Multi-process collaborative mechanized filling mining method for steeply inclined thin vein

Abstract

The invention discloses a steeply inclined thin vein multi-process collaborative mechanized filling mining method, and belongs to the technical field of thin vein mining. The method comprises the steps that a mine is constructed, a standard mining roadway is constructed, and a undercut roadway is constructed; surrounding rocks on the two sides of the ore body are pre-reinforced, high-layer upward parallel holes are constructed, and blast holes in the ore body and blast holes in the surrounding rocks are formed; the method comprises the following steps: caving an ore body and removing ore, then caving surrounding rock and leveling a stope, carrying out coping on a layered combined roadway, and after the layered combined roadway finishes coping, directly carrying out cemented filling by virtue of a height difference generated between the layered combined roadway and the stope by virtue of coping; after the strength meets the requirement, the next cycle is carried out; the continuous collaborative operation of rock drilling, supporting, mining, ore removal and filling can be achieved, and the resource recovery rate is increased; the problems of low recovery rate, high labor intensity and low safety production level of an existing wall cutting and filling method for the thin gold vein with unstable surrounding rock and steeply inclined occurrence are solved.

Description

Technical Field

[0001] This invention belongs to the field of thin vein mining technology, specifically a multi-process coordinated mechanized backfilling mining method for steeply inclined thin veins. Background Technology

[0002] my country is rich in gold resources, and the occurrence of ore bodies is controlled by multiple factors such as geological structure, magmatic activity, and stratigraphic lithology. Gold ore bodies of different genesis types vary significantly in spatial distribution, morphology, scale, and ore characteristics. Among them, volcanic hydrothermal and tectonic hydrothermal gold deposits are the two most important types of gold deposits in my country, accounting for more than 60% of the country's total proven reserves. According to incomplete statistics, in volcanic hydrothermal and tectonic hydrothermal gold deposits, gold ore bodies with a thickness of less than 2.0m and unstable surrounding rock account for more than 65%. The characteristics of such ore bodies can be summarized as: thin and varied in shape, with well-developed structures and fractured rock masses, resulting in a high risk of stope instability during mining. Therefore, it is essential to study safe and efficient mining technologies for such ore bodies.

[0003] Currently, for high-grade gold veins with thin and unstable surrounding rock, the cut-and-fill mining method is commonly used in China. This method is characterized by: ventilation shafts on both sides of the stope, and a ore pass in the middle of the stope; with electric scraper extraction. Its advantages are: a small cut-to-fill ratio and low recovery cost; its disadvantages are: low stope production capacity; high labor intensity; limited space for stope support operations; insufficient control of the surrounding rock, resulting in a high risk of instability; and a low resource recovery rate due to the presence of pillars. Summary of the Invention

[0004] This invention overcomes the shortcomings of the prior art and proposes a multi-process coordinated mechanized backfilling mining method for steeply inclined thin veins; it solves the problems of low recovery rate, high labor intensity and low safety level of the existing wall-cutting and backfilling method for thin gold veins with unstable surrounding rock and steep inclination.

[0005] This invention is achieved through the following technical solution: A multi-stage coordinated mechanized backfilling mining method for steeply dipping thin veins includes the following steps: S1. Mine infrastructure construction and construction of mining access roadways: The mine infrastructure is constructed to the lowest middle section. In the lower footing of the lowest middle section ore body, the mining area ramps, segmented roadways, layered connecting roadways, stopes chutes and ventilation shafts are constructed according to the design parameters. S2, Construction bottom tunnel; S3. Pre-reinforce the surrounding rock on both sides of the ore body; S4. Construct high-level upward parallel holes to form blast holes in the ore body and blast holes in the surrounding rock. S5. The ore body collapses and ore is extracted, then the surrounding rock collapses and the stope is leveled; S6. Apply roof pressure to the layered roadway. After the roof pressure is completed, use the height difference between the layered roadway and the stope to directly perform cemented backfilling. Once the strength meets the requirements, proceed to the next cycle.

[0006] Furthermore, the stope is divided into four working faces according to the process of "rock drilling and support, mining and ore extraction, wall cutting and backfilling and cemented backfilling". Ventilation shafts, layered connecting roadways and stope chutes are set at intervals along the length of the working face.

