High efficient mining method combining medium-length hole and short hole
By combining medium-deep and shallow borehole mining methods, the problem of low mining efficiency of isolation pillars and peach-shaped pillars was solved, achieving efficient and low-cost ore recovery, improving the recovery rate and shortening the cycle.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- WUHAN UNIV OF SCI & TECH
- Filing Date
- 2022-12-23
- Publication Date
- 2026-06-05
AI Technical Summary
Existing technologies for mining isolation pillars suffer from problems such as high mining difficulty, serious resource waste, high cost, and long cycle. In particular, the mining efficiency of isolation pillars and peach-shaped pillars is low and the waste rock mixing rate is high.
The efficient mining method combining medium-deep and shallow holes is adopted. By setting up large and small mining routes in the horizontal direction and blasting the ore alternately, the large and small ore blocks are mined by using medium-deep and shallow holes respectively. Combined with the existing mining area layout, safe and efficient mining can be achieved.
It increased the recovery rate by 20%-40%, reduced the amount of work by 80%, lowered costs by 40%, shortened the recovery cycle by 50%, and reduced the waste rock mixing rate and explosive consumption.
Smart Images
Figure CN115822598B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of blasting mining technology, specifically involving an efficient mining method that combines medium-deep and shallow holes. Background Technology
[0002] like Figure 1 As shown, in order to alleviate the pressure of resource depletion and extend the service life of mines, many underground mines have gradually put the issue of mining residual ore such as isolation pillars on the agenda. These isolation pillars are usually roof and floor pillars left over from early mining designs. If such ore cannot be effectively mined, it will inevitably lead to a waste of mineral resources and reduce the service life of the mine. Isolation pillars are an important legacy of the mining process, and once a mine includes them in its mining operations, the difficulty of mining them is self-evident. How to safely, rationally, and effectively mine these residual isolation pillars while ensuring the safety and stability of the mining area is an urgent problem to be solved.
[0003] like Figure 2 As shown, conventional sublevel caving mining without pillars will form new peach-shaped pillars (ridge residue) in the last mined section. Subsequent mining operations on this residual ore are complex, prone to waste rock contamination, and difficult to control ore size. For example... Figure 3 As shown, conventional access-type backfilling mining requires a certain thickness of roof pillar to be reserved because the upper part of the isolation pillar is loose waste rock. This results in low resource recovery rates, a large number of access routes, significant drilling work, and high mining costs. Figure 4 As shown, the upward approach-caving combined mining method can improve the recovery rate of isolation pillars, but the approach filling results in a large amount of tunneling work, high mining costs, and a long mining cycle. Summary of the Invention
[0004] This invention was developed to address the aforementioned problems and aims to provide an efficient mining method that combines medium-deep and shallow boreholes, offering advantages such as high mining efficiency, minimal engineering workload, low cost, and short cycle time.
[0005] To achieve the above objectives, the present invention employs the following solution:
[0006] This invention provides a highly efficient mining method combining medium-deep and shallow boreholes for mining isolation pillars (horizontal or gently dipping, with an inclination angle not exceeding 25°) and peach-shaped pillars left after caving-to-backfilling mining. The method includes the following steps:
[0007] Step 1, Excavating the mining access road: A large-scale mining access road is excavated at the bottom of the isolation pillar, directly opposite the ridge of the segmented residual peach-shaped pillar above it, forming multiple large-scale mining access roads spaced horizontally. Meanwhile, small-scale mining access roads are excavated between adjacent large-scale mining access roads and at the bottom of the isolation pillar, directly opposite the upper-level stratified ore extraction access road. These serve as caving mining operation space, blasting compensation space, and ore extraction access roads, forming multiple small-scale mining access roads spaced horizontally. The large-scale and small-scale mining access roads are continuously alternated.
[0008] Step 2, Drilling and Hole Layout: The unit blasting boundary is defined by the line connecting the large-scale mining access road and the upper sub-section ore extraction road and the ore body boundary of the peach-shaped pillar above it. Medium-deep hole blasting is used to extract ore within the large-scale mining access road unit, and large ore block units containing peach-shaped pillars are mined. Small-scale mining access roads use shallow hole blasting to mine small ore block units between large-scale access roads.
[0009] Step 3: Detonate ore by blasting.
