Active intelligent control method for water level of mineralized aquifer in coal-uranium coordinated mining area

Abstract

The present invention discloses a method for actively intelligently controlling the water level of aquifers containing uranium in a coordinated coal-uranium mining area. Aiming at the problem of declining water levels in uranium-containing aquifers in a coordinated coal-uranium mining area, the method comprehensively considers the relationship between the two in time and space, and starts with the initial zoning and avoidance of mining space, thereby fundamentally reducing the impact of the two on the mining process. During the mining process, the method effectively controls the water inrush from the coal mine, thereby reducing the loss of groundwater caused by coal mining, thereby achieving the purpose of suppressing the downward trend of the water level of the aquifer containing uranium. By grouting and blocking between the coal mine and the uranium mine, the flow path of the groundwater is blocked. While controlling and restoring the water level of part of the aquifer containing uranium, the migration path of uranium pollutants can also be blocked, thereby ensuring the production safety of the coal mine. By constructing an intelligent water level control system, integrating online monitoring, digital management and intelligent control technologies, and dynamically adjusting the mine water reinjection flow through zoning, the purpose of accurately controlling the water level of the aquifer containing uranium is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of coordinated coal and uranium mining, and in particular to a method for actively intelligently controlling the water level of a ore-bearing aquifer in a coordinated coal and uranium mining area. Background Art

[0002] The energy supply role of coal resources and the strategic uses of uranium are of paramount national importance, leading to the development of these two minerals receiving significant attention. In recent years, significant uranium resources have been discovered in coal-bearing systems, primarily consisting of sedimentary sandstone-type uranium deposits. These sandstone-type uranium deposits occur within mineral-bearing aquifers, and their occurrence is determined by the distribution of uranium concentrations, with the ore bodies often exhibiting irregular shapes.

[0003] From a vertical perspective, coal-measure uranium deposits and coal seams exhibit various stratigraphic relationships. The most significant inter-mining impact occurs in the "uranium above, coal below" scenario. Under these conditions, the coordinated mining of coal and uranium deposits can affect each other within a certain distance. Water-conducting fracture zones formed by coal mining can damage the aquifer above the coal seam, leading to a drop in the water level of the ore-bearing aquifer. The in-situ leaching method used by most sandstone-type uranium deposits has specific requirements for the water level of the ore-bearing aquifer. Excessively low water levels can reduce uranium mining efficiency and even necessitate the suspension of mining. Existing water-level control methods are limited, mostly relying solely on drilling and water injection to raise the water level of the ore-bearing aquifer. However, their effectiveness remains significantly improved. Furthermore, they overlook the crucial influencing factor of coal mine water inrush. Controlling water inrush can reduce groundwater loss and enhance water-level control effectiveness. Furthermore, radioactive contaminants generated during uranium mining may migrate and spread to the coal mine site due to gravity, posing a threat to coal mine production safety and requiring significant attention. Summary of the Invention

[0004] The purpose of the present invention is to utilize a method for actively intelligently regulating the water level of aquifers containing minerals in a coal-uranium coordinated mining area to actively regulate the water level, block the migration path of pollutants, prevent water inrush from mines, reduce environmental damage in ecologically fragile areas, and ensure efficient and safe coordinated mining of coal and coal-bearing symbiotic uranium deposits.

[0005] To achieve the above objectives, a method for actively and intelligently controlling the water level of aquifers in coal-uranium coordinated mining areas has been developed. Based on the concept of "regional control and local management," this method employs a four-pronged approach: "zoning and avoiding mining space, controlling coal mine water inrush, grouting and containment of aquifers, and reinjecting mine water to create artificial watersheds." This method actively controls water levels, inhibits pollutant migration, prevents mine water inrush, and reduces environmental damage in ecologically fragile areas. The method includes the following steps:

[0006] S10 geological exploration, collecting hydrogeological information of the mining area by drilling in the coal and uranium coordinated mining area;

[0007] S20 builds a hydrological database and simulation system, uses online monitoring technology to monitor the underground hydrological conditions in the coal-uranium coordination area in real time, and combines the collected hydrogeological information of the mining area to establish a visual regional hydrogeological database. On this basis, a simulation system is established to optimize the water level control parameters through groundwater system simulation and water level control system simulation, realizing intelligent control of the water level of the mineral-bearing aquifer;

[0008] S30 determines the degree of mutual influence between coal mines and uranium mines, and through groundwater system simulation analysis, determines the scope of coal mining disturbance, the impact of coal mining on uranium-bearing aquifers, and the migration and diffusion of uranium pollutants;

[0009] S40 divides the mining space into zones to avoid any impacts on the stability of the uranium mine shaft caused by overburden movement caused by coal mining, and prevents uranium pollutants from migrating into the coal mine and affecting production safety. On this basis, the mining areas of coal and coal-bearing uranium deposits are divided according to their occurrence locations, reducing the impact of mining on each other.

[0010] S50 controls water inrush in coal mines, controlling water inrush in underground coal mines by filling mining or grouting cracks;

[0011] S60 arranges grouting drilling holes. Considering the location relationship between the coal mine and the uranium mine and the depth of the mineral-bearing aquifer, the grouting drilling holes are designed, including the specific location, number of holes, and drilling depth.

[0012] S70 grouting forms a water barrier. By injecting grouting into the boreholes between the coal mine and the uranium mine to build a water barrier, it blocks the migration of uranium ore fluids to the coal mine with lower water potential, thereby restoring the water level of some mineral-bearing aquifers to a certain extent. At the same time, it can prevent uranium ore pollutants from migrating to the coal mine, ensuring coal mine production safety.

