Waste water recharging method and layered liquid injection device

Abstract

The application discloses a wastewater recharge method and a layered liquid injection device, and belongs to the technical field of in-situ leaching of uranium, and mainly aims to economically dispose of in-situ leaching of uranium process wastewater through the layered liquid injection device, so that the land occupation of evaporation ponds, the construction operation and maintenance investment can be reduced, and the climate restriction of surface disposal of radioactive wastewater and the safety hidden danger of water and soil pollution caused by the climate restriction can be avoided. The main technical scheme of the application is as follows: the wastewater recharge method comprises the following steps: obtaining a layer position of a recharge layer; determining recharge parameters; arranging a layered liquid injection device in a liquid injection well; and injecting wastewater into the recharge layer through the layered liquid injection device.

Description

Technical Field

[0001] This application belongs to the field of in-situ leaching uranium mining technology, specifically relating to a wastewater reinjection method and a stratified injection device. Background Technology

[0002] In related technologies, the process wastewater generated during in-situ leaching uranium mining is generally treated through surface evaporation ponds. The wastewater is naturally evaporated and concentrated by sunlight and wind. The high-salt radioactive wastewater and radioactive bottom mud accumulated in the ponds are treated uniformly when the mine is decommissioned.

[0003] The construction of evaporation ponds requires the acquisition of large areas of land, resulting in significant land resource consumption. The infrastructure investment, including land acquisition and anti-seepage construction, is substantial. Wastewater evaporation efficiency is entirely dependent on climatic conditions such as temperature, rainfall, and wind, making it difficult to continuously meet the wastewater treatment needs of continuous mine production. The anti-seepage layer of the evaporation pond is prone to damage and leakage after long-term use, and high-salt radioactive waste liquid poses a risk of polluting the surrounding water and soil. In extreme weather conditions, the pond may overflow, causing safety and environmental hazards. Furthermore, the evaporation pond requires regular anti-seepage inspections, dredging, slope maintenance, and water level monitoring, significantly increasing the overall production and operation costs of the mine. Summary of the Invention

[0004] In view of this, this application provides a wastewater reinjection method and a stratified injection device. The stratified injection device can economically treat wastewater from uranium leaching processes, reduce the land occupation of evaporation ponds and the investment in infrastructure operation and maintenance, and avoid the climate constraints and water and soil pollution safety hazards caused by the surface treatment of radioactive wastewater.

[0005] To achieve the above objectives, this application mainly provides the following technical solutions: One aspect of this application provides a wastewater reinjection method, comprising: Obtain the layer position of the recharge layer; Determine the reinjection parameters; A stratified injection device is installed in the injection well; Wastewater is injected into the reinjection layer via the stratified injection device.

[0006] Optionally, obtaining the layer location of the re-irrigation layer includes: Open-hole drilling and geological exploration were carried out. A three-dimensional stratigraphic structure model of the mining area was established based on the stratigraphic exploration results; Aquifers that meet preset conditions are selected from the three-dimensional geological structure model of the mining area as the recharge layer.

[0007] Optionally, the geological exploration includes integrated logging and core sampling and testing; the integrated logging is performed after the open-hole drilling; the core sampling and testing is performed during the open-hole drilling, and the sampling strata for the core sampling and testing are determined based on the previous hydrogeological survey report of the mining area.

[0008] Optionally, determining the reinjection parameters includes: The parameters of the three-dimensional stratigraphic structure model of the mining area are assigned to obtain the numerical model of the infiltration mining area recharge. The numerical model for recharge in the leaching extraction area is run to perform numerical simulation and prediction to determine the recharge parameters.

[0009] Optionally, the step of installing a stratified injection device within the injection well includes: Conduct casing installation work; The pipe sections corresponding to the recharge layer and the pipe sections corresponding to the ore-bearing ore body of the casing are respectively constructed to form leaching channels, thereby forming wastewater recharge seepage channels and leaching liquid seepage channels. A reinjection pipe and a leaching solution injection pipe are placed inside the casing, such that the outlet end of the reinjection pipe is aligned and connected to the wastewater reinjection seepage channel, and the outlet end of the leaching solution injection pipe is aligned and connected to the leaching solution seepage channel. A water-stopping device is installed inside the casing and between the wastewater reinjection seepage channel and the leaching solution seepage channel; The sealing device was subjected to a pressure test to check its sealing performance.

