A method for controlling mining-induced damage and ecological restoration in mining areas

Abstract

This invention relates to a method for controlling mining-induced damage and ecological restoration in mining areas. The method includes the following steps: S1, designing parameters before mining to determine the working face mining parameters for the mining area to be mined; S2, mining the mining area according to the working face mining parameters obtained in step S1, and during the working face mining process, performing underground backfilling in local areas around the mined coal seam; S3, dividing the surface subsidence basin into zones after the working face mining is completed; S4, improving the soil in different zones of the surface subsidence basin; S5, planting vegetation in different zones of the improved surface subsidence basin. This method is designed for mining areas with shallow, thick coal seams. It involves designing mining parameters before mining, local grouting and backfilling during mining, and soil improvement and planting of suitable plants after mining. By implementing ecological damage reduction measures throughout the entire mining process, it can minimize the ecological damage caused by mining.

Description

Technical Field

[0001] This invention belongs to the field of coal mining and environmental protection technology, specifically relating to a method for controlling mining-induced damage and ecological restoration in mining areas. Background Technology

[0002] CN 103291303A discloses a mining method using strip coal pillars. This invention mainly controls strata subsidence by leaving coal pillars, and then replaces the pillars with backfill material later. However, this process is complex and cannot achieve high-yield and high-efficiency mining. Furthermore, the coal pillars left during mining are prone to stress concentration. In addition, this method does not involve the restoration of the mining area's ecology.

[0003] Therefore, it is urgent to apply new technologies to control the degree of damage caused by mining, while increasing ecological construction in the development process and promoting the sustainable economic development of mining areas. Summary of the Invention

[0004] This invention addresses the shortcomings of existing technologies by providing a method for controlling mining-induced damage and ecological restoration in mining areas. This method is designed for shallow-buried thick coal seam mining areas. Before mining, mining parameters are designed; during mining, local grouting and filling are carried out; and after mining, soil improvement and suitable plant planting are carried out. Ecological loss reduction measures are taken throughout the entire mining process, which can minimize the ecological damage caused by mining.

[0005] Therefore, the present invention provides a method for controlling mining-induced damage and ecological restoration in mining areas, which includes the following steps: S1. Before mining, parameter design is carried out to determine the working face mining parameters of the mining area to be mined. S2, the mining area is mined according to the working face mining parameters obtained in step S1, and underground backfilling is carried out in the local area around the mined coal body during the mining process; S3, after the working face is mined out, the surface subsidence basin is divided into zones; S4, Soil improvement in different zones of the surface subsidence basin; S5 involves planting vegetation in different zones of the surface subsidence basin after soil improvement.

[0006] In some embodiments of the present invention, in step S1, parameters are designed based on the mining geology, production process, and production efficiency before mining. These parameters include: working face width, working face height, and working face advance speed.

[0007] In some other embodiments of the present invention, in step S2, the local area around the coal seam includes the vicinity of the opening cut, the roadways at both ends of the working face, and the vicinity of the stop line.

[0008] In some embodiments of the present invention, in step S2, the filling distance for underground filling of a local area around the mined coal seam is specified. d The calculation formula is shown in Formula 1:

[0009] Formula 1 in, H The distance between the surface damage control layer and the coal seam. f The average fracture angle of the rock strata. h The thickness of the surface damage control layer, R t The tensile strength of the surface damage control layer, q The load is for the surface damage control layer.

[0010] In some embodiments of the present invention, in step S3, the surface subsidence basin is divided into a self-healing area with self-healing ability and an artificially intervened repair area without self-healing ability.

[0011] In some embodiments of the present invention, having self-repair capability means being able to recover to the level before the disturbance without human intervention, such as the restoration of surface vegetation; not having self-repair capability means requiring human intervention to recover to the level before the disturbance.

[0012] In some embodiments of the present invention, in step S4, the soil in different zones of the surface subsidence basin is tested and analyzed, and then the soil is improved based on the test and analysis results.

[0013] In some embodiments of the present invention, step S4, the method for soil improvement includes inoculating the soil with microorganisms.

[0014] In some preferred embodiments of the present invention, the microorganism is an indigenous mycorrhizal fungus.

[0015] In some embodiments of the present invention, in step S5, the planted vegetation is plants that have been selected and domesticated to adapt to different zones of the subsidence basin after soil improvement.

