A method for mining a gently inclined, extremely thin vein by reserving a strip pillar and horizontal deep hole
By reserving pillars in gently dipping, extremely thin veins and employing horizontal deep-hole differentiated charge blasting, the problems of high ore dilution rate and complex construction in the mining of gently dipping, extremely thin veins were solved, achieving efficient, safe, and low-cost mining results.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- WUHAN UNIV OF SCI & TECH
- Filing Date
- 2026-03-26
- Publication Date
- 2026-06-09
AI Technical Summary
Existing methods for mining gently dipping, extremely thin veins suffer from problems such as high ore dilution rate, low resource utilization rate, large construction volume, high cost, and poor safety. In particular, traditional continuous charge blasting is prone to the mixing of waste rock into the surrounding rock, resulting in a high risk of roof collapse, and the construction process is cumbersome.
The method of horizontal deep-hole mining with pre-reserved pillars is adopted for gently inclined ultra-thin veins. By rationally dividing the ore blocks and reserving top pillars, bottom pillars and strip pillars, the method uses differentiated charge blasting in horizontal deep holes to achieve precise ore recovery, avoid blasting in pillar areas, and combine it with backfill slurry to reduce the mixing of waste rock in the surrounding rock, simplify the construction process, and use pillars to support the stability of the stope.
It significantly improved resource utilization, reduced ore dilution rate, simplified construction procedures, reduced costs, enhanced the safety and construction efficiency of the mining area, and achieved safe and efficient mining results.
Smart Images
Figure CN122169819A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of mining engineering technology, and in particular to a method for mining horizontal deep holes with pre-reserved pillars in gently inclined, extremely thin veins. Background Technology
[0002] The current mining of gently dipping, extremely thin veins mostly adopts conventional shallow-hole or horizontal deep-hole blasting methods. First, the ore blocks and stopes are divided along the strike and dip of the ore body. Preparatory works such as construction of transport roadways and cutting works are carried out. Then, deep holes are constructed in the roadways, and high-explosive blasting is carried out throughout the section using a continuous charge structure. After the ore is blasted, personnel enter the stope to extract the ore. After the mining is completed, a large number of artificial backfill retaining walls are built at the boundaries of each stope. Then, backfill slurry is filled through pipelines. The stability of the stope is maintained by the pillars and backfill bodies. This is how the mining of extremely thin veins and the treatment of goaf areas are completed.
[0003] However, traditional mining methods have many prominent problems in practical applications. Due to the thinness of the ore veins, conventional continuous blasting easily causes a large amount of surrounding rock to collapse, resulting in a high ore dilution rate and low resource utilization. Furthermore, continuous blasting throughout the entire section can cause the top and bottom pillars to collapse together, losing their in-situ support and easily causing roof collapse, resulting in poor safety of the stope. At the same time, it is necessary to build artificial filling retaining walls separately in each stope, which is complicated, involves a large amount of construction, is costly, and inefficient, thus making it difficult to meet the requirements of efficient and safe mining. Summary of the Invention
[0004] To address the aforementioned technical problems, this invention provides a method for mining horizontal deep holes in gently inclined, extremely thin veins with pre-reserved pillars.
[0005] This invention provides a method for mining horizontal deep holes in gently dipping, extremely thin veins with pre-reserved pillars, comprising the following steps: The gently dipping, extremely thin veins are divided into blocks, with top pillars, bottom pillars, and strip pillars left on the blocks, and the blocks are divided into multiple rooms through the strip pillars; Horizontal deep holes are drilled along the sidewalls of the upper and lower transport roadways towards the stope. During the initial blasting, the cutting uphill is used as the blasting compensation space. The mining sequence of the ore block is to retreat from the cutting uphill along the ore body strike to both sides of the ore block. When several rows of horizontal deep holes are close to the cutting uphill, continuous charge is used. After blasting, each stope is connected at the end near the cutting uphill. The subsequent horizontal deep holes in the ore block use discontinuous charge. No charge is used in the sections of the horizontal deep holes that pass through the reserved top pillars, bottom pillars and strip pillars. Each section of explosive charge is connected by detonating cord for detonation. When the horizontal deep holes with discontinuous charge collapse laterally, only the sections that pass through each stope are blasted. The top pillars, bottom pillars and strip pillars are left inside the ore block. The collapsed ore falls on the floor of each stope. After the ore block is mined, a filling pipeline is laid in the upper stage transport roadway. Then, a filling retaining wall is built at the connection between the cutting uphill section and the upper and lower stage transport roadways. The horizontal deep holes passing through the unblasted sections of the top and bottom pillars are sealed with polyurethane sealing bags. Finally, filling slurry is transported to each stope through the laid filling pipeline for filling.
