Electrodeposition device and electrolytic treatment system

Abstract

The invention discloses an electro-deposition device and an electrolytic treatment system, the electro-deposition device comprises a cathode unit and an anode unit, the cathode unit is fixedly connected with the anode unit, and the anode unit is electrically connected with an anode binding post. A reaction cavity is formed in the anode unit, and a material to be electrolyzed is filled in the reaction cavity. The cathode unit comprises a cathode bar, the cathode bar comprises a reaction section, the reaction section is inserted into the reaction cavity, and the reaction section is electrically connected with the cathode binding post. The central axis of the reaction section and the central axis of the reaction cavity are located on the same extension line, the shape of the reaction section is matched with the shape of the reaction cavity, and the shortest distances from any two points on the outer surface of the reaction section to the surface of the inner wall of the reaction cavity are equal. The electro-deposition device can effectively reduce electric field distortion in the electrolysis process.

Description

Technical Field

[0001] The present invention particularly relates to an electrodeposition device and an electrolytic treatment system. Background Art

[0002] Metallurgical electrochemistry is the mainstream dry reprocessing method for spent fuel. Compared with water reprocessing, it has high burnup component processing capacity, low criticality risk and less radioactive waste generation. For MOX spent fuel, an electrodeposition device based on the principle of electrochemical reaction is used as the core equipment to separate and extract spent fuel.

[0003] However, current electrodeposition devices are prone to large electric field distortion when processing large batches, affecting the controllability of the reaction and the separation effect. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide an electrodeposition device and an electrolytic treatment system in view of the above-mentioned deficiencies in the prior art. The electrodeposition device can effectively reduce the electric field distortion during the electrolysis process.

[0005] According to an embodiment of the first aspect of the present invention, there is provided an electrodeposition device, comprising: a reaction component; the reaction component comprising a cathode unit and an anode unit; a reaction chamber is provided inside the anode unit, the reaction chamber contains a material to be electrolyzed, the wall of the reaction chamber is electrically connected to the anode of a power supply, the cathode unit comprises a cathode rod, the cathode rod comprises a reaction section, the reaction section is inserted into the reaction chamber and contacts with the material to be electrolyzed, the reaction section is electrically connected to the cathode of the power supply; the central axis of the reaction section is on the same extension line as the central axis of the reaction chamber, the shape of the reaction section is adapted to the shape of the reaction chamber, and the distance from any position on the outer surface of the reaction section to the corresponding position on the inner wall of the reaction chamber is equal.

[0006] Preferably, the cathode unit also includes a conductive rod, a first cavity is provided inside the reaction section, and the first cavity extends along the axial direction of the reaction section; the conductive rod is inserted into the first cavity, and a first powder layer is filled between the first cavity and the conductive rod, and the first powder layer is made of conductive material; one end of the conductive rod is electrically connected to the cathode of the power supply, and the other end is conductively connected to the cathode rod through the first powder layer.

[0007] Preferably, the anode unit comprises an anode crucible and a conductive tube, the reaction chamber is the inner cavity of the anode crucible; the conductive tube is electrically connected to the anode of the power supply, and the anode crucible is accommodated in the conductive tube; a second powder layer is filled between the conductive tube and the anode crucible, the second powder layer is made of conductive material, and the conductive tube is electrically connected to the anode crucible through the second powder layer.

[0008] Preferably, the reaction section includes a first extension portion and a first end portion, the first end portion is located below the first extension portion, the first extension portion extends in a vertical direction and is connected to the first end portion; the side wall of the reaction chamber includes a second extension portion and a second end portion, the second end portion is located below the second extension portion, the second extension portion extends in a vertical direction and is connected to the second end portion; the second extension portion surrounds the first extension portion, and the second end surrounds the second end portion.

[0009] Preferably, the first extension portion and the second extension portion are cylindrical, and the first end portion and the second end portion are semi-spherical.

[0010] Preferably, the reaction assembly also includes a furnace cover, an air inlet pipe and an exhaust pipe. The furnace cover is installed at the upper end of the anode unit and is used to close the reaction chamber. The air inlet pipe runs through the furnace cover. The air inlet pipe extends in a vertical direction and extends downward into the material to be electrolyzed in the reaction chamber. The air inlet pipe is used to fill the reaction chamber with reducing gas or inert gas; the exhaust pipe runs through the furnace cover and is connected to the reaction chamber.

[0011] Preferably, the cathode rod further comprises a connecting section, wherein the connecting section is located above the reaction section and connected to the reaction section, the connecting section passes through the furnace cover, and is connected to the upper end of the anode unit through the furnace cover.

[0012] Preferably, the outer side of the air intake pipe is coated with a graphite protective layer.

[0013] Preferably, a heating furnace is further included, wherein the reaction component is partially accommodated in an inner cavity of the heating furnace, and the heating furnace is used to heat the reaction component.

[0014] Preferably, the heating furnace includes a shell, an insulation layer and a heating module. The heating module is installed inside the shell and surrounds the reaction component. The heating module is used to heat the reaction component. The insulation layer is located between the shell and the heating module and is used to insulate the heating module and the reaction component.

[0015] Preferably, an air-cooling air inlet is provided at the bottom of the heating furnace, and the air-cooling air inlet is connected to the inner cavity of the heating furnace. An air-cooling exhaust port is provided at the upper end of the side wall of the heating furnace, and the air-cooling exhaust port is connected to the inner cavity of the heating furnace. The air-cooling air inlet is used to supply air to the inner cavity of the heating furnace, and the air-cooling exhaust port is used to exhaust air from the inner cavity of the heating furnace, thereby air cooling the reaction component.

[0016] Preferably, it also includes a temperature measuring unit, a current unit and a controller; the temperature measuring unit is connected to the cathode unit, and is used to measure the temperature value of the cathode unit, and the current unit is electrically connected to the anode unit and the cathode unit, respectively, and is used to measure the current value between the anode unit and the cathode unit; the controller is preset with a temperature threshold range and a current threshold range, and the controller is electrically connected to the temperature measuring unit and the current unit, respectively, and is used to receive the temperature value and issue a first alarm signal when the temperature value exceeds the temperature threshold range; and the controller is also used to receive the current value between the anode unit and the cathode unit, and issue a second alarm signal when the current value exceeds the current threshold range.

