Electro-fenton treatment device and method for uranium activation collection in uranium-containing slurry

Abstract

This invention provides an electro-Fenton treatment device and method for the activation and collection of uranium in uranium-containing slurry, belonging to the field of uranium purification and conversion, uranium enrichment, and other specialized equipment manufacturing. This device activates the Fenton reaction through an electric field, generating hydroxyl radicals (HO) in the uranium-containing slurry. • Highly reactive substances such as Fe activate uranium, thereby improving uranium leaching efficiency. The apparatus includes a reaction vessel, the main body of which is cylindrical. The upper part of the outer wall of the reaction vessel has an inlet / pipe and an outlet / pipe. The top of the reaction vessel has an inspection port and a stirring motor, and the bottom of the reaction vessel has an vent / pipe. A stirring mechanism is installed inside the reaction vessel. An electric field promotes Fe leaching during the reaction. 2+ / Fe 3+ The recycling and regeneration process maintains the high efficiency of the electro-Fenton reaction. Simultaneously, the electric field helps lower the pH of the solution, optimizing reaction conditions and significantly improving uranium activation and leaching rates. This invention effectively reduces oxidant consumption, lowers processing costs, and improves uranium collection efficiency.

Description

Technical Field

[0001] This invention belongs to the field of manufacturing special equipment for uranium purification and conversion, uranium enrichment and other special equipment, and particularly relates to an electro-Fenton treatment device and method for the activation and collection of uranium in uranium-containing slurry. Background Technology

[0002] Uranium ore is a crucial resource in the nuclear energy industry. With the rapid development of nuclear power, the demand for natural uranium is gradually increasing. Therefore, the effective mining and extraction of uranium is of strategic significance for energy supply. Uranium in uranium ore typically exists in two oxidation states: tetravalent uranium (U(IV)) and hexavalent uranium (U(VI)). Hexavalent uranium (such as uranyl ions UO2) is the most abundant oxidation state. 2+ Hexavalent uranium is more readily soluble in acidic solutions, while tetravalent uranium is more difficult to dissolve. Therefore, converting the poorly soluble tetravalent uranium into the readily soluble hexavalent uranium is a significant technical challenge in uranium ore extraction processes.

[0003] Traditional uranium leaching processes primarily rely on the chemical oxidation of acidic or alkaline solutions. Common oxidants include hydrogen peroxide, nitric acid, persulfate, perborate, and ozone. However, these oxidants are inefficient when treating complex minerals, often requiring long reaction times and large chemical dosages, increasing process costs and environmental burden. Studies have shown that treating 50g of ore samples with 0.1g of hydrogen peroxide and 0.1g of sodium perborate, respectively, for 24 hours resulted in uranium leaching rates of only 13.3% and 20.0%, respectively. Furthermore, the uranium leaching process is easily affected by various factors such as mineral particle size, slurry pH, and reaction temperature, leading to significant fluctuations in uranium recovery efficiency.

[0004] To improve uranium leaching efficiency, researchers have proposed various improvement schemes, among which the Fenton reaction method has gradually attracted widespread attention. The Fenton reaction involves the reaction of hydrogen peroxide with ferrous ions (Fe²⁺). 2+ The reaction generates highly oxidizing hydroxyl radicals (HO). • This free radical possesses high oxidizing power and can effectively promote the oxidative dissolution of uranium in uranium ore. However, the traditional Fenton reaction suffers from a slow reaction rate and Fe... 2+ / Fe 3+ Problems such as low cycle efficiency and insufficient free radical generation limit its promotion in practical industrial applications. Summary of the Invention

[0005] The purpose of this invention is to overcome the deficiencies of the prior art and provide an electro-Fenton treatment device and method for the activation and collection of uranium in uranium-containing ore slurry, which realizes the activation and collection of uranium ore through mechanical stirring and electric field-assisted Fenton reaction.

[0006] This invention's device enhances the mixing efficiency of slurry and reagents through a stirring system and utilizes an electric field-assisted reaction to generate more hydroxyl radicals, thereby enhancing uranium oxidation and dissolution. The cathode in this device further enriches uranyl ions, achieving uranium recovery. This invention significantly improves uranium oxidation and enrichment efficiency, reduces the use of chemical reagents, lowers environmental pollution, and simplifies the uranium extraction process, demonstrating broad industrial application prospects.

