A method and apparatus for leaching of uranium ore

Abstract

This invention discloses a leaching method and apparatus for uranium ore, relating to the field of hydrometallurgical technology. The invention provides a novel multifunctional uranium leaching system. Porous electrode plates and conductive injection pipes are installed at both ends of a horizontal rotating reaction chamber. Contact and energization are achieved via anode and cathode wires. An ion exchange resin is filled in a uranium trapping net within the horizontal rotating reaction chamber. Under the influence of an electric field, uranyl ions are enriched on the ion exchange resin. Mechanical force disrupts the uranium ore structure and exposes reaction sites; advanced oxidation promotes the oxidation and dissolution of uranium; the electric field promotes the migration of uranyl ions and enhances the efficiency of the advanced oxidation reaction; and the ion exchange resin adsorbs uranyl ions driven by the electric field in real time. These three factors create a synergistic enhancement effect, significantly reducing acid consumption and improving uranium leaching efficiency and recovery rate.

Description

Technical Field

[0001] This invention relates to the field of hydrometallurgical technology, and more specifically, to a leaching method and apparatus for uranium ore. Background Technology

[0002] Uranium, as an indispensable key raw material for nuclear power generation, plays an irreplaceable role in the global energy structure transformation and low-carbon development strategy. With the rapid growth of nuclear power installed capacity, the global annual demand for uranium is expected to exceed 80,000 tons of uranium equivalent by 2035, placing higher demands on the efficient development and utilization of uranium resources. my country's main uranium deposit types include sandstone, granite, mudstone, and volcanic rock types. Uranium exists in various forms, including as an independent mineral, in an adsorbed state, and in isomorphous states, closely coexisting with a variety of minerals. Sandstone uranium deposits are currently the main type of uranium ore mined in my country, primarily recovered using in-situ CO2+O2 leaching. However, this process is ineffective for the poorly permeable dense sandstone and argillaceous sandstone types within sandstone uranium deposits. For volcanic and granite uranium deposits, traditional processes such as heap leaching and stirred leaching are commonly used. Heap leaching takes 30-90 days and consumes 80-150 kg / t of ore in acid, while stirred leaching, although reducing the time to 5-15 days, has higher energy consumption and is sensitive to particle size distribution. Especially for low-grade uranium ore with a grade below 0.05%, the recovery rate of traditional methods is generally less than 60%, and it generates large amounts of acidic wastewater containing heavy metals, placing significant pressure on the environment. Furthermore, it is noteworthy that there is currently no available technology for the development of argillaceous uranium deposits.

[0003] Therefore, there is an urgent need to develop new leaching methods and equipment for different types of uranium ores in order to achieve efficient uranium leaching and recovery.

[0004] In view of this, the present invention is proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a leaching method and apparatus for uranium ore, which aims to significantly improve the leaching efficiency and recovery rate of uranium.

[0006] This invention is implemented as follows:

[0007] In a first aspect, the present invention provides a leaching method for uranium ore, which uses a multifunctional uranium leaching system for leaching. The multifunctional uranium leaching system includes a horizontal rotary reaction chamber, an external circulation pipeline, a power supply, a rotary motor, a liquid injection chamber, and a control system. The horizontal rotary reaction chamber includes a horizontal rotary reaction chamber body, a horizontal rotary reaction chamber cover, a pH sensor, and a uranium trapping net, which is disposed at the anode end of the horizontal rotary reaction chamber.

[0008] The leaching process includes: placing uranium ore and grinding balls into a horizontal rotary reaction chamber; filling ion exchange resin into a uranium trapping net; adding acid solution and hydrogen peroxide into the horizontal rotary reaction chamber; starting the multi-functional uranium leaching system and simultaneously connecting the power supply; setting the pH value, current, voltage, and rotation speed through the control system; opening the valve to allow the liquid in the chamber to circulate from the anode area to the cathode area through the external circulation pipeline; after the reaction is completed, removing the ion exchange resin from the uranium trapping net for elution to recover uranyl ions; a pH sensor monitors the pH value of the horizontal rotary reaction chamber in real time and feeds back the signal to the control system; when the pH value is higher than the set value, the control system will control the injection chamber to replenish acid solution into the horizontal rotary reaction chamber through the external circulation pipeline in a timely manner to maintain the pH value in the chamber; a microporous filter membrane is filled between the uranium trapping net and the porous electrode sheet.

[0009] In an optional implementation, the DC power supply has a voltage of 1 V / cm-30 V / cm and a current density of 0.1 mA / cm. 2 -5 mA / cm 2 ;

[0010] And / or, the uranium ore is selected from at least one of sandstone-type uranium ore, mudstone-type uranium ore, granite-type uranium ore, and volcanic rock-type uranium ore.

[0011] In an optional embodiment, the ion exchange resin is filled to 60%-90% of the uranium trap volume;

[0012] And / or, the mesh size of the uranium trapping net is 0.1 mm to 1.0 mm;

[0013] And / or, the uranium trapping net is made of 316L stainless steel or titanium alloy.

[0014] In optional embodiments, the ion exchange resin is a strongly basic anion exchange resin or a chelating resin; the strongly basic anion exchange resin includes polystyrene-based quaternary ammonium type I resin, polystyrene-based quaternary ammonium type II resin and polyacrylic acid-based quaternary ammonium type resin; the chelating resin includes iminodiacetic acid type resin, aminophosphonic acid type resin and methylamine oxime type resin.

[0015] In an optional embodiment, the pH value of the leaching solution is not higher than 7.00, and the mass fraction of hydrogen peroxide in the mixed leaching solution is 0.5%-10%.