[0017] Preferably, the material to be electrolyzed includes MOX spent fuel and molten salt electrolyte.

[0018] According to an embodiment of the second aspect of the present invention, there is provided an electrolytic treatment system, comprising a power supply and the above-mentioned electrodeposition device, wherein the power supply comprises an anode terminal and a cathode terminal, wherein the anode terminal is electrically connected to an anode unit of the electrodeposition device, and the cathode terminal is electrically connected to a cathode unit of the electrodeposition device, and the electrodeposition device is used for electrolytic treatment of MOX spent fuel.

[0019] In the electrodeposition device of the present invention, the reaction section of the cathode unit is accommodated in the reaction container of the anode unit, and by arranging the central axis of the reaction section and the anode unit on the same extension line, and by adapting the shape of the reaction section to the shape of the reaction chamber, the shortest distance from any two points on the outer surface of the reaction section to the side wall of the reaction chamber is equal. In other words, the distance from each point on the outer surface of the cathode reaction section to the side wall of the anode reaction chamber is equal. This design greatly promotes the uniform distribution of current density during the electrolysis process, avoids the problems of uneven electrolysis and electric field distortion caused by local overcurrent, thereby improving electrolysis efficiency and product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic structural diagram of an electrodeposition device in some embodiments of the present invention;

[0021] Figure 2 is a schematic diagram of the structure of the reaction assembly in some embodiments of the present invention;

[0022] Figure 3 is a schematic diagram of the structure of a heating furnace in some embodiments of the present invention;

[0023] Figure 4 It is a schematic diagram of the structure of the clamping unit in some embodiments of the present invention.

[0024] In the figure: 1-heating furnace, 11-shell, 12-insulation layer, 13-heating module, 14-air-cooling air inlet, 15-air-cooling exhaust port, 2-reaction component, 21-anode unit, 211-anode crucible, 212-conductive cylinder, 213-first powder layer, 22-cathode unit, 221-cathode rod, 222-conductive rod, 223-second powder layer, 23-inlet pipe, 24-exhaust pipe, 25-furnace cover, 26-first insulating member, 27-second insulating member, 28-thermocouple, 3-clamping unit. DETAILED DESCRIPTION

[0025] The following will be combined with the accompanying drawings in the present invention to clearly and completely describe the technical solutions in the invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of the present invention.

[0026] In the description of the present invention, it should be noted that the terms "upper", "lower" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience and simplification of the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limitations on the present invention.

[0027] In the description of the present invention, the terms “first”, “second” and “third” are used for descriptive purposes only and should not be understood as indicating or implying relative importance.

[0028] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connect", "set", "install", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0029] First of all, it should be noted that metallurgical electrochemistry is the current mainstream dry reprocessing method for spent fuel. Depending on the treatment object, it can be divided into oxide dry process and metal dry process. Compared with the metal dry process, the treatment object and final product of the oxide dry process are both oxides, and the entire process can be carried out in a conventional atmosphere hot chamber, without the need to be carried out in an argon hot chamber like the metal dry process. Overall, the oxide dry process has a simple process flow and a high extraction rate, which is suitable for the current post-processing needs of oxide fuel fast reactors. The corresponding oxide dry process, also known as the Dimitrovgrad dry process (DDP) process, has made few achievements in the research of the DDP process.

[0030] Furthermore, MOX spent fuel, namely mixed oxide (MOX) spent fuel, refers to the spent fuel containing MOX fuel discharged from the nuclear reactor after being irradiated and used in the nuclear reactor. MOX fuel, namely plutonium-uranium oxide mixed fuel, is a kind of uranium dioxide (UO 2 ) and plutonium dioxide (PUO 2 ) nuclear fuel. At present, the post-processing of MOX spent fuel is mostly carried out by the oxide dry post-processing process. However, when the existing electrodeposition device processes a large batch of MOX spent fuel, it is easy to have a large electric field distortion, which affects the controllability of the reaction and the separation effect.

[0031] Specifically, the anode and cathode in the existing electrodeposition device mostly adopt a rod-shaped electrode structure, which will result in the presence of a close part (i.e., the opposite side) and a far part (i.e., the opposite side) between the cathode and the anode, which will lead to uneven distribution of the electric field in the electrolytic cell, thus causing electric field distortion. Due to the uneven distribution of the electric field, there is a direction with a higher reaction speed, and the generated UO 2 Due to the excessive thickness in a certain direction, it will fall into the molten salt. When collecting the product, it is necessary to dissolve the molten salt to separate UO 2 Products and molten salt, dissolving molten salt to separate UO 2 The production of products and molten salt is a complex process that requires a lot of work. Moreover, electric field distortion may also lead to safety issues such as local overheating, electric sparks, and even short circuits inside the electrolytic cell. Therefore, the present invention proposes a molten salt electrolyte isopole electrodeposition device to solve the problem of electric field distortion.

[0032] Example 1

[0033] See also Figure 1 The present invention discloses an electrodeposition device, including: a reaction component 2.

[0034] Among them, the reaction assembly 2 includes a cathode unit 22 and an anode unit 21, the cathode unit 22 is fixedly connected to the anode unit 21, and the anode unit 21 is electrically connected to the anode terminal. A reaction chamber is provided inside the anode unit 21, and the reaction chamber is filled with materials to be electrolyzed, and the materials to be electrolyzed include MOX spent fuel and molten salt electrolyte. The wall of the reaction chamber is electrically connected to the power supply anode to ensure that the current can be smoothly transmitted to the molten salt electrolyte. The cathode unit 22 includes a cathode rod 221, and the cathode rod 221 includes a reaction section, which is inserted into the reaction chamber, and the reaction section is electrically connected to the power supply cathode. The central axis of the reaction section is on the same extension line as the central axis of the reaction chamber, and the shape of the reaction section is adapted to the shape of the reaction chamber, and the distance from any position on the outer surface of the reaction section to the corresponding position on the inner wall of the reaction chamber is equal. In other words, the shortest distance from any two points on the outer surface of the reaction section to the side wall of the reaction chamber is equal, thereby making the electrolysis current density uniformly distributed.

