Method for reducing silicon dioxide in in-situ leaching uranium mining closed cycle system diuranate

Abstract

The invention relates to the technical field of in-situ leaching uranium mining, and provides a method for reducing silicon dioxide in in-situ leaching uranium mining closed cycle system diuranate, which comprises the following steps: controlling silicon dioxide accumulation: reducing the water passing amount of leachate to be less than 340 cubic meters per hour, shortening the single operation period of an adsorption tower to be within 30 days, and switching to a standby adsorption tower after expiration; removing residual silicon dioxide: conveying the resin by adopting compressed air, controlling the conveying pressure to be 0.25-0.3 MPa, carrying out reverse flushing in the conveying process, then transferring the resin to a leaching tower, and pre-flushing with clear water; and carrying out vibration cleaning on the pre-flushed resin to remove residual silicon-containing silt. Through physical control of a main process chain of accumulation control, residue removal and fine matter removal, the content of silicon dioxide in the diuranate product is reduced from the source, the problems that the product adheres to a barrel, discharging is difficult, the quality exceeds the standard and operation safety is poor are solved, and cost reduction and efficiency improvement are achieved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of in-situ leaching of uranium, in particular to a method for reducing the content of silicon dioxide in the closed-circuit system of in-situ leaching of uranium. BACKGROUND

[0002] In the in-situ leaching of uranium process, the production of uranate products needs to inject leaching agents containing CO2 and O2 into injection wells, react with uranium-containing minerals to form a uranium-containing solution, and then be lifted to the ground through extraction wells. After that, the solution is sequentially subjected to adsorption enrichment, saturation elution, and high-concentration uranium-containing solution is sequentially added with acidifying agents and precipitating agents to form a semi-finished slurry, and finally, dehydration treatment is performed to obtain uranate products.

[0003] Since the process adopts a closed-circuit system, both solid and liquid phases are circulated in the system. With the increase of the leaching liquid treatment capacity, miscellaneous ions (especially silicon dioxide) continue to accumulate in the system. The main source of silicon dioxide is fine clay and mineral particles in the ore, which enter the system with the leaching liquid during the leaching process and are enriched on the surface and interstices of the resin in the subsequent ion exchange stage. When the saturated resin is eluted, the enriched silicon dioxide is leached into the uranium-containing solution and eventually enters the uranate product with the process, resulting in an increase in the content of silicon dioxide in the product.

[0004] An increase in the content of silicon dioxide can cause a series of production problems: 1. Product adhesion and unloading difficulty: After the uranate product is unloaded into a barrel, the silicon dioxide will cause the product to stick to the barrel wall, significantly increasing the difficulty of pouring out; 2. High product barrel maintenance cost: The residual product on the barrel wall is extremely alkaline and contains chloride ions, which can accelerate the damage of the barrel wall corrosion layer, requiring frequent re-corrosion treatment and increasing the operation and maintenance cost of the enterprise; 3. Product quality does not meet the standard: Silicon dioxide as an impurity can cause the product to exceed the standard, affecting the product grade; 4. High safety risk: Unloading difficulty requires workers to contact the uranate product for a long time, increasing the occupational health risk.

[0005] In related technologies, the control of the content of silicon dioxide mainly depends on chemical addition, but new miscellaneous ions are introduced, which can destroy the stability of the closed-circuit system. The physical control means mainly include bag filtration and sand filtration, which have the problems of insufficient precision and link faults, and cannot solve the accumulation of silicon dioxide from the root. Therefore, a low-cost, non-external pollution, and process chain covering physical silicon control method is needed to solve the above technical problems. SUMMARY

[0006] In order to solve the technical problems of product barrel sticking, unloading difficulty, quality exceeding standard and operation safety caused by the increase of the content of silicon dioxide in the diuranate product, the application provides a method for reducing the content of silicon dioxide in the diuranate of the in-situ leaching uranium closed loop system.

[0007] Therefore, the application provides a method for reducing the content of silicon dioxide in the diuranate of the in-situ leaching uranium closed loop system, which comprises the following steps: controlling the accumulation of silicon dioxide; reducing the overwater amount of the leaching solution to below 340 cubic meters / hour and shortening the single operation cycle of the adsorption tower to within 30 days, and switching to the standby adsorption tower after the expiration; removing residual silicon dioxide; using compressed air to transport the resin, controlling the transportation pressure to be 0.25-0.3 MPa, performing reverse flushing during the transportation process, and then transferring the resin to the elution tower and pre-flushing with clean water; and performing vibration cleaning on the pre-flushed resin to remove residual silicon-containing silt.