[0016] And / or, the mass ratio of the mixed leachate to the uranium ore is (2.5-4.0):1;

[0017] And / or, the grain size of the uranium ore is 1 mm to 5 mm.

[0018] In an optional embodiment, the acid solution used to control the pH value in the horizontal rotary reaction chamber is selected from at least one of sulfuric acid, nitric acid, and phosphoric acid.

[0019] In an optional embodiment, the rotation speed of the horizontal rotating reaction chamber is controlled to be 10 rpm-500 rpm, and the leaching time is 0.5 h-6.0 h.

[0020] And / or, the temperature is maintained at 20℃-60℃ during the reaction;

[0021] And / or, the mass ratio of grinding balls to uranium ore is (3-5):1;

[0022] And / or, the grinding balls are selected from at least one of zirconia balls, corundum balls and ceramic balls, and the diameter of the grinding balls is 5 mm to 20 mm;

[0023] And / or, the flow rate of the circulating pump is 0.5 mL / min to 5 mL / min;

[0024] And / or, after the reaction is complete, remove the residue from the tank for solid-liquid separation.

[0025] In an optional embodiment, an eluent is used to elute the ion exchange resin to recover uranyl ions; wherein the eluent is selected from at least one of sodium carbonate solution, sodium chloride solution, ammonium sulfate solution, magnesium chloride solution, and ammonium chloride solution.

[0026] Secondly, the present invention also provides a leaching apparatus for implementing the leaching method provided in any of the above embodiments. The multifunctional uranium leaching system includes a horizontal rotary reaction chamber, an external circulation pipeline, a power supply, a rotary motor, a liquid injection chamber, and a control system. The liquid injection chamber is connected to the external circulation pipeline. Both ends of the horizontal rotary reaction chamber are provided with porous electrode plates and conductive liquid injection pipes. Anode wires and cathode wires are provided at corresponding positions on the conductive liquid injection pipes and porous electrode plates. In the working state, the porous electrode plates and conductive liquid injection pipes at both ends of the horizontal rotary reaction chamber are in direct contact with conductivity, and the conductive liquid injection pipes are in contact with the anode wires and cathode wires and are energized. The conductive liquid injection pipes are connected to the external circulation pipeline, and a circulation pump is installed on the external circulation pipeline. During the leaching process, after the valve is opened, the liquid in the chamber is circulated from the anode area to the cathode area through the external circulation pipeline under the action of the circulation pump.

[0027] The horizontal rotary reaction chamber includes a horizontal rotary reaction chamber body, a horizontal rotary reaction chamber cover, a pH sensor, and a uranium trapping net. The uranium trapping net is filled with ion exchange resin. The pH sensor monitors the pH value of the horizontal rotary reaction chamber in real time and feeds back the signal to the control system. When the pH value is higher than the set value, the control system will control the injection chamber to replenish acid into the horizontal rotary reaction chamber in a timely manner through the external circulation pipeline to maintain the pH value in the chamber. A microporous filter membrane is filled between the uranium trapping net and the porous electrode sheet.

[0028] In an optional implementation, the conductive injection tube is used to connect the cathode wire and the anode wire, and also serves as part of the external circulation pipeline;

[0029] And / or, the conductive injection tube is a hollow plastic tube made of carbon black-filled PP conductive plastic or PC carbon nanotube conductive plastic;

[0030] And / or, porous electrode sheets are thin sheets made of carbon black-filled PP conductive plastic or PC carbon nanotube conductive plastic.

[0031] This invention offers the following advantages: It designs a novel multifunctional uranium leaching system. Both ends of a horizontal rotating reaction chamber are equipped with porous electrode plates and conductive injection pipes. Contact and energization are achieved via anode and cathode wires. The horizontal rotating reaction chamber is filled with ion exchange resin, and uranium ions accumulate on the resin under the influence of an electric field. A pH sensor is integrated into the reaction chamber to monitor the pH value of the liquid in real time, and acid is replenished to the reaction chamber promptly via the injection tank. The liquid in the reaction chamber circulates externally from the anode to the cathode area through an external circulation pipeline. During circulation, a microporous filter membrane prevents uranium ore particles from entering the external circulation pipeline and causing blockages. Based on the above structure, the beneficial effects of this invention are as follows: First, the horizontal rotary reaction chamber can effectively reduce mineral particle size and destroy mineral crystal structure through mechanical activation. It can also effectively destroy the physical inclusion layer of some uranium ores (especially mudstone-type uranium ores), exposing more uranium element sites and significantly enhancing reaction activity. Second, acid and hydrogen peroxide are added to the horizontal rotary reaction chamber, and advanced oxidation of uranium ores is carried out under acidic conditions. The iron-bearing minerals (such as hematite and pyrite) contained in the uranium ores themselves act as catalysts to decompose hydrogen peroxide and provide a large number of reactive oxygen species such as hydroxyl radicals. This can not only effectively oxidize uranium elements and enhance their dissolution, but also destroy the organic matter inclusion layer of uranium ores such as mudstone-type and argillaceous sandstone-type uranium ores, realizing the exposure and release of uranium. Third, by applying an electric field to the horizontal rotary reaction chamber to enhance leaching, not only can ferrous ions be continuously regenerated through electrochemical action and hydrogen peroxide generation be promoted, thereby enhancing advanced oxidation and enhancing the release of reactive oxygen species such as hydroxyl radicals, but the external electric field can also drive ion migration, significantly improving the reaction kinetics of the solid-liquid interface. Simultaneously, under acidic conditions, magnesium, calcium, and aluminum ions in uranium ore dissolve from associated minerals, enhancing the conductivity within the reaction chamber without the need for additional conductive agents. Furthermore, the liquid within the reaction chamber can be further circulated via a circulation pump and external circulation pipeline, balancing the pH values ​​at the anode and cathode. This reduces adverse effects such as acid erosion of materials caused by the continuous generation of hydrogen ions in the anode region and metal precipitation and blockage caused by the continuous generation of hydroxide ions in the cathode region. On the other hand, the pH control function of the multifunctional uranium leaching system also prevents excessive acidity from causing the dissolution of too many impurity metal ions, exacerbating resin poisoning and complicating subsequent uranium separation. Therefore, this invention organically combines mechanical action, chemical leaching, and electric field effects. Mechanical force disrupts the mineral structure, advanced oxidation achieves uranium oxidative leaching, and the electric field promotes advanced oxidation and ion migration. The ion exchange resin adsorbs uranyl ions in real time, forming a synergistic enhancement effect. Compared to traditional acid leaching methods, this significantly reduces acid usage and substantially improves uranium leaching efficiency and recovery rate. Attached Figure Description