[0016] In some other embodiments of the present invention, the mining area is a shallow-buried thick coal seam mining area.

[0017] The beneficial effects of this invention are as follows: The method described herein targets shallow-buried, thick coal seam mining areas. Before mining, mining parameters are designed to maximize the mining length of the face, thereby increasing the area of ​​the self-repair zone of the surface subsidence basin. During mining, localized grouting and filling are performed to reduce the subsidence slope of the surrounding soil and rock layers, thus reducing the degree of surface damage. After mining, soil improvement and planting of suitable vegetation are carried out to improve the surface ecological environment. Therefore, the method described in this invention can implement ecological loss reduction measures throughout the entire mining process, minimizing the ecological damage caused by mining to the greatest extent possible. Attached Figure Description

[0018] The invention will now be further described with reference to the accompanying drawings.

[0019] Figure 1 This is a diagram showing the caving trend of overburden after local underground backfilling around the coal face during the mining process. The meanings of the labels in the diagram are as follows: 1-Surface aeolian sand layer; 2-Aquifer; 3-Surface damage control layer; 4-Coal seam; 5-Floor; 6-Goaf; 7-Backfill bearing area near the cut-off point; 8-Backfill bearing area near the stop line. d - Filling distance; f - The average fracture angle of the rock strata.

[0020] Figure 2 This is a schematic diagram of the zoning of surface subsidence basins; the meanings of the labels in the attached diagram are as follows: A - artificially intervened and restored areas without self-healing capabilities (areas surrounding surface subsidence basins); B - self-healing areas with self-healing capabilities (flat bottom areas of surface subsidence basins). Detailed Implementation

[0021] To make the present invention easier to understand, it will be described in further detail below. The following embodiments are for illustrative purposes only and are not limited to the scope of application of the present invention.

[0022] The method for controlling mining-induced damage and restoring the ecology in mining areas involved in this invention includes the following steps: S1. Before mining, parameter design is carried out to determine the working face mining parameters of the mining area to be mined. S2, the mining area is mined according to the working face mining parameters obtained in step S1, and underground backfilling is carried out in the local area around the mined coal body during the mining process; S3, after the working face is mined out, the surface subsidence basin is divided into zones; S4, Soil improvement in different zones of the surface subsidence basin; S5 involves planting vegetation in different zones of the surface subsidence basin after soil improvement.

[0023] In some embodiments of the present invention, in step S1, parameters are designed based on the mining geology, production process and production efficiency before mining.

[0024] Before mining, the present invention rationally determines the mining parameters of the working face based on the mining geology, production process and production efficiency. Among them, large working face mining can increase the area of ​​the self-healing zone B with self-healing ability in the surface subsidence basin.

[0025] This invention involves grouting around the coal seam during mining to perform underground backfilling. This underground backfilling reduces the subsidence slope of the soil and rock layers surrounding the surface subsidence basin, thereby minimizing surface damage.

[0026] In some specific embodiments of the present invention, in step S2, the local area around the coal seam includes the vicinity of the opening cut, the roadways at both ends of the working face, and the vicinity of the stop line.

[0027] In some embodiments of the present invention, in step S2, the filling distance for underground filling of a local area around the mined coal seam is specified. d The calculation formula is shown in Formula 1:

[0028] Formula 1 in, H The distance between the surface damage control layer and the coal seam. f The average fracture angle of the rock strata. h The thickness of the surface damage control layer, R t The tensile strength of the surface damage control layer, q The load is for the surface damage control layer.

[0029] For example, when performing downhole backfilling near the cut, the initial fracture span of the surface damage control layer is first calculated based on the geological exploration data of the mining area and the stratigraphic position, thickness, and relevant physical and mechanical parameters of the surface damage control layer, considering it as a fixed-support beam. L The initial fracture span of the surface damage control layer L The calculation formula is shown in Formula 2:

[0030] Formula 2 in, h The thickness of the surface damage control layer, R t The tensile strength of the surface damage control layer, q The load is for the surface damage control layer.

[0031] Then, determine the distance between the midpoint of the initial fracture span of the surface damage control layer and the cut-in hole. This distance is the filling distance for downhole filling near the cut-in hole. d Filling distance d The calculation formula is shown in Formula 1:

[0032] Formula 1 in H The distance between the surface damage control layer and the coal seam. f The average fracture angle of the rock strata.