[0007] The present invention adopts the following technical solution: An electro-Fenton treatment device for the activation and collection of uranium in uranium-bearing slurry includes a cylindrical reaction vessel. The upper part of the outer wall of the reaction vessel has an inlet / pipe and an outlet / pipe. The top of the reaction vessel has an inspection port and a stirring motor, and the bottom of the reaction vessel has an vent / pipe. A stirring mechanism is installed inside the reaction vessel, comprising a stirring rod and stirring blades. One end of the stirring rod is connected to the stirring motor, and the other end is connected to the stirring blades. The stirring rod inside the reaction vessel serves as the working electrode for the electric field, while the counter electrode is evenly distributed on the inner wall of the reaction vessel. The reaction vessel also has a chemical dosing port / pipe and a leaching agent dosing port. The working electrode and the counter electrode are energized, and the electro-Fenton reaction is achieved through an external electric field.

[0008] Furthermore, both the working electrode and the counter electrode are connected to a DC power supply. The working electrode of the electric field can be connected to the positive terminal of the power supply as an anode or to the negative terminal of the power supply as a cathode. The counter electrode is tubular and adopts a porous structure design.

[0009] Furthermore, the counter electrode is made of 316L stainless steel or titanium alloy, with a platinum or carbon coating on the surface.

[0010] Furthermore, the reaction vessel is made of stainless steel, aluminum alloy, polymer, or concrete, and the inner wall of the reaction vessel is coated with a corrosion-resistant coating. The stirring mechanism is made of conductive material.

[0011] Furthermore, the DC power supply has a voltage range of 1-50V and a current density of 0.1-10mA / cm². 3 .

[0012] Furthermore, the distance between the electrodes is set at 50-500mm.

[0013] An electro-Fenton treatment method for the activated collection of uranium from uranium-bearing slurry includes the following steps: Step 1. Crush the uranium ore and mix it with an appropriate amount of water to prepare a slurry of a certain concentration.

[0014] Step 2. Add the slurry into the reaction tank through the feed port / pipe, start the stirring motor, and set a certain speed.

[0015] Step 3. Start the dosing pump and add hydrogen peroxide and pyrite, or hydrogen peroxide and ferrous sulfate, into the reaction vessel, adjusting the flow rate to a constant value.

[0016] Step 4. Adjust the DC power supply current. Under the assistance of the electric field, hydrogen peroxide reacts with the iron source to generate hydroxyl radicals, which oxidize the uranium in the uranium ore. Set the reaction time.

[0017] Step 5. Collect activated uranyl ions from the cathode of the electric field, and extract uranium from the cathode surface through subsequent steps.

[0018] Step 6. The treated slurry is discharged from the vent / pipe.

[0019] Furthermore, the concentration of hydrogen peroxide is 2%-30%, and the injection amount is adjusted according to the reaction requirements of the slurry.

[0020] Furthermore, the pH value of the slurry is maintained at 1-7, and the water content is 50%-99%.

[0021] Furthermore, the reaction time is 0.5-12 hours, adjusted according to the uranium content and mineral properties in the slurry.

[0022] The beneficial effects of this invention are: This invention significantly enhances the activity of hydroxyl radicals (HO) through an electric field-assisted Fenton reaction. • The formation rate of UO2 accelerates the oxidation process of U(Ⅳ) to U(Ⅵ) in uranium ore, significantly increasing the uranium leaching rate. Simultaneously, the cathode enriches UO2... 2+ This device achieves highly efficient uranium recovery. Compared to traditional uranium leaching processes, it can achieve higher uranium extraction efficiency in a shorter time, with a uranium leaching rate exceeding 90%. By introducing an electric field, this invention significantly improves the utilization rate of oxidants such as hydrogen peroxide. The electric field can promote Fe... 2+ / Fe 3+ The cycle accelerates the generation of free radicals, thereby reducing the consumption of oxidants.

[0023] Compared to the traditional Fenton reaction method, this invention significantly reduces the amount of oxidant used while maintaining the same reaction effect, thus lowering processing costs and environmental pollution. The device is simple in design, compact in structure, and easy to operate. The stirring system and power control system work together to dynamically adjust the reaction process according to actual needs by regulating the mixing and reaction conditions of the slurry.

[0024] The reaction vessel is made of corrosion-resistant materials, giving it a longer service life when processing acidic slurries. This unit is designed for large-scale uranium ore processing, and parameters such as the stirring system, electrodes, and electric field strength can be flexibly adjusted to meet the processing needs of different slurries.