[0032] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 A schematic diagram of the multifunctional uranium leaching system provided in an embodiment of the present invention;

[0034] Figure 2 This is a schematic diagram of the horizontal rotating reaction chamber structure provided in an embodiment of the present invention.

[0035] Key component symbols: 001-Uranium ore particles; 100-Multifunctional uranium leaching system; 101-Anode wire; 102-Cathode wire; 103-Ion exchange resin; 104-Horizontal rotary reaction chamber cover; 105-Uranium trap; 106-Grinding ball; 107-Microporous filter membrane; 108-Porous electrode sheet; 109-Bearing flange; 110-Horizontal rotary reaction chamber; 111-Injection port; 112-Fastening bolt; 113-Conductive injection pipe; 114-pH sensor; 121-Rotating motor; 122-Control system; 123-Drive belt; 124-Circulation pump; 125-External circulation pipeline; 126-Bearing support base; 127-External circulation pipeline valve; 128-Injection chamber. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0037] This invention provides a uranium ore leaching method that organically combines mechanical action, chemical leaching, and electric field action. Mechanical force breaks down the mineral structure, and advanced oxidation achieves uranium oxidation and leaching. The electric field promotes advanced oxidation and ion migration. Ion exchange resin adsorbs uranyl ions in real time, forming a synergistic enhancement effect. The liquid in the chamber is circulated through a circulation system to balance the pH values ​​at both poles, which significantly improves the uranium leaching efficiency and recovery rate.

[0038] like Figure 1 and Figure 2As shown, a multifunctional uranium leaching system 100 is used for leaching. The multifunctional uranium leaching system 100 includes a horizontal rotary reaction chamber 110, an external circulation pipeline 125, a rotary motor 121, a control system 122, and a liquid injection chamber 128. Both ends of the horizontal rotary reaction chamber 110 are equipped with porous electrode plates 108 and conductive liquid injection pipes 113. Anode wires 101 and cathode wires 102 are positioned corresponding to the porous electrode plates 108 in the multifunctional uranium leaching system 100. The liquid injection chamber 128 is connected to the external circulation pipeline 125, allowing acid to be replenished to the horizontal rotary reaction chamber 110 through the external circulation pipeline 125. In the working state (during uranium leaching), the porous electrode plates and conductive liquid injection pipes 113 at both ends of the horizontal rotary reaction chamber 110 are in direct contact with electricity. The conductive liquid injection pipes 113 are in contact with and energized by the anode wires 101 and cathode wires 102 of the multifunctional uranium leaching system 100. In other words, when the multifunctional uranium leaching system 100 is powered on, the porous electrode plates at both ends of the horizontal rotating reaction chamber 110 are simultaneously connected to the power supply through the conductive liquid injection pipe 113, generating an electric field in the horizontal rotating reaction chamber 110, and uranium acyl ions are adsorbed near the uranium trapping net 105.

[0039] The uranium trapping net 105 inside the horizontal rotary reactor 110 is filled with ion exchange resin 103. Under the action of an electric field, uranium amide ions are adsorbed onto the ion exchange resin 103. An external circulation pipeline 125 is provided on the horizontal rotary reactor 110. A conductive injection pipe 113 is connected to the external circulation pipeline 125. A circulation pump 124 and an external circulation pipeline valve 127 are installed on the external circulation pipeline 125. Under the action of the circulation pump, the liquid in the reactor is circulated from the anode area to the cathode area through the external circulation pipeline 125. A microporous filter membrane 107 is filled between the uranium trapping net 105 and the porous electrode sheet 108 to prevent uranium ore particles from entering the external circulation pipeline and causing blockage. An injection port 111 is provided on the horizontal rotary reactor 110. A pH sensor 114 is installed on the injection port cover to monitor the pH value of the solution in the horizontal rotary reactor 110 in real time and feed the signal back to the control system 122. If the pH value is higher than the set value, the control system 122 controls the injection tank 128 to replenish acid into the horizontal rotary reaction chamber 110 in a timely manner through the external circulation pipeline 125 to maintain the pH value in the chamber.

[0040] In some embodiments, the horizontal rotary reaction chamber 110 includes a horizontal rotary reaction chamber body and a horizontal rotary reaction chamber cover 104. A uranium trapping net 105 is disposed inside the horizontal rotary reaction chamber 110 and near the horizontal rotary reaction chamber cover 104. Ion exchange resin 103 is filled on the uranium trapping net 105. The uranium trapping net 105 is connected to the horizontal rotary reaction chamber cover 104 by a spiral. During the ball milling process, the uranium trapping net 105 and the ion exchange resin 103 are stably fixed at the end of the horizontal rotary reaction chamber 110.

