill mining of a large underground iron ore, achieving a backfilling rate of 100%, achieving unexpected technical effects, and effectively ensuring safety during the mining process.

Claims

1. A structural arrangement method for improving the filling and top connection rate of a sand-released stope at the end, wherein a stope (1) is arranged every 40 to 80 m along the direction of the ore body, 3 to 5 partitions are arranged in each stope (1), and pillars (2) are left between two adjacent stopes (1), characterized in that: A rock drilling tunnel (7), an ore discharge tunnel (10), and an ore loading access road (11) are arranged at the lower part of the mining area (1). The rock drilling tunnel (7) and the ore loading access road (11) are arranged along the direction of the ore body. The rock drilling tunnel (7) and the ore loading access road (11) are connected through the ore discharge tunnel (10). A filling inclined shaft (3) is arranged in the intermediate pillars (2) with higher ore body roofs at both ends of the mining area (1). A filling main pipe (4) is hung on the tunnel roof of the filling inclined shaft (3). A filling connecting tunnel (5) is excavated from the filling inclined shaft (3) near the top area of ​​the mining area (1) to the mining area (1), and a filling branch pipe (6) is connected to the mining area (1). Blast holes (8) are drilled in the rock drilling tunnel (7) towards the mining areas of each subdivision. By deepening the blast holes (4) in each subdivision, the filling connecting tunnel (5) is excavated from the filling inclined shaft (3) near the top area of ​​the mining area (1). 8) A depth method is used to form a stepped sand release trough (9) at the top of the stope (1). The height of the sand release trough (9) in each partition is determined according to the distance between the empty filling area and the end sand release point and the gravity slope of the filling slurry to ensure that the average slope of the empty area roof is greater than or equal to the gravity slope of the filling slurry to meet the natural top connection requirements; with the cutting space at the other end of the sand release point at the end of the stope as the free surface, backward blasting is carried out in the rock drilling tunnel (7) toward the end sand release point, and a shovel loader is used to transport the collapsed ore through the mine exit tunnel (10) and the loading access road (11) to the chute for unloading; after the stope is mined, the channel at the bottom of the empty area is closed, and the empty area is filled in batches through the filling main pipe (4) and the filling branch pipe (6).

2. The structural arrangement for improving the filling and top connection rate of the end sand-released mining area according to claim 1 is characterized in that: The stope (1) has a height of 10 to 100 m, and the pillars (2) have a width of 10 to 20 m. The slope of the filling inclined shaft (3) is substantially consistent with the inclination of the ore body, and the maximum deviation between the slope of the filling inclined shaft (3) and the inclination of the ore body is ≤10%. The bottom plate of the filling inclined shaft (3) is 1 to 2 m higher than the contact zone of the ore body roof.

3. The structural arrangement for improving the filling and top connection rate of the end sand-released mining area according to claim 1 or 2, characterized in that: Depending on the distance between the empty area filling region and the end sand release point, the farther from the end sand release point, the smaller the height of the sand release trough (9) above the contact zone of the ore body roof, until the height of the sand release trough (9) is equal to the height of the contact zone with the ore body roof.

4. The structural arrangement for improving the filling and top connection rate of the end sand-released mining area as claimed in claim 3 is characterized by: The mining area (1) is divided into three zones, namely zone I, zone II and zone III, along the strike of the ore body. Zone I, zone II and zone III are arranged from far to near the end sand release point. The height of the sand release trough (9) in zone I is equal to the height of the contact zone with the ore body roof; the sand release trough (9) in zone II is 1.2 to 2.4 m higher than the contact zone with the ore body roof; and the sand release trough (9) in zone III is 2.4 to 4.0 m higher than the contact zone with the ore body roof.

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