[0035] It should be noted that the electrodeposition device in this embodiment is an equipolar electrodeposition device, which is suitable for dry post-processing of oxides in any scenario, and is particularly suitable for dry post-processing of molten salt electrolytes of spent fuel oxides (e.g., MOX spent fuel). Molten salt electrolyte refers to a salt substance that becomes liquid at high temperatures and can be used as a type of electrolyte. This electrolyte is usually in contact with a solid electrode at high temperature, and the ions of the electrolyte will move during the electrolysis process to complete the electrolysis reaction.

[0036] Specifically, during the electrodeposition reaction, the Reduction reaction occurs at the cathode to generate UO 2 When using the traditional rod cathode-rod anode electrode structure, due to the uneven distribution of the electric field, there are directions with higher reaction speeds and directions with lower reaction speeds, which will cause the electrolysis reaction rate in some areas to be too fast and in other areas to be too slow, thereby reducing the overall electrolysis efficiency. Especially for larger processing batches, the generated UO 2 Due to the excessive thickness in a certain direction, it will fall into the molten salt. When collecting the product, it is necessary to dissolve the molten salt to separate UO 2 Products and molten salt increase the workload a lot.

[0037] The electrodeposition device in this embodiment is an equipolar electrodeposition device, with a reaction crucible as the anode (i.e., anode crucible 211) and a reaction rod as the cathode (i.e., cathode rod 221). The distance between electrodes is equal everywhere, that is, by ensuring that the reaction section of the cathode rod 221 is adapted to the shape of the reaction chamber, and the central axes of the two are on the same extension line, the shortest distance from any two points on the outer surface of the reaction section to the side wall of the reaction chamber is equal. This design greatly promotes the uniform distribution of current density during the electrolysis process, avoids the problems of uneven electrolysis and current distortion caused by local overcurrent, thereby improving electrolysis efficiency and product quality. Furthermore, the UO at each part of the cathode (on the reaction section) is 2 The product has a relatively uniform thickness and can be attached to the cathode reaction rod (the reaction section) without falling off, making it easy to collect the product.

[0038] See also Figure 2 The reaction section includes a first extension portion and a first end portion, the first end portion is located below the first extension portion, the first extension portion extends in a vertical direction and is connected to the first end portion. The side wall of the reaction chamber includes a second extension portion and a second end portion, the second end portion is located below the second extension portion, the second extension portion extends in a vertical direction and is connected to the second end portion. The second extension portion surrounds the first extension portion, and the second end portion surrounds the second end portion. The central axes of the first extension portion and the first end portion are on the same extension line, and are on the same extension line as the central axes of the second extension portion and the second end portion.

[0039] Specifically, the first extension and the second extension are cylindrical, and the first end and the second end are hemispherical. Only by adopting a shape formed by a rotating body can it be ensured that the distance from the surface of the reaction section to the side wall of the reaction chamber is equal everywhere, and by setting the first end and the second end to a hemispherical shape, it helps to reduce the edge effect in the electrolysis process, that is, to reduce the phenomenon of increased current density caused by the concentration of electric field lines at the edge of the electrode. The principle of the edge effect is as follows: in common cylindrical cathodes and anodes, the current density reaches the maximum at the tip or edge portion. This is because the current tends to flow in the direction with the least resistance on the path, and at the edge or tip, due to the change in shape, a local high current density area is formed, which in turn affects the process of electrodeposition. The present electrodeposition device effectively avoids the appearance of tip portions of the cathode and anode by setting the first end and the second end to a hemispherical shape.

[0040] Therefore, the equipolar electrodeposition device in this embodiment can effectively avoid uncontrollable electric field distortion caused by an increase in processing volume.

[0041] It should be noted that the shortest distances from any two points on the outer surface of the reaction section to the side wall of the reaction chamber are equal, which means that two points are randomly selected from the outer surface of the reaction section, respectively set as the first point and the second point, the shortest distance from the first point to the side wall of the reaction chamber is the first distance, the shortest distance from the second point to the side wall of the reaction chamber is the second distance, and the first distance is equal to the second distance. It is worth noting that there are inevitably manufacturing errors in the production of the cathode rod 221 and the anode crucible 211. Therefore, the shortest distances from any two points on the outer surface of the reaction section to the side wall of the reaction chamber are equal, which should be understood as the difference between the first distance and the second distance is less than or equal to the preset error tolerance value. In this embodiment, the error tolerance value is 2mm.

[0042] See also Figure 2 In this embodiment, the cathode unit 22 further includes a conductive rod 222. A first cavity is provided inside the reaction section, and the first cavity extends along the axial direction of the reaction section. The conductive rod 222 is inserted into the first cavity, and a first powder layer 213 is filled between the first cavity and the conductive rod 222. The first powder layer 213 is made of a conductive material. One end of the conductive rod 222 is electrically connected to the cathode of the power supply, and the other end is conductively connected to the cathode rod 221 through the first powder layer 213.

[0043] In this embodiment, the cathode rod 221 and the first powder layer 213 are made of graphite powder. Of course, materials with good electrical conductivity such as copper powder can also be used. The conductive rod 222 can be made of materials with good electrical conductivity, such as copper. By filling conductive powder between the reaction rod (i.e., the cathode rod 221) and the conductive rod 222, when power is turned on, the current flows from the reaction rod through the conductive powder and the conductive rod 222 to the cathode of the power supply, and the current is distributed in the part filled with the conductive powder. The current distribution on the reaction rod is more uniform. For the reaction rod material with poor electrical conductivity, the loss of electric energy in the external circuit can also be reduced. The reason why the loss of electric energy in the external circuit can be reduced by filling conductive powder is that the current path through which the current is conducted from the conductive rod 222 to the cathode rod 221 is the shortest, and the current is only distributed in the part filled with graphite powder. The current path is more ideal, which greatly reduces the loss of the external circuit.

