In-situ leaching uranium mine unit pre-oxidation circulation system and method

Abstract

The invention relates to the technical field of in-situ leaching uranium mining, and provides an in-situ leaching uranium mine unit pre-oxidation circulating system and method. The in-situ leaching uranium mine unit pre-oxidation circulation system comprises a liquid extraction drilling hole; a plurality of liquid injection drill holes; the drainage hole is connected with the drainage hole through an ore bed seepage channel; the deep well submersible pump is arranged in the liquid extraction drill hole; the buffer device comprises a tank body, a plurality of communicating pipes arranged at the lower part of the tank body and a sampling nozzle arranged on the tank body; two ends of the lifting pipe are respectively connected with an outlet of the deep well submersible pump and the top of the buffer device; the plurality of liquid injection well inner pipes are respectively connected with the corresponding communicating pipes of the buffer device and the liquid injection drill holes; wherein the deep well submersible pump is used for conveying leaching liquid in the liquid pumping drill holes to the buffer device through the lifting pipe, the leaching liquid is distributed through the buffer device, then is injected into the corresponding liquid injection drill holes through the liquid injection well inner pipes and flows back to the liquid pumping drill holes through the ore bed seepage channel, and a pre-oxidation circulation loop is formed. Pre-oxidation circulation is completed in advance, and the leaching time of a mining area is shortened.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of in-situ leaching of uranium, in particular to an in-situ leaching of uranium mine unit pre-oxidation circulation system and method. BACKGROUND

[0002] In the related art, in the in-situ leaching of uranium process, an oxidant containing oxygen or carbon dioxide and the like is usually injected into the ore bed to oxidize the insoluble divalent and tetravalent uranium into soluble hexavalent uranium, thereby realizing leaching and recovery of uranium. This process needs to rely on the control room system to monitor and control the key parameters such as injection flow rate and oxidant concentration in real time. However, in the actual mine construction process, drilling is often completed before the control room system, resulting in a large number of completed drill holes being idle due to the inability to access the control system in time, not only causing waste of equipment and engineering resources, but also significantly prolonging the overall development cycle of the mine and increasing the construction and operation costs. SUMMARY

[0003] In order to solve the technical problems of the above-mentioned existing in-situ leaching of uranium process, that is, the long-term idle of the completed drill holes due to the mismatch of the drilling construction and the control room construction time sequence, thereby prolonging the development cycle, wasting equipment resources, and increasing the comprehensive cost, the first aspect of the present application proposes an in-situ leaching of uranium mine unit pre-oxidation circulation system.

[0004] The second aspect of the present application also proposes an in-situ leaching of uranium mine unit pre-oxidation circulation method.

[0005] Therefore, the first aspect of the present application proposes an in-situ leaching of uranium mine unit pre-oxidation circulation system, which comprises: a pumping drill hole; a plurality of injection drill holes; connected through the ore bed seepage channel between the pumping drill hole; a deep well submersible pump arranged in the pumping drill hole; a buffer device comprising a tank body, a plurality of communication pipes arranged at the lower part of the tank body, and a sampling nozzle arranged on the tank body; a lifting pipe, both ends of the lifting pipe being connected with the outlet of the deep well submersible pump and the top of the buffer device, respectively; a plurality of injection well inner pipes, respectively connected with the corresponding communication pipes of the buffer device and each injection drill hole; wherein the deep well submersible pump is used to transport the leaching solution in the pumping drill hole to the buffer device through the lifting pipe, the leaching solution is distributed by the buffer device and then injected into the corresponding injection drill hole through each injection well inner pipe, and then flows back to the pumping drill hole through the ore bed seepage channel, forming a pre-oxidation circulation loop.

[0006] In combination with the first aspect, in some implementable manners, the in-situ leaching of uranium mine unit pre-oxidation circulation system, the tank body comprises: an upper tank body, the top of the upper tank body being provided with a straight pipe flange for connecting the lifting pipe; and a lower tank body, which is detachably connected with the upper tank body.

[0007] With reference to the first aspect, in some possible implementation manners, the in-situ leaching uranium mine unit pre-oxidation circulation system further includes: a flow guide plate arranged on the upper tank body, used for slowing down the liquid flow rate and promoting gas-liquid separation.

[0008] With reference to the first aspect, in some possible implementation manners, the in-situ leaching uranium mine unit pre-oxidation circulation system further includes: a support arranged at the bottom of the tank body, used for supporting the tank body.

[0009] With reference to the first aspect, in some possible implementation manners, the in-situ leaching uranium mine unit pre-oxidation circulation system further includes: an epoxy resin anticorrosive layer formed on the inner surface and the outer surface of the tank body; and a rust-proof paint layer formed on the surface of the support.