[0006] Preferably, the process of dividing gently dipping, extremely thin veins into blocks includes the following steps: In gently dipping, extremely thin veins, stages are divided along the dip of the ore body, and at each stage, blocks are divided along the strike of the ore body.
[0007] Preferably, the following steps are also included: Upper-stage transport roadways and lower-stage transport roadways are arranged at the top and bottom of the ore block, respectively. A cutting ramp is arranged along the dip of the ore body in the middle of the ore block. The two ends of the cutting ramp are connected to the upper-stage transport roadway and the lower-stage transport roadway via the upper-stage ramp and the lower-stage ramp, respectively.
[0008] Preferably, the cutting bottom plate is flush with the bottom plate of the ore body.
[0009] Preferably, the bottom of both the upper and lower stage transport roadways is 0.5m-1m lower than the bottom plate of the ore body.
[0010] Preferably, the row spacing of the horizontal deep holes is 1m-2m, and the number of rows of continuous charging horizontal deep holes adjacent to the cutting uphill section is 2-4.
[0011] Preferably, the filling pipeline includes a main filling pipeline and branch filling pipelines. The main filling pipeline is arranged at the highest point of the roof of each stope in the cutting uphill section. The branch filling pipelines are arranged at the highest point of each stope, and the discharge port of the branch filling pipelines is located at the midpoint of the direction of the ore body along the mining area.
[0012] The technical solution provided by the embodiments of the present invention has the following advantages compared with the prior art: This invention rationally divides gently dipping, extremely thin ore veins into blocks and establishes top pillars, bottom pillars, and strip pillars. This not only effectively supports the stope roof with the pillars, improving the overall stability of the stope, but also optimizes the mining space layout by regularly separating the stops using the strip pillars. Simultaneously, it employs horizontal deep-hole differentiated charge blasting, using the cutting uphill as blasting compensation space to achieve double-sided retreat mining along the strike. The initial section uses continuous charge, connecting the stops after blasting to ensure smooth ore extraction. Subsequent sections use discontinuous charge, avoiding the areas where the top, bottom, and strip pillars are located, and only implementing lateral caving in the stope sections. This method enables precise ore recovery, significantly reduces the mixing of waste rock with surrounding rock, effectively lowers the ore dilution rate, and allows the installed top and bottom pillars to directly replace traditional manual backfill retaining walls. Only a small number of retaining walls need to be built at the connection between the cutting uphill and the stage transport roadway, eliminating the need for separate construction in each stope. This greatly simplifies the retaining wall construction process, thereby significantly improving construction efficiency and reducing costs. At the same time, the use of pillars provides stable support for the stope, further simplifying the construction process and improving the safety of stope operations. Ultimately, this method enables safe, efficient, and low-cost mining of gently dipping, extremely thin ore veins. Attached Figure Description
[0013] Figure 1 A schematic diagram of a gently inclined, extremely thin vein mining area provided by the present invention; Figure 2 A schematic diagram of mine recovery provided by the present invention; Figure 3 This is a schematic diagram of the mine filling provided by the present invention; Figure 4 Provided by the present invention Figure 1 Cross-sectional view along the AA direction; Figure 5 Provided by the present invention Figure 2 Cross-sectional view along the BB direction; Figure 6 Provided by the present invention Figure 3 Cross-sectional view along the CC direction; Figure 7 Provided by the present invention Figure 2 Cross-sectional view along the DD direction.
[0014] Explanation of reference numerals in the attached figures: 1. Upper stage transport roadway; 2. Pillar; 3. Horizontal deep hole; 4. Interstitial pillar; 5. Lower stage transport roadway; 6. Cutting uphill; 6-1. Upper stage uphill slope; 6-2. Lower stage uphill slope; 7. Bottom pillar; 8. Top pillar; 9. Ore; 10. Filling pipeline; 10-1. Main filling pipeline; 10-2. Branch filling pipeline; 11. Filling retaining wall. Detailed Implementation
[0015] The following detailed description of a specific embodiment of the present invention is provided in conjunction with the accompanying drawings. However, it should be understood that the scope of protection of the present invention is not limited to the specific embodiment.
[0016] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the technical solution of this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.
[0017] The present invention will be described below through several specific embodiments. To keep the following description of the embodiments clear and concise, detailed descriptions of known functions and components may be omitted. When any component of an embodiment of the present invention appears in more than one drawing, the component may be represented by the same reference numerals in each drawing.