[0010] Optionally, the wastewater reinjection method further includes: Dynamically monitor the hydrological parameters of the recharge layer; The recharge flow rate and pressure are adjusted in real time based on the hydrological parameters of the recharge layer obtained from dynamic monitoring.

[0011] Another aspect of this application provides a stratified injection device for use in any of the above-described wastewater reinjection methods; the stratified injection device includes a sleeve, a reinjection injection pipe, a leaching solution injection pipe, and a water-stopping device; The casing is installed inside the borehole of the injection well; The casing is provided with a wastewater reinjection seepage channel for the pipe section corresponding to the reinjection layer, and the casing is provided with a leaching solution seepage channel for the pipe section corresponding to the ore body of the ore layer. The reinjection pipe, the leaching solution injection pipe, and the water-stopping device are all located inside the casing. The outlet end of the reinjection pipe is aligned and connected to the wastewater reinjection seepage channel, the outlet end of the leaching solution injection pipe is aligned and connected to the leaching solution seepage channel, and the water-stopping device is located between the wastewater reinjection seepage channel and the leaching solution seepage channel inside the casing.

[0012] Optionally, the stratified injection device further includes a main injection pipe, which is connected to the inlet ends of the reinjection injection pipe and the leaching solution injection pipe, respectively.

[0013] Optionally, the reinjection pipe and the leaching solution injection pipe operate in a time-sharing manner.

[0014] Optionally, both the reinjection pipe and the leaching solution injection pipe are equipped with a regulating valve, a flow meter, and a pressure gauge, with the flow meter and the pressure gauge located downstream of the regulating valve.

[0015] By employing the above technical solution, this application has at least the following beneficial effects: The wastewater reinjection method provided in this application firstly obtains the layer location of the reinjection layer, then determines the reinjection parameters, then sets up a stratified injection device in the injection well, and finally injects wastewater into the reinjection layer through the stratified injection device. This method enables the underground treatment of wastewater from in-situ leaching uranium mining, avoiding the land acquisition and infrastructure construction investment problems associated with surface evaporation pond treatment, reducing the infrastructure costs of mine production, and overcoming the constraints of climate conditions on wastewater treatment operations. It is suitable for the wastewater treatment needs of continuous production in in-situ leaching uranium mines, ensuring the continuous and stable operation of wastewater treatment.

[0016] The layered injection device provided in this application can be directly installed inside the casing of the injection well to carry out operations without the need to drill an additional reinjection well, thereby reducing the construction costs and time consumption caused by drilling new wells. Attached Figure Description

[0017] Figure 1 This is a flowchart of a wastewater reinjection method according to an optional embodiment of this application; Figure 2 This is a schematic diagram of the structure of a layered liquid injection device according to an optional embodiment of this application.

[0018] The reference numerals in the attached figures are as follows: 100. Recharge layer; 200. Ore-bearing layer; 1. Sleeve; 11. Wastewater reinjection seepage channel; 12. Leachate seepage channel; 2. Reinjection injection pipe; 3. Leachate injection pipe; 4. Water stop device; 5. Main injection pipe; 6. Regulating valve; 7. Flow meter; 8. Pressure gauge. Detailed Implementation

[0019] The present application will be described in detail below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the present application can be combined with each other.

[0020] This embodiment provides a wastewater reinjection method, see [link to relevant documentation]. Figure 1 As shown, the method includes: Step S1: Obtain the layer position of the recharge layer 100.

[0021] The wastewater reinjection method provided in this application can be applied to fields such as in-situ leaching uranium mining. Specifically, it can be used to treat wastewater generated during the in-situ leaching uranium mining process, specifically radioactive process wastewater where the extraction volume exceeds the injection volume. In wastewater treatment, the layer position of the reinjection layer 100 can first be determined. Here, the reinjection layer 100 refers to an aquifer with no mineral exploitation value. During construction, the layer position of the reinjection layer 100 is determined and marked by drilling, logging, and core sampling to explore geological parameters. These geological parameters include lithology, burial depth, porosity, permeability coefficient, background groundwater quality, aquitard distribution, and formation stability. The layer position of the reinjection layer 100 includes the top interface depth, bottom interface depth, and effective thickness.

