High-recovery-rate step-by-step mechanized mining method for gently inclined thin ore body

Abstract

The invention discloses a step-by-step mechanized mining method for a gently inclined thin ore body with a high recovery rate. Comprising the following steps that S1, a stope is divided, an ore body is divided into panels, a plurality of mining units are arranged in the trend of the panels, and panel interval columns are reserved between the adjacent panels in the trend; when the inclination angle of the ore body is 0-10 degrees, a stope is arranged in the mining unit in the vertical direction; when the inclination angle of the ore body ranges from 10 degrees to 20 degrees, the stope is arranged in a pseudo-inclined mode in the mode that a certain included angle is formed between the stope and the trend, and meanwhile the slope of the stope does not exceed 10 degrees; s2, a mining preparation cutting project is arranged in the mining unit, S3, each ore block is divided into a first-step stope and a second-step stope, and mining is carried out step by step; s4, after stoping of the whole single stope is completed, a subsequent filling process is adopted in time to treat the goaf; according to the method, the ore block structure and the stoping sequence are optimized, the top plate and the surrounding rock are supported through the one-step high-strength filling body, ground pressure management is remarkably improved, the stope operation environment is improved, and finally the goals of safety, high efficiency and high recovery rate are achieved.

Description

Technical Field

[0001] This invention relates to the field of mining technology, and in particular to a step-by-step mechanized mining method for gently dipping thin ore bodies with high recovery rates. Background Technology

[0002] Gently dipping and near-horizontal thin ore bodies are a common type of ore body in underground mining that is difficult to fully recover. How to improve the recovery rate and reduce the impact of mining has always been a technical challenge in the mining industry. The main problems are low working space and low level of mechanization, high proportion of pillars and difficulty in recovery, and large exposed roof area with the risk of sudden collapse.

[0003] In existing technologies, the full-face method and room-and-pillar method are the main mining methods for this type of ore body. To maintain stope stability and ensure mining safety, it is necessary to leave large permanent pillars (such as strip pillars, point pillars, etc.) to support the roof, resulting in generally low recovery rates. These permanent pillars account for a high proportion of the ore volume, and in traditional mining methods used for thin ore bodies, the preparatory works cannot safely recover these pillars, leading to a large amount of ore being permanently left underground, resulting in resource waste. The limited mining height of thin ore bodies severely restricts the application of trackless mechanized mining equipment. Although low-profile specialized equipment exists, existing technical solutions often fail to adequately consider how to construct a continuous and unobstructed operating channel system throughout the entire ore block. Summary of the Invention

[0004] To address the long-standing core problems in mining gently dipping thin ore bodies, such as low ore recovery rate, low level of mechanization, difficulty in controlling the stability of the stope roof, and low safety and reliability, this application provides a step-by-step mechanized mining method for gently dipping thin ore bodies with high recovery rate.

[0005] This application provides a step-by-step mechanized mining method for gently dipping thin ore bodies with high recovery rate, employing the following technical solution:

[0006] A step-by-step mechanized mining method for gently dipping thin ore bodies with high recovery rate, characterized by comprising the following steps:

[0007] S1. Mining area division: The ore body is divided into panels, and multiple mining units are arranged along the strike of the panels. Inter-panel pillars are left between adjacent panels along the strike. When the dip angle of the ore body is 0~10°, the mining area is arranged perpendicular to the strike within the mining unit. When the dip angle of the ore body is 10~20°, the mining area is arranged in a pseudo-dipping manner with a certain angle to the strike, and the slope of the mining area does not exceed 10°.

[0008] S2. Arrange the preparatory cutting works within the mining unit, including: panel roadways, panel connecting uphill roadways, stope connecting cross roadways, stope connecting roadways, stope cutting cross roadways, and stope cutting uphill roadways;

[0009] S3. Divide each ore block into a first-step mining area and a second-step mining area, and carry out step-by-step mining;

[0010] S4. After the entire single mining area has been mined out, the subsequent backfilling process should be used to treat the goaf in a timely manner.

[0011] Optionally, in step S2, multiple parallel panel roadways along the strike of the ore body are arranged to divide the ore body into panels.