[0013] S80 arranges water injection boreholes. Based on the critical water level value of uranium in-situ leaching mining, a certain number of water injection boreholes are arranged between the grouting water barrier and the uranium ore body.

[0014] The S90 water injection forms a hydraulic curtain, which lifts the drainage water generated during coal mining to the surface through the coal mine drainage system and connects it to the surface water pump station. The surface water pump station is connected to the water injection borehole, and the coal mine drainage water is injected back into the uranium-bearing aquifer to form a hydraulic curtain;

[0015] S100 builds an intelligent water level control system, including a coal mine drainage system, a surface water delivery system, a mineralized aquifer water level monitoring system, and a water injection system;

[0016] S110 regularly regulates the water level of mineral-bearing aquifers, integrates online monitoring, digital management and artificial intelligence, and dynamically adjusts the mine pumping and mineral-bearing aquifer reinjection rates in different zones, improving the ability and accuracy of coordinated mining water level control.

[0017] Furthermore, in step S10, the hydrogeological information of the mining area is collected by drilling, the drilling positions include the surface and underground, the drilling density is determined according to the geological complexity, and the drilling depth is not less than the coal seam burial depth; the hydrogeological information of the mining area includes the stratigraphic position, lithology, structural structure, stratum contact relationship, pore water pressure, and ground stress of the detected strata.

[0018] Furthermore, in step S20, the underground hydrological conditions include the coal mine groundwater level, the mine water inflow, and the water level of the uranium-bearing aquifer.

[0019] Furthermore, in step S30, the coal mining disturbance range refers to the development range of the water-conducting fracture zone above the coal mine site and the movement boundary position of the overlying rock strata; the impact on the uranium-bearing aquifer refers to the lowering of the water level in the aquifer and the change in the integrity and water-proof properties of the aquiclude.

[0020] Furthermore, in step S40, the uranium in situ leaching mining is carried out under the natural occurrence conditions of the ore deposit, by injecting prepared chemical reagents into the ore layer through a liquid injection borehole drilled from the surface to the ore layer, reacting chemically with the minerals to dissolve the uranium in the ore, and then pumping the uranium-containing solution to the surface.

[0021] Furthermore, in step S50, the filling mining method refers to filling the goaf to support the goaf roof, thereby avoiding damage to the upper impermeable layer due to the movement of the overlying rock strata in the mining area, thereby reducing the possibility of water inrush accidents in coal mines and reducing the amount of water inrush in coal mines; performing working face skipping mining can also reduce the damage to the overlying rock strata in the mining area and protect the upper impermeable layer to a certain extent.

[0022] Furthermore, in step S60, the grouting drilling hole may be opened on the ground or in a coal mine.

[0023] Furthermore, in step S60, the water-blocking wall formed by grouting and drilling is located between the coal mine and the uranium mine.

[0024] Furthermore, in step S60, the drilling depth meets the requirement that the grouting body penetrates the mineral-bearing aquifer, the specific layout meets the mining area topography and water level control requirements, and is optimized through groundwater system simulation and water level control system simulation.

[0025] Furthermore, in step S60, after the grouting is completed, full borehole grouting and sealing is performed to restore the integrity of the aquiclude.

[0026] Furthermore, in step S70, the water-blocking wall formed by grouting needs to separate the uranium mine from the coal mine, including two forms: one is a fully enclosed closed loop form surrounding the uranium ore body, and the other is a semi-enclosed U-shaped form between the coal mine and the uranium mine.

[0027] Furthermore, in step S80, the specific number and distribution of water injection boreholes need to comprehensively consider the water level control requirements of the mineral-bearing aquifer, the size and occurrence of the uranium ore body, the shape of the outer water-blocking wall, and the topography and terrain of the mining area. Finally, the drilling layout plan is optimized through groundwater system simulation.

[0028] Furthermore, in step S90, an annular water injection pipeline and a branch water injection pipeline are constructed according to the positions of the water injection boreholes, and the water injection pump station is connected to all the water injection boreholes through the annular water injection pipeline and the branch water injection pipeline.

[0029] Furthermore, in step S100, by installing intelligent control valves on the branch water injection pipelines connecting each water injection borehole, point-to-point water injection adjustments can be performed according to the water level conditions of the mineral-bearing aquifers in different areas, thereby achieving dynamic and precise control of the water level of the mineral-bearing aquifers in different zones.

[0030] Furthermore, in step S110, after the water level of the mineral-bearing aquifer reaches the critical water level for uranium in situ leaching mining after a certain period of regulation, the water level changes are continuously monitored by the mineral-bearing aquifer water level monitoring system. When the water level of the mineral-bearing aquifer drops, based on the visualization database and simulation system established in the early stage, the coal mine groundwater subsystem, the uranium mine groundwater subsystem and the regional overall groundwater system are simulated and studied through the groundwater system simulation, and the water level regulation system is simulated to simulate the impact of various regulation measures including grouting water blocking on the groundwater level, assist in analyzing and optimizing the water level regulation parameters, enhance the coal mine water inrush control measures according to the analysis results, add grouting boreholes and water injection boreholes in appropriate areas, and adjust the mine pumping and aquifer reinjection rates through the water level intelligent regulation system to achieve pumping and injection balance and improve the accuracy of coordinated mining water level regulation.

[0031] Furthermore, the auxiliary analysis optimizes water level control parameters, including coal mine water inrush control scheme, grouting water blocking scheme, and mine water reinjection scheme.

[0032] Furthermore, the water level of the mineral-bearing aquifer reaches the critical water level for in-situ leaching of uranium, which refers to the minimum water level required for normal uranium mining.