[0022] For example, step S1 includes: Step S101: Open hole drilling and geological exploration.

[0023] The uranium mining network for in-situ leaching includes multiple pumping wells and multiple injection wells. All pumping and injection wells require open-hole drilling, with geological exploration conducted during and after drilling to obtain formation parameters. Open-hole drilling refers to a drilling process where the borehole is formed by continuously drilling from top to bottom without casing 1. The borehole wall is directly exposed throughout the drilling process, without casing 1 for wall protection and cementing. Therefore, during the open-hole drilling phase, comprehensive logging and core sampling can be conducted to collect original geological data from each formation. Then, based on this original geological data, laboratory tests and calculations can be performed to obtain the required formation parameters. Afterward, once all formations at the target depth have been fully exposed, geological exploration completed, and formation parameters calculated, casing 1 is then installed for wall protection and cementing operations.

[0024] Specifically, formation exploration includes integrated logging and core sampling and testing. Integrated logging involves one or more of the following: resistivity logging, sonic logging, gamma logging, and well temperature logging. Integrated logging is conducted after open-hole drilling is completed. Core sampling and testing are carried out simultaneously with open-hole drilling, with sampling strata determined based on the previous hydrogeological survey report of the mining area. It should be noted that core sampling and testing involves real-time collection of in-situ rock samples during drilling, and sampling is conducted at fixed points based on the previous hydrogeological survey report of the mining area, ensuring accurate acquisition of physical rock samples from the target strata. Subsequently, integrated logging is performed on the borehole, resulting in stable logging curve data, and ensuring that the resistivity, gamma, and other logging responses accurately reflect the vertical distribution characteristics of the formation. In this embodiment, core data and logging curve data can be compared and verified to improve the accuracy of formation determination. At the same time, the sampling layer is preset with reference to the previous hydrogeological survey report of the mining area, eliminating the need for continuous and indiscriminate coring of the entire borehole. This allows for targeted sampling of candidate aquifers and aquitards, reducing the waste of drilling and coring materials and time. Under the premise of completing the 100% determination of the reinjection layer, the exploration period is shortened and the construction cost of the drilling exploration stage is controlled.

[0025] It should be noted that in actual implementation, the well network for in-situ leaching uranium mining includes multiple pumping wells and multiple injection wells. For each pumping and injection well, open-hole drilling and stratigraphic exploration are performed, and each borehole independently generates corresponding single-hole vertical stratigraphic data. This allows for the accurate acquisition of the vertical stratigraphic distribution characteristics of each injection well within the mining area; simultaneously, it provides comprehensive, detailed, and accurate single-hole stratigraphic foundation data for the subsequent establishment of a three-dimensional stratigraphic structure model of the mining area, improving the accuracy of stratigraphic characterization.

[0026] Step S102: Establish a three-dimensional stratigraphic structure model of the mining area based on the stratigraphic exploration results.

[0027] First, single-hole vertical stratigraphic data can be obtained through single-hole open-hole drilling, integrated logging, and core sampling. Based on the single-hole vertical stratigraphic data, a single-hole vertical stratigraphic structure model can be constructed. Then, the single-hole vertical stratigraphic structure models corresponding to all boreholes in the mining area are summarized, and spatial interpolation and stratigraphic interface splicing are carried out in combination with the planar coordinates of each borehole to construct a three-dimensional stratigraphic structure model of the mining area.