[0010] With reference to the first aspect, in some possible implementation manners, the in-situ leaching uranium mine unit pre-oxidation circulation system further includes: a multi-way distributor, an inlet of the multi-way distributor being connected with the multiple communication pipes of the buffer device, multiple outlets of the multi-way distributor being respectively connected with the inner pipes of the multiple injection wells, and the multi-way distributor being provided with adjusting valves used for independently adjusting flow rates of the multiple injection branches.

[0011] With reference to the first aspect, in some possible implementation manners, a spacing between the liquid pumping borehole and each injection borehole is less than or equal to 30 m.

[0012] The second aspect of the present application provides an in-situ leaching uranium mine unit pre-oxidation circulation method, which uses the in-situ leaching uranium mine unit pre-oxidation circulation system in any of the above technical solutions, and includes the following steps. Constructing a unit closed-loop circulation system independent of the centralized control room system: connecting the liquid pumping borehole and the injection borehole through the circulation system buffer device to form a closed loop process of liquid pumping, buffering and liquid injection; using a deep-well submersible pump to lift the leaching liquid in the liquid pumping borehole to the surface buffer device, and then injecting the leaching liquid into the injection borehole through the buffer device to realize pre-oxidation in the unit; Adding an oxidizing agent: according to the pumping test data of the ore deposit, hydrogen peroxide is injected into the injection borehole as an oxidizing agent; Monitoring and control: after the system runs for a set time, the residual oxygen concentration and the uranium concentration in the leaching liquid are monitored, and hydrogen peroxide is supplemented according to the residual oxygen concentration; System transfer and reuse: after the pre-oxidation is completed, the circulation system is disassembled and connected to the surface pipeline of the centralized control room to seamlessly connect the pre-oxidation stage and the centralized mining stage.

[0013] With reference to the second aspect, in some possible implementation manners, the hydrogen peroxide is injected into the injection borehole, and specifically includes: injecting the hydrogen peroxide into the injection borehole at a standard of 150 mg / L to 190 mg / L.

[0014] With the second aspect, in some possible implementation manners, the residual oxygen concentration in the leaching solution is monitored, specifically including: monitoring the residual oxygen concentration in the leaching solution through a sampling nozzle on the buffer device; when the residual oxygen concentration is monitored to be lower than 10 mg / L, supplementing hydrogen peroxide into the injection borehole.

[0015] Compared with the related art, the present application has the following technical effects: The in-situ leaching uranium mine unit pre-oxidation circulation system provided by the present application includes a liquid extraction borehole, a plurality of liquid injection boreholes, a deep well submersible pump, a buffer device, a riser pipe, and a plurality of liquid injection well inner pipes. The conventional in-situ leaching mining needs to wait until the centralized control room and all surface pipelines are completed before starting pre-oxidation, which has a long cycle and high cost. The pre-oxidation circulation system provided by the present application performs pre-oxidation on the boreholes for which the centralized control room construction is not completed, and the leaching solution in the boreholes is lifted to the buffer device by the deep well submersible pump, and then distributed to the plurality of liquid injection boreholes by the buffer device. The liquid injection borehole is provided with a filter, which can form a leaching channel in the ore-bearing aquifer, thereby realizing the pre-oxidation process. The system effectively solves the problem that pre-oxidation cannot be performed in time in the mining area due to incomplete centralized control room system construction, ensures the smooth production of the in-situ leaching uranium mine mining area, completes the unit pre-oxidation circulation in advance, shortens the leaching time of the mining area, accelerates the concentration improvement of the leaching solution of the mining area, and enables the developed borehole to contribute to the production capacity as soon as possible.

[0016] Additional aspects and advantages of the present application will become apparent in the description that follows, or will be learned by practice of the application. BRIEF DESCRIPTION OF DRAWINGS

[0017] The above and / or additional aspects and advantages of the present application will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings in which: Figure 1 A schematic diagram of an in-situ leaching uranium mine unit pre-oxidation circulation system in one embodiment of the present application is shown; Figure 2 A top view schematic diagram of a buffer device in one embodiment of the present application is shown; Figure 3 A front view schematic diagram of a buffer device in one embodiment of the present application is shown; Figure 4 A sectional view of a buffer device in one embodiment of the present application is shown; Figure 5 A flowchart of an in-situ leaching uranium mine unit pre-oxidation circulation method in one embodiment of the present application is shown.

[0018] Among them, Figures 1 to 4 The correspondence between the reference signs and the component names in the accompanying drawings is as follows: 1 Straight pipe flange, 2 Bolt, 3 Connecting pipe, 4 Screw, 5 Sampling nozzle, 6 Tank body, 7 Support, 8 Buffer device, 9 Lifting pipe, 10 Deep well submersible pump, 11 Pumping borehole, 12 Injection borehole, 13 Mine seepage channel, 14 Injection well inner pipe, 15 Distribution box. Detailed Implementation

[0019] To better understand the above-mentioned objectives, features, and advantages of this application, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0020] Many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of this application is not limited to the specific embodiments disclosed below.