[0044] Please continue reading Figure 2, the anode unit 21 includes an anode crucible 211 and a conductive tube 212. The reaction chamber is the inner cavity of the anode crucible. The conductive tube 212 is electrically connected to the anode of the power supply, and the anode crucible 211 is accommodated in the conductive tube 212. A second powder layer 223 is filled between the conductive tube 212 and the anode crucible 211, and the second powder layer 223 is made of a conductive material. The conductive tube 212 is electrically connected to the anode crucible 211 through the second powder layer 223. In this embodiment, the anode crucible 211 and the second powder layer 223 can also be made of graphite material. The conductive tube 212 can be made of a material with good conductive properties and easy to process and shape, such as copper. The advantage of filling conductive powder between the anode crucible 211 and the conductive tube 212 is that graphite powder is filled between the anode graphite crucible and the conductive tube 212, so that when the anode crucible 211 assembly is powered on, the current flows through the graphite crucible in the shortest path. In addition, the flow of conductive powder at high temperature effectively compensates for the difference in thermal expansion and ensures good contact of the electrical path.

[0045] It can be seen that in this embodiment, the cathode rod 221, the anode crucible 211, the first (conductive) powder, and the second (conductive) powder are all made of graphite material. To be more specific, the reaction rod (cathode rod 221) is a carbon fiber woven composite material, which refers to a material woven from carbon fibers. The advantage of this material is that it has good electrical conductivity and chemical stability, and has high strength and modulus, and can withstand high loads.

[0046] The reaction crucible (anode crucible 211) is made of pyrolytic graphite material, which is high-temperature treated material with high purity and density. Pyrolytic graphite has high mechanical strength and can withstand large current density and mechanical stress during electrolysis, thus extending the service life of the anode. Pyrolytic graphite exhibits excellent corrosion resistance in a variety of environments, especially in acidic or alkaline molten salt electrolytes, and can work stably without being corroded or dissolved.

[0047] See also Figure 3 The reaction assembly 2 further includes a furnace cover 25, an air inlet pipe 23 and an exhaust pipe 24. The furnace cover 25 is installed at the upper end of the anode unit 21 to close the reaction chamber. The air inlet pipe 23 runs through the furnace cover 25. The air inlet pipe 23 extends vertically and extends downward into the material to be electrolyzed in the reaction chamber. The air inlet pipe 23 is used to fill the reaction chamber with reducing gas or inert gas. The exhaust pipe 24 runs through the furnace cover 25 and is connected to the reaction chamber.

[0048] Further, the furnace cover 25 is installed on the top of the anode crucible 211, specifically connected to the top of the anode crucible 211 through a sealing insulating member. The sealing insulating member can be made of insulating materials such as rubber. The furnace cover 25 is sealed and connected to the anode crucible 211 through the first insulating member 26. The advantage is that since the anode crucible 211 is conducting current, and the furnace cover 25 is a position that needs to be frequently disassembled and touched, for the health of the staff, it is necessary to set an insulating member to prevent the furnace cover 25 from being energized, thereby ensuring the personal safety of the staff when disassembling the furnace cover 25. The cathode rod 221 runs through the furnace cover 25, and the connecting section located at the upper end of the cathode rod 221 is sealed and connected to the furnace cover 25 through the second insulating member 27. The second insulating member 27 can also be made of insulating materials such as rubber. Similarly, since the cathode rod 221 is also conducting current, therefore, for the health of the staff, a cathode sealing member made of insulating material is also used to prevent the furnace cover 25 from being conductive.

[0049] Furthermore, the cathode rod 221 also includes a connecting section, which is located above the reaction section and connected to the reaction section, and the outer side wall of the connecting section is connected to the top of the anode unit 21, and the connecting section passes through the furnace cover 25 and is connected to the upper end of the anode unit 21 through the furnace cover 25. By providing the connecting section and connecting the connecting section to the upper end of the anode unit 21, it is convenient to disassemble and recycle the cathode rod 221. Moreover, by reserving the connecting section, the staff can easily disassemble and replace the conductive rod 222, the first powder layer 213, etc.

[0050] Furthermore, the connection between the furnace cover 25 and the anode crucible 211 is a quick clamping device (i.e., the clamping unit 3) of a lever structure, which is located on the shell 11 of the heating furnace 1, and a first insulating member 26 is installed between the furnace cover 25. The connection between the furnace cover 25 and the cathode rod 221 is a quick clamping device (i.e., the clamping unit 3) of a lever structure, which is located on the furnace cover 25, and a second insulating member 27 is installed between the quick clamping device and the cathode rod 221.

[0051] In other words, the connection between the anode crucible 211 assembly (i.e., the anode unit 21) and the cathode rod 221 assembly (i.e., the cathode unit 22) and the furnace cover 25 is a quick clamping device (i.e., the clamping unit 3) of a lever structure for clamping and fixing. It can be seen that the cathode rod 221 assembly is assembled with the furnace cover 25 as a whole. When recovering the cathode product, it is only necessary to lift out the cathode rod 221 assembly as a whole, without involving the disassembly and assembly of other components. The cathode rod 221 assembly and the furnace cover 25 are components that need to be disassembled frequently, and are fixed with a clamping device to facilitate disassembly and assembly and reduce the difficulty of operation. The structure of the clamping unit 3 is shown in FIG. Figure 4Specifically, the middle of the compression rod of the clamping device is the fulcrum (rotating axis) of the lever. When the bolt is tightened, the bolt extends to push up one end of the lever, and the other end presses down to clamp the two components. In this way, the two components are not directly connected by bolts, which can reduce the size of the equipment and facilitate insulation.

[0052] The sealing of the reaction chamber can be ensured by sealingly connecting the cathode rod 221, the anode crucible 211 and the furnace cover 25. The reaction chamber is filled with reducing gas (for example, chlorine, hydrogen, etc., which can provide the required electrons for the deposition process or reduce the activation energy of the reaction, thereby promoting the reduction deposition of metal ions on the cathode surface) and / or inert gas (for example, argon, helium, etc., which can prevent the electrolysis products from being oxidized in the air atmosphere).