[0041] The structure and working principle of other parts of the multifunctional uranium leaching system 100 can refer to existing technology. A rotary motor 121 drives a transmission belt 123 to rotate. The transmission belt 123 is connected to the horizontal rotary reaction chamber 110 via a rotating shaft, thereby driving the horizontal rotary reaction chamber 110 to rotate. Parameters such as pH value, rotation speed, current, and voltage can be set on the control system 122. Specifically, the control system 122 may be an integrated circuit chip with signal processing capabilities. The aforementioned control system 122 can be a general-purpose processor, including a central processing unit, digital signal processor, application-specific integrated circuit, field-programmable gate array or other programmable logic device, discrete gate or transistor logic device, or discrete hardware component. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this invention. This general-purpose processor can be a microprocessor, and the control system 122 provided in this embodiment can also be any conventional processor.

[0042] The material of the horizontal rotary reaction chamber 110 is not limited, such as corundum, ceramic or ABS plastic, and the inner wall is coated with corrosion-resistant polytetrafluoroethylene coating.

[0043] The material of bearing flange 109 is not limited, such as 304 stainless steel, 316 stainless steel, and titanium alloy. The material of microporous filter membrane 107 is not limited, such as polyethersulfone, cellulose acetate, and polyvinylidene fluoride.

[0044] The type of uranium ore leached is not limited. In some embodiments, the uranium ore is selected from at least one of sandstone-type uranium ore, mudstone-type uranium ore, granite-type uranium ore, and volcanic rock-type uranium ore, and the uranium ore can be any one or more of the above.

[0045] In some embodiments, the filling amount of ion exchange resin 103 is 60%-90% of the volume of uranium trapping net 105, such as 60%, 70%, 80%, 90%, etc. The mesh size of uranium trapping net 105 is 0.1 mm-1.0 mm, such as 0.1 mm, 0.3 mm, 0.5 mm, 0.8 mm, 1.0 mm, etc. For circular meshes, the mesh size refers to the pore diameter; for square or irregular meshes, the mesh size refers to the distance between the two farthest points on the inner wall of the pore. Uranium trapping net 105 is made of 316L stainless steel or titanium alloy. The conductive injection tube 113 and the porous electrode sheet 108 are both made of carbon black-filled PP conductive plastic or PC carbon nanotube conductive plastic. During operation, the conductive injection tube 113 is used to connect the cathode wire 102 and the anode wire 101, and also serves as part of the external circulation pipeline 125.

[0046] Furthermore, the ion exchange resin 103 is a strongly basic anion exchange resin 103 or a chelating resin; the strongly basic anion exchange resin 103 includes polystyrene-based quaternary ammonium type I resin, polystyrene-based quaternary ammonium type II resin, and polyacrylic acid-based quaternary ammonium type resin, etc.; the chelating resin includes iminodiacetic acid type (IDA) resin, aminophosphonic acid type resin, and geminal aminooxime type resin, etc. All of the above ion exchange resins can effectively adsorb uranyl ions.

[0047] The uranium ore leaching method provided in this embodiment of the invention uses the aforementioned multifunctional uranium leaching system 100 for leaching operations. The leaching process includes: placing uranium ore particles 001 and grinding balls 106 into a horizontal rotary reaction chamber 110; filling uranium trapping net 105 with ion exchange resin 103; covering the horizontal rotary reaction chamber with its cover 104 and sealing it with fastening bolts 112; connecting the horizontal rotary reaction chamber 110 to a drive belt 123 and placing it on a bearing support base 126; and then connecting it to an external circulation pipeline 125 via a bearing flange 109; adding acid solution and hydrogen peroxide into the horizontal rotary reaction chamber 110 through the injection port 111; setting parameters such as rotation speed, voltage, current, and pH value through the control system 122; starting the multifunctional uranium leaching system 100 and simultaneously connecting the power supply; and energizing the anode wire 101 and cathode wire 102 through the conductive injection pipe 113 with the porous electrode plate 108 of the multifunctional uranium leaching system. Connect the conductive injection pipe 113 to the external circulation pipe 125, and open the circulation pump 124 and the external circulation pipe valve 127 to allow the liquid in the chamber to circulate from the anode area to the cathode area through the external circulation pipe 125. During the reaction, uranyl ions generated during uranium leaching are adsorbed onto the ion exchange resin 103. A microporous filter membrane 107 is filled between the uranium trapping net 105 and the porous electrode sheet 108 to prevent uranium ore particles from entering the external circulation pipe and causing blockage. After the reaction, the uranium trapping net 105 is removed to elute the ion exchange resin 103 to recover uranyl ions.

[0048] In some embodiments, the particle size of the uranium ore is 1 mm to 5 mm, such as 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, etc. The mass ratio of the grinding balls to the uranium ore is (3-5):1, such as 3:1, 4:1, 5:1, etc. The grinding balls 106 are selected from at least one of zirconia balls, corundum balls, and ceramic balls, and the material of the grinding balls 106 can be any one or more of the above. The diameter of the grinding balls 106 is 5 mm to 20 mm, such as 5 mm, 8 mm, 10 mm, 13 mm, 15 mm, 18 mm, 20 mm, etc.

