High-efficiency mining technology of mechanized pre-cut roof and deep hole blasting for top and bottom pillars

Abstract

The present invention discloses a mechanized pre-cut roof medium-long hole blasting top and bottom pillar high-efficiency mining technology method; it relates to the field of underground mining technology, and comprises the following steps: S1, first fill the empty area with tailings, and after the strength reaches the requirement, divide the ore body stope into plate areas, and carry out mining in the plate area in the first and second step stopes; S2, take the remaining pedestrian ventilation tunnel as the cutting tunnel, and dig a cutting shaft upward in the middle of the cutting tunnel of the first step; S3, first cut the top at the top and bottom pillar of the ore body, and support the ore body top plate, and lower the cut ore through the cutting shaft to the remaining Pedestrian ventilation tunnel for mining; S4, using the cutting skylight and the cutting tunnel as free surfaces to form a cutting groove, and digging downward parallel medium-deep holes on the steps for positive blasting and inclined upward mining; S5, using the directional throwing effect of downward parallel medium-deep hole blasting, the ore is thrown into the retained pedestrian ventilation tunnel, and finally the ore is transported through the vein through the ore extraction and entered into the trackless mining lane along the vein by the scraper; S6, the mining site where the top and bottom pillars are mined in the first step is filled with tailings, and after the maintenance is completed, the second step of mining is carried out according to the above steps until the mining of the entire top and bottom pillars is completed. The effect of this application is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of underground mining, in particular to a high-efficiency mining method of top and bottom pillars by mechanized pre-cutting of top and middle deep holes and blasting. Background Art

[0002] The mining of gently inclined-inclined ore bodies has always been a recognized problem in the mining industry at home and abroad. At present, the main mining methods for mining gently inclined-inclined ore bodies include the room-and-pillar method, the full-scale method, the backfill method and related modified schemes. The safe recovery of residual ore in gently inclined-inclined ore bodies is one of the major technical problems that must be solved in the field of mining technology today.

[0003] Because room-and-pillar mining requires the placement of a hopper above the haulage tunnel, a 5-10m high top or bottom pillar is typically retained to maintain the stability of the ore structure. The ore body is typically gently inclined, medium-thick, and thick, with an inclined length of 15-20m, resulting in a large number of pillars remaining. The main mining methods for recovering these top and bottom pillars include retreating upward fan-shaped medium-deep hole mining and upward approach-fill mining. While the retreating upward fan-shaped medium-deep hole mining method has high production capacity, it leaves a large number of triangular pillars that cannot be recovered after mining, and the roof surrounding rock easily mixes with the ore, resulting in high losses and dilution. While the upward approach-fill mining method has a lower dilution loss rate, it also involves a large amount of mining and cutting work, low production capacity, and high mining costs. Therefore, finding a mining method with high production capacity, a low mining-to-cut ratio, good safety, and high economic benefits for top and bottom pillar recovery is key to achieving the safe, economical, and efficient recovery of top and bottom pillars of residual ore resources. Summary of the Invention

[0004] In order to achieve safe, economical and efficient recovery of top and bottom pillar residual ore resources, the present application provides a mechanized pre-cut top medium and deep hole blasting top and bottom pillar efficient mining technology method.

[0005] This application provides a mechanized pre-cut roof deep hole blasting method for efficient top and bottom pillar recovery, which adopts the following technical solutions:

[0006] A mechanized pre-cut roof medium-long hole blasting top and bottom pillar efficient mining technology method comprises the following steps:

[0007] S1. First, fill the empty area with tailings. After the strength reaches the required level, divide the ore body stope into panels. Within the panels, carry out mining in one or two steps.

[0008] S2: Using the remaining pedestrian ventilation tunnel as the cutting tunnel, dig a cutting shaft upwards in the middle of the cutting tunnel in one step;

[0009] S3. First, cut the top of the ore body at the top and bottom pillars, and support the top of the ore body. The cut ore is lowered through the cutting shaft to the remaining pedestrian ventilation tunnel for exiting the mine;

[0010] S4: Using the cutting skylight and the cutting lane as free surfaces to form a cutting groove, dig parallel medium-long holes on the steps and then blast them upwards;

[0011] S5. Utilize the directional throwing effect of downward parallel medium-long hole blasting to throw the ore into the remaining pedestrian ventilation tunnel, and finally use the scraper to pass through the vein and enter the trackless ore discharge tunnel along the vein;

[0012] S6. Fill the stope where the top and bottom pillars have been mined in the first step with tailings. After the maintenance is completed, carry out the second step of mining according to the above steps until the mining of the entire top and bottom pillars is completed.