[0008] In some possible implementations, the overwater amount of the leaching solution is reduced to below 340 cubic meters / hour, and the single operation cycle of the adsorption tower is shortened to within 30 days, specifically including: controlling the overwater amount of the leaching solution to be within 340 cubic meters / hour from the initial 380 cubic meters / hour, and shortening the single operation cycle of the adsorption tower to 30 days from 45 days.

[0009] In some possible implementations, the reverse flushing is performed during the transportation process, specifically including: controlling the single resin transportation time to be 35-45 minutes, and performing 2-3 times of reverse flushing during the transportation.

[0010] In some possible implementations, the medium for the reverse flushing is compressed air or clean water, and the single reverse flushing lasts for 10-15 minutes.

[0011] In some possible implementations, the flow rate of the clean water pre-flushing is controlled to be 40-50 cubic meters / hour.

[0012] In some possible implementations, the vibration screening is performed on the pre-flushed resin, specifically including: using a 55-65 mesh vibration screen to perform vibration cleaning on the eluted resin.

[0013] In some possible implementations, the vibration frequency of the vibration screen is 40-50 Hz, and the single tank cleaning time is 1.5-2 hours.

[0014] In some possible implementations, the method for reducing the content of silicon dioxide in the diuranate of the in-situ leaching uranium closed loop system further comprises: setting a sight glass on the main pipeline of the leaching solution, the inlet and outlet pipelines of the adsorption tower and the discharge pipeline, so as to monitor the effect of impurity removal by observing the state of the fluid.

[0015] In some feasible methods, the pre-rinsing step is carried out in two stages within the scrubbing tower: the first stage uses an upward flow rinse to loosen the resin bed, and the second stage uses a downward flow rinse to carry away suspended sediment.

[0016] In some feasible ways, methods for reducing silica in uranate diurethane in in-situ leaching closed-loop uranium production systems also include: periodically switching a portion of the pre-rinsing water from the rinsing tower to the inlet pipeline of the adsorption tower to backwash the inner wall of the pipeline.

[0017] Compared with related technologies, this application has the following technical advantages: This application provides a method for reducing silica in uranate diabetic acid in a closed-loop uranate production system. Through physical control of the main process chain—"controlled accumulation-residue removal-fine particle removal"—the method fundamentally reduces the silica content in uranate diabetic acid products, solving problems such as product sticking to containers, difficult unloading, exceeding quality standards, and operational safety issues, thereby achieving cost reduction and efficiency improvement.

[0018] 1. Stable silica content meets standards: Through control of the main process chain, the silica content in diuranate products can be stably controlled below 0.08%, and the miscellaneous indicators of the products meet the first-class industry standards; 2. Solves the problems of sticking to the drum and unloading: The product's adhesion is significantly reduced, the amount of residue on the drum wall during unloading is reduced by more than 90%, the drum turning efficiency is increased by 60%, the time when operators are in direct contact with the product is reduced to 1 / 3 of the original time, and the occupational health risks are reduced; 3. Reduced operation and maintenance costs: The service life of the anti-corrosion layer on the product barrel has been extended from the original 6 months to 18 months, and the anti-corrosion maintenance cost has been reduced by more than 65%; 4. Strong system compatibility: The entire process adopts physical methods without the addition of exogenous chemical reagents, avoiding the introduction of new impurity ions, ensuring the stability of the closed-loop system, and eliminating the need for large-scale modification of existing process equipment, resulting in low modification costs and easy implementation.

[0019] Additional aspects and advantages of this application will become apparent in the following description or may be learned by practice of this application. Attached Figure Description

[0020] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 A schematic flowchart of a method for reducing silica in uranate in a closed-loop uranate recovery system according to one embodiment of this application is shown. Figure 2 A schematic flowchart of a method for reducing silica in uranate in a closed-loop uranate recovery system according to another embodiment of this application is shown. Detailed Implementation

[0021] 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.

[0022] 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.

[0023] The following reference Figure 1 and Figure 2 This application describes a method for reducing silica in uranate in a closed-loop uranate recovery system according to some embodiments of the present application.