[0028] Specifically, the three-dimensional stratigraphic structure model of the mining area can be a global stratigraphic spatial model constructed using modeling software such as GMS, EVS, and Leapfrog Geo. In practical applications, the three-dimensional stratigraphic structure model of the mining area can be based on the single-hole longitudinal stratigraphic structure model of all boreholes within the mining area, combined with spatial interpolation and stratigraphic interface splicing and integration using the planar coordinates of each borehole. This model, built using the stratigraphic parameters obtained above, can fully present the three-dimensional spatial distribution relationship of strata within the mining area, clearly distinguishing the spatial locations of the ore-bearing ore body 200, the recharge layer 100, and the aquitard. It can fully output information such as the depth of the top interface, the depth of the bottom interface, the effective thickness, the interlayer spacing, and the planar distribution range of each stratum, providing a complete model basis for subsequent layered injection device deployment and recharge numerical simulation modeling. Here, the ore-bearing ore body 200 refers to the distribution portion of the uranium ore body in the ore-bearing aquifer, the recharge layer 100 refers to the non-ore-bearing aquifer, and the aquitard refers to a dense rock layer with extremely low permeability, through which groundwater is difficult to penetrate.

[0029] Step S103: Select aquifers that meet the preset conditions from the three-dimensional geological structure model of the mining area as recharge layer 100.

[0030] The preset conditions are pre-defined access standards for the reinjection layer, which are formulated based on the safety requirements for reinjection operations of wastewater from in-situ leaching uranium mining. In actual implementation, the screening work is carried out using complete stratigraphic parameters within the three-dimensional stratigraphic structure model of the mining area. From the multiple aquifers marked in the three-dimensional stratigraphic structure model of the mining area, the target aquifer with no mineral mining value and meeting the safety requirements for reinjection permeability and sealing is selected and determined as the reinjection layer 100 used in this method.

[0031] Specifically, the target aquifer has good permeability and well-developed pores and fractures, making it suitable for long-term, high-flow-rate wastewater reinjection operations in in-situ uranium leaching mines, thus avoiding problems such as reinjection pipeline blockage and formation pressure water accumulation. Simultaneously, the target aquifer exhibits excellent sealing properties, with stable water-resistant layers distributed vertically, ensuring reliable hydraulic isolation. Furthermore, the target aquifer contains no uranium or other exploitable minerals and is not included in the ore body mining strata, so reinjection operations will not cause mineral resource depletion. Additionally, the target aquifer has a stable overall structure, without fractures, broken zones, or other adverse structures, ensuring that long-term wastewater reinjection will not induce geological hazards such as formation collapse or disruption of the regional groundwater hydrological environment. In addition, hydrogeochemical conditions must be comprehensively considered. For example, the original groundwater of the target aquifer should have a high degree of compatibility with the hydrochemical composition of the radioactive process wastewater to be reinjected, making it less likely that secondary mineral precipitation such as hydroxides, sulfates, and carbonates will clog the formation pores after reinjection; the background indicators of the groundwater in the target aquifer, such as pH, redox potential, and ion concentration, should be similar to those of the reinjected wastewater to avoid violent water-rock reactions; the groundwater runoff conditions in the target aquifer should be gentle, and the diffusion rate of the reinjected wastewater should be controllable to reduce the risk of radioactive contamination plume spreading outward. Furthermore, if the mineral components of the target aquifer can undergo adsorption and precipitation reactions with radionuclides and other dissolved components in the reinjected wastewater, preventing large-scale migration of nuclides and resulting groundwater pollution in the surrounding area, then this target aquifer can be given priority.

[0032] Step S2: Determine the reinjection parameters.

[0033] In this embodiment, the reinjection parameters can be determined through hydrogeological numerical simulation. Here, the reinjection parameters include the reinjection water volume and the reinjection pressure.

[0034] For example, step S2 includes: Step S201: Assign parameters to the three-dimensional stratigraphic structure model of the mining area to obtain the numerical model of the in-situ leaching mining area recharge.