[0012] Between two adjacent panel roadways, multiple panel connecting roads are arranged at intervals to divide the panel into regular mining units.

[0013] In the middle of the mining unit, a continuous inter-block pillar is left along the strike; in the middle of the connecting uphill between two adjacent panels, a stope connecting cross passage is arranged to evenly divide each mining unit into two identical blocks.

[0014] In the cross roadway connecting the mining area and the roadway in the panel area, the mining area connecting roadway is excavated to both sides;

[0015] A cutting ramp is arranged between the panel roadway and the stope connecting cross roadway to connect the panel roadway and the stope connecting cross roadway; a cutting cross roadway is arranged at the bottom of the cutting ramp perpendicular to the stope direction.

[0016] Optionally, in step S3, during mining, a low-profile rock drilling rig is used to drill horizontal parallel blast holes in the cutting cross passage to excavate the entire span of the ore chamber or pillar in one go. Explosives are manually loaded, detonated by digital electronic detonators, and detonated by an electric detonation network equipped with a detonator.

[0017] Optionally, when the ore body thickness is greater than 2.0m, the entire thickness of the ore body is mined in one go; when the ore body thickness is between 1.5 and 2.0m, a 2.0m thick layer of ore and rock is mined in one go using a mixed mining method to meet the minimum operating height of the equipment; when the ore body thickness is between 0.8 and 1.5m, the ore body and surrounding rock are mined in two layers. First, the upper 2.0m thick layer of surrounding rock is collapsed; after all the collapsed waste rock is mined, the lower ore body is then mined.

[0018] Optionally, a loading chamber may be installed in the connecting cross passage of the stope. The floor of the loading chamber must be lower than that of the connecting cross passage to ensure that the loader can load the ore smoothly. A remote-controlled loader may be used in the stope to load the collapsed ore and transport it to the loading chamber in the connecting cross passage of the stope, where it will be loaded into the parked mining truck.

[0019] Optionally, in step S4, after the entire single stope has been mined out, the goaf is treated with subsequent backfilling technology in a timely manner; before backfilling the goaf, the connecting passages of each stope leading to the goaf are sealed with backfilling retaining walls; 2 to 4 drainage corrugated pipes are suspended in the goaf and led out from the bottom of the backfilling retaining walls, wherein the first-step stope is backfilled with high-strength cemented backfill and the second-step stope is backfilled with low-strength cemented backfill.

[0020] Optionally, before backfilling, based on the dip angle of the ore body, a backfilling connecting shaft and a backfilling operation roadway are constructed above the adjacent two-step mining area. Backfilling pipelines are suspended in the backfilling operation roadway, and the discharge port of the backfilling pipeline is ensured to be at least 2.0m higher than the roof of the goaf to achieve a better backfilling and roof connection effect.

[0021] Optionally, once the entire panel has been mined and the panel roadways are no longer used as return air roadways, the pillars between panels and the pillars between blocks can be recovered; the pillars to be recovered are all continuous pillars, and the mining process of layered filling is adopted, and the recovery is carried out by the "retreat mining" method.

[0022] When recovering each continuous pillar, the existing transport roadway in the pillar is first used as a cutting roadway. After widening, a bottom-pulling space of about 2.0m high is formed. Then, the top is pulled back to the full thickness of the pillar. Finally, the goaf is filled in multiple times.

[0023] In summary, this application includes the following beneficial technical effects:

[0024] This application minimizes ore loss by employing a phased mining and differentiated backfilling process, and designing recyclable continuous pillars; it creates accessibility for low-profile trackless equipment by flexibly adopting full-thickness or layered mining schemes based on the ore body thickness, thereby achieving mechanized operations to improve safety and efficiency; and it significantly improves ground pressure management and the working environment of the stope by optimizing the ore block structure and mining sequence, and utilizing a one-step high-strength backfill to support the roof and surrounding rock, ultimately achieving the goals of safety, high efficiency, and high recovery rate. Attached Figure Description

[0025] Figure 1 This is a diagram of a gently inclined, stepwise mechanized mining method with high recovery rate provided by the present invention;

[0026] Figure 2 yes Figure 1 Sectional view along the middle II-II direction;

[0027] Figure 3 This is a diagram of a high-recovery-rate, gently inclined, step-by-step mechanized mining method with pseudo-inclined arrangement provided by the present invention.