[0024] like Figure 1 As shown, this application proposes a method for reducing silica in uranate diuranate in a closed-loop uranate recovery system, comprising the following steps: S202: Control silica accumulation: Reduce the leaching solution flow rate to below 340 cubic meters per hour and shorten the single operation cycle of the adsorption tower to within 30 days. After the expiration, switch to the standby adsorption tower. S204: Removal of residual silica: The resin is transported using compressed air, with the transport pressure controlled at 0.25MPa-0.3MPa. During the transport process, reverse flushing is performed, and then the resin is transferred to the scrubbing tower and pre-rinsed with clean water. S206: Vibration cleaning is performed on the pre-rinsed resin to remove residual silica-containing sludge.

[0025] The method for reducing silica in uranate diurethane in a closed-loop uranium leaching system provided in this application effectively reduces the accumulation of silica in the system by reducing the leaching solution flow rate to below 340 cubic meters per hour and shortening the single operation cycle of the adsorption tower to within 30 days. By rationally controlling the flow rate and operating cycle, the method avoids the continuous enrichment of silica due to prolonged operation and excessive water flow, thus inhibiting the accumulation trend of silica at its source, maintaining the relative balance of silica components within the closed-loop uranium leaching system, and ensuring the stable operation of the system.

[0026] Compressed air is used to transport the resin, with the transport pressure controlled between 0.25 MPa and 0.3 MPa. Backwashing is performed during transport to more thoroughly loosen and remove residual silica from the resin surface and crevices. The resin is then transferred to a rinsing tower and pre-rinsed with clean water to further remove residual silica, improving resin purity and facilitating subsequent uranium adsorption and extraction.

[0027] Vibration cleaning of the pre-rinsed resin can effectively remove residual fine silica-containing silt, ensuring a high degree of cleanliness, reducing the impact of silica on the quality of diuranate products, and improving the economic benefits and product quality of in-situ leaching uranium mining.

[0028] Through a three-step synergistic approach of "controlling accumulation, clearing residues, and removing fine particles," the silica content in the final product, uranate, is systematically reduced from source reduction and process cleanup to deep purification. This effectively solves the problem of product quality degradation caused by excessive silicon impurities, enabling it to meet higher-level product quality standards.

[0029] The silica content is consistently within acceptable limits: the silica content in diuranate products can be stably controlled below 0.08%, and the miscellaneous indicators of the products meet the industry's first-class standards; Solving the problems of sticking to the drum and unloading: Product adhesion is significantly reduced, the amount of residue on the drum wall during unloading is reduced by more than 90%, the drum turning efficiency is increased by 60%, the time when operators are in direct contact with the product is reduced to 1 / 3 of the original time, and occupational health risks are reduced; Reduced operation and maintenance costs: The service life of the anti-corrosion layer on the product barrel has been extended from the original 6 months to 18 months, and the anti-corrosion maintenance cost has been reduced by more than 65%; The system has strong compatibility: it adopts physical methods throughout the process without the addition of exogenous chemical reagents, avoids the introduction of new impurity ions, ensures the stability of the closed-loop circulation system, and does not require large-scale modification of existing process equipment, resulting in low modification costs and easy implementation.

[0030] In some embodiments provided in this application, the leachate flow rate is reduced to below 340 cubic meters per hour, and the single operation cycle of the adsorption tower is shortened to within 30 days. Specifically, this includes controlling the initial leachate flow rate of 380 cubic meters per hour to below 340 cubic meters per hour, and shortening the single operation cycle of the adsorption tower from 45 days to 30 days.

[0031] In this embodiment, the initial leachate flow rate of 380 cubic meters per hour was controlled to within 340 cubic meters per hour, reducing the scouring and carrying of silica-containing minerals by the water flow and lowering the amount of silica entering the closed-loop circulation system. Simultaneously, the single-cycle operation of the adsorption tower was significantly shortened from 45 days to 30 days, preventing the resin in the adsorption tower from becoming saturated due to excessive silica adsorption during prolonged operation. This effectively suppressed the accumulation rate of silica in the system and maintained the relative stability of the system's composition.

[0032] The rational adjustment of water flow rate and operating cycle makes the closed-loop circulation system for in-situ leaching uranium mining operate more smoothly. It reduces problems such as pipeline blockage and equipment wear caused by silica accumulation, lowers the equipment failure rate, and improves the continuity and reliability of the entire production process.

[0033] The reduction in silica content in the system alleviates the burden on subsequent silica removal processes, improves the cleaning efficiency and quality of the resin, and facilitates the adsorption and extraction of uranium by the resin, thereby enhancing the overall efficiency and product quality of in-situ leaching uranium mining.