[0021] The following reference Figures 1 to 5 This application describes a pre-oxidation cycle system and method for in-situ leaching uranium mine units according to some embodiments.

[0022] like Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, the first aspect of this application proposes a pre-oxidation circulation system for an in-situ leaching uranium mine unit, comprising: a pumping borehole 11; multiple injection boreholes 12; connected to the pumping borehole 11 via a mineral layer seepage channel 13; a deep-well submersible pump 10 disposed in the pumping borehole 11; a buffer device 8 comprising a tank 6, multiple connecting pipes 3 disposed at the lower part of the tank 6, and a sampling nozzle 5 disposed on the tank 6; a riser pipe 9, the two ends of which are respectively connected to the outlet of the deep-well submersible pump 10 and the top of the buffer device 8; and multiple injection well inner pipes 14, respectively connected to the corresponding connecting pipes 3 of the buffer device 8 and each injection borehole 12; wherein, the deep-well submersible pump 10 is used to transport the leachate in the pumping borehole 11 to the buffer device 8 via the riser pipe 9, and the leachate is distributed by the buffer device 8 and injected into the corresponding injection borehole 12 through each injection well inner pipe 14, and flows back to the pumping borehole 11 via the mineral layer seepage channel 13, forming a pre-oxidation circulation loop.

[0023] The pre-oxidation circulation system for uranium leaching mine units provided in this application includes a pumping borehole 11, multiple injection boreholes 12, a deep-well submersible pump 10, a buffer device 8, a riser pipe 9, and multiple injection well inner pipes 14. Traditional in-situ leaching mining requires the completion of a central control room and all surface pipelines before pre-oxidation can begin, resulting in a long cycle and high cost. The pre-oxidation circulation system provided in this application pre-oxidizes boreholes where the central control room construction is not yet complete. Power is supplied to the deep-well submersible pump 10 via a distribution box 15. The deep-well submersible pump 10 lifts the leaching fluid from the pumping borehole 11 to the buffer device 8, which then distributes it to the multiple injection boreholes 12. The injection boreholes 12 are equipped with filters, which can form leaching channels within the ore-bearing aquifer, thereby realizing the pre-oxidation process. This system effectively solves the problem of the inability to carry out pre-oxidation in a timely manner in mining areas due to the incomplete construction of the central control room system. It ensures the smooth operation of production in in-situ leaching uranium mines, completes the unit pre-oxidation cycle ahead of schedule, shortens the leaching time in mining areas, accelerates the increase of leaching solution concentration in mining areas, and enables the developed boreholes to quickly contribute to production capacity.

[0024] The system employs an intra-unit liquid circulation mode, where the leachate is rapidly recovered after flowing through the ore layer and reinjected after the addition of hydrogen peroxide, ensuring an effective concentration and continuous supply of oxidant in the ore layer. Compared to the traditional method of injecting carbon dioxide or oxygen through injection borehole 12, this system utilizes hydrogen peroxide solution to avoid the "gas blockage" problem that is easily caused by gas injection. Furthermore, its higher solubility and more uniform distribution along the seepage path result in more thorough contact with the uranium minerals, significantly improving the oxidation reaction rate and efficiency, thus laying a solid foundation for subsequent leaching.

[0025] This circulating system, operating as an independent module, can be easily disassembled and transferred to the next unit for reuse after completing the pre-oxidation task of the current unit. This "one machine, multiple uses" approach improves equipment utilization and avoids the huge investment required to configure a dedicated ground circulating system for each unit. Furthermore, after pre-oxidation, the system's main pipelines and equipment can be directly connected to the subsequently constructed surface pipelines of the central control room, achieving a "seamless connection" from pre-oxidation to large-scale production. This simplifies the process, avoids redundant construction, and significantly reduces the overall cost of mining.

[0026] The sampling nozzle 5 of the buffer device 8 in the system provides a convenient window for real-time monitoring of key chemical indicators in the leachate. Based on the monitoring data, the consumption status of the oxidant and the leaching effect can be accurately determined, and the dosage of hydrogen peroxide can be adjusted in a timely manner, achieving refined and intelligent management of the pre-oxidation process. This dynamic control mechanism ensures that the entire pre-oxidation process is always in an optimal state, guaranteeing the stability of system operation and the controllability of treatment effect.

[0027] The pre-oxidation circulation system for in-situ leaching uranium mines provided in this application has successfully solved a series of key technical problems in the traditional pre-oxidation stage of in-situ leaching uranium mines, such as long construction period, low efficiency, high cost and difficult control, through structural innovation and process reengineering. It provides a brand-new technical equipment solution for the efficient and economical development of in-situ leaching uranium mines.

[0028] like Figure 1 and Figure 3 As shown, in some embodiments provided in this application, the tank 6 includes: an upper tank, the top of which is provided with a straight pipe flange 1 for connecting the lifting pipe 9; and a lower tank, which is detachably connected to the upper tank.