[0018] like Figures 1-7 As shown, this invention discloses a method for mining gently dipping, extremely thin ore veins with pre-reserved pillars in horizontal deep holes. This method is applicable to mining gently dipping, extremely thin ore veins with an inclination angle of 5°-30° and a thickness of 0.8m-2.0m. The steps are as follows: (1) Layout of ore blocks: In gently dipping, extremely thin veins, stages are divided along the dip of the ore body, with a stage length of 40m-50m. Mineral blocks are divided along the strike of the ore body, with a block width of 50m-70m. Interstitial pillars 4, with a width of 2m-4m, are left on both sides of the mineral blocks to support the stope boundaries on both sides of the mineral blocks. Top pillars 8 and bottom pillars 7 are left at the top and bottom of the mineral blocks, respectively. Top pillars 8 have a width of 1m-1.5m, and bottom pillars 7 have a width of 1.5m-2m. Strip pillars 2, with a width of 2m-5m and a spacing of 8m-15m, are left inside the mineral blocks. The mineral blocks are divided into 6-10 rooms by the strip pillars 2. The strip pillars 2 not only support the roof but also divide the mineral blocks into independent rooms, which facilitates subsequent regional mining and backfilling management. (2) Sampling and cutting: Along the strike of the ore body, upper-stage transport roadway 1 and lower-stage transport roadway 5 are arranged at the top and bottom of the ore block, respectively. The bottom of upper-stage transport roadway 1 and lower-stage transport roadway 5 is 0.5m-1m lower than the bottom plate of the ore body, providing passage for subsequent drilling, blasting and ore extraction operations. Cutting ramp 6 is arranged in the middle of the ore block along the dip of the ore body. Cutting ramp 6 runs through the entire oblique length of the ore block. At both ends of cutting ramp 6, it is connected to upper-stage transport roadway 1 and lower-stage transport roadway 5 through upper-stage ramp 6-1 and lower-stage ramp 6-2, respectively. The bottom plate of cutting ramp 6 is flush with the bottom plate of the ore body, ensuring that it can serve as both a blasting compensation space and a main passage for loader. (3) Layout of blast holes and blasting mining: Horizontal deep holes 3 are constructed along the sidewalls of the upper stage transport roadway 1 and the lower stage transport roadway 5 towards the mining area. The horizontal deep holes 3 are spaced 1m-2m apart and run through the entire length of the ore block. Their arrangement direction is parallel to the strike of the ore body. During the initial blasting, the cutting uphill 6 serves as the blasting compensation space. The mining sequence of the ore block is to retreat from the cutting uphill 6 along the ore body direction to both sides of the ore block. The 2-4 rows of horizontal deep holes 3 near the cutting uphill 6 are continuously charged with explosives. After blasting, each ore block is connected at the end near the cutting uphill 6, forming a passage for the loader, which facilitates the passage of the mini remote-controlled unmanned loader in each ore block. The subsequent horizontal deep holes 3 within the ore block are charged discontinuously. No explosives are charged in the sections of horizontal deep holes 3 that pass through the reserved top pillar 8, bottom pillar 7, and strip pillar 2. Explosives are charged only in the sections corresponding to each stope. Each segment of explosive charge is connected by a detonating cord to ensure that the blasting energy is concentrated in the stope area. When the horizontal deep holes 3 with discontinuous charges blast laterally, only the sections passing through each stope are blasted, while the top pillar 8, bottom pillar 7, and strip pillar 2 remain intact and are left inside the ore block. The blasted ore 9 falls on the floor of each stope, waiting for subsequent mining operations. (4) Ore extraction: The mining operation is carried out using remote intelligent control technology of micro remote-controlled unmanned shovels. The shovels enter each mining area through the cutting incline 6 and transport the collapsed ore 9 to the cutting incline 6. Temporary transfer points are set up in the cutting incline 6, and the ore 9 is loaded into mining trucks by a loader or a slag rake and transported to the surface. The entire mining process does not require personnel to enter the goaf area, which fundamentally ensures the safety of the operation. (5) Filling: After the ore block is mined, a filling pipeline 10 is laid in the upper stage transport roadway 1. The main filling pipeline 10-1 is arranged in the cutting uphill 6 at the highest point of the roof of each stope, so as to ensure that the filling slurry can flow into each stope by gravity. The branch filling pipeline 10-2 is led out from the main filling pipeline 10-1 and arranged at the highest point of each stope. The discharge port of the branch filling pipeline 10-2 is located at the midpoint of the direction of the ore body along the stope, so as to ensure that the filling slurry is evenly distributed. At the junction of the cutting uphill section 6 with the upper stage transport roadway 1 and the lower stage transport roadway 5, a filling retaining wall 11 is constructed to seal the filling area. At the same time, polyurethane sealing bags are used to seal the horizontal deep holes 3 that pass through the unblasted sections of the top pillar 8 and bottom pillar 7 to prevent the filling slurry from leaking from the deep holes. Finally, the filling slurry is transported to each stope through the filling pipe 10 for filling. After the filling body solidifies, the mining operation of the entire block is completed.