[0033] The beneficial effects of the present invention are as follows: the present invention grasps the key contradiction in the coordinated mining of the upper sandstone-type uranium mine and the lower coal mine heterogeneous symbiotic resources, that is, the mining cracks in the lower coal seam develop upward to destroy the aquifer, causing the water level of the mineral-bearing aquifer to drop, resulting in the inability to carry out uranium in-situ leaching mining, and the migration and diffusion of uranium pollutants threaten the safety of coal mining. Taking into account the temporal and spatial relationship between coal mines and uranium mines, the present invention utilizes means such as mining space zoning avoidance, controlling coal mine water inrush, grouting containment of aquifers, and mine water reinjection to construct a hydraulic curtain to regulate the water level of the mineral-bearing aquifer to the maximum extent, block the migration path of uranium pollutants, prevent coal mine water inrush, and reduce environmental damage in ecologically fragile areas, so as to achieve non-interference between coal mining and uranium mining or interference within a controllable range. Through the implementation of this technical invention, the coordinated mining of the upper sandstone-type uranium mine and the lower coal mine heterogeneous symbiotic resources can be guaranteed to be carried out efficiently and safely, in order to realize the revitalization and utilization of uranium and coal resources that coexist in this mode. Its specific advantages are:

[0034] (1) Fundamentally weakening the mutual interference between coal mines and uranium mines. Based on geological exploration work, comprehensive consideration of the temporal and spatial relationship between coal mines and uranium mines, and reasonable planning to avoid the mining space of the two, can fundamentally reduce the mutual influence between the two, and prevent uranium extraction wells and monitoring wells from being damaged by the movement of rock formations such as dislocation and deflection;

[0035] (2) Guaranteed coal mine production safety. Grouting in the mineral-bearing aquifer can not only reduce the flow of groundwater into the coal mine goaf and reduce the possibility of water inrush, but also block the migration of uranium pollutants into the coal mine, thus ensuring coal mine production safety in many aspects.

[0036] (3) Ensured the normal operation of uranium in-situ leaching. The water level of the mineralized aquifer is crucial to in-situ leaching. By zoning the mining space in the early stage, controlling the water inrush from the coal mine during the coordinated mining process, grouting the groundwater around the uranium mine, and building an intelligent water level control system, integrating online monitoring, digital management, and intelligent control technologies, the system dynamically adjusts the mine pumping and the injection flow of the mineralized aquifer in different zones, and actively raises the water level of the mineralized aquifer, it ensures that the water level of the mineralized aquifer is normalized to meet the needs of uranium in-situ leaching.

[0037] (4) Reduced environmental damage in ecologically fragile areas. By controlling underground coal mine water inflow, the water level drop in the mineral-bearing aquifer can be slowed down. By recycling the mine drainage water through the intelligent water level control system and re-injecting it into the stratum, a large amount of water resources can be saved, the water level of the mineral-bearing aquifer can be maintained stable, and the environment in ecologically fragile areas can be protected. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 A schematic diagram of the mutual influence of the coordinated mining of coal and uranium according to the present invention;

[0039] Figure 2This is a schematic diagram of the mining space zoning avoidance of the present invention;

[0040] Figure 3 Schematic diagram of coal mine water inrush control by backfill mining according to the present invention;

[0041] Figure 4 This is a schematic diagram of grouting and blocking of a mineral-bearing aquifer according to the present invention;

[0042] Figure 5 Schematic diagram of a hydraulic curtain constructed for mine water reinjection according to the present invention;

[0043] FIG6 is a top view of the water-blocking wall and the water injection drilling of the present invention;

[0044] Figure 7 This is a flow chart of the active water level control of a mineral-bearing aquifer according to the present invention;

[0045] In the figure, 10 is the coal seam; 20 is the uranium ore body; 30 is the water-conducting fracture zone; 31 is the unfilled water-conducting fracture zone; 32 is the filled water-conducting fracture zone; 40 is the coal mine rock migration boundary; 50 is the uranium ore contaminant; 60 is the ore-bearing aquifer; 70 is the aquiclude; 71 is the lower aquiclude;

[0046] 72-upper aquiclude; 80-optimal avoidance distance; 90-uranium mine shaft; 91-uranium mine water level monitoring well; 92-uranium mine injection well;

[0047] 93-Uranium mine pumping well; 100-Mined-out area; 110-Ore-bearing aquifer water level; 111-Initial ore-bearing aquifer water level; 112-Ore-bearing aquifer water level after coordinated coal-uranium mining; 113-Ore-bearing aquifer water level after controlling coal mine water inrush; 114-Ore-bearing aquifer water level after grouting and containment; 115-Ore-bearing aquifer water level after complete control; 120-Backfill; 130-Grouting borehole; 131-Surface grouting borehole; 132-Underground grouting borehole; 140-Water-blocking wall ;141-Fully enclosed water-blocking wall;142-Semi-enclosed water-blocking wall;150-Underground tunnel of coal mine;160-Coal mining area;170-Coal mine drainage system;171-Mine bottom parking lot;172-Coal mine drainage pipeline;173-Ground industrial square;180-Ground water supply system;190-Water injection system;191-Ground water injection pump station;192-Annular water injection pipeline;193-Branch water injection pipeline;194-Water injection drilling hole;195-Intelligent control valve. DETAILED DESCRIPTION

[0048] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0049] This embodiment takes the Nalinggou coal-uranium coordinated mining area in Inner Mongolia Autonomous Region as an example to explain in detail the method for active intelligent control of water levels in mineral-bearing aquifers in the coal-uranium coordinated mining area. The control implementation process can be summarized as "isolation-control-blocking-injection".