[0029] In this embodiment, the tank 6 includes an upper tank and a lower tank. A straight pipe flange 1 is provided at the top of the upper tank for connecting the riser pipe 9. This standardized interface design makes the connection between the riser pipe 9 and the tank 6 simple and quick, reducing installation difficulty and time costs. At the same time, the upper and lower tanks are detachably connected. When the equipment malfunctions or requires internal cleaning or component replacement, the upper and lower tanks can be quickly separated to directly inspect or replace damaged parts internally without the need for complex operations on the entire tank 6, thus improving maintenance efficiency.

[0030] The detachable structure allows tank 6 to be flexibly adjusted according to actual production needs. For example, in pre-oxidation circulation systems of in-situ leaching uranium mines of different sizes or types, the upper and lower tanks of different specifications or materials can be replaced to meet specific process requirements such as pressure and flow rate, thereby enhancing the versatility and adaptability of the equipment.

[0031] In some embodiments provided in this application, the pre-oxidation circulation system for in-situ leaching uranium mine units further includes: a guide plate disposed on the upper tank to slow down the liquid flow rate and promote gas-liquid separation.

[0032] In this embodiment, the guide plate can change the flow path of the leachate within the tank 6, making its flow more orderly and effectively slowing down the liquid flow rate. With the flow rate reduced, the liquid's residence time within the tank 6 is extended, allowing the components in the leachate to mix and react fully, improving the pre-oxidation effect, resulting in more complete uranium leaching and increased resource utilization.

[0033] During the pre-oxidation process, the leachate may carry gas. The baffle plate disrupts the gas-liquid mixture, using gravity to cause the gas to rise and the liquid to sink, achieving effective gas-liquid separation. The separated gas can be discharged promptly, preventing gas accumulation in the system from affecting normal equipment operation and oxidation reaction efficiency.

[0034] Smooth liquid flow and good gas-liquid separation can reduce the impact and corrosion of the liquid on the inside of the tank and subsequent equipment, extend the service life of the equipment, reduce the maintenance and replacement costs of the equipment, and ensure the long-term stable operation of the system.

[0035] like Figure 3 As shown, in some embodiments provided in this application, the pre-oxidation circulation system for in-situ leaching uranium mine units further includes: a support 7, disposed at the bottom of the tank 6, for supporting the tank 6.

[0036] In this embodiment, the support 7 provides stable support for the tank 6, ensuring its stability during operation and preventing it from shaking or shifting due to equipment vibration, liquid impact, or external interference. This ensures the smooth operation of the entire pre-oxidation circulation system, avoiding problems such as loose pipe connections and liquid leakage caused by the instability of the tank 6, and guaranteeing the continuity and safety of production.

[0037] In-situ uranium leaching mines have complex environments and may have uneven ground. The support frame 7 can be adjusted and fixed according to the actual terrain, so that the tank 6 can adapt to different installation environments and ensure that the tank 6 is in a horizontal or suitable tilt position, which is conducive to the normal flow and distribution of leachate in the tank 6.

[0038] The support frame 7 raises the tank 6 to a certain height, providing convenient operating space for the installation, inspection, and maintenance of the equipment. Workers can more easily inspect, clean, and repair the bottom of the tank 6 and related pipelines, improving work efficiency and reducing maintenance difficulty and costs.

[0039] In some embodiments provided in this application, the pre-oxidation circulation system for in-situ leaching uranium mine units further includes: an epoxy resin anti-corrosion layer formed on the inner and outer surfaces of the tank 6; and an anti-rust paint layer formed on the surface of the support 7.

[0040] In this embodiment, the leachate in contact with tank 6 has a complex composition and is corrosive. The epoxy resin anti-corrosion layer is chemically stable and can effectively prevent the leachate from directly contacting the metal material of tank 6, avoiding electrochemical corrosion, extending the service life of tank 6, reducing the risk of liquid leakage due to corrosion, and ensuring stable system operation.

[0041] The support frame 7 is located in a complex mining environment and is susceptible to rust due to moisture and oxygen. The anti-rust paint layer forms a protective film on the surface of the support frame 7, isolating it from moisture and oxygen, preventing rust, and ensuring that the support frame 7 always maintains sufficient strength and stability to provide reliable support for the tank body 6.

[0042] In some embodiments provided in this application, the pre-oxidation circulation system of the in-situ leaching uranium mine unit further includes: a multi-channel distributor, the inlet of which is connected to multiple connecting pipes 3 of the buffer device 8, the multiple outlets of which are respectively connected to the inner pipes 14 of each injection well, and the multi-channel distributor is provided with regulating valves for independently adjusting the flow rate of each injection branch.