[0053] For example, in this embodiment, in the first stage of the electrodeposition reaction, that is, from the beginning of power on to the appearance of obvious UO 2 During the stage between deposition layers, chlorine gas can be introduced into the reaction chamber through the gas inlet pipe 23 to accelerate the reduction reaction. In the second stage of the electrodeposition reaction, obvious UO 2 When depositing the layer, helium can be introduced into the reaction chamber through the air inlet pipe 23 to prevent the electrolysis products from being oxidized in the air atmosphere.

[0054] It should be noted that, in order to prevent the air intake pipe 23 from affecting the electrodeposition reaction, a graphite protective layer is installed on the outer wall of the air intake pipe 23, which effectively protects the air intake pipe 23 and keeps the air intake in the pipe. In other words, the outer side of the air intake pipe is coated with a graphite protective layer.

[0055] See also Figure 1 and Figure 3 In this embodiment, the device further includes a heating furnace 1, and the reaction component 2 is partially accommodated in the inner cavity of the heating furnace 1, and the heating furnace 1 is used to heat the reaction component 2. The reaction component 2 is heated by the heating furnace 1, such as in the electrodeposition treatment of MOX spent fuel, especially the molten salt electrolyte in the reaction chamber is heated and kept warm, so that the molten salt electrolyte is kept in a molten state. The heating furnace 1 can provide a stable and controllable temperature environment to ensure that the electrodeposition process is carried out under optimal conditions.

[0056] Specifically, the heating furnace 1 includes a shell 11, a heat-insulating layer 12 and a heating module 13. The heating module 13 is installed inside the shell 11 and surrounds the reaction component 2. The heating module 13 is used to heat the reaction component 2. The heat-insulating layer 12 is located between the shell 11 and the heating module 13, and is used to keep the heating module 13 and the reaction component 2 warm.

[0057] In other words, the heating module 13 is placed inside the insulation layer 12, the shell 11 is located outside the insulation layer 12, the upper part of the heating furnace 1 is open, the reaction container is placed at the upper opening of the heating furnace 1, and the heating furnace 1 is used to heat the reaction container (i.e., the reaction component 2). In addition, in order to improve the insulation effect of the heating furnace 1, an insulation layer 12 is also installed at the bottom of the furnace cover 25. In this embodiment, the insulation layer 12 is made of fiber insulation material. The insulation layer 12 is a fiber insulation material, which can be glass wool, rock wool, etc.

[0058] Among them, an air-cooling air inlet 14 is opened at the bottom of the heating furnace 1, and the air-cooling air inlet 14 is connected to the inner cavity of the heating furnace 1. An air-cooling exhaust port 15 is opened at the upper end of the side wall of the heating furnace 1, and the air-cooling exhaust port 15 is connected to the inner cavity of the heating furnace 1. The air-cooling air inlet 14 is used to supply air to the inner cavity of the heating furnace 1, and the air-cooling exhaust port 15 is used to exhaust air from the inner cavity of the heating furnace 1, so as to air-cool the reaction component 2.

[0059] In other words, the heating furnace 1 is also provided with an air cooling system, which includes an air cooling air inlet 14, an air cooling exhaust port 15 and a fan, the air inlet is connected to the fan, the air cooling air inlet 14 is located at the bottom of the heating furnace 1, and the air cooling exhaust port 15 is located at the upper part of the heating furnace 1. In other words, the lower end of the furnace cavity of the heating furnace 1 is connected to the air cooling air inlet 14, and the upper end of the furnace cavity is connected to the air cooling exhaust port 15.

[0060] During the electrodeposition process, the temperature in the heating furnace 1 needs to be maintained within a certain range to ensure the smooth progress of the electrodeposition reaction. The specific temperature range is 600-700°C. Preferably, it can be 600, 630, 650, 700°C.

[0061] However, a large amount of heat is generated during the heating process. If it is not dissipated in time, it may cause the temperature in the furnace to be too high, affecting the quality and efficiency of the electrodeposition. When the temperature in the furnace chamber of the heating furnace 1 is too high, cold air can be sent into the furnace chamber of the heating furnace 1 through the fan in the air cooling system, and the hot air can be discharged through the air cooling exhaust port 15, thereby effectively reducing the temperature in the furnace and helping the reaction component 2 to cool down to maintain a suitable temperature. In addition, after the electrodeposition process is completed, the heating furnace 1 stops heating first, and then the fan in the air cooling system is used to send cold air into the furnace chamber of the heating furnace 1 to help the reaction component 2 to cool down quickly.

[0062] In this embodiment, the device further includes a temperature measuring unit, a current unit and a controller. The temperature measuring unit is connected to the cathode unit 22 and is used to measure the temperature value of the cathode unit 22. Specifically, the temperature measuring unit can be a thermocouple 28, the top of the thermocouple 28 is connected to the top of the conductive rod 222, and is used to measure the temperature inside the conductive rod 222, thereby obtaining the temperature value inside the cathode unit 22.

[0063] The current unit is electrically connected to the anode unit 21 and the cathode unit 22, respectively, and is used to measure the current value between the anode unit 21 and the cathode unit 22. The controller is preset with a temperature threshold range (for example: 650-700°C) and a current threshold range. The controller is electrically connected to the temperature measuring unit and the current unit, respectively, and is used to receive the temperature value and send a first alarm signal when the temperature value exceeds the temperature threshold range; and the controller is also used to receive the current value between the anode unit 21 and the cathode unit 22, and send a second alarm signal when the current value exceeds the current threshold range.

[0064] The controller sends out a first alarm signal and a second alarm signal to remind the staff to manually adjust the current and temperature. In some embodiments, the controller can be electrically connected to the fan to send out a first alarm signal when the temperature value exceeds the temperature threshold range, and at the same time, control the fan to send cold air into the furnace cavity of the heating furnace 1 to help cool the furnace cavity.