[0050] The mining area is rich in coal and uranium resources, and the overall occurrence pattern is uranium on top and coal on the bottom. Figure 2 As shown, the uranium ore body 20 is located in a sandstone-type mineralized aquifer 60 above the main mining seam 10 of the coal mine. Approximately 150 meters above the coal seam 10 lies the lower aquitard 71, separated by over 100 meters. The upper aquitard 71 is discontinuous and has a thickness of 20 meters, while the lower aquitard 71 is complete and has a thickness of 20 meters. The uranium ore body 20 near the lower aquitard 71 is approximately 400 meters deep and 2-3 meters thick. The static water level in the mining area is over 100 meters deep, with a dynamic water level of 230 meters. The mining area is 1,300 meters above sea level, with a 170-meter difference in elevation between the well area and the surrounding water level. The groundwater level at a depth of 170 meters drops by 2-3 meters annually, and extraction has already caused the static water level to drop by 40-50 meters. Coal mining in this mining area has caused the water level in the uranium-bearing aquifer to drop, impacting in-situ leaching of the uranium ore. The water level of the mineral-bearing aquifer needs to be actively regulated to ensure the normal operation of uranium solution mining.

[0051] The specific implementation steps of the active control method of the water level of the mineralized aquifer in the coal-uranium coordinated mining area are as follows:

[0052] Step S10: Geological Exploration: In the coal-uranium coordinated mining area, boreholes are drilled from the surface or underground into the top and bottom strata of the coal seam 10 and the top and bottom strata of the uranium-bearing aquifer 60 to obtain hydrogeological information of the mining area. This includes detecting the stratigraphic position, lithology, structural structure, stratigraphic contact relationships, pore water pressure, and geostress of the strata. Rock physical and mechanical properties of each stratum are tested based on the cores obtained from the drilling. Rock physical and mechanical properties of the strata include density, color, porosity, permeability, crack density, crack connectivity, water absorption and expansion characteristics, compressive strength, tensile strength, cohesion, internal friction angle, elastic modulus, Poisson's ratio, and fracture toughness. Drilling locations include both surface and underground locations. The density of the exploration boreholes is determined based on the complexity of the stratum structure. The drilling depth should not be less than the burial depth of the coal seam. Geological structures prone to water conduction, such as faults, sinkholes, and karst caves, are particularly detected. All boreholes are fully grouted during the drill back process.

[0053] Step S20 involves building a hydrological database and simulation system. Online monitoring technology is used to monitor groundwater levels, mine water inflow, and uranium-bearing aquifer levels in real time. Combined with data collected from geological exploration, a visual regional hydrogeological database is established. Based on this database, groundwater system simulation and water level control system simulation are performed. The combination of groundwater system simulation and water level control system simulation can simulate groundwater movement within different regions before and after regulation. This provides a more intuitive view of groundwater level changes after different regulation methods, which plays a significant role in improving subsequent regulation plans.

[0054] Step S30 determines the degree of mutual influence between coal mines and uranium mines. The scope of coal mining disturbance, the impact of coal mining on uranium-bearing aquifers, and the migration and diffusion of uranium pollutants are determined through groundwater system simulation analysis. Specifically, based on the borehole geological information collected from the above-mentioned geological exploration activities, the spatial location of the coal seam 10 and the uranium ore body 20 is determined. The development range of the coal mine water-conducting fracture zone 30 and the rock migration boundary 40 are determined through numerical simulation, physical similarity simulation, and field measurements. Figure 1 and Figure 2 As shown, groundwater system simulation was used to determine the migration and diffusion range of uranium contaminants 50 and the water level drop in the uranium-bearing aquifer 60. The impact of the development range of the water-conducting fracture zone 30 on the stability of the aquitard 70 above the coal mine and the water level 110 of the aquitard was analyzed. The damage to the uranium mine shaft 90 within the rock migration boundary 40 was analyzed, and the impact of the migration and diffusion of uranium contaminants 50 on coal mine production safety was analyzed. The scope of coal mining disturbance refers to the development range of the water-conducting fracture zone above the coal mine stope and the location of the rock migration boundary of the overlying strata. The impact on the uranium-bearing aquifer refers to the water level drop within the aquitard and changes in the integrity and water-resistance of the aquitard.

[0055] It should be noted that the water level 110 of the mineral-bearing aquifer plays an important role in uranium in-situ leaching. Only when the water level in the mineral-bearing aquifer 60 meets certain conditions can uranium mining be carried out normally. In addition, coal mining activities are likely to destroy the integrity of the aquiclude 70, resulting in a significant drop in the water level 110 of the mineral-bearing aquifer. Therefore, during the coordinated coal and uranium mining process, some means are needed to maintain the water level 110 of the mineral-bearing aquifer stable within a specific range to ensure the normal progress of coordinated mining.

[0056] Step S40 demarcates the mining space for avoidance. Based on the aforementioned mutual influence between the two, the location of the coal mine and the location of the uranium ore body 20, and the development needs of both, the mining area is rationally divided. Considerations include the respective mineral rights, underground coal mine radiation protection requirements, subsequent coal mine development plans, the distribution, number, and depth of various surface boreholes in the uranium mining area, the stability requirements of various uranium mine shafts 90, and the water level requirements of the ore-bearing aquifers for in-situ leaching of uranium. In-situ leaching of uranium involves injecting a prepared chemical reagent into the ore layer through a liquid injection borehole drilled from the surface under the natural conditions of the ore deposit. The chemical reagent reacts with the minerals, dissolving the uranium in the ore, and then pumping the uranium-containing solution to the surface.