[0013] Furthermore, in step S1, after filling pipes are set up and isolation walls are built in the empty area of ​​room-and-pillar mining as required, tailings cementation filling is carried out.

[0014] Furthermore, in step S2, the remaining pedestrian ventilation tunnel is used as the cutting tunnel, and a YGZ-90 drill is used to drill an upward straight hole in the middle of the cutting tunnel in step one to excavate a cutting shaft, so that the cutting shaft also serves as a chute, and pedestrians and materials go up to the top plate of the ore body through the pedestrian material return air shaft.

[0015] Furthermore, in step S3, the inclination angle after cutting is too large, making it difficult to install medium-deep hole equipment. Therefore, the top of the ore body is cut to form a step of ≤10°. After cutting, the top plate is supported by anchor rods to ensure the safety of subsequent mining. Subsequent transportation of pedestrians and material equipment can reach the top plate of the ore body through the cutting tunnel retained in the upper and middle sections through the pedestrian material return air shaft, avoiding the transportation of pedestrians and materials through the empty area.

[0016] Furthermore, in step S4, a down-the-hole drill is used to drill parallel medium-depth holes in the forward row of blastholes, and the hole depth is the vertical thickness of the ore body. After the drilling is completed, the blastholes are cleaned and charged. The forward row of holes is blasted in 2 to 3 rows each time. Micro-differences between rows and between holes can be used to enhance the superposition effect of detonation waves, reduce the large block rate and blasting vibration, and reduce the impact on the surrounding area.

[0017] Furthermore, in step S5, after the medium-deep hole blasting process, fresh air flows in from the off-vein transport tunnel, passes through the vein through the mine and enters the retained pedestrian ventilation tunnel, and then enters the mining area. The polluted air passes through the upper cutting top layer and flows into the pedestrian material return air shaft excavated in the retained cutting tunnel, and finally flows into the retained cutting tunnel and enters the off-vein transport tunnel.

[0018] Furthermore, in step S5, the ore mined from the top layer is raked by an electric rake into the retained pedestrian ventilation tunnel, and the ore from the medium and deep hole blasting is thrown into the retained pedestrian ventilation tunnel. Then, an electric scraper is used to transport the ore through the vein into the retained pedestrian ventilation tunnel to load the ore, and the ore is shoveled and transported to the transport tunnel outside the vein.

[0019] Furthermore, in step S6, high-strength filling materials are used to fill the top and bottom columns of the first step. After the filling and curing are completed, the top and bottom columns of the second step are mined.

[0020] In summary, this application has the following beneficial technical effects:

[0021] This application efficiently utilizes the original pedestrian ventilation tunnel as a free surface for upward construction of cutting shafts, which greatly reduces the mining and cutting workload during top and bottom pillar recovery, shortens the mine preparation time, and improves the utilization rate of old projects; adopts pre-cut top downward parallel medium and deep hole blasting bottom pillars, fully utilizes the directional throwing effect of the medium and deep holes, improves the production efficiency of the mine, and greatly reduces the transportation and production costs of ore. The pre-cut top support method reduces the risk of roof collapse and increases the safety and economic benefits of the mine; the upper and middle sections of the cutting pull bottom tunnel are used as pedestrian and material transportation channels, avoiding the risk of direct empty area transportation of materials, personnel, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a cross-sectional view of the mechanized pre-cut top and deep hole blasting top and bottom pillar mining method;

[0023] Figure 2 It is a plan view of the mechanized pre-cut top and deep hole blasting top and bottom pillar mining method;

[0024] Description of reference numerals:

[0025] 1. Off-vein transport tunnel; 2. Retained chute; 3. Retained cutting tunnel in the upper and middle sections; 4. Pedestrian material return air shaft; 5. Anchor support; 6. Mine-out through the vein; 7. Pedestrian ventilation tunnel; 8. Cutting skylight; 9. Electric rake chamber; 10. Downward parallel medium-deep hole blasthole; 11. Filling body; 12. Cutting groove; 13. Ore body roof; 14. Step; 15. Ore. DETAILED DESCRIPTION

[0026] The following is combined with Figure 1-2 This application is described in further detail.