[0035] The parameter assignment process involves using modeling software such as GMS and PHREEQC to embed field-measured hydrological and water quality parameters into the numerical processing of the three-dimensional stratigraphic structure model of the mining area. This transforms the static three-dimensional stratigraphic structure model of the mining area into a computable and dynamic numerical model for groundwater recharge in the leaching mining area. By assigning both hydrological and water quality parameters to the three-dimensional stratigraphic structure model of the mining area, the numerical model for groundwater recharge in the leaching mining area can simultaneously possess stratigraphic seepage characteristics and groundwater chemical features. This allows it to realistically reflect the actual laws governing groundwater seepage, migration, and water quality evolution in the leaching mining area, providing a computable numerical simulation platform for recharge condition simulation and parameter determination. Here, the field-measured hydrological parameters are stratigraphic parameters such as lithology, burial depth, porosity, permeability coefficient, aquitard distribution, and stratigraphic stability obtained through open-hole drilling and stratigraphic exploration. The water quality parameters are background groundwater quality parameters obtained from the previous hydrogeological survey report of the mining area, used to characterize the original hydrochemical characteristics of the groundwater.

[0036] Step S202: Run the numerical model for reinjection in the leaching extraction area to perform numerical simulation and prediction, and determine the reinjection parameters.

[0037] Among them, it can simulate the seepage state and water chemical change law of wastewater reinjection under different reinjection parameters and reinjection conditions. Through iterative calculation, the optimal reinjection water volume and reinjection pressure for the reinjection layer 100 can be solved, and the reinjection parameters can be determined.

[0038] It should be noted that during the simultaneous determination of reinjection parameters, leaching parameters, including the injection pressure and volume of the leaching solution, can also be determined. In actual implementation, while assigning parameter values ​​to the three-dimensional stratigraphic structure model of the mining area to obtain the numerical model for reinjection in the in-situ leaching mining area, a numerical model for leaching in the in-situ leaching mining area is simultaneously generated. Subsequently, the numerical model for leaching in the in-situ leaching mining area is run to conduct hydrogeological numerical simulation calculations to determine the leaching parameters. Therefore, in-situ leaching mining operations can be carried out based on these leaching parameters.

[0039] Step S3: Install a stratified injection device in the injection well.

[0040] In this embodiment, the layered injection device includes a sleeve 1, a reinjection injection pipe 2, a leaching solution injection pipe 3, and a water-stopping device 4.

[0041] For example, step S3 includes: Step S301: Carry out the casing 1 lowering operation; Step S302: Construct leaching channels for the pipe section of casing 1 corresponding to the recharge layer 100 and the pipe section corresponding to the ore-bearing ore body 200, respectively, to form wastewater recharge seepage channel 11 and leaching liquid seepage channel 12. Step S303: Lower the reinjection pipe 2 and the leaching solution injection pipe 3 into the inside of the casing 1, so that the outlet end of the reinjection pipe 2 is aligned and connected to the wastewater reinjection seepage channel 11, and the outlet end of the leaching solution injection pipe 3 is aligned and connected to the leaching solution seepage channel 12. Step S304: Install a water-stopping device 4 inside the casing 1 and between the wastewater reinjection seepage channel 11 and the leaching solution seepage channel 12; Step S305: Perform a pressure test on the sealing device 4 to check its sealing performance.

[0042] Step S4: Inject wastewater into the reinjection layer 100 via a stratified injection device.

[0043] In this embodiment, wastewater can be injected into the reinjection layer 100 through the reinjection injection pipe 2 according to the reinjection parameters determined in step S2.

[0044] The methods for constructing leaching channels include at least one of the following: hydraulic perforation, hydraulic slotting, mechanical slotting, hydraulic sandblasting fracturing, and high-energy gas deflagration.

[0045] By applying the technical solution of this embodiment, firstly, the stratum of the reinjection layer 100 is obtained; then, the reinjection parameters are determined; subsequently, a stratified injection device is set in the injection well; and finally, wastewater is injected into the reinjection layer 100 through the stratified injection device. This enables the underground treatment of wastewater from in-situ leaching uranium mining, avoiding the land acquisition and infrastructure construction investment problems caused by the surface evaporation pond treatment mode, reducing the infrastructure costs of mine production, and eliminating the constraints of climate conditions on wastewater treatment operations. It can adapt to the wastewater treatment needs of continuous production in in-situ leaching uranium mines, ensuring the continuous and stable operation of wastewater treatment.

[0046] Furthermore, as a refinement and extension of the specific implementation methods of the above embodiments, the wastewater reinjection method also includes: Step S5: Dynamically monitor the hydrological parameters of the recharge layer 100.