[0049] In some embodiments, the pH value of the leaching solution is 0.10-7.00, such as 0.10, 0.50, 1.00, 1.50, 2.00, etc., preferably 0.10-2.00. The acid solution and hydrogen peroxide are mixed to obtain a mixed leaching solution, wherein the mass fraction of hydrogen peroxide in the mixed leaching solution is 0.5%-10%, such as 0.5%, 1.0%, 2.0%, 3.0%, 4.0%, 5.0%, 6.0%, 7.0%, 8.0%, 9.0%, 10.0%, etc., preferably 2%-5%. The mass ratio of the mixed leaching solution to uranium ore is (2.5-4.0):1, such as 2.5:1, 2.8:1, 3.0:1, 3.3:1, 3.5:1, 3.8:1, 4.0:1, etc. The acid used to control the pH value inside the horizontal rotary reaction chamber 110 is selected from at least one of sulfuric acid, nitric acid and hydrochloric acid, and the acid can be any one or more of the above.

[0050] In some embodiments, the anode wire 101 and the cathode wire 102 are connected to a DC power supply with a voltage intensity of 1 V / cm-30 V / cm, such as 1 V / cm, 5 V / cm, 10 V / cm, 15 V / cm, 20 V / cm, 25 V / cm, 30 V / cm, etc., preferably 10 V / cm-20 V / cm; the current density is 0.1 mA / cm². 2 -5 mA / cm 2 For example, it can be 0.1 mA / cm 2 0.5 mA / cm 2 1.0 mA / cm 2 1.5 mA / cm 2 2.0 mA / cm 2 2.5 mA / cm 2 3.0 mA / cm 2 3.5 mA / cm 2 4.0 mA / cm 2 4.5 mA / cm 2 5.0 mA / cm 2 Etc., preferably 1.0 mA / cm 2 -3.0 mA / cm 2 .

[0051] In some embodiments, the rotational speed of the horizontal rotary reaction chamber 110 during the reaction is controlled at 100 rpm to 500 rpm, such as 100 rpm, 200 rpm, 300 rpm, 400 rpm, 500 rpm, etc.; the leaching time is 0.5 h to 6.0 h, such as 0.5 h, 1.0 h, 2.0 h, 3.0 h, 4.0 h, 5.0 h, 6.0 h, etc. The temperature is maintained at 20℃ to 60℃ during the reaction using the horizontal rotary reaction chamber 110, such as 20℃, 30℃, 40℃, 50℃, 60℃, etc. The circulation pump flow rate is 0.5 mL / min to 5 mL / min, such as 0.5 mL / min, 1 mL / min, 1.5 mL / min, 2 mL / min, 2.5 mL / min, 3 mL / min, 4 mL / min, 5 mL / min, etc.

[0052] Furthermore, after the reaction is complete, the residue in the tank is removed and solid-liquid separation is performed by filtration or other methods. The resulting filtrate can be recycled. An eluent is used to elute the ion exchange resin to recover uranyl ions; wherein the eluent is selected from at least one of sodium carbonate solution, sodium chloride solution, ammonium sulfate solution, magnesium chloride solution, and ammonium chloride solution, and the eluent can be any one or more of the above.

[0053] The leaching method for uranium ore provided in this embodiment of the invention has the following advantages:

[0054] (1) By organically combining mechanical action, chemical leaching, and electric field action, the mechanical force destroys the mineral structure, and advanced oxidation achieves uranium oxidative leaching. The electric field promotes advanced oxidation and ion migration, and the ion exchange resin adsorbs uranyl ions in real time, forming a synergistic enhancement effect, which significantly improves the leaching efficiency and recovery rate of uranium. Experiments show that when using this invention to treat typical granite uranium ore, the uranium leaching rate can reach 85%-95%, and the recovery rate can reach 90%-96%, which is significantly higher than the traditional multi-stage stirring acid leaching method. For mudstone-type uranium ore, the uranium leaching and recovery can also reach more than 90%, providing a reliable new process and equipment for the mining of mudstone-type uranium ore.

[0055] (2) The present invention adopts a built-in ion exchange resin collection system, which realizes the integration of leaching and collection, avoids the disadvantage of the need for subsequent separation steps in the traditional method, and simplifies the process flow.

[0056] (3) By coupling advanced oxidation technology and electric field enhancement, this invention reduces the dependence on strong acids and strong oxidants, reduces the consumption of chemical reagents, and lowers the treatment cost and environmental impact.

[0057] (4) The device of the present invention has a simple structure, is easy to operate, and is suitable for uranium ore processing of different scales and types, and has wide applicability.

[0058] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0059] The ball milling apparatus used in the following embodiments and comparative examples is as follows: Figure 1 and Figure 2 As shown, the specific structure is described in the instruction manual above, and the specific parameters are as follows:

[0060] The horizontal rotary reactor chamber 110 is made of 304 stainless steel, with its inner wall coated with a corrosion-resistant coating (polytetrafluoroethylene). The lower part of the chamber cover 104 is connected to the uranium trapping net 105 via a spiral connector. The uranium trapping net 105 is made of 316L stainless steel with a mesh size of 0.5 mm.

[0061] Example 1

[0062] In this embodiment, the uranium trapping net 105 is filled with a strong base anion exchange resin (polystyrene skeleton quaternary ammonium type I resin), with a filling amount of 80% of the uranium trapping net volume and a filling mass of 400 g.

[0063] The test ore was taken from a argillaceous sandstone uranium deposit in Inner Mongolia (uranium grade 0.028%), accompanied by a large amount of clay minerals. The uranium ore was crushed to approximately 3 mm, and 500 g of ore and 2 kg of zirconium oxide grinding balls (10 mm in diameter) were added to a horizontal rotary leaching chamber. 3% hydrogen peroxide (i.e., 3% by mass in the mixed leaching solution) was added to the chamber, and the pH was set to 0.50 (adjusted with sulfuric acid). The liquid-to-solid ratio was 3:1 (i.e., the mass ratio of the mixed leaching solution to the ore was 3:1). The multi-functional uranium leaching system was started, the rotation speed was set to 300 rpm, and a DC power supply was connected at 15 V / cm and a current density of 2.0 mA / cm². 2 The processing time was 4 hours, the temperature was maintained at 40℃, and the circulation pump flow rate was 1 mL / min. After ball milling, the residue was removed and filtered. The ion exchange resin was eluted with 1 M sodium carbonate solution to recover uranyl ions.