[0027] The present application discloses a method for efficient mining of top and bottom pillars by mechanized pre-cutting of top and middle-long holes through blasting, which comprises the following steps:

[0028] Step 1: For the empty areas mined by the room-pillar method, after setting up filling pipes and building isolation walls according to the mine filling construction specifications, carry out tailings cementation filling. After the filling strength reaches the requirements, the remaining gently inclined medium-thick to thick large top and bottom pillars are divided into a panel every 50 to 60 meters along the strike direction of the ore body. The panel area is divided into one and two step stopes for mining. The width of the one-step stope is 8 to 10 meters, and the width of the two-step stope is 8 to 10 meters. The mining height of the stope is the height of the bottom pillar.

[0029] Step 2: Use the remaining pedestrian ventilation tunnel 7 as the cutting tunnel, use the YGZ-90 drill to drill an upward straight hole in the middle of the cutting tunnel in step 1 to excavate the cutting shaft 8, and transport pedestrians and materials to the ore body roof 13 through the cutting shaft 8.

[0030] Step 3: Since the inclination angle after top cutting is too large, it is difficult to install medium- and long-hole equipment. Therefore, the top of the ore body roof 13 at the top and bottom pillars is first cut 2-3 meters, forming a step 14 with a slope of ≤10°. The cut ore 15 is lowered through the cutting shaft 8 to the remaining pedestrian ventilation tunnel 7 for exit. After top cutting, the ore body roof 13 is supported by anchor bolts 5 to ensure the roof safety during subsequent mining. Subsequent transportation of people, materials, and equipment can be carried out through the remaining cutting tunnel 3 and the pedestrian material return air shaft 4 to the ore body roof 13, avoiding the need for people and materials to pass through the empty area.

[0031] Step 4: Use the cutting skylight 8 and the remaining pedestrian ventilation tunnel 7 as free surfaces to form a cutting groove 12, and dig downward parallel medium-depth holes 10 on the step 14 for upward mining by positive blasting. Down-the-hole drilling is used to drill downward parallel medium-depth holes with a hole depth equal to the vertical thickness of the ore body. After drilling, clean the blastholes and load explosives. Forward blasting is carried out in 2 to 3 rows each time. Micro-differences between rows and holes can be used to enhance the superposition effect of detonation waves, reduce the rate of large blocks and blasting vibrations, and reduce the impact on the surrounding areas.

[0032] Step 5: Utilize the directional throwing effect of the downward parallel medium-deep hole 10 blasting to throw the ore 15 blasted from the medium-deep hole into the retained pedestrian ventilation tunnel 7, and then use an electric scraper to enter the retained pedestrian ventilation tunnel 7 through the ore-discharging vein 6 to load the ore. After the scraper shovels the ore, it is transported to the off-vein transport tunnel 1 through the ore-discharging vein 6 for ore-discharging. After the ore-discharging is completed, the mine is ventilated immediately. Fresh air flows in from the off-vein transport tunnel 1, enters the retained pedestrian ventilation tunnel 7 through the ore-discharging vein 6, and then enters the mine. The polluted air passes through the upper cutting top layer and flows into the excavated pedestrian material return air shaft 4, and finally flows into the cutting tunnel 3 retained in the upper middle section.

[0033] Step six: The post-filling pipeline is connected to the empty area through the off-vein transport tunnel 1, the chute 2 retained in the upper middle section and the cutting tunnel 3 retained in the upper middle section, and the pedestrian material return air shaft 4 to fill the mining area where the top and bottom pillars have been mined in the first step with tailings. After the maintenance is completed, the second step of mining and filling is carried out according to the above steps until the mining of the entire top and bottom pillars is completed.

[0034] By adopting the above technical solution, after filling the empty areas of the room-and-pillar mining method with tailings, a cutting shaft 8 is excavated upwards using the pedestrian ventilation tunnel 7 retained by the original room-and-pillar mining method as the free surface. The cutting shaft 8 also serves as a chute. Subsequently, a cutting trough is formed using the cutting shaft 8 and the retained pedestrian ventilation tunnel 7 as the free surface. Pedestrians and materials ascend to the ore body roof 13 through the pedestrian material return air shaft 4. Downward parallel medium-long holes are drilled on the steps 14 for blasting and mining. The ore is thrown into the pedestrian ventilation tunnel 7 and then transported to the external ore transport tunnel 1 using the original cutting and pulling process as the main transportation channel. By fully utilizing the directional throwing effect of the medium-long holes, the transportation cost of the ore is greatly reduced, overcoming the difficulties of low ore output and large mining and cutting workload.