[0025] By optimizing reaction conditions (such as stirring speed, solid-liquid ratio, and voltage), this invention improves efficiency and reduces operating costs in industrial production. Furthermore, it reduces the use of chemical reagents and the emission of hazardous waste. Compared to traditional chemical treatment methods, this invention is more environmentally friendly while improving uranium extraction efficiency, helping to reduce the environmental impact of mining operations. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure provided for an embodiment of the present invention; In the diagram: 1-Reaction vessel, 2-Inlet / pipe, 3-Outlet / pipe, 4-Stirring motor, 5-Vacuum outlet / pipe, 6-Stirring mechanism, 7-Counter electrode, 8-DC power supply, 9-Dosing pump, 10-Dosing port / pipe. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention are described clearly and completely below. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0028] Unless otherwise specified, all raw materials and reagents used in this invention are from the conventional market.

[0029] like Figure 1 As shown, an electro-Fenton treatment device for uranium activation and collection in uranium-containing ore slurry according to the present invention includes a reaction tank 1. The main body of the reaction tank 1 is cylindrical, and an inlet / pipe 2 and an outlet / pipe 3 are provided on the upper part of the outer wall of the reaction tank 1 to facilitate the addition of ore slurry and subsequent discharge of ore liquid. The top of the reaction tank 1 has an inspection port and a stirring motor 4 to facilitate subsequent inspection and maintenance of the reaction tank 1. The bottom of the reaction tank 1 has a drain port / pipe 5 for discharging the treated precipitate. A stirring mechanism 6 is installed inside the reaction tank 1. The stirring mechanism 6 includes a stirring rod and a stirring blade. One end of the stirring rod is connected to the stirring motor 4, and the other end is connected to the stirring blade. Rapid mixing of ore slurry and activating reagent is achieved by mechanical stirring. The electro-Fenton reaction is achieved by applying an external electric field. The stirring rod inside the reaction tank 1 is the working electrode of the electric field, and the counter electrode is evenly distributed on the inner wall of the reaction tank 1. The reaction tank 1 also has a dosing port / pipe 10 and a leaching agent dosing port.

[0030] Both the working electrode and the counter electrode 7 are connected to a DC power supply. The counter electrode 7 adopts a porous structure design, which increases the effective reaction area to enhance the activity of the electro-Fenton reaction and also serves to collect UO2. 2+ The effect.

[0031] The power supply is a DC power supply 8, with a voltage setting of 1-50V and a current density of 0.1-10mA / cm². 3 The voltage and current are adjusted according to the conductivity of the slurry and the reaction requirements. The electrodes 7 are spaced 50-500 mm apart to ensure a uniform electric field distribution. The electrodes are periodically cleaned of enriched uranyl ions to ensure continuous and efficient operation.

[0032] The reaction vessel 1 is made of 304 stainless steel to ensure the mechanical strength and resistance to acid and alkali corrosion. The inner wall of the reaction vessel 1 is coated with a polytetrafluoroethylene (PTFE) coating to further enhance corrosion resistance. It should be noted that in other embodiments of the present invention, the materials of the reaction vessel 1 and the coating on its inner wall can be selected according to requirements.

[0033] The stirring rod is made of highly conductive titanium alloy or high-purity graphite, serving both stirring and electrode functions. It should be noted that in other embodiments of the invention, the material of the stirring blades can also be selected according to requirements. The working electrode of the electric field can be the anode, such as... Figure 1 As shown, it can also be a cathode, such as Figure 1 As shown.

[0034] The counter electrode 7 is made of 316 stainless steel and has a uranium platinum or carbon coating on its surface.

[0035] The height of reaction vessel 1 is 2.6-3.2m, and in specific implementation, it can be selected as 2.6m, 2.8m, 3m or 3.2m. The diameter is 2.4-2.8m, and in specific implementation, it can be selected as 2.4m, 2.6m or 2.8m, etc.

[0036] The diameters of the inlet / pipe 2, outlet / pipe 3, and vent / pipe 5 are 5mm-20mm, for example, they can be 5mm, 10mm, 15mm, or 20mm, etc. The diameters of the dosing port / pipe 10 and the leaching agent dosing port are generally 10-50mm, for example, they can be 10mm, 20mm, 30mm, 40mm, or 50mm, etc. The dosing port / pipe 10 is connected to the dosing pump 9. Of course, the diameter of the dosing port / pipe 10 can be set according to the properties of the added oxidant and iron-containing materials or the reaction rate during the reaction process, and is not limited to the above-mentioned 10-50mm. For example, it can be 5mm, 60mm, 75mm, 100mm, etc., and this invention does not limit it.