[0057] When dividing the mining area, the horizontal projection distance between the coal mine and the uranium mine is mainly used as the starting point. The larger the distance, the smaller the mutual influence. The optimal avoidance distance is determined by combining groundwater system simulation and water level control system simulation with other numerical simulations and physical similarity simulations. Figure 2 As shown, the solution aims to minimize the occurrence of problems such as coal mine contamination by radioactive substances, reduced uranium in-situ leaching efficiency, and damage to the uranium mine shaft 90 caused by mining. The solution is then verified, optimized, and improved. This approach can fundamentally reduce the mutual impact between the two during subsequent mining.

[0058] Step S50 controls water inflow from the coal mine. After mining the coal seam 10, a goaf 100 is formed. The coal seam roof loses support and collapses, forming a water-conducting fracture zone 30. When the water-conducting fracture zone 30 develops into the mineralized aquifer 60, cracks or even fractures form in the lower aquiclude 71, significantly reducing its water-repelling properties. Consequently, groundwater from the surrounding area flows into the goaf 100 along the channels in the water-conducting fracture zone 30, causing the water level 110 of the mineralized aquifer above the goaf 100 to drop sharply from the initial mineralized aquifer level 111. This affects the water level in the upper uranium mining area near the coal mine, causing it to gradually drop, eventually stabilizing near the coal-uranium coordinated mining mineralized aquifer level 112. This reduces uranium mining efficiency. When this water level falls below the critical value required for in-situ leaching, uranium mining is forced to cease.

[0059] By effectively controlling the occurrence of coal mine water inrush and blocking the leakage outlet of groundwater, the downward trend of the water level in the mineral-bearing aquifer 60 can be suppressed as much as possible. Figure 3As shown, a backfill mining method is first employed. The backfill 120 can be made of waste rock, water-sand, paste, or high-water-density materials. The filling method is global dense filling. By filling the goaf 100 to support the mine roof, the unfilled water-conducting fracture zone 31 is reduced to the size of the filled water-conducting fracture zone 32, significantly reducing the development range of the water-conducting fracture zone 30 and preventing damage to the impermeable layer 70 above the coal mine due to movement of the overburden in the mine. After the backfill 120 formed in the goaf has provided stable support for the roof above, drilling is performed into the roof strata, and grouting is performed to fill the interconnected fracture groups within the filled water-conducting fracture zone 32 and the roof delamination fractures. On the one hand, grouting can fill the space of roof cracks and reduce the evolution of internal cracks in the roof caused by subsequent roof sinking. On the other hand, it can repair the cracks when the degree of development of roof cracks is low, prevent the cracks from developing upward as early as possible, increase the effectiveness of crack repair, and help maintain the comprehensive water-isolating capacity of the rock formation after mining disturbance, thereby reducing the possibility of water gushing in coal mines.

[0060] After effectively controlling the underground water inrush in the coal mine, the water level in the uranium mine's aquifer was optimized through groundwater system simulation and water level control system simulation, further improving or adding relevant measures. Due to the recharge of groundwater in the surrounding area, the water level in the aquifer could be restored to a certain extent to the level after the water inrush was controlled.

[0061] Step S60 arranges grouting boreholes. The grouting boreholes 130 are designed based on the positional relationship between the coal mine and the uranium ore body 20 and the buried depth of the ore-bearing aquifer 60. Figure 4 As shown in the figure, including distribution form, specific location, number of boreholes and drilling depth, etc., after the design is completed, it will be optimized through groundwater system simulation and water level control system simulation.

[0062] Among them, the number and distribution of grouting boreholes 130 need to comprehensively consider the size and occurrence of the uranium ore body 20. The drilling depth meets the requirement that the grouting body penetrates the mineral-bearing aquifer, and the specific layout meets the topography and water level control requirements of the mining area, and is optimized through groundwater system simulation and water level control system simulation. The decline in the water level 110 of the uranium mineral-bearing aquifer is mainly caused by the influence of coal mining, so in order to ensure the efficiency of water level control, the uranium ore body 20 and the coal mine should be separated on both sides of the water-blocking wall 140 formed by grouting the grouting boreholes 130. The opening position of the grouting borehole 130 can be on the ground or underground in the coal mine. Figure 4As shown, when grouting from the surface grouting borehole 131, the topography of the mining area should be considered so that the drilling depth can be adjusted to ensure that the grouting depth reaches the bottom of the mineralized aquifer 60. From the coal mine underground tunnel 150, an oblique upward borehole is drilled toward the uranium mine to the lower aquifer 71 to form an underground grouting borehole 132. Through directional grouting, a water barrier 140 is formed between the coal mine and the uranium mine, thereby preventing the groundwater around the uranium ore body 20 from flowing into the coal mine, thereby slowing the decline in the water level 110 of the mineralized aquifer. It should be noted that after the grouting is completed, the entire borehole must be grouted to restore the integrity of the aquifer 70.

[0063] In step S70, grouting is performed to form a water-blocking zone. In order to raise and restore the water level 110 of the mineral-bearing aquifer in the uranium mining area as much as possible and ensure the normal progress of uranium in-situ leaching, grouting is performed in the mineral-bearing aquifer 60 through the grouting boreholes 130 arranged as described above to form a water-blocking wall 140 to block the groundwater near the uranium ore body 20, reduce the loss of groundwater in the uranium mining area, and thus restore and maintain the water level of the mineral-bearing aquifer 60 to a certain extent.

[0064] Furthermore, before the water-blocking wall 140 is built, uranium contaminants 50 would migrate from the uranium ore body 20 to the coal mine with groundwater, seriously threatening the coal mine's production safety. Constructing the water-blocking wall 140 between the uranium and coal mines blocks the migration path of uranium contaminants 50, ensuring coal mine production safety.