[0034] In some embodiments provided in this application, backwashing is performed during the conveying process, specifically including: controlling the single resin conveying time to be 35 to 45 minutes, and performing 2 to 3 backwashings during the conveying period.

[0035] In this embodiment, controlling the resin delivery time to 35 to 45 minutes per cycle, and performing 2 to 3 reverse flushing cycles during this period, allows the compressed air to form a stronger and more uniform impact airflow. The reverse force generated by the reverse flushing can effectively loosen and peel off silica particles adhering to the resin surface and deep crevices. Compared with unidirectional delivery, this significantly improves the silica removal rate and reduces the amount of silica residue in the resin.

[0036] Two to three reverse rinsing cycles ensure complete coverage of all parts of the resin, avoiding any blind spots and guaranteeing a deep overall cleaning. This treatment significantly improves the resin's purity, providing a solid foundation for subsequent pre-rinsing in the scrubbing tower and uranium adsorption processes, ultimately contributing to improved uranium product quality and yield.

[0037] Reasonable time control and flushing frequency arrangement ensure the cleaning effect while avoiding increased energy consumption and wasted time due to excessive operation, making the entire resin transportation and pretreatment process more efficient and compact, and improving the overall efficiency of the in-situ leaching uranium production process.

[0038] In some embodiments provided in this application, the backwashing medium is compressed air or clean water, and a single backwash lasts for 10 to 15 minutes.

[0039] In this embodiment, the backwashing medium is either compressed air or clean water. Compressed air has a strong impact force, which can form a continuous and uniform airflow within 10 to 15 minutes, penetrating deep into the resin crevices to forcefully loosen and peel off impurities such as silica adhering to it. Clean water, with its fluidity and solubility, can effectively wash away the loosened impurities. The two can be used alternately or alone to comprehensively and thoroughly remove impurities from the surface and interior of the resin, greatly improving the purity of the resin and creating favorable conditions for subsequent uranium adsorption.

[0040] A reasonable rinsing time ensures sufficient cleaning while avoiding damage to the resin due to over-rinsing. A duration of 10 to 15 minutes allows for precise control of rinsing intensity and range, maintaining the stability of the resin's physical structure and chemical properties, ensuring its long-term good adsorption capacity and performance, and extending the resin's service life.

[0041] In some embodiments provided in this application, the flow rate of the clean water pre-rinse is controlled to be 40 cubic meters per hour to 50 cubic meters per hour.

[0042] In this embodiment, the flow rate range creates a stable water flow with a certain impact force, effectively washing away residual impurities such as silica-containing silt that have loosened on the resin surface after reverse rinsing. The water flow is neither too slow to completely remove impurities nor too fast to cause excessive rinsing and damage to the resin, ensuring that the resin achieves a high degree of cleanliness.

[0043] An appropriate flow rate avoids violent impacts of the water flow on the resin, preventing resin particles from breaking or colliding and causing structural damage, thus maintaining the physical integrity of the resin and ensuring that its subsequent uranium adsorption performance is not affected. Pre-rinsing at this flow rate can complete the cleaning task in a shorter time, reducing the time spent on the rinsing process and improving the efficiency of the entire in-situ leaching uranium production process. At the same time, reasonable control of the flow rate also avoids water waste, reduces production costs, and has good economic benefits.

[0044] In some embodiments provided in this application, the pre-rinsed resin is subjected to vibratory sieving, specifically including: using a 55 to 65 mesh vibratory screen to vibrate and clean the rinsed resin.

[0045] In this embodiment, the 55-65 mesh screen has a suitable aperture size, which can effectively intercept larger particles of silica-containing silt, broken resin, and other impurities, allowing pure resin that meets the particle size requirements to pass through smoothly. This precise separation can greatly improve the purity of the resin, reduce the interference of impurities on the subsequent uranium adsorption process, ensure the adsorption effect, and improve the quality of uranium products.

[0046] The vibration generated during the operation of the vibrating screen allows resin particles to tumble and collide fully, ensuring ample contact with the screen and air. This not only helps to further shake off tiny impurities adhering to the resin surface but also promotes the removal of moisture from between the resin particles, resulting in a drier and cleaner resin. This screening process is simple to operate, highly continuous, and can quickly complete the cleaning of large quantities of resin, reducing the resin's residence time in the cleaning stage, improving the efficiency of the entire in-situ leaching uranium production process, and reducing production costs.