[0037] An electro-Fenton treatment method for the activated collection of uranium from uranium-bearing slurry includes the following steps: Step 1. Crush the uranium ore and mix it with an appropriate amount of water to prepare a slurry of a certain concentration.

[0038] Step 2. Add the slurry into the reaction tank 1 through the feed port / pipe 2, start the stirring motor 4, and set a certain speed.

[0039] Step 3. Start the dosing pump 9 and add hydrogen peroxide and pyrite, or hydrogen peroxide and ferrous sulfate, into the reaction tank 1, adjusting the flow rate to a constant value.

[0040] Step 4. Adjust the DC power supply current to 8. Under the assistance of the electric field, hydrogen peroxide reacts with the iron source to generate hydroxyl radicals, which oxidize the uranium in the uranium ore. Set the reaction time.

[0041] Step 5. Collect activated uranyl ions from the cathode of the electric field, and extract uranium from the cathode surface through subsequent steps.

[0042] Step 6. The treated slurry is discharged from the vent / pipe 5.

[0043] Furthermore, the concentration of hydrogen peroxide is 2%-30%, and the injection amount is adjusted according to the reaction requirements of the slurry.

[0044] Furthermore, the pH value of the slurry is maintained between 1 and 7, and the water content is 50%-99%.

[0045] Furthermore, the reaction time is 0.5-12 hours, adjusted according to the uranium content and mineral properties in the slurry.

[0046] Example 1 The test ore was taken from a argillaceous sandstone uranium deposit in Inner Mongolia (uranium grade 0.035%). It was fine-grained and contained abundant illite, kaolinite, calcite, and potassium feldspar. The uranium ore was crushed to below 200 mesh and mixed with an appropriate amount of water to prepare a 5% slurry.

[0047] The slurry is fed into the reaction tank 1 through the feed port / pipe 2, and the stirring motor 4 is started and the speed is set to 500 rpm to mix the slurry evenly. Start dosing pump 9 to add hydrogen peroxide, and adjust the flow rate to 0.1 m. 3 / h; Adjust the DC power supply current density to 1 A / cm² 3 The reaction continues for 0.5 hours to ensure the activation of uranium; After the reaction is complete, the activated uranyl ions are collected from the two electrodes of the electric field.

[0048] The uranium content in the digestion solution was determined using ICP-OES.

[0049] Under the experimental conditions, the activation rate of uranium was 88%, and the uranium recovery rate was 93%.

[0050] Example 2 The test ore was taken from a sandstone uranium deposit in the Songliao Basin (uranium grade 0.043%), occurring in nodular form, and associated with large amounts of uranium ore, uranium phosphate, pyrite, and sphalerite. The uranium ore was crushed to below 200 mesh and mixed with an appropriate amount of water to prepare a 5% slurry.

[0051] The slurry is fed into the reaction tank 1 through the feed port / pipe 2, and the stirring motor 4 is started and the speed is set to 500 rpm to mix the slurry evenly. Start dosing pump 9 to add hydrogen peroxide, and adjust the flow rate to 0.1 m. 3 / h; Adjust the DC power supply current density to 1 A / cm² 3 The reaction continues for 0.5 hours to ensure the activation of uranium; After the reaction is complete, the activated uranyl ions are collected from the two electrodes of the electric field.

[0052] The uranium content in the digestion solution was determined using ICP-OES.

[0053] Under the experimental conditions, the activation rate of uranium was 90%, and the uranium recovery rate was 91%.

[0054] Example 3 The test ore was taken from a hard rock uranium deposit in Shaoguan, Guangdong Province (uranium grade 0.104%), mainly in vein and massive forms, with abundant uranium-calcium ore, hematite, pyrite, and calcite. The uranium ore was crushed to below 200 mesh and mixed with an appropriate amount of water to prepare a 5% slurry.

[0055] The slurry is fed into the reaction tank 1 through the feed port / pipe 2, and the stirring motor 4 is started and the speed is set to 500 rpm to mix the slurry evenly. Start dosing pump 9 to add hydrogen peroxide, and adjust the flow rate to 0.1 m. 3 / h; Adjust the DC power supply current density to 1 A / cm² 3 The reaction continues for 0.5 hours to ensure the activation of uranium; After the reaction is complete, the activated uranyl ions are collected from the two electrodes of the electric field.

[0056] The uranium content in the digestion solution was determined using ICP-OES.

[0057] Under the experimental conditions, the activation rate of uranium was 90%, and the uranium recovery rate was 93%.