[0065] It should be noted that the coal mine water-conducting fracture zone 30 is the main reason for the drop in the water level 110 of the ore-bearing aquifer. In order to significantly reduce the loss of water in the ore-bearing aquifer 60 near the uranium ore body 20, the water-blocking wall 140 should separate the uranium ore body 20 from the coal mining area 160. As shown in Figure 6, the shape of the water-blocking wall can be divided into a fully enclosed water-blocking wall 141 (such as Figure 6a ) and semi-enclosed water-blocking wall (such as Figure 6b )142. The former has a stronger control effect than the latter, but the latter is also less expensive. Common concrete can be used as the grouting material, as the raw materials are readily available and economical. Alternatively, high- or ultra-high-water-content materials with no or low water content can be used, leveraging their water absorption and solidification properties to form a water-blocking wall 140. This can also fill rock fissures and enhance water barrier capabilities. After grouting is completed, all boreholes are fully grouted and sealed.

[0066] After constructing water-blocking wall 140 to separate uranium ore body 20 from coal mining area 160, the layout of grouting boreholes is optimized based on the changes in the water level 110 of the uranium-bearing aquifer through groundwater system simulation and water level control system simulation, further increasing the number of boreholes. Due to the recharge of groundwater in the surrounding area, the water level of the uranium-bearing aquifer can be restored to a certain extent to the water level 114 of the aquifer after grouting.

[0067] Step S80: Arrange water injection boreholes. After determining the water level elevation requirement of the uranium mining area's ore-bearing aquifer 60, a certain number of water injection boreholes 194 are reasonably designed and constructed between the water-blocking wall 140 and the uranium ore body 20. Figure 5 As shown, a ring water injection pipeline 192 and a branch water injection pipeline 193 are constructed according to the position of the water injection borehole.

[0068] To ensure efficient water level control, water injection boreholes are generally distributed between the water-blocking wall 140 and the uranium ore body 20. Their depth must also reach the bottom of the mineralized aquifer 60 to avoid large gaps. The specific number and distribution of water injection boreholes 194 require a comprehensive consideration of the water level control requirements of the mineralized aquifer 110, the size and occurrence of the uranium ore body 20, the shape of the surrounding water-blocking wall 140, and the topography of the mining area. Finally, the borehole layout plan is optimized through groundwater system simulation.

[0069] Step S90: injecting water to form a hydraulic curtain. The coal mine drainage water is injected into the uranium ore-bearing aquifer 60 through the above-mentioned water level intelligent control system to form a hydraulic curtain, thereby further raising the water level 110 of the ore-bearing aquifer around the uranium ore body 20.

[0070] During the regulation process, drainage water generated during coal mining is first lifted from the pit yard 171 through the coal mine drainage pipeline 172 to the surface industrial plaza 173. It is then stored in the water injection pump station 191 via the surface water delivery system 180 for future use. When water level adjustment is needed, a certain amount of mine water is transported and injected into the water injection borehole 194. Furthermore, the drainage water is reinjected into the mineral-bearing aquifer, achieving water recycling, saving significant amounts of water and protecting the ecological environment.

[0071] After the hydraulic curtain is formed, the mine water reinjection flow rate is optimized and adjusted based on the changes in the uranium mine's aquifer water level (110) through groundwater system simulation and water level control system simulation. Through the combined effects of mine drainage water reinjection and groundwater recharge in the surrounding area, the aquifer water level can be restored to a certain extent to the fully regulated aquifer water level (115).

[0072] Step S100: Constructing an intelligent water level control system: When it is necessary to further raise the water level of the mineral-bearing aquifer, it is necessary to construct a water level control system for active control. The intelligent water level control system mainly consists of a coal mine drainage system 170, a ground water supply system 180, a water injection system 190 and a mineral-bearing aquifer water level monitoring system.

[0073] like Figure 5As shown, the coal mine drainage system 170 lifts the drainage water from the underground parking lot 171 to the ground industrial square 173 through the drainage pipe 172, and then transports it to the water injection pump station 191 through the ground water supply system 180. The water injection pump station 191 is located between the coal mine drainage system 170 and the water injection system 190 to control the total water injection volume and play a scheduling role. The water injection pump station 191 is connected to all water injection boreholes 194 through a ring water injection pipeline 192 and a branch water injection pipeline 193. By installing an intelligent control valve 195 on the branch water injection pipeline 193 connecting each water injection borehole 194, point-to-point water injection adjustment can be performed according to the water level 110 of the mineral-bearing aquifer in different areas, thereby achieving dynamic and precise control of the water level 110 of the mineral-bearing aquifer in different zones.

[0074] Step S110: Regularly regulate the water level of the mineralized aquifer. By building an intelligent water level regulation system, integrating online monitoring, digital management, and intelligent control technologies, and dynamically adjusting the mine water re-injection flow rate by zoning, the goal of precisely regulating the water level of the mineralized aquifer is achieved. During the water level regulation process, changes in the mineralized aquifer water level are monitored throughout the uranium mine water level monitoring well 91. When the mineralized aquifer water level 110 in the uranium mining area rises from the initial coal-uranium coordinated mining mineralized aquifer water level 112 to the fully regulated mineralized aquifer water level 115, and meets the requirements for in-situ leaching, the uranium injection well 92 and extraction well 93 can begin operation and resume mining. However, due to the continuous loss of groundwater around the uranium mining area, water injection into the injection borehole 194 is not immediately stopped. Instead, regular, intelligent regulation of the water level of the mineralized aquifer 60 continues.