[0047] In some embodiments provided in this application, the vibration frequency of the vibrating screen is 40Hz-50Hz, and the cleaning time for a single tank is 1.5 to 2 hours.

[0048] In this embodiment, a vibration frequency of 40Hz-50Hz generates just the right amount of vibration force. This avoids insufficient cleaning power due to a frequency that is too low, failing to effectively remove residual silica-containing silt and other impurities from the resin surface and crevices; and also avoids excessive collisions that could damage the resin due to a frequency that is too high. At this frequency, the resin particles tumble and rub against each other fully, allowing for efficient separation of impurities and significantly improving the purity of the resin.

[0049] The 1.5 to 2-hour single-tank cleaning time has been scientifically optimized to ensure that the resin has sufficient time to undergo thorough cleaning in the vibrating screen to remove various impurities, while avoiding energy waste and reduced production efficiency caused by excessive cleaning time. This achieves a good balance between cleaning quality and efficiency. Resin cleaned using this method has a significantly reduced impurity content, providing high-quality raw materials for subsequent uranium adsorption and other processes, helping to improve the recovery rate and quality of uranium products and reduce production costs.

[0050] In some embodiments provided in this application, the method for reducing silica in uranate in a closed-loop uranate leaching system further includes: installing sight glasses on the main leaching pipeline, the inlet and outlet pipelines of the adsorption tower, and the discharge pipeline to monitor the impurity removal effect by observing the fluid state.

[0051] In this embodiment, the sight glass allows operators to directly observe the fluid state, such as color, transparency, and the presence of suspended matter. This intuitive information allows for real-time monitoring of the content and changes in impurities such as silica within the system, enabling timely detection of anomalies during the impurity removal process, such as a sudden increase in impurities. This allows for rapid adjustment of process parameters to ensure stable impurity removal results. Timely monitoring of the fluid state helps prevent problems such as pipe blockage and equipment wear caused by impurity accumulation. Once an anomaly is detected, preventative measures can be taken to avoid escalation, ensuring the stable operation of the closed-loop uranium leaching system, reducing equipment failures and downtime, and improving production efficiency.

[0052] Based on the fluid state observed through the sight glass, the impurity removal process can be optimized in a targeted manner, such as adjusting the leaching solution flow rate and the adsorption tower operating cycle, to improve impurity removal efficiency, reduce production costs, and enhance the quality of diuranate products.

[0053] In some embodiments provided in this application, the pre-rinsing step with clean water is carried out in two stages in the rinsing tower: the first stage uses upward flow rinsing to loosen the resin bed, and the second stage uses downward flow rinsing to carry away suspended sludge.

[0054] In this embodiment, the first stage employs upward flow rinsing, where clean water flows from bottom to top, forming a counter-current contact with the resin bed. This upward flow force generates a uniform and effective force on the resin particles, loosening the tightly packed resin bed. The loosened resin bed creates favorable conditions for subsequent silt removal, increasing the voids between resin particles and making it easier for suspended silt to be carried away by the water flow. This avoids the problem of silt retention caused by a dense resin bed and improves the initial adjustment effect on the resin structure during rinsing.

[0055] The second stage employs a downflow rinsing method, where clean water flows from top to bottom, utilizing gravity to create a strong carrying capacity. In the loosened resin bed, suspended sediment is easily carried away, and the downflow rinsing effectively removes this sediment from the scrubbing tower. This phased, multi-directional rinsing method creates complementary rinsing forces; the upflow creates conditions for the downflow, and the downflow completes the final cleaning, ensuring thorough removal of suspended sediment and significantly improving the resin's purity.

[0056] After two stages of rinsing, the resin reaches a high level of cleanliness, which is beneficial for subsequent processes such as uranate adsorption and ensures the quality of the diuranate product. At the same time, the optimized rinsing design improves rinsing efficiency, reduces rinsing time and water consumption, and lowers production costs.

[0057] In some embodiments provided in this application, the method for reducing silica in uranate in a closed-loop uranate recirculation system for in-situ leaching further includes: periodically switching a portion of the pre-rinsing water from the rinsing tower to the inlet pipeline of the adsorption tower to backwash the inner wall of the pipeline.