[0010] Preferably, the efficient mining method combining deep and shallow holes provided by the present invention may also have the following characteristics: in step 1, the large-scale mining roadway is directly opposite the ridge of the upper segmented peach-shaped ore pillar, the small-scale mining roadway is directly opposite the upper layered mining roadway, and the large and small-scale mining roadways are arranged alternately.
[0011] Preferably, the efficient mining method combining deep and shallow holes provided by the present invention may also have the following features: in step 1, the size of the large-scale mining route is designed to be (3×3m)~(5×5m), and the size of the small-scale mining route is designed to be (2.5×2.5m)~(3.5×3.5m).
[0012] Preferably, the efficient mining method combining deep and shallow holes provided by the present invention may further include: isolation pillars are reserved to isolate the lower middle level backfill mining area from the upper middle level caving mining area, and peach-shaped pillars are the residual ore bodies of the last segment of the upper middle level bottomless sublevel caving mining method.
[0013] Preferably, the efficient mining method combining medium-deep and shallow holes provided by the present invention may also have the following feature: the height of the isolation pillar is 9-15m.
[0014] Preferably, the efficient mining method combining medium-deep and shallow holes provided by the present invention may also have the following characteristics: in step 3, medium-deep hole blasting is carried out as a whole to extract ore, and shallow hole blasting is carried out to extract ore after the upper bulk material has stabilized.
[0015] Preferably, the efficient mining method combining medium-deep and shallow holes provided by the present invention may also have the following characteristics: in step 3, blasting is carried out step by step and blasting is carried out one approach at a time, and ore is extracted after each blasting, and blasting and ore extraction are carried out in a cycle.
[0016] Preferably, the efficient mining method combining medium-deep and shallow holes provided by the present invention may also have the following feature: in step 3, the lag distance of the mining operation between the access routes is determined according to the overburden descent rate, the stability of the loose material, and the size of the area where the support pressure increases.
[0017] Preferably, the efficient mining method combining medium-deep and shallow holes provided by the present invention may also have the following feature: in step 3, the mining lag distance between mining blocks is not less than 10m.
[0018] Preferably, the efficient mining method combining medium-deep and shallow holes provided by the present invention may also have the following features: before tunneling and mining, the existing development works in the mining area are fully utilized to arrange the isolation pillars and peach-shaped pillar residual ore mining and cutting works, and the layered transportation roadways and connecting roadways of the residual ore mining mining area are set up in combination with the segmented rock drilling roadways, segmented connecting roadways, and the slope roadways and segmented vein roadways of the mining area.
[0019] The role and effect of invention
[0020] The efficient mining method combining medium-deep and shallow holes provided by this invention eliminates the need for backfilling. Instead, it directly establishes multiple large-scale mining routes and multiple small-scale mining routes spaced apart horizontally, alternating between them. Unit blasting boundaries are defined by the line connecting the large-scale mining routes and the upper segmented ore extraction routes, along with the ore body boundary of the upper peach-shaped pillar. Within the large-scale mining route unit, medium-deep hole blasting is used to extract ore, mining the large ore block unit containing the peach-shaped pillar. The small-scale mining routes use shallow holes to mine the small ore block units between the large-scale routes, performing blasting ore extraction. This method effectively solves the technical challenges of mining isolated pillars and peach-shaped pillars. While ensuring sufficient mining and increasing the recovery rate, it also significantly shortens the mining cycle and workload, reduces costs, and achieves safe and efficient mining of isolated pillars. Furthermore, this method has a low waste rock mixing rate and requires less explosives. Attached Figure Description
[0021] Figure 1 This is a schematic diagram of the occurrence structure of the ore body in the existing technology;
[0022] Figure 2 A schematic diagram of the structure of a new ridge residue formed by caving mining in existing technology;
[0023] Figure 3A schematic diagram of the route filling and backfilling process in existing technologies;
[0024] Figure 4 This is a schematic diagram of three existing methods for combined access-caving recovery.
[0025] Figure 5 This is a schematic diagram of the mining of the isolation pillar and the peach-shaped pillar above it, as described in an embodiment of the present invention.
[0026] Figure 6 for Figure 5 Enlarged view of the mid-mining area;
[0027] Figure 7 for Figure 5 A schematic diagram of the structure viewed along the I-I direction;
[0028] Figure 8 for Figure 5 A schematic diagram of the structure viewed along the Ⅰ-Ⅰ direction;
[0029] Figure 9 for Figure 5 Schematic diagram of the structure along the III-III direction;
[0030] Figure 10 This is a schematic diagram of the blasting process involved in an embodiment of the present invention.