[0028] Figure 4 yes Figure 3 Sectional view along the middle II-II direction;

[0029] Explanation of reference numerals in the attached figures:

[0030] 1. Panel pillar; 2. Block pillar; 3. First-stage stope; 4. Second-stage stope; 5. Ore heap; 6. Upper panel roadway; 7. Lower panel roadway; 8. Stope connecting cross roadway; 9. Stope connecting roadway; 10. Stope cutting cross roadway; 11. Stope cutting uphill; 12. First-stage backfill; 13. Second-stage backfill; 14. Backfill retaining wall; 15. Ore body; 16. Surrounding rock; 17. Anchor bolt. Detailed Implementation

[0031] The following is in conjunction with the appendix Figure 1-4 This application will be described in further detail.

[0032] This application discloses a step-by-step mechanized mining method for gently dipping thin ore bodies with high recovery rate, the method comprising the following steps:

[0033] S1. Mining area division: The ore body is divided into panels, and multiple mining units are arranged along the strike of the panels. Inter-panel pillars are left between adjacent panels along the strike. When the dip angle of the ore body is 0~10°, the mining area is arranged perpendicular to the strike within the mining unit. When the dip angle of the ore body is 10~20°, the mining area is arranged in a pseudo-dipping manner with a certain angle to the strike, and the slope of the mining area does not exceed 10°.

[0034] S2. Arrange the preparatory cutting works within the mining unit, including: panel roadways, panel connecting uphill roadways, stope connecting cross roadways, stope connecting roadways, stope cutting cross roadways, and stope cutting uphill roadways;

[0035] S3. Divide each ore block into a first-step mining area and a second-step mining area, and carry out step-by-step mining;

[0036] S4. After the entire single mining area has been mined out, the subsequent backfilling process should be used to treat the goaf in a timely manner.

[0037] Example 1;

[0038] refer to Figure 1 and Figure 2 The dip angle of the ore body is 0~10°, so the mining unit is set up with a step-by-step stop along the vertical strike. The ore body designed for mining is a gently dipping thin ore body with a thickness of 0.8~3.0m and a dip angle of 0~10°. The ore body is divided into panels for mining, and mining units are arranged along the strike of the panels. Vertical panel roadways between adjacent panels are reserved with inter-panel pillars. Within the panel roadways, every 100~120m along the strike is divided into a mining unit for mining.

[0039] The specific mining steps are as follows:

[0040] 1. Divide the mining area into mining units;

[0041] 2. First, the ore body is divided into panels by arranging panel roadways along the strike of the ore body. The cross-sectional dimensions of the panel roadways are 4.5×4.3m.

[0042] 3. Between two adjacent panel roadways, a panel connecting incline is arranged approximately every 100m to serve as a ventilation and transportation passage, dividing the panel into regular mining units. The cross-sectional dimensions of the panel connecting incline are 4.5×4.3m.

[0043] 4. At the midpoint of the mining unit, a continuous inter-block pillar is left along the strike. Within the inter-block pillar, between two adjacent panel connecting uphill sections, a stope connecting cross passage is arranged, evenly dividing each mining unit into two identical blocks and serving as a ventilation and transportation channel during mining. The cross-sectional dimensions of the stope connecting cross passage are 4.5 × 4.3 m.

[0044] 5. Within the ore block, a parallel connection is made to the hillside to divide the ore block into regular one-step and two-step stopes, with a stope span of 10-12m. No top pillars, bottom pillars, or inter-pillars are left between the stopes.

[0045] 6. In the cross roadways connecting the mining area and the roadways in the upper and lower panels, at corresponding positions every 10 to 12 meters, mining area connecting roads are excavated to both sides at an angle of 40 to 50 degrees with the roadways to connect the mining areas. The cross-sectional specifications of the mining area connecting roads are 3.5 × 3.0 meters.