[0058] In this embodiment, during long-term operation, the inner wall of the adsorption tower inlet pipeline gradually accumulates dirt formed by impurities such as silica. Backwashing with pre-rinsing water, flowing in the opposite direction to the normal inlet flow, generates a strong impact force, effectively flushing away the silica and other impurities adhering to the inner wall of the pipeline. This prevents impurities from accumulating and causing blockages, ensuring unobstructed flow and allowing the leachate to smoothly enter the adsorption tower.

[0059] Cleaning the inner walls of the pipeline ensures stable flow rate and velocity of the leachate, providing uniform and stable feed conditions for the adsorption tower. This helps stabilize the uranium adsorption process by the resin within the adsorption tower, improves adsorption efficiency, and guarantees stable quality and yield of diuranate products.

[0060] Regular backflushing reduces the corrosion and wear of pipe walls caused by impurities in the pipeline, and reduces the frequency of pipeline repair or replacement due to blockage, thereby extending the service life of the adsorption tower inlet pipeline and related equipment, and reducing equipment maintenance and production costs.

[0061] In practical applications, when using compressed air to transport resin, at least one Venturi accelerator is installed in the transport pipeline to increase the resin flow rate and prevent resin deposition. The Venturi effect creates localized high-speed sections in the pipeline, effectively preventing resin deposition or blockage and ensuring smooth and continuous transport. Simultaneously, the acceleration enhances resin fluidization and reduces frictional resistance between resin particles and the pipe wall, thus lowering energy consumption and reducing resin wear, achieving efficient, low-loss, and stable transport.

[0062] Vibration cleaning employs a three-dimensional vibration mode, including a vertical amplitude of 2-5 mm and a horizontal amplitude of 1-3 mm, with the two vibrations occurring synchronously with a 90-degree phase difference. Through the coordinated operation of the vertical and horizontal amplitudes and the generation of a composite three-dimensional motion trajectory using the 90-degree phase difference, resin particles undergo intense tumbling and diffusion on the screen surface. This effectively disrupts the adhesion structure between the silt and resin, significantly improving the removal efficiency and cleaning uniformity for fine silicon-containing impurities.

[0063] The sight glass is a pressure-resistant sight glass with an illumination device and is connected to an image recognition system. When the turbidity of the fluid exceeds the threshold, it automatically issues an early warning signal. This enables real-time, automatic, and intelligent monitoring of the impurity content of the pipeline fluid. By replacing manual judgment with image recognition, it can promptly warn of abnormal sediment content, facilitate rapid adjustment of process parameters, effectively prevent pipeline blockage and system fluctuations, and ensure stable production operation.

[0064] After vibration cleaning, the resin surface potential is adjusted by adding a potential regulator to maintain the resin surface zeta potential within the range of -30mV to -40mV, thereby enhancing the resin's resistance to silica scale adsorption. By adjusting the resin surface potential to a strongly negative value (-30mV to -40mV), electrostatic repulsion effectively prevents negatively charged silica particles from adsorbing and forming scale on the resin surface, significantly enhancing the resin's anti-fouling ability, thus extending its service life and maintaining stable system operation.

[0065] In specific embodiments, such as Figure 2 As shown, this application provides a method for reducing silica in uranate diuranate in a closed-loop uranate recovery system through in-situ leaching. This is achieved through a three-step synergistic physical operation of "controlled accumulation - residual removal - fine particle removal," and the specific steps include: S302: Reduce silica accumulation in the system: Optimize the leachate flow rate, controlling the initial 380 cubic meters / hour leachate flow rate to within 340 cubic meters / hour, ensuring sufficient contact and exchange between the resin and the leachate to trap impurities; at the same time, limit the single operation cycle of the adsorption tower, shortening the original 45-day operation cycle to 30 days, and immediately switch to the standby adsorption tower after the expiration date to avoid long-term accumulation of silica-containing impurities in the adsorption tower and blockage of resin pores; S304: Transfer and treatment system for accumulated silica: The resin is transferred using compressed air as a power source, and the resin conveying pressure is controlled at 0.25MPa-0.3MPa. The appropriate pressure is used to break up the cemented silt on the surface of the resin and in the internal pores. The single resin transfer time is controlled at 35 to 45 minutes. During the transfer, 2 to 3 reverse flushes are performed to remove the silt and resin mixture remaining at the bottom of the adsorption tower. The resin is then conveyed to the rinsing tower, and 120 cubic meters of clean water are introduced into the saturated resin bed in the rinsing tower for pre-rinsing to remove the silt attached to the resin surface and prevent the silt from entering the subsequent process with the qualified liquid during rinsing. S306: Silica removal in the system: The washed resin is cleaned by vibrating with a 60-mesh vibrating screen. Through the screen's interception and vibration separation, the fine silica-containing silt remaining in the resin gaps is removed.