[0075] The process of intelligent water level control in mineral-bearing aquifers is as follows: Figure 7 As shown in the figure, during the water level control process, online detection technology is used to monitor changes in the coal mine groundwater level, mine water inflow, and the water level 110 of the uranium-bearing aquifer in real time. The collected data is then integrated and a visualization database is established to provide data support for groundwater system simulation. When the water level 110 of the ore-bearing aquifer drops, the coal mine groundwater subsystem, the uranium mine groundwater subsystem, and the overall regional groundwater system are simulated using the previously established visualization database and simulation system. Simulation of the control effects is then combined with the water level control system simulation to assist in analyzing and optimizing water level control parameters. Based on the optimization results, coal mine water inflow control measures are enhanced, and grouting and water injection boreholes are added in appropriate areas. The optimal extraction and injection flow rates for uranium in-situ leaching and mine water reinjection are also determined. This assists in analyzing and optimizing water level control parameters, including coal mine water inflow control plans, grouting water blocking plans, and mine water reinjection plans. The water level of the ore-bearing aquifer reaches the critical water level for uranium in-situ leaching, which refers to the minimum water level required for normal uranium mining.

[0076] The intelligent water level control system remotely controls the intelligent control valve 195 on the branch water injection pipeline 193 belonging to the corresponding water injection borehole 194 in the area to perform water injection operations, thereby realizing dynamic zone adjustment of the water level 110 of the mineral-bearing aquifer, ensuring that the water level 110 of the mineral-bearing aquifer is normalized to meet the needs of uranium in-situ leaching mining, thereby ensuring that the uranium mine can be mined stably and efficiently.

[0077] The proposed method for actively regulating the water level of aquifers in a coordinated coal-uranium mining area addresses the problem of declining water levels in uranium-bearing aquifers during coordinated coal-uranium mining. This method abandons traditional single-point water level regulation methods and comprehensively considers the spatial and temporal relationship between the two. Initially, the method utilizes spatial zoning to avoid impacts of both during the mining process, fundamentally reducing their impact. During the mining process, the method effectively controls water inflow from the coal mine, thereby blocking groundwater leaks and suppressing the downward trend in the water level of the aquifer. Grouting and containment between the coal and uranium mines cuts off groundwater escape routes. While controlling and restoring the water level of some aquifers, it also blocks the migration path of uranium contaminants, ensuring coal mine production safety. A visual database is also established, and through groundwater system simulation and water level control system simulation, feedback optimization of water level control parameters is performed to achieve intelligent regulation of the water level of the aquifer, improving the capability and accuracy of coordinated mining water level control. In addition, by reinjecting coal mine drainage water to raise the water level of the uranium-bearing aquifer, the problem of coal mine drainage water treatment is solved, a large amount of water resources is saved, and the ecological environment of the mining area is protected.

Claims

1. A method for active intelligent control of water level in a mineral-bearing aquifer in a coal-uranium coordinated mining area, characterized in that: Based on the concept of "regional regulation and local management," a four-pronged approach has been developed: "zoning of mining space for avoidance - control of coal mine water inrush - grouting of aquifers for containment - and reinjection of mine water to create an artificial watershed." This approach proactively regulates water levels, inhibits pollutant migration, prevents mine water inrush, and reduces environmental damage in ecologically fragile areas. The steps include the following: S10 geological exploration, collecting hydrogeological information of the mining area by drilling in the coal and uranium coordinated mining area; S20 builds a hydrological database and simulation system, uses online monitoring technology to monitor the underground hydrological conditions in the coal-uranium coordination area in real time, and combines the collected hydrogeological information of the mining area to establish a visual regional hydrogeological database. On this basis, a simulation system is established to optimize the water level control parameters through groundwater system simulation and water level control system simulation, realizing intelligent control of the water level of the mineral-bearing aquifer; S30 determines the degree of mutual influence between coal mines and uranium mines, and through groundwater system simulation analysis, determines the scope of coal mining disturbance, the impact of coal mining on uranium-bearing aquifers, and the migration and diffusion of uranium pollutants; S40 divides the mining space into zones to avoid any impacts on the stability of the uranium mine shaft caused by overburden movement caused by coal mining, and prevents uranium pollutants from migrating into the coal mine and affecting production safety. On this basis, the mining areas of coal and coal-bearing uranium deposits are divided according to their occurrence locations, reducing the impact of mining on each other. S50 controls water inrush in coal mines, controlling water inrush in underground coal mines by filling mining or grouting cracks; S60 arranges grouting drill holes. Considering the location relationship between the coal mine and the uranium mine and the depth of the ore-bearing aquifer, the grouting drill holes are designed, including the specific location, number of holes, and depth. The grouting drill holes are opened on the ground or underground in the coal mine. S70 grouting forms a water barrier. By injecting grouting into the boreholes between the coal mine and the uranium mine to build a water barrier, it blocks the migration of uranium fluids to the coal mine with lower water potential, thereby restoring the water level of some ore-bearing aquifers to a certain extent. At the same time, it can prevent uranium pollutants from migrating to the coal mine, ensuring coal mine production safety. The water barrier formed by grouting needs to separate the uranium mine from the coal mine. It can be of two forms: a fully enclosed closed loop that surrounds the uranium ore body, and a semi-enclosed U-shaped form that blocks the coal mine from the uranium ore body. S80 arranges water injection boreholes. Based on the critical water level value of uranium in-situ leaching mining, a certain number of water injection boreholes are arranged between the grouting water barrier and the uranium ore body; and ring water injection pipelines and branch water injection pipelines are constructed according to the location of the water injection boreholes. The S90 water injection forms a hydraulic curtain, which lifts the drainage water generated during coal mining to the surface through the coal mine drainage system and connects it to the surface water pump station. The surface water pump station is connected to the water injection borehole, and the coal mine drainage water is injected back into the uranium-bearing aquifer to form a hydraulic curtain; The S100 system builds an intelligent water level control system, including a coal mine drainage system, a surface water delivery system, a mineralized aquifer water level monitoring system, and a water injection system. By installing intelligent control valves on the branch injection pipelines connecting each injection borehole, point-to-point water injection adjustments are performed based on the mineralized aquifer water level in different areas, achieving dynamic and precise control of the mineralized aquifer water level in each zone. S110 regularly regulates the water level of mineralized aquifers, integrating online monitoring, digital management, and artificial intelligence to dynamically adjust the mine pumping and aquifer reinjection rates in different zones, improving the ability and accuracy of coordinated mining water level control. After the water level of the mineralized aquifer reaches the critical water level for uranium in-situ leaching after a certain period of regulation, the water level changes are continuously monitored through the mineralized aquifer water level monitoring system. When the water level of the mineralized aquifer drops, based on the previously established visualization database and simulation system, a groundwater system simulation is conducted to study the coal mine groundwater subsystem, the uranium mine groundwater subsystem, and the overall regional groundwater system. The water level control system is also simulated to study the impact of various control measures, including grouting water blocking, on the groundwater level. This assists in analyzing and optimizing water level control parameters. Based on the analysis results, coal mine water inrush control measures are enhanced, and grouting and water injection boreholes are added in appropriate areas. The mine pumping and aquifer reinjection rates are adjusted through the intelligent water level control system to achieve a balance between pumping and injection, thereby improving the accuracy of coordinated mining water level control.