[0007] Furthermore, the working face is 200m long, with ventilation shafts every 50m and layered connecting roadways and ore chutes every 100m.

[0008] Furthermore, mines using ramp development will use the main ramp as a mining area ramp; mines using other development methods or with a strike length of more than 300m will have a mining area ramp every 300 to 500m.

[0009] Furthermore, the slope of the layered connecting roadway is 0 to 20%. The first layered connecting roadway, which connects to the middle section, is constructed downwards to the ore body at a slope of 20%. This layered connecting roadway is connected to the middle section roadway or segment roadway and serves as a transportation channel for personnel, equipment, materials and ore in the mining area, as well as an intake airway and a safety exit in the mining area.

[0010] Furthermore, an external loading roadway is laid out at the bottom of the ore pass in the middle transport roadway.

[0011] Furthermore, in step S3, the ore and rock are artificially separated, and only the surrounding rock is reinforced with anchor cables and steel mesh. The anchor cables are arranged in a "quincunx" pattern.

[0012] Furthermore, in step S4, the construction of high-level upward parallel holes is carried out: after the bottom roadway and surrounding rock reinforcement are completed, upward parallel holes are constructed in the ore body and surrounding rock respectively using a mining trolley. The spacing between blast holes in the ore body is 0.6m and the spacing between blast holes in the surrounding rock is 0.8m. The arrangement of blast holes is in a "quincunx" shape.

[0013] Furthermore, in step S5, the ore body is caved and ore is extracted: the ore body is caved from one side of the ventilation shaft to the other side using blasting methods, and the ore is extracted using a leveling and haulage machine; the surrounding rock is caved and the mining area is leveled: a large-scale wall-cutting and filling process is adopted to blast and fill the mining area with the surrounding rock on both sides of the ore body, providing working space for subsequent mechanized rock drilling, ore extraction and leveling.

[0014] Furthermore, in step S6, the adhesive filling is carried out directly without constructing a filling retaining wall, and working space is left at the same time as the adhesive filling.

[0015] The beneficial effects of this invention compared to the prior art are as follows: This invention enables continuous and coordinated operations of rock drilling, support, mining, ore extraction, and backfilling, and can improve resource recovery rate, reduce labor intensity, and enhance safety production levels. It achieves pillarless, multi-stage, coordinated, continuous, mechanized wall cutting and cemented backfilling in steeply inclined, thin veins. The characteristics of this invention's method are: 1) The working face is divided into four processes according to the direction of "rock drilling and support, mining and ore extraction, and wall cutting and backfilling and cemented backfilling", so as to realize continuous and efficient collaborative operation of processes such as "rock drilling, support, mining, ore extraction and backfilling", which can increase the utilization coefficient of traditional mine rooms from 0.4 to more than 0.8; 2) No pillars are set between the working faces of the process, and no top or bottom pillars are set between the intermediate sections. While improving the resource recovery rate, the amount of repeated bottom pulling work between intermediate sections is reduced, thereby realizing continuous filling mining between the strike and intermediate sections. 3) Mechanized rock drilling equipment was used to construct 3.75m high-layer upward parallel holes for ore extraction and wall cutting, increasing the traditional mine production capacity from 30t / d to 70t / d; 4) The "ore-rock separation and pre-reinforcement" technology is adopted, which uses anchor cables and mesh to pre-reinforce only the surrounding rock on both sides of the ore body, thereby reducing dilution during mining and improving the stability of the stope.

[0016] The method of this invention has significant advantages over existing cut-and-fill mining methods: First, the work area is divided according to the process to achieve efficient and coordinated operation of multiple processes and improve the utilization efficiency of the ore blocks; Secondly, the bottoming process is carried out only once in the lowest mining section, and no top or bottom pillars are set between the sections, so as to realize continuous mining from the lowest mining section to the return air elevation, thereby improving the stope recovery rate. Third, by significantly reducing the wall cutting and filling process, the working space for mechanized equipment is provided, and the rock drilling, ore extraction and leveling processes that limit the mine's production capacity are changed from manual operations to mechanized operations, which greatly reduces labor intensity and improves labor productivity. Fourth, separate pre-reinforcement measures are taken for the surrounding rocks on both sides of the ore body to reduce dilution while improving the stability of the ore stope and the level of safe production. Fifth, the boundaries of the ore blocks are no longer artificially defined along the strike. Ventilation shafts are set every 50m, and layered connecting roadways and ore chutes are set every 100m. There are no pillars between the ore blocks along the strike. On the one hand, this solves the problem of low recovery rate due to the inability to recover pillars. On the other hand, it provides working space for mechanized continuous drilling, ore extraction and leveling. Personnel and equipment are no longer configured according to the ore blocks. They can be considered in a coordinated manner for the whole mine according to the process, so as to realize assembly line operation and improve production efficiency. Attached Figure Description