[0019] The above inventions are merely a few specific embodiments of the present invention. However, the embodiments of the present invention are not limited thereto, and any variations that can be conceived by those skilled in the art should fall within the protection scope of the present invention.
Claims
1. A method for mining horizontal deep holes in gently dipping, extremely thin veins with pre-reserved pillars, characterized in that, Includes the following steps: The gently dipping, extremely thin veins are divided into blocks, with top pillars, bottom pillars, and strip pillars left on the blocks, and the blocks are divided into multiple rooms through the strip pillars; Horizontal deep holes are drilled along the sidewalls of the upper and lower transport roadways towards the stope. During the initial blasting, the cutting uphill is used as the blasting compensation space. The mining sequence of the ore block is to retreat from the cutting uphill along the ore body strike to both sides of the ore block. When several rows of horizontal deep holes are close to the cutting uphill, continuous charge is used. After blasting, each stope is connected at the end near the cutting uphill. The subsequent horizontal deep holes in the ore block use discontinuous charge. No charge is used in the sections of the horizontal deep holes that pass through the reserved top pillars, bottom pillars and strip pillars. Each section of explosive charge is connected by detonating cord for detonation. When the horizontal deep holes with discontinuous charge collapse laterally, only the sections that pass through each stope are blasted. The top pillars, bottom pillars and strip pillars are left inside the ore block. The collapsed ore falls on the floor of each stope. After the ore block is mined, a filling pipeline is laid in the upper stage transport roadway. Then, a filling retaining wall is built at the connection between the cutting uphill section and the upper and lower stage transport roadways. The horizontal deep holes passing through the unblasted sections of the top and bottom pillars are sealed with polyurethane sealing bags. Finally, filling slurry is transported to each stope through the laid filling pipeline for filling.
2. The method for mining horizontal deep holes with pre-reserved pillars in gently dipping, extremely thin veins as described in claim 1, characterized in that... The process of dividing gently dipping, extremely thin veins into blocks includes the following steps: In gently dipping, extremely thin veins, stages are divided along the dip of the ore body, and at each stage, blocks are divided along the strike of the ore body.
3. The method for mining horizontal deep holes with pre-reserved pillars in gently dipping, extremely thin veins as described in claim 1, characterized in that... It also includes the following steps: Upper-stage transport roadways and lower-stage transport roadways are arranged at the top and bottom of the ore block, respectively. A cutting ramp is arranged along the dip of the ore body in the middle of the ore block. The two ends of the cutting ramp are connected to the upper-stage transport roadway and the lower-stage transport roadway via the upper-stage ramp and the lower-stage ramp, respectively.
4. The method for mining horizontal deep holes with pre-reserved pillars in gently dipping, extremely thin veins as described in claim 1, characterized in that... The cutting of the upper slope is flush with the bottom plate of the ore body.
5. The method for mining horizontal deep holes with pre-reserved pillars in gently dipping, extremely thin veins as described in claim 1, characterized in that... The bottom of both the upper and lower stage transport roadways is 0.5m-1m lower than the bottom plate of the ore body.
6. The method for mining horizontal deep holes with pre-reserved pillars in gently dipping, extremely thin veins as described in claim 1, characterized in that... The spacing between the horizontal deep holes is 1m-2m, and there are 2-4 rows of continuous horizontal deep holes for charging adjacent to the cutting uphill section.
7. The method for mining horizontal deep holes with pre-reserved pillars in gently dipping, extremely thin veins as described in claim 1, characterized in that... The filling pipeline includes a main filling pipeline and branch filling pipelines. The main filling pipeline is located at the highest point of the roof of each stope during the cutting uphill section. The branch filling pipelines are located at the highest point of each stope, and the discharge port of each branch filling pipeline is located at the midpoint of the direction of the ore body along the mining area.