[0031] In the diagram, 1-filling body, 2-ore pass, 3-stope connecting roadway, 4-shallow hole, 5-medium-deep hole, 6-transport roadway, 7-layered transport roadway, 8-large-size mining access roadway, 9-small-size mining access roadway, 10-surrounding rock, 11-isolation pillar, 12-peach-shaped pillar. Detailed Implementation
[0032] The following describes in detail, with reference to the accompanying drawings, the specific implementation scheme of the efficient recovery method combining medium-deep and shallow holes involved in this invention.
[0033] The stope structure parameters in this embodiment (after conversion from caving to backfilling mining): The height of the isolation pillar ore body is 12m. The upper and middle sections are caving mining areas and have been completely mined. The caving stope access spacing is 15m. There are residual peach-shaped pillars on both sides of the access. The lower part of the isolation pillar is a backfilling stope and has been completely backfilled.
[0034] like Figures 5-9 As shown, the efficient recovery method combining medium-deep borehole 5 and shallow borehole 4 provided in this embodiment specifically includes the following steps:
[0035] 1) Mining and cutting engineering layout: Make full use of the existing mining and cutting engineering horizontal transport roadway 6, ore pass 2, ventilation shaft and connecting roadway 3, etc., and arrange corresponding ventilation and connecting horizontal roadways and short-distance inclined ramps in combination with the needs of isolation pillar mining.
[0036] 2) Excavation and mining access: A large-scale mining access 8 is excavated at the ridge of the segmented residual peach-shaped pillar 12 directly above the bottom of the isolation pillar 11. The large-scale mining access 8 has a size of 4m×4m. A small-scale mining access 9 is excavated at the top of the stratified ore extraction access, directly above the bottom of the isolation pillar 11. The small-scale mining access 9 has a size of 3m×3m and serves as the caving mining operation space, blasting compensation space, and ore extraction access.
[0037] 3) Drilling and hole layout: The unit blasting boundary is defined by the line connecting the large-scale mining access road 8 and the upper sub-section ore extraction access road and the ore body boundary of the peach-shaped ore pillar 12 above it. Medium-deep hole blasting is used to extract ore in the large-scale mining access road unit. Shallow holes and medium-deep holes are laid in the small-scale mining access road to mine the ore between the large-scale access road units.
[0038] By optimizing the borehole layout, blasting units are defined by the line connecting the large-scale mining approach and the upper sub-section ore extraction approach, as well as the boundary of the ore body above the peach-shaped pillar 12, thus arranging large and small ore block units alternately. Medium-deep hole blasting is used to mine the large ore block units containing the peach-shaped pillar, while shallow hole blasting is used to mine the small ore block units between the large ore block units.
[0039] 4) Blasting ore extraction: Based on the overburden descent rate, the stability of the bulk material, and the size of the area where the support pressure increases, the lag distance for mining operations between simultaneously mining blocks is determined to be 15m. For example... Figure 10 As shown, deep-hole blasting is performed first to extract ore, and then shallow-hole blasting is performed after the upper bulk material has stabilized. Blasting is carried out step by step, one approach at a time (multiple approaches are also possible), and ore is extracted after each blast. Blasting and ore extraction are carried out in a cycle, which is not a differential blasting.
[0040] In the above method, the fresh air flows into the isolation pillar mining area through the intake air shaft, the mining ramp, the connecting roadway, and the layered transport roadway. After passing through the working face, the polluted air enters the upper horizontal return air roadway through the pedestrian ventilation shaft and is discharged to the surface through the return air system.
[0041] To demonstrate the effectiveness of the present invention, the method of the present invention is compared with the prior art under the same conditions:
[0042] Table 1 Comparison of mining effectiveness
[0043]
[0044] The recovery results are shown in Table 1 above. Compared with the existing caving or backfilling methods, the recovery rate of the combined deep-hole and shallow-hole recovery method in this invention is increased by 20% to 40%. Compared with the three existing access-caving combined recovery methods, the recovery rate of the method in this invention is also higher. Moreover, the method in this invention does not require the complex and cumbersome operation of the access-caving combined recovery method. The amount of engineering work, cost and cycle are much lower than the access-caving combined recovery method. The amount of tunneling work (the amount of engineering work to excavate roadways in the ore block) is reduced by about 80%, the relative recovery cost is reduced by about 40%, the recovery time is reduced by more than 50%, and there is no need for backfilling and maintenance.