[0017] Figure 1 This is a layout diagram of the mining and cutting project and the longwall mining face; Figure 2 for Figure 1 BB cross-section diagram in the middle; Figure 3 for Figure 1 CC cross-section view in the middle; Figure 4 This is a layout diagram for "pre-reinforcement of ore-rock separation" and borehole arrangement; Figure 5 for Figure 4 AA section view in the middle; Figure 6 for Figure 5 DD cross-section view in the middle; Figure 7 This is a flowchart of a multi-process, efficient, collaborative, continuous mining technology.

[0018] In the diagram: 2-Sectional roadway; 3-Mining area ramp; 4-Layered connecting roadway; 5-Reach connecting roadway; 6-Mining pass; 7-Intermediate loading roadway; 8-Ventilation riser; 9-Ore body; 10-Surrounding rock; 11-Mining trolley; 12-Blast hole in ore body; 15-Blast hole in surrounding rock. Detailed Implementation

[0019] To make the technical problems to be solved, the technical solutions, and the beneficial effects of this invention clearer, the invention will be further described in detail with reference to the embodiments and accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. The technical solutions of this invention are described in detail below with reference to the embodiments and accompanying drawings, but the scope of protection is not limited thereto.

[0020] This embodiment proposes a multi-process collaborative mechanized backfilling mining method for steeply dipping thin veins. It adopts a mechanized upward wall cutting + cemented continuous backfilling method. The vein being mined is a high-grade thin gold vein with a steeply dipping, structurally altered, unstable surrounding rock, containing 6.973 million tons of ore, 40,536 kg of gold, an average grade of 5.81 g / t, and an average thickness of less than 2.0 m.

[0021] The parameters of the mine are as follows (see appendix for details). Figures 1 to 3 ): 1) Strike length of the stope: The strike is divided into 4 working faces according to the processes of "rock drilling and support, mining and ore extraction, wall cutting and backfilling and cemented backfilling". Each working face is 50m long, and the total working face length is 200m. Ventilation shafts are set every 50m, and layered connecting roadways and stope chutes are set every 100m. Connecting roadways are set between ventilation shafts 8.

[0022] 2) Stope height: The stope height is the middle section height, taken as 60m.

[0023] 3) Segment height: Each middle section is divided into 4 segments, with a segment height of 15m.

[0024] 4) Layer height: The mining trolley 11 is used to drill upward parallel holes with a hole depth of 3.75m and a layer height of 3.75m (approximately 2.0 times that of the current common method).

[0025] 5) Stope width: The minimum working roadway width for rock drilling and ore extraction equipment on the market at present is 2.8m. The stope width designed for this method is 2.8m, of which the ore body thickness is ≤0.8m and the wall cutting width is ≥2.0m (the wall cutting width on one side is ≥1.0m).

[0026] The layout of the stope preparation roadways for the mechanized upward shearing + cemented continuous filling mining method proposed in this application is as follows (see appendix for details). Figures 1 to 3 ): 1) Layout of the mining area ramp 3: Mines using ramp development can use the main ramp as the mining area ramp 3; mines using other development methods or with a strike length of more than 300m can have a mining area ramp 3 every 300-500m. The mining area ramp 3 is used as a passage for personnel and equipment, and also serves as a safety exit and ventilation intake for the mining area.

[0027] 2) Layout of Section 2: Section 2 should be located at approximately 42m below the footwall of the ore body, and can be adjusted appropriately according to the height and slope of the ore body and its layers.

[0028] 3) Layout of ventilation wells 8: A ventilation well 8 is laid out every 50m along the ore body. The ventilation well 8 is only used for ventilation and filling wells and is not used as a pedestrian passage.