[0033] Similarly, the filling distance for underground backfilling at both ends of the working face and near the stop line can be determined. After backfilling, filling bearing areas 7 and 8 can be formed to reduce the subsidence slope of aquifer 2 and surface aeolian sand layer 1.

[0034] In some embodiments of the present invention, in step S3, the surface subsidence basin is divided into self-repairing areas with (certain) self-repairing capabilities and artificial intervention remediation areas without self-repairing capabilities. Self-repairing capability means that the area can recover to its pre-disturbance level without human intervention, such as surface vegetation restoration; lack of self-repairing capability means that artificial intervention is required to recover to its pre-disturbance level. In other words, artificial intervention remediation areas without self-repairing capabilities require stronger human intervention for remediation. Soil testing and improvement are conducted in different zones, and different types of suitable plants are selected for planting.

[0035] In some embodiments of the present invention, in step S4, the soil in different zones of the surface subsidence basin is tested and analyzed, and then the soil is improved based on the test and analysis results.

[0036] In this invention, the objects of detection and analysis include the physicochemical properties of soil, such as moisture and nutrient content.

[0037] In some embodiments of the present invention, step S4, the method for soil improvement includes inoculating the soil with microorganisms.

[0038] In some preferred embodiments of the present invention, the microorganisms are indigenous mycorrhizae. Inoculating the soil with indigenous mycorrhizae that are beneficial to the growth of local indigenous plants facilitates the absorption of water and nutrients by the plants, thereby promoting plant growth and development.

[0039] In some embodiments of the present invention, in step S5, the planted vegetation consists of plants that have been selected and acclimatized to adapt to different zones of the subsidence basin after soil improvement. Planting vegetation improves the ecological environment of the land surface.

[0040] In some other embodiments of the present invention, the mining area is a shallow-buried thick coal seam mining area.

[0041] In some specific embodiments of the present invention, the mining damage control and ecological restoration method of the present invention specifically includes the following steps: Step 1: Determine the working face mining parameters of the mining area to be mined based on the geological conditions, production process and production efficiency. Among them, large working face mining can increase the area of ​​the self-healing zone B with self-healing ability in the surface subsidence basin. Step 2: Mining the mining area according to the working face mining parameters obtained in Step 1, and carrying out underground backfilling near the opening, the roadways at both ends of the working face and near the stop line during the mining process, in order to reduce the subsidence slope of the corresponding surface soil and rock layer. When performing downhole backfilling near the cut-in hole, the calculation should first be performed based on the geological exploration data of the mining area and the location, thickness, and relevant physical and mechanical parameters of the surface damage control layer, considering the fixed support beam. Initial fracture span of the surface damage control layer:

[0042] in, h The thickness of the surface damage control layer, R t The tensile strength of the surface damage control layer, q The load for the surface damage control layer; Then determine the distance between the midpoint of the initial fracture span of the surface damage control layer and the incision eye (i.e. The filling distance for downhole filling near the cut-in hole d ),

[0043] in, H The distance between the surface damage control layer and the coal seam. f The average fracture angle of the rock strata; Similarly, the filling distance for underground filling in the roadways at both ends of the working face and near the stop line can be determined; The filling bearing area formed after filling can reduce the subsidence slope of the aquifer and the surface aeolian sand layer; Step 3: After the working face is mined out, the surface subsidence basin is divided into two zones: a self-healing zone B with (certain) self-healing capabilities and an artificially intervened and repaired zone A without self-healing capabilities. Step 4: Conduct soil testing and analysis in different zones (A and B) of the surface subsidence basin, including physical and chemical properties such as moisture and nutrient content, and then improve the soil through measures such as inoculation. Step 5: Select and acclimatize plants that can adapt to different zones (A and B) of the subsidence basin after soil improvement for planting to improve the surface ecological environment.