[0047] In this embodiment, the hydrological parameters of the recharge layer 100 include the water level parameters, water pressure parameters, flow rate parameters, and water quality parameters of the recharge layer 100.

[0048] The water level and water quality parameters of the recharge layer 100 can be monitored and obtained by drilling observation wells connected to the recharge layer 100, and the water pressure and flow parameters of the recharge layer 100 can be collected in real time by pressure gauge 8 and flow meter 7 installed on the recharge injection pipe 2.

[0049] Step S6: Adjust the recharge flow rate and recharge pressure in real time based on the hydrological parameters of the recharge layer 100 obtained from dynamic monitoring.

[0050] In this embodiment, based on the water level, water pressure, flow rate, and water quality parameters of the recharge layer 100 obtained in real time through step S5, the dynamic changes in the groundwater seepage state and hydrochemical environment inside the recharge layer 100 can be monitored in real time. This allows for dynamic adjustment of the preset recharge flow rate and recharge pressure according to the actual recharge conditions of the recharge layer 100, ensuring that the actual recharge conditions always match the permeability and water storage conditions of the recharge layer 100. This avoids problems such as excessive formation pressure, water accumulation, seepage blockage, or abnormal water quality fluctuations during the recharge process, ensuring that wastewater recharge operations can be carried out stably, safely, and efficiently in the long term, and improving the stability and controllability of in-situ leaching uranium wastewater recharge operations.

[0051] Furthermore, in order to achieve Figure 1 The wastewater reinjection method shown in this application provides a stratified injection device, see [link to relevant documentation]. Figure 2 As shown, the device includes a casing 1, a reinjection pipe 2, a leaching solution injection pipe 3, and a water-stopping device 4. The casing 1 is installed inside the borehole of the injection well. The casing 1 is provided with a wastewater reinjection seepage channel 11 for the pipe section corresponding to the reinjection layer 100, and a leaching solution seepage channel 12 for the pipe section corresponding to the ore body 200 of the ore layer. The reinjection pipe 2, the leaching solution injection pipe 3, and the water-stopping device 4 are all installed inside the casing 1. The outlet end of the reinjection pipe 2 is aligned and connected to the wastewater reinjection seepage channel 11, the outlet end of the leaching solution injection pipe 3 is aligned and connected to the leaching solution seepage channel 12, and the water-stopping device 4 is located between the wastewater reinjection seepage channel 11 and the leaching solution seepage channel 12 inside the casing 1.

[0052] The layered injection device provided in this application embodiment can be directly installed inside the casing of the injection well to carry out operations without the need to drill an additional reinjection well, thereby reducing the construction costs and time consumption caused by drilling new wells.

[0053] The stratified injection device also includes a main injection pipe 5, which is connected to the inlet ends of the reinjection injection pipe 2 and the leaching liquid injection pipe 3 respectively. The main injection pipe 5 is used to connect to an external liquid supply system to deliver the corresponding working fluid to the reinjection injection pipe 2 and the leaching liquid injection pipe 3 respectively.

[0054] Specifically, both the reinjection pipe 2 and the leaching solution injection pipe 3 are equipped with regulating valves 6. These valves allow for independent, time-sharing operation of the two pipes, ensuring that only one is connected to the main injection pipe 5 at any given time. In practice, during leaching operations, only the leaching solution injection pipe 3 is activated to complete the leaching solution injection process; similarly, during wastewater reinjection operations, only the reinjection pipe 2 is activated to complete the wastewater reinjection process, thus enabling the leaching and wastewater reinjection operations to be carried out independently and alternately at different times.

[0055] Among them, the reinjection pipe 2 and the leaching liquid injection pipe 3 are also equipped with a flow meter 7 and a pressure gauge 8, which are located downstream of the regulating valve 6.

[0056] Specifically, in actual implementation, based on the real-time flow data collected by the flow meter 7 and the real-time pressure data collected by the pressure gauge 8, the regulating valve 6 can be controlled to adjust the valve opening, thereby regulating the pressure and flow rate of the working fluid to adapt to the formation hydrological bearing conditions and preset operating parameters corresponding to the reinjection layer 100 or the ore-bearing ore body 200.