[0045] In summary, the method of the present invention can effectively improve the recovery rate and efficiency of residual ore in isolated pillars, and has the advantages of small engineering workload, low cost, short cycle, low consumption of blasting explosives, and low waste rock mixing rate, which is of great practical significance for the recovery of mineral resources.
[0046] The above embodiments are merely illustrative examples of the technical solutions of the present invention. The efficient recovery method combining medium-deep and shallow boreholes involved in the present invention is not limited to the content described in the above embodiments, but is defined by the scope of the claims. Any modifications, additions, or equivalent substitutions made by those skilled in the art based on these embodiments are within the scope of protection claimed by the claims of the present invention.
Claims
1. A highly efficient mining method combining medium-deep and shallow boreholes for mining isolation pillars and peach-shaped pillars left after the conversion from caving to backfilling mining, characterized in that, Includes the following steps: Step 1, Excavating the mining access road: A large-scale mining access road is excavated at the bottom of the isolation pillar, directly opposite the ridge of the segmented residual peach-shaped pillar above it, forming multiple large-scale mining access roads spaced horizontally. Meanwhile, small-scale mining access roads are excavated between adjacent large-scale mining access roads and at the bottom of the isolation pillar, directly opposite the upper-level stratified ore extraction access road. These serve as caving mining operation space, blasting compensation space, and ore extraction access roads, forming multiple small-scale mining access roads spaced horizontally. The large-scale and small-scale mining access roads are continuously alternated. Step 2, Drilling and Hole Layout: The unit blasting boundary is defined by the line connecting the large-scale mining access road and the upper sub-section ore extraction road and the ore body boundary of the peach-shaped pillar above it. Medium-deep hole blasting is used to extract ore within the large-scale mining access road unit, and large ore block units containing peach-shaped pillars are mined. Small-scale mining access roads use shallow hole blasting to mine small ore block units between large-scale access roads. Step 3: Detonate ore by blasting; In step 1, the large-scale mining access road is directly opposite the ridge of the upper segmented peach-shaped ore pillar, and the small-scale mining access road is directly opposite the upper stratified ore extraction access road. The large and small-scale mining access roads are arranged alternately. In step 3, the ore is first extracted by medium-deep hole blasting, and then shallow hole blasting is performed after the upper bulk material has stabilized. In step 3, blasting is carried out step by step, and ore is extracted after each blast. The blasting and ore extraction are carried out in a cycle.
2. The efficient recovery method combining medium-deep and shallow boreholes according to claim 1, characterized in that: in, In step 1, the dimensions of the large-scale mining access road are designed to be (3×3m) to (5×5m), and the dimensions of the small-scale mining access road are designed to be (2.5×2.5m) to (3.5×3.5m).
3. The efficient recovery method combining medium-deep and shallow boreholes according to claim 1, characterized in that: in, The isolation pillar is a reserved isolation pillar used to separate the lower middle level backfill mining area from the upper middle level caving mining area. The peach-shaped pillar is the residual ore body of the last segment of the upper middle level bottomless sublevel caving mining.
4. The efficient recovery method combining medium-deep and shallow boreholes according to claim 1, characterized in that: in, The height of the isolation pillar is 9-15m.
5. The efficient recovery method combining medium-deep and shallow boreholes according to claim 1, characterized in that: in, In step 3, the lag distance for the inter-path mining operation is determined based on the overburden descent rate, the stability of the loose material, and the size of the area where the support pressure increases.
6. The efficient recovery method combining medium-deep and shallow boreholes according to claim 5, characterized in that: in, In step 3, the lag distance between mining blocks is not less than 10m.
7. The efficient recovery method combining medium-deep and shallow boreholes according to claim 1, characterized in that: in, Before tunneling and mining, make full use of the existing development works in the mining area to arrange the isolation pillars and peach-shaped pillars for the mining and cutting of residual ore. Combine the segmented rock drilling roadways, segmented connecting roadways, mining slope roadways and segmented vein roadways to set up the layered transportation roadways and connecting roadways for the mining area of residual ore.