[0044] Example 1 This embodiment provides a method for controlling mining-induced damage and ecological restoration in mining areas. This method has been applied to a mining project in western China. Specific details are as follows: Step 1: Based on the geological conditions, production technology, and production efficiency of a certain mine in western China, determine the working face parameters for the mining area to be mined: advance length 1800m, working face length 300m, coal seam is nearly horizontal, average burial depth 140m, average mining thickness 4m. Large working face mining can increase the area of ​​self-healing zone B, which has self-healing capabilities, in the surface subsidence basin. Step 2: Mining the mining area according to the working face mining parameters obtained in Step 1, and carrying out underground backfilling near the opening, the roadways at both ends of the working face and near the stop line during the mining process, in order to reduce the subsidence slope of the corresponding surface soil and rock layer. When performing downhole backfilling near the cut-in hole, the calculation should first be performed based on the geological exploration data of the mining area and the location, thickness, and relevant physical and mechanical parameters of the surface damage control layer, considering the fixed support beam. Initial fracture span of the surface damage control layer: =56m in, h The thickness of the surface damage control layer is 20m. R t The tensile strength of the surface damage control layer is 4 MPa. q The load for the surface damage control layer; 1 MPa; Then determine the distance between the midpoint of the initial fracture span of the surface damage control layer and the incision eye (i.e. The filling distance for downhole filling near the cut-in hole d ), =74m in, H The distance between the surface damage control layer and the coal seam is 80m. f The average fracture angle of the rock strata is 60°. Similarly, the filling distance for underground filling in the roadways at both ends of the working face and near the stop line can be determined; The filling bearing area formed after filling can reduce the subsidence slope of the aquifer and the surface aeolian sand layer; Step 3: After the working face is mined out, the surface subsidence basin is divided into two zones: a self-healing zone B with (certain) self-healing capabilities and an artificially intervened and repaired zone A without self-healing capabilities. Step 4: Conduct soil testing and analysis in different zones (A and B) of the surface subsidence basin, including physical and chemical properties such as moisture and nutrient content, and then improve the soil through measures such as inoculation. Step 5: Select and acclimate plants that can adapt to different zones (A and B) of the subsidence basin after soil improvement for planting. Plant shrubs such as Caragana korshinskii in zone A and alfalfa in zone B to improve the surface ecological environment.

[0045] It should be noted that the embodiments described above are only for explaining the present invention and do not constitute any limitation on the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory terms, not limiting terms. Modifications can be made to the present invention within the scope of the claims, and revisions can be made to the present invention without departing from the scope and spirit of the present invention. Although the present invention described herein relates to specific methods, materials, and embodiments, it does not mean that the present invention is limited to the specific examples disclosed herein; on the contrary, the present invention can be extended to all other methods and applications with the same function.

Claims

1. A method for controlling mining-induced damage and ecological restoration in mining areas, comprising the following steps: S1. Before mining, parameter design is carried out to determine the working face mining parameters of the mining area to be mined; the mining area to be mined is a shallow buried thick coal seam mining area. S2, The mining area is mined according to the working face mining parameters obtained in step S1. During the working face mining process, underground backfilling is carried out in local areas around the mined coal body. These local areas include the vicinity of the cut-in point, the roadways at both ends of the working face, and the vicinity of the stop line. The backfilling distance for these local areas around the mined coal body is specified. d The calculation formula is shown in Formula 1: Formula 1 in, H The distance between the surface damage control layer and the coal seam. φ The average fracture angle of the rock strata. h The thickness of the surface damage control layer, R t The tensile strength of the surface damage control layer, q The load for the surface damage control layer; S3. After the working face is mined out, the surface subsidence basin is divided into two zones: a self-healing zone with self-healing ability and an artificially intervened and repaired zone without self-healing ability. S4, Soil improvement is carried out on soil in different zones of the surface subsidence basin; the method of soil improvement includes inoculating the soil with microorganisms; the microorganisms are indigenous mycorrhizal fungi; S5 involves planting vegetation in different zones of the surface subsidence basin after soil improvement.

2. The method according to claim 1, characterized in that, In step S1, parameters are designed based on the mining geology, production process, and production efficiency before mining begins.

3. The method according to claim 1 or 2, characterized in that, In step S4, the soil in different zones of the surface subsidence basin is tested and analyzed, and then soil improvement is carried out based on the test and analysis results.

4. The method according to claim 1 or 2, characterized in that, In step S5, the planted vegetation consists of plants that have been selected and domesticated to adapt to different zones of the subsidence basin after soil improvement.

Images