[0046] 7. In the first and second step mining areas, a cutting ramp is arranged between the panel roadways and the connecting cross roadways of the mining area to connect the panel roadways and the connecting cross roadways of the mining area, providing conditions for ventilation in the mining area. At the same time, it provides compensation space for blasting operations. The cross-sectional dimensions of the cutting ramp in the mining area are 3.5×3.0m.

[0047] 8. A cutting cross passage is arranged at the bottom of the cutting incline, perpendicular to the mining area, to create initial working space for subsequent mining. The cross-sectional dimensions of the cutting cross passage are 3.5 × 3.0 m.

[0048] 9. Each ore block is divided into first-stage and second-stage mining areas, which are mined in an alternating order. First, the two first-stage mining areas are mined. After the first-stage mining areas are completed, they are promptly backfilled and cured to reach the design strength and be sufficient to support the roof of the second-stage mining area before the second-stage mining area is resumed.

[0049] 10. During the mining of the ore body, a DD2 N low-profile rock drilling rig is used to drill horizontal parallel blast holes in the cutting cross passage. The blast hole depth is 3.0~3.5m. The entire span of the stope is mined in one go. No. 2 rock explosives are manually loaded and detonated by digital electronic detonators and electric detonation network with detonators.

[0050] 11. When the ore body thickness is greater than 2.0m, the entire thickness of the ore body is mined in one go; when the ore body thickness is between 1.5 and 2.0m, a mixed ore and rock mining method is used to mine the 2.0m thick ore and rock layer in one go to meet the minimum operating height of the equipment; when the ore body thickness is between 0.8 and 1.5m, the ore body and surrounding rock are mined in two layers. First, the upper 2.0m thick surrounding rock of the ore body is collapsed; after all the collapsed waste rock is mined, the lower ore body is then mined.

[0051] 12. Fresh air enters the working face from the lower panel roadway via the panel connecting uphill roadway, the working face connecting cross roadway, and the working face connecting roadway. After cleaning the working face, the polluted air is collected in the upper panel roadway via the goaf and the upper working face connecting roadway, and then discharged into the centralized return air shaft via the panel return air uphill roadway. After the mining of each working face is completed, all working face connecting roads should be sealed in a timely manner to reduce short circuits, cross-ventilation, and air leakage, and to ensure unobstructed ventilation.

[0052] 13. After ensuring that the air quality in the mining area meets the working conditions, use a prying trolley or manual labor to remove loose rocks from the roof. When the stability of the surrounding rock of the roof is poor or there are cracks in the roof that affect safety, use anchor bolts to support the relevant locations.

[0053] 14. A loading chamber shall be installed at a fixed location in the connecting cross passage of the stope. The floor of the loading chamber shall be lower than that of the connecting cross passage to ensure that the loader can load the ore smoothly. In the stope, the WJ-1.5 remote-controlled loader shall scoop up the collapsed ore and transport it to the loading chamber in the connecting cross passage of the stope, where it shall be loaded into the parked mining truck.

[0054] 15. After the entire mining area is completed, the goaf should be treated promptly using subsequent backfilling technology. Before backfilling, all connecting passages leading to the goaf should be sealed with backfill retaining walls. Two to four drainage corrugated pipes should be suspended in the goaf, extending from the bottom of the backfill retaining walls. High-strength cemented backfill should be used for the first-stage mining area, while low-strength cemented backfill should be used for the second-stage mining area.

[0055] 16. To ensure the quality of roof connection during the first-stage stope filling, before filling, a filling connecting shaft and filling operation roadway shall be constructed above the adjacent second-stage stope, based on the dip angle of the ore body. Filling pipelines shall be suspended within the filling operation roadway, ensuring that the discharge port of the filling pipeline is at least 2.0m above the roof of the goaf to achieve a better roof connection effect.

[0056] 17. Once the entire panel has been mined and the panel roadways are no longer used as return air roadways, the pillars between panels and the pillars between blocks can be recovered. The pillars to be recovered are all continuous pillars, and the mining process of layered filling is adopted, and the recovery is carried out by the "retreat mining" method.