[0057] The serial numbers in this application are for descriptive purposes only and do not represent the superiority or inferiority of any particular implementation scenario. The above disclosures are merely a few specific implementation scenarios of this application; however, this application is not limited thereto, and any variations conceived by those skilled in the art should fall within the protection scope of this application.

Claims

1. A wastewater reinjection method, characterized in that, include: Obtain the layer position of the recharge layer; Determine the reinjection parameters; A stratified injection device is installed in the injection well; Wastewater is injected into the reinjection layer via the stratified injection device.

2. The method according to claim 1, characterized in that, The layer at which the recharge layer is obtained includes: Open-hole drilling and geological exploration were carried out. A three-dimensional stratigraphic structure model of the mining area was established based on the stratigraphic exploration results; Aquifers that meet preset conditions are selected from the three-dimensional geological structure model of the mining area as the recharge layer.

3. The method according to claim 2, characterized in that, The geological exploration includes integrated well logging and core sampling and testing; the integrated well logging is carried out after the open borehole drilling; the core sampling and testing is carried out during the open borehole drilling, and the sampling strata for the core sampling and testing are determined based on the previous hydrogeological survey report of the mining area.

4. The method according to claim 2, characterized in that, The determination of the reinjection parameters includes: The parameters of the three-dimensional stratigraphic structure model of the mining area are assigned to obtain the numerical model of the infiltration mining area recharge. The numerical model for recharge in the leaching extraction area is run to perform numerical simulation and prediction to determine the recharge parameters.

5. The method according to claim 1, characterized in that, The method of installing a stratified injection device in the injection well includes: Conduct casing installation work; The pipe sections corresponding to the recharge layer and the pipe sections corresponding to the ore-bearing ore body of the casing are respectively constructed to form leaching channels, thereby forming wastewater recharge seepage channels and leaching liquid seepage channels. A reinjection pipe and a leaching solution injection pipe are placed inside the casing, such that the outlet end of the reinjection pipe is aligned and connected to the wastewater reinjection seepage channel, and the outlet end of the leaching solution injection pipe is aligned and connected to the leaching solution seepage channel. A water-stopping device is installed inside the casing and between the wastewater reinjection seepage channel and the leaching solution seepage channel; The sealing device was subjected to a pressure test to check its sealing performance.

6. The method according to claim 1, characterized in that, Also includes: Dynamically monitor the hydrological parameters of the recharge layer; The recharge flow rate and pressure are adjusted in real time based on the hydrological parameters of the recharge layer obtained from dynamic monitoring.

7. A stratified liquid injection device, characterized in that, The device is applied to the wastewater reinjection method according to any one of claims 1 to 6; the device includes a sleeve, a reinjection injection pipe, a leaching solution injection pipe, and a water-stopping device. The casing is installed inside the borehole of the injection well; The casing is provided with a wastewater reinjection seepage channel for the pipe section corresponding to the reinjection layer, and the casing is provided with a leaching solution seepage channel for the pipe section corresponding to the ore body of the ore layer. The reinjection pipe, the leaching solution injection pipe, and the water-stopping device are all located inside the casing. The outlet end of the reinjection pipe is aligned and connected to the wastewater reinjection seepage channel, the outlet end of the leaching solution injection pipe is aligned and connected to the leaching solution seepage channel, and the water-stopping device is located between the wastewater reinjection seepage channel and the leaching solution seepage channel inside the casing.

8. The apparatus according to claim 7, characterized in that, It also includes a main injection pipe, which is connected to the inlet end of the reinjection injection pipe and the leaching solution injection pipe, respectively.

9. The apparatus according to claim 8, characterized in that, The reinjection pipe and the leaching solution injection pipe operate in shifts.

10. The apparatus according to claim 7, characterized in that, Both the reinjection pipe and the leaching solution injection pipe are equipped with a regulating valve, a flow meter, and a pressure gauge, with the flow meter and pressure gauge located downstream of the regulating valve.

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