[0065] In other words, the control system (i.e., the controller, temperature measuring unit, and current unit) is set to automatically shut down under abnormal conditions, including over-temperature alarm, current over-limit alarm, etc.

[0066] The controller may be a commercially available PLC (Programmable Logic Controller) control device or a PAC device (Programmable Automation Controller), or an industrial computer capable of interactive operation.

[0067] In summary, the electrodeposition device in this embodiment is a molten salt electrolyte equipolar electrodeposition device, and the electrodeposition device in this embodiment will be further described below in conjunction with the accompanying drawings.

[0068] See also Figures 1 to 3 The device comprises a heating furnace 1, a reaction container, a power supply and a control system. The power supply and control system adopt automatic and manual control modes.

[0069] See also Figure 1The reaction vessel is placed in a heating furnace 1, including an anode crucible 211 assembly connected to the anode of the power supply, a cathode rod 221 assembly connected to the cathode of the power supply, an air inlet pipe 23, an exhaust pipe 24, a furnace cover 25, a sealing member, and an insulating member, wherein the cathode rod 221 assembly is placed in the center of the reaction vessel, the anode crucible 211 assembly is placed on the outermost side, and the furnace cover 25 is placed above the anode crucible 211 assembly to ensure the sealing of the device; the upper end of the cathode rod 221 assembly is sealed and connected to the furnace cover 25 through a first insulating member 26 (or referred to as a cathode sealing member), and the furnace cover 25 is sealed and connected to the top of the anode crucible 211 assembly through a second insulating member 27 (or referred to as a sealing insulating member), the air inlet pipe 23, the exhaust pipe 24 are connected to the furnace cover 25, and the connection between the anode crucible 211 assembly and the cathode rod 221 assembly and the furnace cover 25 is a lever structure quick clamping unit 3 for clamping and fixing to further ensure the sealing of the device. The reaction vessel is filled with reducing and / or inert gas.

[0070] See also Figure 2 The heating furnace 1 includes a shell 11, an insulation layer 12, and a heating module 13. The insulation layer 12 is a fiber insulation material, the heating module 13 is placed inside the insulation layer 12, the shell 11 is located outside the insulation layer 12, the upper part of the heating furnace 1 is open, the reaction container is placed at the upper opening of the heating furnace 1, and the heating furnace 1 is used to heat the reaction container. The heating furnace 1 is provided with an air cooling system, the air cooling system includes an air cooling air inlet 14, an air cooling exhaust port 15 and a fan, the air inlet is connected to the fan, the air cooling air inlet 14 is located at the bottom of the heating furnace 1, and the air cooling exhaust port 15 is located at the upper part of the heating furnace 1.

[0071] See also Figure 3 The anode assembly includes a graphite crucible, a conductive cylinder 212, and graphite powder, wherein the conductive cylinder 212 is placed at the outermost side, and the graphite crucible is placed inside the conductive cylinder 212. The graphite crucible is in the shape of a cylindrical body with a hemispherical bottom, and contains molten salt electrolyte (NaCl-2CsCl). The graphite crucible and the conductive cylinder 212 are filled with graphite powder. The top of the graphite crucible and the top of the conductive cylinder 212 are connected via an insulating member, and the conductive cylinder 212 is connected to the anode terminal. When the power is turned on, the current flows from the conductive cylinder 212 through the graphite powder, through the graphite crucible, and into the molten salt.

[0072] See also Figure 3 The cathode assembly includes a graphite rod, a conductive rod 222, and graphite powder. The graphite rod is in the shape of a cylindrical body with a hemispherical bottom. The hemispherical end is immersed in molten salt, and the bottom is filled with graphite powder. The conductive rod 222 is placed in the graphite rod. The top of the graphite rod is connected to the top of the conductive rod 222 through an insulating member. A thermocouple 28 is placed in the conductive rod 222 for temperature measurement. The top of the thermocouple 28 is connected to the top of the conductive rod 222. The conductive rod 222 is inserted into the graphite powder and connected to the cathode of the power supply. When the power is turned on, the current flows from the molten salt into the graphite rod, and then vertically passes through the graphite powder and flows into the conductive rod 222.

[0073] The bottom hemisphere of the graphite crucible is concentric with the bottom hemisphere of the graphite rod, which ensures that the distance between the anode and the cathode is the same everywhere, the electrolysis current density is evenly distributed, and the cathode product thickness is uniform.

[0074] The furnace cover 25 is the sealing boundary of the reaction vessel, on which the cathode rod 221 assembly, the air inlet pipe 23, the exhaust pipe 24, the thermocouple 28, etc. need to be arranged. The air inlet pipe 23 is equipped with a graphite protective layer to keep the air in the pipe continuously, prevent the molten salt from flowing back, and effectively protect the air inlet pipe 23.

[0075] The cathode rod 221 assembly is assembled with the furnace cover 25 as a whole. When the cathode product is recovered, only the cathode rod 221 assembly needs to be lifted out as a whole, without involving the disassembly and assembly of other components. The cathode rod 221 assembly and the furnace cover 25 are parts that need to be disassembled frequently, and are fixed by the clamping unit 3, which is convenient for disassembly and assembly and reduces the difficulty of operation.

[0076] In order to ensure that the atmosphere in the device does not overflow, seals are provided between the furnace cover 25 assembly and the components of the anode crucible 211 assembly, and between the anode assembly and the heating furnace 1. In order to achieve effective isolation between the cathode and anode and ensure the effectiveness of the conductive circuit, insulating parts are provided to insulate the cathode assembly and the anode assembly, and the cathode conductive cylinder 212 and the graphite rod.

[0077] The following will be combined with the attached Figure 1 The specific working process of the electrodeposition device is described as follows:

[0078] Before starting the electrodeposition reaction, the pre-treated (i.e., removing the cladding and crushing) MOX spent fuel and molten salt electrolyte (NaCl-2CsCl) are first placed in the reaction chamber of the anode crucible 211. The MOX spent fuel and molten salt electrolyte in the anode crucible 211 are heated to 630-650° C. by the heating furnace 1. Then, the anode crucible 211 is connected to the anode terminal of the power supply, and the cathode rod 221 is connected to the cathode terminal of the power supply.