[0066] In S304, the backflushing medium is compressed air or clean water, and each backflushing lasts for 10 to 15 minutes to ensure that the "sludge-resin" mixture at the bottom of the tower is completely removed.

[0067] The flow rate of the pre-rinsing water in S304 is controlled at 40-50 cubic meters per hour to ensure that the rinsing water is in full contact with the resin without damaging the resin's adsorption performance.

[0068] The vibration frequency of the 60-mesh vibrating screen in S306 is 40Hz-50Hz, and the cleaning time for a single tank is 1.5 to 2 hours, ensuring that the fine mud and sand in the resin gaps are completely removed and flowed out with the cleaning water, while the resin is trapped by the screen and enters the cleaning tank.

[0069] During the implementation of S302 to S306, transparent test mirrors need to be installed on the main leaching liquid pipeline, the inlet and outlet pipelines of the adsorption tower, and the discharge pipeline to observe the silt content in the fluid in real time in order to monitor the impurity control effect at each stage.

[0070] 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.

[0071] 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.

[0072] 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. A method for reducing silica in uranate diuranate in a closed-loop uranate recovery system, characterized in that, Includes the following steps: Control silica accumulation: reduce the leaching solution flow rate to below 340 cubic meters per hour and shorten the single operation cycle of the adsorption tower to within 30 days, and switch to the standby adsorption tower after the expiration. Residual silica removal: The resin is transported using compressed air, with the transport pressure controlled at 0.25MPa-0.3MPa. Backwashing is performed during transport, and the resin is then transferred to a scrubbing tower and pre-rinsed with clean water. The pre-rinsed resin is then subjected to vibration cleaning to remove residual silica-containing sludge.

2. The method for reducing silica in uranate in a closed-loop uranate recovery system according to claim 1, characterized in that, The reduction of leachate flow rate to below 340 cubic meters per hour and the shortening of the single-cycle operation of the adsorption tower to within 30 days specifically include: By controlling the initial leachate flow rate of 380 cubic meters per hour to within 340 cubic meters per hour, the single operation cycle of the adsorption tower is shortened from 45 days to 30 days.

3. The method for reducing silica in uranate in a closed-loop uranate recovery system according to claim 1, characterized in that, The reverse flushing process during the conveying process specifically includes: Control the resin delivery time for each cycle to 35 to 45 minutes, and perform 2 to 3 reverse flushes during delivery.

4. The method for reducing silica in uranate in a closed-loop uranate recovery system according to claim 3, characterized in that, The medium for backwashing is compressed air or clean water, and a single backwash lasts for 10 to 15 minutes.

5. The method for reducing silica in uranate in a closed-loop uranate recovery system according to claim 1, characterized in that, The flow rate of the pre-rinsing water is controlled at 40 cubic meters per hour to 50 cubic meters per hour.

6. The method for reducing silica in uranate in a closed-loop uranate recovery system according to claim 1, characterized in that, The process of vibrating and sieving the pre-washed resin specifically includes: The resin after rinsing is cleaned by vibration using a 55 to 65 mesh vibrating screen.

7. The method for reducing silica in uranate in a closed-loop uranate recovery system according to claim 6, characterized in that, The vibration frequency of the vibrating screen is 40Hz-50Hz, and the cleaning time for a single tank is 1.5 to 2 hours.

8. The method for reducing silica in diuranate in a closed-loop uranate recovery system according to any one of claims 1 to 7, characterized in that, Also includes: Sight glasses are installed on the main leaching solution pipeline, the inlet and outlet pipelines of the adsorption tower, and the discharge pipeline to monitor the impurity removal effect by observing the fluid state.

9. The method for reducing silica in diuranate in a closed-loop uranate recovery system according to any one of claims 1 to 7, characterized in that, The pre-rinsing step with clean water is carried out in two stages in the rinsing tower: the first stage uses upward flow rinsing to loosen the resin bed, and the second stage uses downward flow rinsing to carry away suspended silt.

10. The method for reducing silica in diuranate in a closed-loop uranate recovery system according to any one of claims 1 to 7, characterized in that, Also includes: Periodically switch some of the pre-rinsing water from the scrubbing tower to the inlet pipeline of the adsorption tower to backwash and clean the inner wall of the pipeline.

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