[0035] The following is a specific example of a mechanized pre-cut top deep hole blasting top and bottom pillar recovery method.

[0036] A mine originally used the room-and-pillar method. The orebody was 10 to 20 meters thick, with an inclination of 10 to 30 degrees. The center section was 30 meters high, with a 7-meter-high room and 3-meter-high pillars. 8 to 10-meter-high top and bottom pillars were left. This left a large amount of high-value top and bottom pillar resources, making them difficult to recover and resulting in low economic returns. The main steps of the mechanized pre-cut top and deep-hole blasting method for top and bottom pillar recovery are as follows:

[0037] Step 1: First, fill the empty areas of the room-and-pillar mining method with tailings. After the filling strength reaches the required level, divide the gently inclined medium-thick to thick large roof and bottom pillar ore body into a panel every 60m along the strike direction of the ore body. Mining is carried out in one or two step stopes within the panel. The width of the first step stope is 8-10m, and the width of the second step stope is 8-10m. The mining height of the stope is the height of the bottom pillar, which is 10m.

[0038] Step 2: Using the remaining pedestrian ventilation tunnel 7 as the cutting tunnel, a YGZ-90 drill is used to excavate a cutting shaft 8 in the middle of the cutting tunnel in step 1. The shaft has a size of 2×2 meters. Pedestrians and materials are transported up to the ore body roof 13 through the cutting shaft 8.

[0039] Step 3: Use a YT-28 drill to drill the top 13 of the ore body at the top and bottom pillars, first cut 2 to 3 meters of the top, and form a step 14 with a slope of ≤10°. The cut ore 15 is lowered through the cutting shaft 8 to the remaining pedestrian ventilation tunnel 7 for exiting the mine. After the top is cut, the ore body roof 13 is supported by anchor bolts 5 to ensure the safety of subsequent mining. The anchor bolt spacing is 1.0×1.0m. Subsequent transportation of pedestrians and materials and equipment can reach the ore body roof 13 through the remaining cutting tunnel 3 and the pedestrian material return air shaft 4.

[0040] Step 4: Use the cut skylight 8 and the remaining pedestrian ventilation tunnel 7 as free surfaces to form a cutting groove 12, and use a down-the-hole drill to drill parallel medium-deep holes 10 on the step 14 for upward blasting. The diameter of the blasthole is ф60mm~ф76mm, the hole depth is the vertical thickness of the ore body, the blasthole spacing is 1.8m~2.0m, the hole spacing is 1.6~1.8m, the blasthole charging coefficient is 0.75~0.85, and the blasthole is blocked at a length of about 1.5m when the blasthole is 6~8m. When the blasthole depth exceeds 10m, the blasthole is blocked by 2.5m.

[0041] Step 5: After the rock drilling is completed, clean the blasthole and use the BQF-100 charge device to charge the explosives. The explosives are powdered ammonium nitrate explosives and non-electric detonator millisecond detonator with micro-difference blasting. The positive row hole blasting is 2 to 3 rows each time. Using the directional throwing effect of the medium-deep hole 10 blasting, the blasted ore 15 is thrown into the remaining pedestrian ventilation tunnel 7. The thrown ore 15 is 2m 3 The electric scraper enters the retained pedestrian ventilation tunnel 7 through the ore-discharging vein 6 to load ore. The scraper scoops the ore and transports it through the ore-discharging vein 6 to the off-vein transport tunnel 1 for ore-discharging. The mine is ventilated immediately after the ore-discharging is completed. Fresh air enters from the off-vein transport tunnel 1, passes through the ore-discharging vein 6 and enters the retained pedestrian ventilation tunnel 7, and then enters the mine. The polluted air passes through the upper cutting top layer and is collected into the excavated pedestrian material return air shaft 4, and finally into the retained cutting tunnel 3.

[0042] Step six: The post-filling pipeline is connected from the off-vein transport tunnel 1 through the chute 2 and the cutting tunnel 3 retained in the upper and middle sections, and through the pedestrian material return air shaft 4 to the empty area, and the mining area where the top and bottom pillars are mined in the first step is filled with tailings. After the maintenance is completed, the top and bottom pillars in the second step are mined and filled according to the above steps until the mining of the entire top and bottom pillars is completed.