[0079] During the electrodeposition reaction, the Reduction reaction occurs at the cathode to generate UO 2 When the traditional rod cathode-rod anode electrode structure is used, due to the uneven distribution of the electric field, there is a direction with a higher reaction rate, and the generated UO 2 Due to the excessive thickness in a certain direction, it will fall into the molten salt. When collecting the product, it is necessary to dissolve the molten salt to separate UO 2 The equipolar electrodeposition device of the present invention is used, with the reaction crucible as the anode and the reaction rod as the cathode. The distance between electrodes at each location is equal, and the UO at each location of the cathode is 2The product has a relatively uniform thickness and can be attached to the cathode reaction rod without falling, making it easy to collect the product. For larger processing batches, the degree of electric field distortion of the rod-shaped electrode structure will increase. The equipolar electrodeposition device of the present invention can effectively avoid uncontrollable electric field distortion caused by increased processing volume.

[0080] The beneficial effects of the electrodeposition device with equal electrode spacing in this embodiment are:

[0081] 1. A conductive rod 222 with a smaller diameter is coaxially installed in the cathode reaction rod, and conductive powder (i.e. graphite powder) is filled between the reaction rod and the conductive rod 222. When power is turned on, the current flows from the reaction rod through the conductive powder and the conductive rod 222 to the cathode of the power supply. The current is distributed in the part filled with the conductive powder. The current distribution on the reaction rod is more uniform. For the reaction rod material with poor conductivity, the loss of electric energy in the external circuit can also be reduced. This is because the current path through which the current is conducted from the conductive rod 222 to the cathode rod 221 is the shortest, and the current is only distributed in the part filled with graphite powder. The current path is more ideal, which greatly reduces the loss of the external circuit.

[0082] 2. Conductive powder is filled between the anode reaction crucible and the conductive tube 212. When power is turned on, the current flows from the conductive tube 212 through the conductive powder into the reaction crucible, and the current is distributed in the part filled with the conductive powder, so that the current distribution in the reaction crucible is more uniform. For reaction crucible materials with poor conductivity, the loss of electric energy in the external circuit can also be reduced. This is because graphite powder is filled between the anode graphite crucible and the conductive tube 212, so that when power is turned on at the anode crucible 211 assembly, the current flows through the graphite crucible in the shortest path. In addition, the flow of conductive powder at high temperature effectively compensates for the difference in thermal expansion and ensures good contact of the electrical path.

[0083] 3. The distance between the anode and cathode is the same everywhere, the electrolysis current density is evenly distributed, the cathode product thickness is uniform, and the reaction is highly controllable.

[0084] 4. The reaction vessel is heated in the heating furnace 1 by the heating module 13 . The heating module 13 is cylindrical, which ensures that the reaction vessel is heated evenly.

[0085] 5. In the present invention, the connection between the anode crucible 211 assembly and the cathode rod 221 assembly and the furnace cover 25 is a quick clamping unit 3 of a lever structure, which is easy to disassemble and reduce the risk of short circuit between the anode and cathode.

[0086] 6. The air intake pipe 23 is wrapped with a layer of graphite tube, and the air intake in the pipe is kept continuously, so as to prevent the molten salt from flowing back and effectively protect the air intake pipe 23.

[0087] Example 2

[0088] The present invention also discloses an electrolytic treatment system, comprising a power supply and the electrodeposition device in Example 1, wherein the power supply comprises an anode terminal and a cathode terminal, the anode terminal is electrically connected to the anode unit 21 of the electrodeposition device, and the cathode terminal is electrically connected to the cathode unit 22 of the electrodeposition device. The electrodeposition device is used for electrolytic treatment of MOX spent fuel.

[0089] Specifically, the electrodeposition device includes a heating furnace 1, a reaction vessel (i.e., a reaction component 2), a power supply and a control system (i.e., a controller). The heating furnace 1 includes a heating module 13, an insulation layer 12 and a shell 11, and the heating furnace 1 is used to heat the reaction vessel (i.e., the reaction component 2). The reaction vessel includes an anode crucible 211 component (i.e., an anode unit 21) connected to the anode of the power supply, a cathode rod 221 component (i.e., a cathode unit 22) connected to the cathode of the power supply, an air inlet pipe 23, an exhaust pipe 24, a furnace cover 25, a sealing member and an insulating member. The upper end of the cathode rod 221 component is connected to the furnace cover 25 through an insulating member, and the furnace cover 25 is connected to the top of the anode crucible 211 component through an insulating member. The anode crucible 211 component includes a graphite crucible (i.e., an anode crucible 211), a conductive cylinder 212 and graphite powder. The top of the graphite crucible and the top of the conductive cylinder 212 are connected through an insulating member. The graphite powder is located between the graphite crucible and the conductive cylinder 212. The shape of the graphite crucible is a cylindrical body with a hemispherical bottom. The molten salt electrolyte is placed in a graphite crucible, and the conductive cylinder 212 is connected to the anode of the power supply. The cathode rod 221 assembly includes a graphite rod, a conductive rod 222 and graphite powder. The top of the graphite rod and the top of the conductive rod 222 are connected via an insulating member. The graphite powder is located between the graphite rod and the conductive rod 222. The graphite rod is in the shape of a cylindrical cylinder with a hemispherical bottom. The conductive rod 222 is connected to the cathode of the power supply. The bottom hemisphere of the graphite crucible is concentric with the bottom hemisphere of the graphite rod. The distance between the anode and the cathode of the device is the same everywhere, the electrolysis current density is evenly distributed, and the thickness of the cathode product is even.

[0090] The present electrolytic treatment system, by adopting the electrodeposition device in Example 1, can effectively reduce the electric field distortion in the molten salt electrolyte, thereby improving the controllability of the electrolytic reaction and improving the subsequent product quality.