[0043] In this embodiment, the multi-channel distributor connects the connecting pipe 3 of the buffer device 8 to the inner pipe 14 of the injection well, and the regulating valve on it can independently adjust the flow rate of each injection branch. The operator can accurately control the amount of leaching fluid injected into each injection borehole according to the characteristics of the ore layer and the difference in uranium content in different injection boreholes 12, so that the oxidation reaction is more complete, the uranium leaching efficiency is improved, and the uneven flow rate can be avoided, which may lead to insufficient or excessive oxidation in some areas.

[0044] In response to changes in geological conditions and adjustments in production scale during mining operations, the flow rate of each branch can be quickly changed via regulating valves without requiring large-scale modifications to the overall system. This flexibility allows the system to better adapt to different operating conditions, ensuring continuous and stable production. Independent flow rate adjustment avoids leachate waste, ensuring that every drop of leachate plays its maximum role in the appropriate location, improving resource utilization and reducing production costs.

[0045] When a problem occurs in a certain injection branch, the flow rate of that branch can be shut off by adjusting the valve without affecting the normal operation of other branches. This makes it easier for staff to repair the faulty branch, reduces downtime, and improves the overall operating efficiency of the system.

[0046] In some embodiments provided in this application, the distance between the liquid extraction borehole 11 and each liquid injection borehole 12 is less than or equal to 30 meters.

[0047] In this embodiment, a suitable spacing facilitates the formation of good leaching channels for the leachate within the ore layer. A distance of less than 30 meters allows the leachate to circulate more efficiently between the pumping borehole 11 and the injection borehole 12, fully contacting and reacting with the uranium ore, increasing the uranium leaching rate, ensuring the pre-oxidation circulation system functions fully, and improving resource extraction efficiency.

[0048] By comprehensively considering the thickness of the ore layer and the distribution of uranium content, unit selection can be optimized to develop more reasonable mining plans tailored to the characteristics of different regions. In areas with high uranium content and thick ore layers, mining efforts can be intensified to achieve precise mining and improve resource utilization.

[0049] By combining the layout selection unit of the central control room, the distance between each borehole and the central control room can be made more reasonable, which facilitates centralized monitoring and operation of processes such as liquid extraction and injection, improves the convenience and efficiency of production management, and reduces labor costs.

[0050] like Figure 5 As shown, the second aspect of this application proposes a pre-oxidation cycle method for in-situ leaching uranium mine units, employing the pre-oxidation cycle system for in-situ leaching uranium mine units as described in any of the above embodiments, comprising the following steps: S202: Construct a unit closed-loop circulation system independent of the central control room system: Connect the pumping borehole and the injection borehole through the circulation system buffer device to form a closed-loop process of pumping, buffering and injection; use a deep well submersible pump to lift the leachate in the pumping borehole to the surface buffer device, and then inject it into the injection borehole through the buffer device to realize pre-oxidation within the unit. S204: Adding oxidant: Based on the data from the ore deposit pumping test, hydrogen peroxide is injected into the injection borehole as an oxidant; S206: Monitoring and Control: After the system has been running for a set time, monitor the residual oxygen concentration and uranium concentration in the leachate, and replenish hydrogen peroxide according to the residual oxygen concentration; S208: System Transfer and Reuse: After the pre-oxidation is completed, the circulation system will be disassembled and connected to the surface pipeline of the central control room to seamlessly connect the pre-oxidation stage with the central control mining stage.

[0051] The pre-oxidation cycle method for in-situ leaching uranium mine units provided in this application constructs a pre-oxidation cycle system independent of the central control room system, enabling unit pre-oxidation operations to proceed without waiting for the completion of all surface facilities in the entire mine. This significantly advances the critical production preparation step of pre-oxidation, allowing for the parallel advancement of ore layer chemical modification and surface infrastructure construction. It effectively breaks through the bottleneck of the traditional sequential operation mode and significantly shortens the overall cycle from mine construction to formal production.

[0052] Hydrogen peroxide is added as an oxidant during liquid injection drilling. Its high solubility in solution fundamentally avoids the gas blockage problem common in traditional gas injection methods, ensuring uniform distribution and stable transport of the oxidant along the ore layer's seepage path. Combined with real-time monitoring and feedback control of residual oxygen and uranium concentration in the leachate, the optimal chemical environment required for pre-oxidation can be precisely maintained, significantly improving the oxidation efficiency of tetravalent uranium and laying a solid foundation for subsequent efficient leaching.

[0053] The "build-run-transfer" process makes the entire cyclical system a standardized operational module. After completing the pre-oxidation of one unit, the system can be quickly disassembled and transferred to the next unit for reuse. This "one machine, multiple uses" model greatly improves the utilization efficiency of equipment assets and avoids redundant investment. At the same time, the seamless integration design between the pre-oxidation system and the subsequent centralized control system smooths the transition from the preparation stage to the large-scale production stage, optimizes the overall production process, and effectively reduces the total life cycle operating costs.