2. The method for active intelligent control of water level in a ore-bearing aquifer in a coal-uranium coordinated mining area according to claim 1 is characterized in that: In step S10, the hydrogeological information of the mining area is collected by drilling, the drilling locations include the surface and underground, the drilling density is determined according to the complexity of the geology, and the drilling depth is not less than the burial depth of the coal seam; the hydrogeological information of the mining area includes the stratigraphic position, lithology, structural structure, stratum contact relationship, pore water pressure, and ground stress of the detected strata.

3. The method for active intelligent control of water level in a coal-uranium coordinated mining area according to claim 1 is characterized in that: In step S20, the underground hydrological conditions include the coal mine groundwater level, the mine water inflow, and the water level of the uranium-bearing aquifer.

4. The method for active intelligent control of water level in a ore-bearing aquifer in a coal-uranium coordinated mining area according to claim 1 is characterized in that: In step S30, the coal mining disturbance range refers to the development range of the water-conducting fracture zone above the coal mine site and the movement boundary position of the overlying rock strata; the impact on the uranium-bearing aquifer refers to the reduction of the water level in the aquifer and the change in the integrity and water-proof properties of the aquiclude.

5. The method for active intelligent control of water level in a ore-bearing aquifer in a coal-uranium coordinated mining area according to claim 1 is characterized in that: In step S40, the uranium leaching mining is carried out under the natural occurrence conditions of the ore deposit. The prepared chemical reagents are injected into the ore layer through a liquid injection borehole drilled from the surface to the ore layer, reacting chemically with the minerals to dissolve the uranium in the ore, and then the uranium-containing solution is pumped to the surface.

6. The method for active intelligent control of water level in a coal-uranium coordinated mining area according to claim 1 is characterized in that: In step S50, the backfill mining method refers to filling the goaf to support the goaf roof, thereby preventing the upper aquiclude from being damaged due to the movement of the overlying rock strata in the mining area, thereby reducing the possibility of water inrush accidents in the coal mine and reducing the amount of water inrush in the coal mine; Skip mining on the working face can also reduce damage to the overlying rock strata in the mining area and protect the aquiclude above to a certain extent.

7. The method for active intelligent control of water level in a coal-uranium coordinated mining area according to claim 1 is characterized in that: In step S70, a water-blocking wall formed by grouting and drilling is located between the coal mine and the uranium mine.

8. The method for active intelligent control of water level in a coal-uranium coordinated mining area according to claim 1 is characterized in that: In step S60, the drilling depth meets the requirement that the grouting body penetrates the mineral-bearing aquifer, the specific layout meets the mining area topography and water level control requirements, and is optimized through groundwater system simulation and water level control system simulation.

9. The method for active intelligent control of water level in a ore-bearing aquifer in a coal-uranium coordinated mining area according to claim 1 is characterized in that: In step S70, after the grouting is completed, full borehole grouting is performed to restore the integrity of the aquiclude.

10. The method for active intelligent control of water level in a ore-bearing aquifer in a coal-uranium coordinated mining area according to claim 1, characterized in that: In step S80, the specific number and distribution of water injection boreholes need to comprehensively consider the water level control requirements of the mineral-bearing aquifer, the size and occurrence of the uranium ore body, the shape of the outer water-blocking wall, and the topography and terrain of the mining area. Finally, the drilling layout plan is optimized through groundwater system simulation.

11. The method for active intelligent control of water level in a coal-uranium coordinated mining area according to claim 1, characterized in that: In step S90, the surface water pump station is connected to all water injection boreholes through a ring water injection pipeline and branch water injection pipelines.

12. The method for active intelligent control of water level in a ore-bearing aquifer in a coal-uranium coordinated mining area according to claim 1, characterized in that: The auxiliary analysis optimizes water level control parameters, including coal mine water inrush control scheme, grouting water blocking scheme, and mine water reinjection scheme.

13. The method for active intelligent control of water level in aquifers containing minerals in a coordinated coal and uranium mining area according to claim 1, characterized in that: The water level of the mineral-bearing aquifer reaches the critical water level for in-situ leaching of uranium, which refers to the minimum water level required for normal uranium mining.

Images