[0029] 4) Layout of the mining pass 6: A mining pass 6 is laid out every 100m on one side of the segment roadway 2.

[0030] 5) Layout of Layered Connecting Roadways 4: A layered connecting roadway 4 is laid out every 100m. The slope of the layered connecting roadway 4 is 0 to 20%. The first layered connecting roadway, which connects to the middle section, is constructed downwards to the ore body at a slope of 20%. This roadway connects to the middle section roadway or segment roadway and serves as a transportation channel for personnel, equipment, materials, and ore in the mining area. It also serves as an intake ventilation roadway and a safety exit in the mining area.

[0031] 6) Layout of external loading roadway 7: External loading roadway 7 is laid out at the bottom of the ore pass in the middle section of the transport roadway.

[0032] The "ore-rock separation pre-reinforcement technology" proposed in this application for the mechanized upward shearing + cemented continuous backfill mining method is as follows: The ore and rock were artificially separated, and only the surrounding rock was reinforced using anchor cables and steel mesh. The reinforced area on one side of the surrounding rock was 1.0m wide, with anchor cables 5m long and spaced 0.8m apart, arranged in a "quincunx" pattern. See attached document for details. Figures 4-6 .

[0033] The mining process flow of the mechanized upward cutting wall + cemented continuous backfilling mining method proposed in this application is as follows (see appendix). Figure 7 ): 1) Infrastructure: Infrastructure construction will be carried out in one phase, from the initial design of the development system to the lowest production stage. 2) Construction of mining access roadways: After the completion of the mine infrastructure, the mining area ramp 3, segmented roadways 2, layered connecting roadways 4, stope chute 6 and ventilation shaft 8 are constructed in the footwall of the lowest middle section of the ore body according to the design parameters.

[0034] 2) Construction of the bottom-level tunnel: The bottom-level tunnel is constructed using the same tunnel excavation method as the main tunnel, with a minimum width of 2.8m × 2.8m. Due to the adoption of a bottom-up continuous mining process, the bottom-level tunnel is only constructed in the lowest middle section, and there is no need to reconstruct the bottom-level tunnel for the next middle section mining.

[0035] 3) “Ore-rock separation” pre-reinforcement: As the construction progress of the bottom tunnel is carried out, the surrounding rock 10 on both sides of the ore body 9 is pre-reinforced. The reinforcement method is described above.

[0036] 4) Construction of upward parallel boreholes in high-level sections: After the bottom roadway and surrounding rock reinforcement are completed, upward parallel boreholes are constructed at the ore body 9 and surrounding rock 10 using mining trolley 11, with a borehole depth of 3.75m. The spacing of boreholes 12 in the ore body is 0.6m; the spacing of boreholes 15 in the surrounding rock is 0.8m, and the boreholes are arranged in a "quincunx" pattern.

[0037] 5) Collapsed ore body and ore extraction: The ore body is collapsed from one side of the ventilation shaft 8 to the other side by blasting, and the ore is extracted by the leveling loader 16.

[0038] 6) Collapsed surrounding rock and leveling of the stope: A large-scale wall-cutting and filling process is adopted to blast and fill the surrounding rock 10 within a range of 1.0m on both sides of the ore body 9 into the stope, providing working space for subsequent mechanized rock drilling, ore extraction and leveling.

[0039] 7) Layered connecting roadway roof sealing: After the stope is leveled, layered connecting roadway 4 is sealed with roof sealing, with a single sealing height of 3.75m; 8) Tailings cemented backfill: After the top capping of the layered connecting roadway 4 is completed, cemented backfill is carried out directly with the help of the height difference between the layered connecting roadway 4 and the stope (without constructing a backfill retaining wall). The cemented backfill height is 1.125m, and a 3m working space is left. 9) Once the tailings strength reaches the required level, proceed to the next cycle.

[0040] The economic and technical indicators of the mechanized upward shearing + cemented continuous backfill mining method proposed in this application are as follows: Impoverishment rate: 18%; Recovery rate: 90% (pillarless mining, approximately 5% higher than the cut-and-cover mining method); Cutting-to-slaughter ratio: 52.11 m / kt, 460.44 m3 / kt.