[0064] The uranium content was determined by ICP-MS, and the uranium leaching rate was calculated to be 89%, with a recovery rate of 93%.

[0065] The uranium leaching rate is calculated as follows: (uranium content in the remaining liquid + uranium content desorbed by the resin) / (uranium content in the original ore); the recovery rate is calculated as follows: (uranium content desorbed by the resin) / (uranium content in the remaining liquid + uranium content desorbed by the resin).

[0066] Example 2

[0067] In this embodiment, the uranium trapping net 105 is filled with a strong alkaline anion exchange resin (same as in Embodiment 1), the filling amount is 80% of the volume of the uranium trapping net, and the filling quality is the same as in Embodiment 1.

[0068] The test ore was taken from a carbonaceous-silica mudstone-type uranium deposit in Guangdong Province (uranium grade 0.035%), with pitchblende as the main uranium mineral. The uranium ore was crushed to approximately 2 mm, and 500 g of ore was added to a horizontal rotary reactor along with 2 kg of corundum grinding balls (15 mm in diameter). 5% hydrogen peroxide was added to the reactor, and the pH was set to 1.00 (adjusted with nitric acid), with a liquid-to-solid ratio of 4:1. The multi-functional uranium leaching system was started, with a rotation speed of 400 rpm, and a DC power supply of 20 V / cm, a current density of 3 mA / cm², a treatment time of 3 hours, a temperature maintained at 50℃, and a circulation pump flow rate of 1.5 mL / min. The ion exchange resin was eluted using a 1 M magnesium chloride solution.

[0069] The test results showed that the uranium leaching rate reached 92% and the recovery rate was 95%.

[0070] Example 3

[0071] In this embodiment, the uranium trapping net 105 is filled with a strong alkaline anion exchange resin (same as in Embodiment 1), the filling amount is 80% of the volume of the uranium trapping net, and the filling quality is the same as in Embodiment 1.

[0072] The test ore was taken from a tight sandstone-type uranium deposit in Inner Mongolia (uranium grade 0.052%), and the ore was loose and porous. The uranium ore was crushed to approximately 4 mm, and 500 g of ore and 2 kg of ceramic grinding balls (8 mm in diameter) were added to a horizontal rotary reactor. 2% hydrogen peroxide was added to the reactor, and the pH was set to 1.50 (adjusted with phosphoric acid), with a liquid-to-solid ratio of 2.5:1. The multi-functional uranium leaching system was started, the rotation speed was set to 350 rpm, and a DC power supply was connected at 12 V / cm, current density 1.5 mA / cm², processing time 5 hours, temperature maintained at 30℃, and circulation pump flow rate 2 mL / min. The ion exchange resin was eluted using a 0.5 M ammonium sulfate solution.

[0073] The test results showed that the uranium leaching rate was 87% and the recovery rate was 91%.

[0074] Example 4

[0075] In this embodiment, the uranium trapping net 105 is filled with a strong base anion exchange resin (polystyrene skeleton quaternary ammonium type I resin), with a filling amount of 60% of the uranium trapping net volume and a filling mass of 300 g.

[0076] The test ore was taken from a granite-type uranium deposit in Guangdong Province (uranium grade 0.035%), with pitchblende as the main uranium mineral. The uranium ore was crushed to approximately 1 mm, and 500 g of ore was added to a horizontal rotary reactor along with 1.5 kg of corundum grinding balls (5 mm in diameter). 0.5% hydrogen peroxide was added to the reactor, and the pH was set to 3.00 (adjusted with sulfuric acid), with a liquid-to-solid ratio of 2.5:1. The multi-functional uranium leaching system was started, with a rotation speed of 100 rpm, and a DC power supply connected at 1 V / cm, a current density of 0.1 mA / cm², a treatment time of 0.5 hours, a temperature maintained at 20℃, and a circulation pump flow rate of 2.5 mL / min. The ion exchange resin was eluted using a 1 M magnesium chloride solution.

[0077] The test results showed that the uranium leaching rate reached 73% and the recovery rate was 70%.

[0078] Example 5

[0079] In this embodiment, the uranium trapping net 105 is filled with a strong base anion exchange resin (polystyrene skeleton quaternary ammonium type I resin), with a filling amount of 90% of the uranium trapping net volume and a filling mass of 450 g.

[0080] The test ore was taken from a volcanic uranium deposit in Jiangxi Province (uranium grade 0.057%), with pitchblende as the main uranium mineral. The uranium ore was crushed to approximately 5 mm, and 500 g of ore was added to a horizontal rotary reactor along with 2.5 kg of corundum grinding balls (20 mm in diameter). 10% hydrogen peroxide was added to the reactor, and the pH was set to 1.00 (adjusted with sulfuric acid), with a liquid-to-solid ratio of 4:1. The multi-functional uranium leaching system was started, with a rotation speed of 500 rpm. A DC power supply was connected at 30 V / cm, a current density of 5.0 mA / cm², a treatment time of 6 hours, a temperature maintained at 60℃, and a circulation pump flow rate of 3 mL / min. The ion exchange resin was eluted using a 1 M ammonium chloride solution.

[0081] The test results showed that the uranium leaching rate reached 85% and the recovery rate was 90%.