[0043] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A mechanized pre-cut top deep hole blasting top and bottom pillar efficient mining technology method, characterized by The steps include: S1. First, fill the empty area with tailings. After the strength reaches the required level, divide the ore body into multiple panels. Within the panels, carry out mining in one or two steps. S2: Using the remaining pedestrian ventilation tunnel as the cutting tunnel, dig a cutting shaft upwards in the middle of the cutting tunnel in one step; S3. First, cut the top of the ore body roof at the top and bottom pillars to form a step, and then support the ore body roof. The cut ore is lowered through the cutting shaft to the remaining pedestrian ventilation tunnel for exiting the mine; S4: Using the cutting skylight and the cutting lane as free surfaces to form a cutting groove, dig parallel medium-long holes on the steps and then blast them upwards; In step S4, a down-the-hole drill is used to drill parallel medium-depth holes in the forward row of blastholes. The hole depth is equal to the vertical thickness of the ore body. After the drilling is completed, the blastholes are cleaned and charged. The forward row of holes is blasted in 2 to 3 rows at a time. Micro-differences between rows and holes can be used to enhance the superposition effect of detonation waves, reduce the large block rate and blasting vibration, and reduce the impact on the surrounding area. S5. Utilize the directional throwing effect of downward parallel medium-long hole blasting to throw the ore into the remaining pedestrian ventilation tunnel, and finally use the scraper to pass through the vein and enter the trackless ore discharge tunnel along the vein; In step S5, after the medium-long hole blasting process, fresh air flows in from the off-vein transport tunnel, passes through the ore outlet and into the retained pedestrian ventilation tunnel, and then enters the stope. The polluted air flows through the upper cutting top layer and enters the excavated pedestrian material return air shaft, and finally enters the cutting tunnel retained in the upper middle section and enters the off-vein transport tunnel. S6. Fill the stope where the top and bottom pillars have been mined in the first step with tailings. After the maintenance is completed, carry out the second step of mining according to the above steps until the mining of the entire top and bottom pillars is completed.

2. The method for high-efficiency mining of top and bottom pillars by mechanized pre-cutting deep hole blasting according to claim 1 is characterized by: In step S1, after the filling pipes are set up and the isolation wall is built in the empty area of ​​the room-and-pillar method as required, the tailings cementation filling is carried out.

3. The high-efficiency mining method of mechanized pre-cut roof and deep hole blasting for top and bottom pillars according to claim 2 is characterized by: In step S2, the remaining pedestrian ventilation tunnel is used as the cutting tunnel, and a YGZ-90 drill is used to drill an upward straight hole in the middle of the cutting tunnel in step 1 to excavate a cutting shaft. The cutting shaft is also used as a chute, and pedestrians and materials go up to the top of the ore body through the pedestrian material return air shaft.

4. The method of high-efficiency mining technology of mechanized pre-cutting roof and deep hole blasting for top and bottom pillars according to claim 1 is characterized by: In step S3, the inclination angle after cutting is too large, making it difficult to install medium-deep hole equipment. Therefore, the top of the ore body is cut to form a step of ≤10°. After cutting, the top plate is supported by anchor rods to ensure the safety of subsequent mining. Subsequent transportation of pedestrians and material equipment can reach the top plate of the ore body through the cutting tunnel retained in the upper and middle sections through the pedestrian material return air shaft, avoiding the transportation of pedestrians and materials through the empty area.

5. The method for high-efficiency mining of top and bottom pillars by mechanized pre-cutting deep hole blasting according to claim 1 is characterized by: In step S5, the ore mined from the top layer is raked by an electric rake into the retained pedestrian ventilation tunnel, and the ore from the medium and deep hole blasting is thrown into the retained pedestrian ventilation tunnel. Then, an electric scraper is used to enter the retained pedestrian ventilation tunnel from the ore outlet through the vein to load the ore, and the ore is shoveled and transported to the transport tunnel outside the vein.

6. The method of high-efficiency mining by mechanized pre-cutting roof and deep hole blasting according to claim 1 is characterized by: In step S6, high-strength filling materials are used to fill the top and bottom columns of the first step. After the filling and curing are completed, the top and bottom columns of the second step are mined.

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