[0057] 18. When recovering continuous pillars, first utilize the existing haulage roadway in the middle of the pillar as a cutting roadway, widening it to create a bottom-pulling space of approximately 2.0m in height. Then, use the roof-lifting method to mine back to the full thickness of the pillar, and finally fill the goaf in two or three stages. When recovering the pillar, leave a 0.5-1.0m thick ore layer as a "wall protection" to reduce the dilution rate. When constructing bottom-pulling and roof-lifting on both sides of the continuous pillar, use smooth blasting as much as possible to ensure the "verticality" and dimensional specifications of the pillar.

[0058] Example 2;

[0059] refer to Figure 3 and Figure 4 In this embodiment, the designed mining ore body is a gently dipping thin ore body with a thickness of 0.8~3.0m and a dip angle of 10~20°. The ore body is divided into panels for mining, with each panel being 300~400m long. Mining units are arranged along the strike of the panels, and inter-panel pillars are left between adjacent panels along the strike. The mining units are divided in the panel roadways at a certain angle to the strike.

[0060] Therefore, in this embodiment, the panel connecting incline is arranged at a certain angle to the strike, with a pseudo-inclination and a slope of no more than 10°, serving as the main channel for ore transportation and ventilation. The panel roadway cross-section is 4.5×4.3m. At the same time, the first and second step stopes are also arranged at an inclination, parallel to the panel connecting incline, i.e., the pseudo-inclination direction; the remaining steps are not significantly different from those in Embodiment 1.

[0061] This invention provides a high-recovery, step-by-step mechanized mining method for gently dipping thin ore bodies. By adopting a comprehensive mining method that combines "step-by-step mining, timely backfilling, mechanized operation and optimized roadway layout", it effectively solves the problems of low recovery rate, poor safety and low level of mechanization in traditional mining methods for gently dipping thin ore bodies. Specifically, by dividing the ore block into a first-stage stope and a second-stage stope, and adopting an orderly mining process of "mining the first-stage stope first, high-intensity backfilling, and then mining the second-stage stope," the stability of the stope structure is significantly improved, reducing the risk of roof collapse. Furthermore, the "wall protection + smooth blasting" technology used in the subsequent backfilling and pillar recovery stages greatly increases the overall recovery rate and reduces the dilution rate. Simultaneously, based on the thickness and dip characteristics of the ore body, this invention flexibly adopts strategies of full-thickness mining or layered mining, and vertical or pseudo-dipping layouts, and is equipped with low-profile drilling rigs, loaders, and other trackless equipment, enabling mechanized continuous operation under gently dipping thin ore body conditions. This ensures operational safety while improving mining efficiency and recovery rate. In addition, by optimizing the ventilation system and setting up auxiliary projects such as cutting roadways and backfilling connection shafts, the working environment and backfilling roof connection quality of the stope are further enhanced. In summary, this invention achieves high recovery rate and high efficiency mining of gently dipping thin ore bodies while ensuring safety, and improves the safety and mechanization level of mining, thus having significant technical and economic benefits.

[0062] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A step-by-step mechanized mining method for gently dipping thin ore bodies with high recovery rate, characterized in that: Includes the following steps: S1. Mining area division: The ore body is divided into panels, and multiple mining units are arranged along the strike of the panels. Inter-panel pillars are left between adjacent panels along the strike. When the dip angle of the ore body is 0~10°, the mining area is arranged perpendicular to the strike within the mining unit. When the dip angle of the ore body is 10~20°, the mining area is arranged in a pseudo-dipping manner with a certain angle to the strike, and the slope of the mining area does not exceed 10°. S2. Arrange the preparatory cutting works within the mining unit, including: panel roadways, panel connecting uphill roadways, stope connecting cross roadways, stope connecting roadways, stope cutting cross roadways, and stope cutting uphill roadways; S3. Divide each ore block into a first-step mining area and a second-step mining area, and carry out step-by-step mining; S4. After the entire single mining area has been mined out, the subsequent backfilling process should be used to treat the goaf in a timely manner.