[0082] Example 6

[0083] The only difference from Example 2 is that the DC power supply has a voltage of 1 V / cm and a current density of 0.1 mA / cm. 2 The results showed that the uranium leaching rate was 78% and the recovery rate was 89%.

[0084] Example 7

[0085] The only difference from Example 2 is that the DC power supply has a voltage of 30 V / cm and a current density of 5 mA / cm. 2The results showed that the uranium leaching rate was 88%, and the recovery rate was 88%.

[0086] Example 8

[0087] The only difference from Example 2 is that the ion exchange resin used is a polystyrene-based quaternary ammonium type II resin. The results showed that the uranium leaching rate was 92% and the recovery rate was 93%.

[0088] Example 9

[0089] The only difference from Example 2 is that the ion exchange resin used is an iminodiacetic acid (IDA) resin. The results showed a uranium leaching rate of 91% and a recovery rate of 90%.

[0090] Example 10

[0091] The only difference from Example 2 was the addition of 0.5% hydrogen peroxide (i.e., 0.5% by mass of hydrogen peroxide in the mixed leaching solution) to the horizontal rotary reaction chamber and the setting of the pH value to 5.00. The results showed a uranium leaching rate of 47% and a recovery rate of 92%.

[0092] Example 11

[0093] The only difference from Example 2 was the addition of 10% hydrogen peroxide (i.e., 0.5% by mass of hydrogen peroxide in the mixed leaching solution) to the horizontal rotary reaction chamber and the setting of the pH value to 0.00. The results showed a uranium leaching rate of 92% and a recovery rate of 93%.

[0094] Example 12

[0095] The only difference from Example 2 was the liquid-to-solid ratio, which was 2.0:1. The results showed a uranium leaching rate of 68% and a recovery rate of 92%.

[0096] Example 13

[0097] The only difference from Example 2 was the liquid-to-solid ratio, which was 6.0:1. The results showed a uranium leaching rate of 85% and a recovery rate of 78%.

[0098] Example 14

[0099] The only difference from Example 2 was that the elution solution was a 1 M hydrochloric acid solution. The results showed that the uranium leaching rate was 90% and the recovery rate was 58%.

[0100] Example 14

[0101] The only difference from Example 2 was the circulation pump flow rate: 5 mL / min. The results showed a uranium leaching rate of 88% and a recovery rate of 82%.

[0102] Comparative Example 1

[0103] The same ore and reagents as in Example 1 were used, but without electrotreatment; all other conditions remained the same. The results showed a uranium leaching rate of 62% and a recovery rate of 58%.

[0104] Comparative Example 2

[0105] The same ore and reagents as in Example 1 were used, but the ion exchange resin collection system was not used; all other conditions remained the same. After the reaction, uranium was recovered using a conventional precipitation method, resulting in a uranium leaching rate of 65% and a recovery rate of 72%.

[0106] Comparative Example 3

[0107] The same ore and reagents as in Example 1 were used, but without the addition of grinding balls. Leaching was performed only by rotating the reaction chamber under energized conditions, with all other conditions remaining the same. The results showed a uranium leaching rate of 45% and a recovery rate of 40%.

[0108] Comparative Example 4

[0109] The same ore and reagents as in Example 1 were used, but the circulating pump was not used to circulate the liquid in the reaction chamber; all other conditions remained the same. Results showed a uranium leaching rate of 70%, a recovery rate of 68%, and that metal hydroxide precipitates blocked the porous conductive layer in the cathode region after the reaction.

[0110] Comparative Example 5

[0111] The same ore and reagents as in Example 1 were used, but the pH in the chamber was not controlled by a control system. Only 0.1 M sulfuric acid solution was added to the reaction chamber before leaching began (even though the initial nitric acid concentration in the horizontal rotating reaction chamber was 0.1 M), with all other conditions remaining the same. The results showed a uranium leaching rate of 30% and a recovery rate of 75%, indicating that the acid added to the chamber was not replenished in time after consumption, resulting in insufficient uranium leaching.

[0112] Comparative Example 6

[0113] The same ore and reagents as in Example 1 were used, but the pH in the chamber was not controlled by a control system. Only a 2 M sulfuric acid solution was added to the reaction chamber before leaching began (even though the initial nitric acid concentration in the horizontal rotating reaction chamber was 2 M), with all other conditions remaining the same. The results showed a uranium leaching rate of 80%, a recovery rate of only 45%, and the presence of other metallic impurities. This indicates that the pH in the chamber was too low, resulting in excessive leaching of impurity ions and reducing uranium recovery efficiency.

[0114] The above experimental results fully demonstrate that the present invention, through the organic combination of mechanical ball milling, electric field action, and ion exchange resin collection, significantly improves the leaching efficiency and recovery rate of uranium and reduces the amount of acid used. The liquid circulation system promotes the acid-base balance in the chamber and reduces the risk of blockage and deactivation, with effects that are significantly better than traditional methods.