[0041] It should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0042] The detailed descriptions listed above are merely specific descriptions of feasible implementation methods of this application and are not intended to limit the scope of protection of this application. All equivalent implementation methods or modifications made without departing from the spirit of the art of this application should be included within the scope of protection of this invention.

Claims

1. A multi-stage coordinated mechanized backfilling mining method for steeply dipping thin veins, characterized in that, Includes the following steps: S1. Mine infrastructure construction and construction of mining access roadways: The mine infrastructure is constructed to the lowest middle section. In the lower footing of the lowest middle section ore body, the mining area ramps, segmented roadways, layered connecting roadways, stopes chutes and ventilation shafts are constructed according to the design parameters. S2, Construction bottom tunnel; S3. Pre-reinforce the surrounding rock on both sides of the ore body; S4. Construct high-level upward parallel holes to form blast holes in the ore body and blast holes in the surrounding rock. S5. The ore body collapses and ore is extracted, then the surrounding rock collapses and the stope is leveled; S6. Apply roof pressure to the layered roadway. After the roof pressure is completed, use the height difference between the layered roadway and the stope to directly perform cemented backfilling. Once the strength meets the requirements, proceed to the next cycle.

2. The multi-stage coordinated mechanized backfilling mining method for steeply dipping thin veins according to claim 1, characterized in that, The stope is divided into four working faces according to the process of "rock drilling and support, mining and ore extraction, wall cutting and backfilling and cemented backfilling". Ventilation shafts, layered connecting roadways and stope chutes are set at intervals along the length of the working face.

3. The multi-stage coordinated mechanized backfilling mining method for steeply dipping thin veins according to claim 2, characterized in that, The working face is 200m long, with ventilation shafts every 50m and layered connecting roadways and ore chutes every 100m.

4. The multi-stage coordinated mechanized backfilling mining method for steeply dipping thin veins according to claim 1, characterized in that, Mines using ramp development shall use the main ramp as the mining area ramp; mines using other development methods or with a strike length of more than 300m shall have a mining area ramp every 300 to 500m.

5. The multi-stage coordinated mechanized backfilling mining method for steeply dipping thin veins according to claim 2, characterized in that, The slope of the layered connecting roadway is 0 to 20%. The first layered connecting roadway, which connects to the middle section, is constructed downwards to the ore body at a slope of 20%. This layered connecting roadway is connected to the middle section roadway or the segment roadway and serves as a transportation channel for personnel, equipment, materials and ore in the mining area, as well as an intake airway and a safety exit in the mining area.

6. The multi-stage coordinated mechanized backfilling mining method for steeply dipping thin veins according to claim 5, characterized in that, An external loading roadway is set up at the bottom of the ore pass in the middle section of the transport roadway.

7. The multi-stage coordinated mechanized backfilling mining method for steeply dipping thin veins according to claim 1, characterized in that, In step S3, the ore and rock are artificially separated, and only the surrounding rock is reinforced with anchor cables and steel mesh. The anchor cables are arranged in a "quincunx" pattern.

8. The multi-stage coordinated mechanized backfilling mining method for steeply dipping thin veins according to claim 1, characterized in that, In step S4, the construction of high-level upward parallel holes is carried out: after the bottom roadway and surrounding rock reinforcement are completed, upward parallel holes are constructed in the ore body and surrounding rock using a mining rig. The spacing between blast holes in the ore body is 0.6m and the spacing between blast holes in the surrounding rock is 0.8m. The arrangement of blast holes is in a "quincunx" shape.

9. The multi-stage coordinated mechanized backfilling mining method for steeply dipping thin veins according to claim 1, characterized in that, In step S5, the ore body is caved and ore is extracted: the ore body is caved from one side of the ventilation shaft to the other side using blasting methods, and the ore is extracted using a leveling and haulage machine; the surrounding rock is caved and the mining area is leveled: a large-scale wall-cutting and filling process is adopted to blast and fill the mining area with the surrounding rock on both sides of the ore body, providing working space for subsequent mechanized rock drilling, ore extraction and leveling.

10. The multi-stage coordinated mechanized backfilling mining method for steeply dipping thin veins according to claim 1, characterized in that, In step S6, the adhesive filling is carried out directly without constructing a filling retaining wall, and working space is left at the same time as the adhesive filling.

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