[0058] Comparative Example 1 The test ore was taken from a argillaceous sandstone uranium deposit in Inner Mongolia (uranium grade 0.035%). It was fine-grained and contained abundant illite, kaolinite, calcite, and potassium feldspar. The uranium ore was crushed to below 200 mesh and mixed with an appropriate amount of water to prepare a 5% slurry.

[0059] The slurry is fed into the reaction tank 1 through the feed port / pipe 2, and the stirring motor 4 is started and the speed is set to 500 rpm to mix the slurry evenly. Adjust the DC power supply current density to 1 A / cm² 3 The reaction lasted for 0.5 hours; After the reaction is complete, the activated uranyl ions are collected from the two electrodes of the electric field.

[0060] Under the experimental conditions, the activation rate of uranium was 20%, and the uranium recovery rate was 15%.

[0061] Comparative Example 2 The test ore was taken from a argillaceous sandstone uranium deposit in Inner Mongolia (uranium grade 0.035%). It was fine-grained and contained abundant illite, kaolinite, calcite, and potassium feldspar. The uranium ore was crushed to below 200 mesh and mixed with an appropriate amount of water to prepare a 5% slurry.

[0062] The slurry is fed into the reaction tank 1 through the feed port / pipe 2, and the stirring motor 4 is started and the speed is set to 500 rpm to mix the slurry evenly. Start dosing pump 9 to add hydrogen peroxide, and adjust the flow rate to 0.1 m. 3 / h; The uranium content in the digestion solution was determined using ICP-OES.

[0063] Under the experimental conditions, the activation rate of uranium was 55%, and the uranium recovery rate was 25%.

[0064] In summary, the apparatus and method of the present invention can improve the activation rate and recovery rate of uranium when processing low-grade uranium-bearing ore.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for processing uranium in uranium-containing slurry using an electro-Fenton treatment device, characterized in that, The apparatus includes a cylindrical reaction vessel with an inlet / pipe and an outlet / pipe on the upper part of its outer wall. An inspection port and a stirring motor are located at the top of the vessel, and a vent / pipe is located at the bottom. A stirring mechanism, comprising a stirring rod and stirring blades, is installed inside the vessel. One end of the stirring rod is connected to the stirring motor, and the other end is connected to the stirring blades. The stirring rod inside the vessel serves as the working electrode for the electric field, while the counter electrode is evenly distributed on the inner wall of the vessel. The vessel also has a chemical inlet / pipe and an extractant inlet. Both the working and counter electrodes are energized, and the electro-Fenton reaction is achieved through an external electric field. The DC power supply has a voltage of 1-50 V and a current density of 0.1-10 mA / cm². 2 Both the working electrode and the counter electrode are connected to a DC power supply. The working electrode of the electric field is connected to the positive terminal of the power supply as the anode, or connected to the negative terminal of the power supply as the cathode. The counter electrode is in the same way and is tubular with multiple holes. The processing method is as follows: Step 1. Crush the uranium ore and mix it with an appropriate amount of water to prepare a slurry of a certain concentration, wherein the pH value of the slurry is between 1 and 7; Step 2. Add the slurry into the reaction tank through the feed port / pipe, start the stirring motor, and set a certain speed; Step 3. Start the dosing pump and add hydrogen peroxide and pyrite, or hydrogen peroxide and ferrous sulfate, into the reaction vessel, adjusting the flow rate to a constant value; Step 4. Adjust the DC power supply current. Under the assistance of the electric field, hydrogen peroxide reacts with the iron source to generate hydroxyl radicals, which oxidize the uranium in the uranium ore. Set the reaction time. The concentration of hydrogen peroxide is 2%-30%. The injection amount is adjusted according to the reaction requirements of the slurry. Step 5. Collect activated uranyl ions from the cathode of the electric field and extract uranium from the cathode surface; Step 6. The treated slurry is discharged from the vent / pipe.

2. The method according to claim 1, characterized in that, The counter electrode is made of 316L stainless steel or titanium alloy and coated with platinum or carbon coating.

3. The method according to claim 1, characterized in that, The reaction vessel is made of stainless steel, aluminum alloy, polymer or concrete. The inner wall of the reaction vessel is coated with a corrosion-resistant coating, and the stirring mechanism is made of conductive material.

4. The method according to claim 1, characterized in that, The distance between the electrodes is set at 50-500mm.

5. The method according to claim 1, characterized in that, Step 1, moisture content is 50%-99%.

6. The method according to claim 1, characterized in that, The reaction time for step 4 is 0.5-12 hours, and the specific reaction time is adjusted according to the uranium content and mineral properties in the slurry.

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