2. The step-by-step mechanized mining method for gently dipping thin ore bodies with high recovery rate according to claim 1, characterized in that: In step S2, multiple parallel panel roadways along the strike of the ore body are arranged to divide the ore body into panels. Between two adjacent panel roadways, multiple panel connecting roads are arranged at intervals to divide the panel into regular mining units. In the middle of the mining unit, a continuous inter-block pillar is left along the strike; in the middle of the connecting uphill between two adjacent panels, a stope connecting cross passage is arranged to evenly divide each mining unit into two identical blocks. In the cross roadway connecting the mining area and the roadway in the panel area, the mining area connecting roadway is excavated to both sides; A cutting ramp is arranged between the panel roadway and the stope connecting cross roadway to connect the panel roadway and the stope connecting cross roadway; a cutting cross roadway is arranged at the bottom of the cutting ramp perpendicular to the stope direction.

3. The step-by-step mechanized mining method for gently dipping thin ore bodies with high recovery rate according to claim 2, characterized in that: In step S3, during mining, a low-profile rock drilling rig is used to drill horizontal parallel blast holes in the cutting cross passage to excavate the entire span of the ore chamber or pillar in one go. Explosives are manually loaded, detonated by digital electronic detonators, and detonated by an electric detonation network equipped with a detonator.

4. The step-by-step mechanized mining method for gently dipping thin ore bodies with high recovery rate according to claim 3, characterized in that: When the ore body thickness is greater than 2.0m, the entire thickness of the ore body is mined in one go; when the ore body thickness is between 1.5 and 2.0m, the ore and rock mixed mining method is used to mine the 2.0m thick ore and rock in one go to meet the minimum operating height of the equipment; when the ore body thickness is between 0.8 and 1.5m, the ore body and surrounding rock are mined in two layers. First, the upper 2.0m thick surrounding rock of the ore body is collapsed; after all the collapsed waste rock is mined, the lower ore body is then mined.

5. A step-by-step mechanized mining method for gently dipping thin ore bodies with high recovery rate according to claim 4, characterized in that: A loading chamber is set up in the connecting cross roadway of the stope. The floor of the loading chamber must be lower than that of the connecting cross roadway of the stope to ensure that the loader can load the ore smoothly. A remote-controlled loader is used in the stope to scoop up the collapsed ore and transport it to the loading chamber in the connecting cross roadway of the stope, where it is loaded into the parked mining truck.

6. A step-by-step mechanized mining method for gently dipping thin ore bodies with high recovery rate according to claim 5, characterized in that: In step S4, after the entire single stope has been mined out, the goaf is treated with subsequent backfilling process in a timely manner. Before backfilling the goaf, the connecting passages of each stope leading to the goaf are sealed with backfilling retaining walls. Two to four drainage corrugated pipes are suspended in the goaf and led out from the bottom of the backfilling retaining walls. The first-step stope is backfilled with high-strength cemented backfill, and the second-step stope is backfilled with low-strength cemented backfill.

7. A step-by-step mechanized mining method for gently dipping thin ore bodies with high recovery rate according to claim 6, characterized in that: Before backfilling, based on the dip angle of the ore body, a backfilling connecting shaft and a backfilling operation roadway are constructed above the adjacent two-step mining area. Backfilling pipelines are suspended in the backfilling operation roadway, and the discharge port of the backfilling pipeline is ensured to be more than 2.0m higher than the roof of the goaf to achieve a better backfilling and roof connection effect.

8. A step-by-step mechanized mining method for gently dipping thin ore bodies with high recovery rate according to claim 7, characterized in that: Once the entire panel has been mined and the panel roadways are no longer used as return air roadways, the panel pillars and block strike pillars can be recovered. All pillars to be recovered are continuous pillars, and the mining process of layered filling is adopted, and the "retreat mining" method is used for recovery. When recovering each continuous pillar, the existing transport roadway in the pillar is first used as a cutting roadway. After widening, a bottom-pulling space of about 2.0m high is formed. Then, the top is pulled back to the full thickness of the pillar. Finally, the goaf is filled in multiple times.

Images