[0054] This pre-oxidation cycle method for in-situ leaching uranium mines successfully solves the core problems of long construction period, unstable efficiency, and difficulty in cost control in the pre-oxidation stage of in-situ leaching uranium mines through innovative process design and systematic dynamic control, providing a reliable process path for the efficient and economical development of in-situ leaching uranium mines.

[0055] In some embodiments provided in this application, hydrogen peroxide is injected into the injection borehole, specifically including injecting hydrogen peroxide into the injection borehole at a concentration of 150 mg / L to 190 mg / L.

[0056] In this embodiment, the concentration range was optimized and determined based on ore deposit pumping test data. This ensures that the injected fluid has sufficient oxidation potential, allowing divalent and tetravalent uranium to be rapidly and fully oxidized into easily leached hexavalent uranium, thereby effectively guaranteeing the rate and thoroughness of the pre-oxidation reaction. Simultaneously, this upper concentration limit avoids ineffective hydrogen peroxide decomposition and reagent waste caused by excessive dosage, controlling raw material costs while achieving the technical objectives and realizing the optimal balance between technical effectiveness and economic benefits.

[0057] Compared to the "gas blockage" problem easily caused by traditional carbon dioxide and oxygen injection, the use of this specific concentration of hydrogen peroxide solution avoids the risk of gas retention in the ore layer pores, ensuring smooth flow of the leaching solution in the ore layer seepage channels. This allows the oxidant to achieve a more uniform distribution within the pre-oxidation unit, resulting in more sufficient contact with the uranium minerals, thereby significantly improving the overall pre-oxidation uniformity and efficiency of the unit.

[0058] This concentration range establishes a clear benchmark for dynamic monitoring and control of the process. During operation, the consumption of oxidant can be directly judged by monitoring the residual oxygen concentration. When the residual oxygen is lower than the threshold required to maintain effective oxidation (e.g., 10 mg / L), operators can accurately replenish it according to this initial addition concentration standard, thereby maintaining the stability of the chemical environment of the pre-oxidation system and ensuring the controllability and stability of the entire cycle process.

[0059] In some embodiments provided in this application, monitoring the residual oxygen concentration in the leachate specifically includes: monitoring the residual oxygen concentration in the leachate through a sampling nozzle on a buffer device; and when the residual oxygen concentration is detected to be below 10 mg / L, adding hydrogen peroxide to the injection borehole.

[0060] In this embodiment, the residual oxygen concentration is monitored using a sampling nozzle on the buffer device, enabling timely and accurate acquisition of information on the remaining oxidant in the leaching solution. This helps to accurately determine the extent of the pre-oxidation reaction, ensuring the oxidation reaction proceeds continuously and stably, allowing the uranium minerals to be fully oxidized, and improving the uranium leaching efficiency.

[0061] By setting a time limit for adding hydrogen peroxide when the residual oxygen concentration falls below 10 mg / L, waste caused by blindly adding oxidant is avoided. This ensures effective pre-oxidation while allowing for reasonable control of oxidant usage, reducing production costs and improving economic efficiency.

[0062] This dynamic monitoring and replenishment mechanism can maintain an appropriate concentration of oxidant in the leachate, prevent problems such as poor pre-oxidation effect due to insufficient oxidant or equipment corrosion caused by excessive oxidant, and ensure the stable and reliable operation of the entire pre-oxidation cycle system.

[0063] In practical applications, the pre-oxidation circulation system for in-situ uranium leaching mine units also includes an automatic control system. This system is communicatively connected to the deep-well submersible pump 10, the online monitoring sensor located at the sampling nozzle 5, and the regulating valve of the multi-way distributor. It automatically adjusts the power of the submersible pump and / or the flow rate of each injection branch based on monitored residual oxygen and uranium concentration data. The automatic control system enables intelligent regulation of the pre-oxidation process, automatically adjusting the submersible pump power and the flow rate of each branch based on real-time monitoring data. This significantly improves oxidant utilization efficiency and pre-oxidation uniformity, ensuring stable and efficient system operation while reducing manual intervention costs.

[0064] The step of injecting hydrogen peroxide into the injection borehole 12 involves precisely controlling the dosage using a metering pump to maintain the hydrogen peroxide concentration in the leachate within the range of 150 mg / L to 190 mg / L. This precise addition of hydrogen peroxide via metering effectively maintains the optimal oxidant concentration in the leachate, ensuring the efficiency of the pre-oxidation reaction, avoiding reagent waste, and fundamentally preventing gas blockage, thus significantly improving the accuracy and economy of process control.

[0065] The buffer device 8 also includes a liquid level sensor, which is connected to an automatic alarm system to monitor the liquid level in tank 6 and prevent overflow or cavitation. Through the linkage between the liquid level sensor and the automatic alarm system, real-time monitoring and early warning of the liquid level in buffer tank 6 are achieved, effectively preventing overflow or cavitation accidents, ensuring continuous and stable system operation, and improving operational safety and automation management.