[0115] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A leaching method for uranium ore, characterized in that, Leaching is performed using a multifunctional uranium leaching system, which includes a horizontal rotary reaction chamber, an external circulation pipeline, a power supply, a rotary motor, a liquid injection chamber, and a control system. The horizontal rotary reaction chamber includes a horizontal rotary reaction chamber body, a horizontal rotary reaction chamber cover, a pH sensor, and a uranium trapping net, which is located at the anode end of the horizontal rotary reaction chamber. Both ends of the horizontal rotary reaction chamber are provided with porous electrode plates and conductive liquid injection pipes, and anode and cathode wires are provided at corresponding positions on the conductive liquid injection pipes and porous electrode plates. The leaching process includes: placing uranium ore and grinding balls into the horizontal rotary reaction chamber; filling the uranium trapping net with ion exchange resin; adding acid solution and hydrogen peroxide into the horizontal rotary reaction chamber; starting the multi-functional uranium leaching system and simultaneously connecting the power supply; setting the pH value, current, voltage, and rotation speed through the control system; opening the valve to allow the liquid in the chamber to circulate from the anode area to the cathode area through the external circulation pipeline; after the reaction is completed, removing the ion exchange resin from the uranium trapping net for elution to recover uranyl ions; the pH sensor monitors the pH value of the horizontal rotary reaction chamber in real time and feeds back the signal to the control system; when the pH value is higher than the set value, the control system will control the injection chamber to replenish the acid solution into the horizontal rotary reaction chamber through the external circulation pipeline in a timely manner to maintain the pH value in the chamber; a microporous filter membrane is filled between the uranium trapping net and the porous electrode sheet.

2. The leaching method according to claim 1, characterized in that, The DC power supply has a voltage range of 1 V / cm to 30 V / cm and a current density of 0.1 mA / cm². 2 -5 mA / cm 2 ; And / or, the uranium ore is selected from at least one of sandstone-type uranium ore, mudstone-type uranium ore, granite-type uranium ore, and volcanic rock-type uranium ore.

3. The leaching method according to claim 1, characterized in that, The amount of ion exchange resin used is 60%-90% of the volume of the uranium trapping net; And / or, the mesh size of the uranium trapping net is 0.1 mm-1.0 mm; And / or, the uranium trapping net is made of 316L stainless steel or titanium alloy.

4. The leaching method according to any one of claims 1-3, characterized in that, The ion exchange resin is a strongly basic anion exchange resin or a chelating resin; the strongly basic anion exchange resin includes polystyrene-based quaternary ammonium type I resin, polystyrene-based quaternary ammonium type II resin and polyacrylic acid-based quaternary ammonium type resin; the chelating resin includes iminodiacetic acid type resin, aminophosphonic acid type resin and amine oxime type resin.

5. The leaching method according to claim 1, characterized in that, The pH value of the leachate solution is not higher than 7.00, and the mass fraction of hydrogen peroxide in the mixed leachate is 0.5%-10%. And / or, the mass ratio of the mixed leachate to the uranium ore is (2.5-4.0):1; And / or, the particle size of the uranium ore is 1 mm to 5 mm.

6. The leaching method according to claim 5, characterized in that, The acid solution used to control the pH value inside the horizontal rotary reaction chamber is selected from at least one of sulfuric acid, nitric acid, and phosphoric acid.

7. The leaching method according to claim 1, characterized in that, The rotation speed of the horizontal rotating reaction chamber was controlled at 10 rpm-500 rpm, and the leaching time was 0.5 h-6.0 h. And / or, the temperature is maintained at 20℃-60℃ during the reaction; And / or, the mass ratio of the grinding ball to the uranium ore is (3-5):1; And / or, the grinding balls are selected from at least one of zirconia balls, corundum balls and ceramic balls, and the diameter of the grinding balls is 5 mm to 20 mm; And / or, the flow rate of the circulating pump is 0.5 mL / min to 5 mL / min; And / or, after the reaction is complete, remove the residue from the tank for solid-liquid separation.

8. The leaching method according to claim 1, characterized in that, The ion exchange resin is eluted with an eluent to recover uranyl ions; wherein the eluent is selected from at least one of sodium carbonate solution, sodium chloride solution, ammonium sulfate solution, magnesium chloride solution, and ammonium chloride solution.

9. A leaching apparatus for carrying out the leaching method according to any one of claims 1-8, characterized in that, The multifunctional uranium leaching system includes a horizontal rotary reaction chamber, an external circulation pipeline, a power supply, a rotary motor, a liquid injection chamber, and a control system. The liquid injection chamber is connected to the external circulation pipeline. Both ends of the horizontal rotary reaction chamber are equipped with porous electrode plates and conductive liquid injection pipes. Anode and cathode wires are installed on the conductive liquid injection pipes at corresponding positions to the porous electrode plates. In operation, the porous electrode plates and conductive liquid injection pipes at both ends of the horizontal rotary reaction chamber are in direct contact and conductive. The conductive liquid injection pipes are energized in contact with the anode and cathode wires. The conductive liquid injection pipes are connected to the external circulation pipeline, on which a circulation pump is installed. During the leaching process, after the valve is opened, the liquid in the chamber is circulated from the anode area to the cathode area through the external circulation pipeline by the circulation pump. The horizontal rotary reaction chamber includes a horizontal rotary reaction chamber body, a horizontal rotary reaction chamber cover, a pH sensor, and a uranium trapping net. The uranium trapping net is filled with ion exchange resin. The pH sensor monitors the pH value of the horizontal rotary reaction chamber in real time and feeds back the signal to the control system. When the pH value is higher than the set value, the control system will control the injection chamber to replenish acid into the horizontal rotary reaction chamber in a timely manner through the external circulation pipeline to maintain the pH value inside the chamber. A microporous filter membrane is filled between the uranium trapping net and the porous electrode sheet.

10. The leaching apparatus according to claim 9, characterized in that, The conductive injection tube is used to connect the cathode wire and the anode wire, and also serves as part of the external circulation pipeline; And / or, the conductive injection tube is a hollow plastic tube made of carbon black-filled PP conductive plastic or PC carbon nanotube conductive plastic; And / or, the porous electrode sheet is a thin sheet made of carbon black-filled PP conductive plastic or PC carbon nanotube conductive plastic.

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