[0091] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. An electrodeposition device, characterized in that: include: React Components (2); The reaction assembly (2) comprises a cathode unit (22) and an anode unit (21); The anode unit (21) has a reaction chamber inside, the reaction chamber contains a material to be electrolyzed, the wall of the reaction chamber is electrically connected to the anode of the power supply, the cathode unit (22) comprises a cathode rod (221), the cathode rod (221) comprises a reaction section, the reaction section is inserted into the reaction chamber and contacts the material to be electrolyzed, and the reaction section is electrically connected to the cathode of the power supply; The central axis of the reaction section and the central axis of the reaction chamber are on the same extension line, and the shape of the reaction section is adapted to the shape of the reaction chamber, and the distance from any position on the outer surface of the reaction section to the corresponding position on the inner wall of the reaction chamber is equal.

2. The electrodeposition device according to claim 1, characterized in that: The cathode unit (22) further includes a conductive rod (222), A first cavity is provided inside the reaction section, and the first cavity extends along the axial direction of the reaction section; The conductive rod (222) is inserted into the first cavity, a first powder layer (213) is filled between the first cavity and the conductive rod (222), the first powder layer (213) is made of a conductive material, one end of the conductive rod (222) is electrically connected to the cathode of the power supply, and the other end is conductively connected to the cathode rod (221) through the first powder layer (213).

3. The electrodeposition device according to claim 2, characterized in that: The anode unit (21) comprises an anode crucible (211) and a conductive cylinder (212), and the reaction cavity is the inner cavity of the anode crucible (211); The conductive cylinder (212) is electrically connected to the anode of the power supply, and the anode crucible (211) is accommodated in the conductive cylinder (212); A second powder layer (223) is filled between the conductive tube (212) and the anode crucible (211), the second powder layer (223) is made of a conductive material, and the conductive tube (212) is electrically connected to the anode crucible (211) through the second powder layer (223).

4. The electrodeposition device according to any one of claims 1 to 3, characterized in that: The reaction section includes a first extension portion and a first end portion, wherein the first end portion is located below the first extension portion, and the first extension portion extends in a vertical direction and is connected to the first end portion; The side wall of the reaction chamber includes a second extension portion and a second end portion, the second end portion is located below the second extension portion, and the second extension portion extends in a vertical direction and is connected to the second end portion; The second extending portion surrounds the first extending portion, and the second end portion surrounds the second end portion.

5. The electrodeposition device according to claim 4, characterized in that: The first extension portion and the second extension portion are cylindrical, and the first end portion and the second end portion are semi-spherical.

6. The electrodeposition device according to claim 1, characterized in that: The reaction assembly (2) further comprises a furnace cover (25), an air inlet pipe (23) and an exhaust pipe (24); the furnace cover (25) is mounted on the upper end of the anode unit (21) and is used to close the reaction chamber; the air inlet pipe (23) passes through the furnace cover (25); the air inlet pipe (23) extends in a vertical direction and extends downward into the material to be electrolyzed in the reaction chamber; the air inlet pipe (23) is used to fill the reaction chamber with reducing gas or inert gas; The exhaust pipe (24) passes through the furnace cover (25) and is communicated with the reaction chamber.

7. The electrodeposition device according to claim 6, characterized in that: The cathode rod (221) further comprises a connecting section, which is located above the reaction section and connected to the reaction section, and the connecting section passes through the furnace cover (25) and is connected to the upper end of the anode unit (21) through the furnace cover (25).

8. The electrodeposition device according to claim 6, characterized in that: The outer side of the air intake pipe (23) is coated with a graphite protective layer.

9. The electrodeposition device according to claim 1, characterized in that: It also comprises a heating furnace (1), wherein the reaction component (2) is partially accommodated in an inner cavity of the heating furnace (1), and the heating furnace (1) is used to heat the reaction component (2).

10. The electrodeposition device according to claim 9, characterized in that: The heating furnace (1) comprises a shell (11), a heat-insulating layer (12) and a heating module (13); the heating module (13) is installed inside the shell (11) and surrounds the reaction component (2); the heating module (13) is used to heat the reaction component (2). The heat-insulating layer (12) is located between the shell (11) and the heating module (13), and is used to keep the heating module (13) and the reaction component (2) warm.

11. The electrodeposition device according to claim 9, characterized in that: The bottom of the heating furnace (1) is provided with an air-cooling air inlet (14), and the air-cooling air inlet (14) is connected to the inner cavity of the heating furnace (1). The upper end of the side wall of the heating furnace (1) is provided with an air-cooling exhaust port (15), and the air-cooling exhaust port (15) is connected to the inner cavity of the heating furnace (1). The air-cooling air inlet (14) is used to supply air to the inner cavity of the heating furnace (1), and the air-cooling exhaust port (15) is used to exhaust air from the inner cavity of the heating furnace (1), thereby air-cooling the reaction component (2).

12. The electrodeposition device according to claim 11, characterized in that: It also includes a temperature measuring unit, a current unit and a controller; The temperature measuring unit is connected to the cathode unit (22) and is used to measure the temperature value of the cathode unit (22); the current unit is electrically connected to the anode unit (21) and the cathode unit (22) respectively and is used to measure the current value between the anode unit (21) and the cathode unit (22); The controller is preset with a temperature threshold range and a current threshold range, and the controller is electrically connected to the temperature measuring unit and the current unit respectively, for receiving the temperature value, and issuing a first alarm signal when the temperature value exceeds the temperature threshold range; and The controller is also used to receive the current value between the anode unit (21) and the cathode unit (22), and to issue a second alarm signal when the current value exceeds a current threshold range.

13. The electrodeposition device according to claim 1, characterized in that: The materials to be electrolyzed include MOX spent fuel and molten salt electrolyte.

14. An electrolytic treatment system, characterized in that: The invention comprises a power source and the electrodeposition device according to any one of claims 1 to 13, wherein the power source comprises an anode terminal and a cathode terminal, wherein the anode terminal is electrically connected to an anode unit (21) of the electrodeposition device, and the cathode terminal is electrically connected to a cathode unit (22) of the electrodeposition device, and the electrodeposition device is used for electrolyzing MOX spent fuel.

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