[0066] like Figures 1 to 5 As shown in the specific embodiments, this application aims to provide a pre-oxidation cycle method for in-situ uranium leaching mine units. By constructing a unit closed-loop cycle system independent of the central control room system, borehole pre-oxidation is achieved before the construction of the central control room, the leaching process is started in advance, the leaching efficiency of the mining area is improved, the mining cost is reduced, and the seamless connection between the equipment and the central control room system is achieved.

[0067] Technical solution steps: Step 1: Precise Dosing of Peroxide and Unit Selection Based on the pumping test data of the deposit, the instantaneous pumping rate was determined, and hydrogen peroxide was injected into the "seven-point" borehole unit (consisting of seven boreholes) at a standard of 150-190 mg / L. The seven boreholes include one pumping borehole and six injection boreholes.

[0068] The selection of units takes into account the thickness of the ore layer, the distribution of uranium content, and the layout of the central control room to ensure that the spacing between boreholes within the unit meets the conditions for the formation of leaching channels.

[0069] Step 2: Constructing an independent loop system Equipment configuration: A 5.5KW or 7.5KW deep well submersible pump (UPVC lift pipe + cable) is lowered into the pumping borehole, and a UPVC injection pipe is lowered into the injection borehole to a depth of 150-200m.

[0070] Buffer device installation: The buffer device of the circulation system is fixed near the liquid extraction borehole by a 304 stainless steel bracket. The tank is placed horizontally, and the top flat welding flange (GB / T9119-2010 standard) is sealed to the liquid extraction pipe. Six M20×1.5 threaded straight pipes on the side are connected to the liquid injection line to form a "liquid extraction-buffering-liquid injection" closed loop.

[0071] Corrosion protection design: The tank body is coated with an epoxy resin anti-corrosion layer of ≥200μm inside and out, the outer layer of the support is coated with anti-rust paint, and the welds are subjected to ultrasonic testing (Level II or above).

[0072] Step 3: Dynamic Regulation of Pre-oxidation After the submersible pump has been running for 24 hours, leachate is collected through the sampling nozzle to monitor residual oxygen concentration (10-15 mg / L) and uranium concentration (15-20 mg / L). The sampling nozzle is equipped with a pressure relief valve.

[0073] When the residual oxygen concentration is less than 10 mg / L, hydrogen peroxide is added through injection drilling to achieve dynamic equilibrium.

[0074] Step 4: Pre-oxidation termination and system transfer Pre-oxidation should be stopped when the uranium concentration in the leaching solution reaches 15-20 mg / L or the predicted peak value in the mining area.

[0075] The surface buffer tank and well pipelines are disassembled and connected to the surface pipelines in the central control room, achieving a seamless connection between pre-oxidation and central control. The equipment can be reused in the central control room system, reducing resource waste.

[0076] The above-mentioned pre-oxidation circulation method for uranium mining units involves adding peroxide (hydrogen peroxide) to the injection borehole, injecting the leachate from the extraction borehole into the injection borehole through a circulation system buffer device, and allowing the leaching agent in the injection borehole to flow into the extraction borehole through the leaching channels formed between the borehole filters, thus forming a closed circulation system for the effective oxidation of the uranium ore body within the ore layer.

[0077] This application discloses a pre-oxidation circulation method for a uranium leaching unit. The method involves using a submersible pump to lift the leaching solution from the extraction borehole 11 to the surface, where it flows into a connected circulation system buffer device 8. The solution is then injected into the injection borehole 12 via the circulation system buffer device 8. The circulation system buffer device 8 includes a buffer tank 6 and a support 7. The support 7 is fixed to the lower end of the tank 6. A straight pipe is connected to the upper end of the tank 6, with a flange at the other end. The upper part of the tank 6 has an openable / closeable structure, with both ends fixed by detachable bolts 2. The lower part of the tank 6 is connected to six straight pipes, each with threads at the other end. A sampling port communicating with the interior of the tank 6 is located in the middle of the tank 6, allowing sampling via a valve.

[0078] This application discloses a pre-oxidation cycle method for in-situ leaching uranium mine units, which includes the following steps: Based on the pumping test data of the ore deposit, the instantaneous pumping volume was obtained, and hydrogen peroxide was added according to the pumping volume, with 150 mg / L as the addition standard.

[0079] The deep well submersible pump connection cable and lift pipe were lowered to a depth of 200m in the borehole, and the injection pipe was also lowered to a depth of 200m in the borehole.

[0080] Install the circulation system buffer device to a depth of 5 meters in the liquid extraction borehole. Keep the device tank level and tighten bolts 2 and screws 4 of the circulation system buffer device to achieve a sealing effect.

[0081] Connect the pumping pipe to the circulation system buffer device, connect the injection line to the circulation system buffer device, and connect the deep well submersible pump to the power supply.

[0082] After one day of operation, samples were taken from the buffer device of the circulation system to monitor the residual oxygen concentration and leachate concentration.

[0083] If the residual oxygen concentration does not reach 10 mg / L, add hydrogen peroxide to the injection borehole and continue operation, repeating step 5.

[0084] Stop injecting when the residual oxygen concentration in the leachate reaches 10 mg / L, repeat step 5, monitor the leachate concentration, and stop operation when the concentration reaches 15 mg / L or the leachate concentration reaches the predicted peak value of the leachate concentration in the mining area, and connect the injection pipeline to the central control room system for operation.

[0085] In this application, the term "multiple" refers to two or more unless otherwise expressly defined. The terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; "linking" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0086] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0087] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An in-situ leaching uranium mine unit pre-oxidation cycle system, characterized in that, The in-situ leaching uranium mine unit pre-oxidation circulation system comprises: a leaching borehole; a plurality of injection boreholes; a seepage channel connecting the leaching borehole and the injection boreholes; a deep well submersible pump arranged in the leaching borehole; a buffer device comprising a tank, a plurality of communication pipes arranged at the lower part of the tank, and a sampling nozzle arranged on the tank; a lifting pipe, two ends of the lifting pipe being connected to the outlet of the deep well submersible pump and the top of the buffer device, respectively; a plurality of injection well pipes, each of which is connected to a corresponding communication pipe of the buffer device and a corresponding injection borehole; wherein the deep well submersible pump is used to transport the leaching solution in the leaching borehole to the buffer device through the lifting pipe, the leaching solution is distributed through the buffer device and then injected into the corresponding injection borehole through the injection well pipe, and finally flows back to the leaching borehole through the seepage channel, forming a pre-oxidation circulation loop.

2. The in-situ leaching uranium mine unit pre-oxidation circulation system according to claim 1, characterized in that, The tank comprises: an upper tank, the top of the upper tank being provided with a straight pipe flange for connecting the lifting pipe; a lower tank, which is detachably connected to the upper tank.

3. The in-situ leaching uranium mine unit pre-oxidation circulation system according to claim 2, characterized in that, Further comprising: a flow guide plate arranged on the upper tank, used to slow down the flow rate of the liquid and promote gas-liquid separation.

4. The in-situ leaching uranium mine unit pre-oxidation circulation system according to claim 1, characterized in that, Further comprising: a support arranged at the bottom of the tank, used to support the tank.

5. The in-situ leaching uranium mine unit pre-oxidation circulation system according to claim 4, characterized in that, Further comprising: an epoxy resin anticorrosive layer formed on the inner and outer surfaces of the tank; a rust-proof paint layer formed on the surface of the support.

6. The in-situ leaching uranium mine unit pre-oxidation circulation system according to claim 1, characterized in that, Further comprising: a multi-way distributor, the inlet of the multi-way distributor being connected to the plurality of communication pipes of the buffer device, the plurality of outlets of the multi-way distributor being connected to the plurality of injection well pipes, respectively, and the multi-way distributor being provided with adjusting valves for independently adjusting the flow rates of the injection branches.

7. The in-situ leaching uranium mine unit pre-oxidation circulation system according to claim 1, characterized in that, The distance between the leaching borehole and each injection borehole is less than or equal to 30 meters.

8. A method of pre-oxidation cycle for an in-situ leaching uranium mine unit, characterized in that, The in-situ leaching uranium mine unit pre-oxidation circulation system according to any one of claims 1 to 7 comprises the following steps: constructing a unit closed loop circulation system independent of the centralized control room system: connecting the leaching borehole and the injection borehole through the circulation system buffer device to form a closed loop process of leaching, buffering, and injection; using the deep well submersible pump to lift the leaching solution in the leaching borehole to the surface buffer device, and then injecting it into the injection borehole to realize pre-oxidation in the unit; adding an oxidizing agent: injecting hydrogen peroxide into the injection borehole as an oxidizing agent according to the data of the mine water pumping test; monitoring and control: after the system runs for a set time, monitoring the residual oxygen concentration and uranium concentration in the leaching solution, and supplementing hydrogen peroxide according to the residual oxygen concentration; system transfer and reuse: after the pre-oxidation is completed, the circulation system is disassembled and connected to the surface pipeline of the centralized control room to seamlessly connect the pre-oxidation stage and the centralized mining stage.

9. The in-situ leaching uranium mine block pre-oxidation cycling method according to claim 8, characterised by the fact that, The injection of hydrogen peroxide into the injection borehole specifically comprises: injecting hydrogen peroxide into the injection borehole at a standard of 150 mg / L to 190 mg / L.

10. The in-situ leaching uranium mine block pre-oxidation cycling method according to claim 8, characterised by that, The monitoring of the residual oxygen concentration in the leaching solution specifically comprises: monitoring the residual oxygen concentration in the leaching solution through the sampling nozzle on the buffer device; when the residual oxygen concentration is lower than 10 mg / L, supplementing hydrogen peroxide into the injection borehole.

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