Liquid metal collecting system of rare earth molten salt electrolytic furnace

Abstract

The present application relates to rare earth electrolysis technical field, specifically to a rare earth molten salt electrolysis furnace liquid metal collecting system, comprising a molten salt electrolysis tank, a receiver is arranged at the bottom of the molten salt electrolysis tank, a cathode rod is arranged in the molten salt electrolysis tank above the receiver, a cavity is arranged in the cathode rod, an opening is arranged on the lower end surface of the cathode rod, the cavity is connected with the outside through the opening, a valve structure for plugging the opening is arranged in the cavity, a mold is arranged in a box, the inside of the box is connected with a negative pressure device through a pipeline B, the box is vacuumized through the negative pressure device, a negative pressure is formed in the cavity, the valve structure moves downward under the action of the negative pressure to open the opening, the liquid metal gathered in the receiver flows into the mold in the box through the opening, the cavity and a pipeline A under the action of the pressure difference, the whole collecting process only needs to move the cathode rod downward to suck into the receiver, the discharging operation time is greatly shortened, the electrolysis production efficiency is improved, and the electrolysis tank downtime is reduced.

Description

Technical Field

[0001] This invention relates to the field of rare earth electrolysis technology, specifically to a liquid metal collection system for rare earth molten salt electrolysis furnaces. Background Technology

[0002] Molten salt electrolysis is a metal refining technology that uses molten salt as the electrolyte. Its principle is that metal ions are reduced and precipitated at the cathode under the action of direct current to form liquid metal.

[0003] The cathode of the rare earth molten salt electrolytic cell is a solid D90-110X750mm tungsten rod. The precipitated liquid metal is discharged from the cell in two ways: clamping and scooping. In both ways, the current is turned off when discharging. The solid tungsten cathode is pushed from the center of the electrolytic cell to the edge of the cell. Then, clamps are used to lift the metal collector filled with liquid metal from the bottom of the electrolytic cell to the furnace platform. Then, the clamps are rotated 90 degrees to pour the liquid metal into the mold. Alternatively, a titanium spoon is used to scoop the liquid metal from the metal collector at the bottom of the electrolytic cell and pour it into the mold.

[0004] The above operation has the following drawbacks: First, the process of unloading the precipitated liquid metal requires a power outage and production stoppage, which disrupts the stable high-temperature process environment inside the electrolytic cell, significantly reduces electrolytic production efficiency, and also wastes additional electrical energy used to reheat and restore operating conditions.

[0005] Secondly, the operation involves many steps, such as pushing the cathode, lifting the collector, and manually scooping out the casting, which is labor-intensive and poses a high risk to the safety of the workers, as the operators are in close contact with the high-temperature molten electrolyte and metal.

[0006] Third, repeatedly moving the cathode and repeatedly opening and closing the furnace will cause temperature fluctuations in the electrolytic cell, accelerate the erosion and wear of the refractory lining, and shorten the overall service life of the electrolytic cell.

[0007] Fourth, during the unloading process, the liquid metal and molten electrolyte are exposed to air for a long time, which can easily lead to oxidation, reduce the yield of metal products, and affect the purity of the final product. Summary of the Invention

[0008] To address the aforementioned technical problems, this invention provides a liquid metal collection system for rare earth molten salt electrolysis furnaces. The technical problem it solves is that the process of unloading the precipitated liquid metal requires a power outage and production halt, significantly reducing electrolysis production efficiency. The technical solution adopted by this invention to solve the above-mentioned technical problems is as follows: A liquid metal collection system for a rare earth molten salt electrolysis furnace includes: Molten salt electrolytic cell; The receiver is located at the bottom of the molten salt electrolysis cell; The cathode rod is located inside the molten salt electrolysis cell above the receiver; The cavity is located inside the cathode rod; The opening is located on the lower end face of the cathode rod, and the cavity is connected to the outside through the opening; A valve structure for sealing the opening, the valve structure is located inside the cavity; Pipeline A and the housing: One end of pipeline A is connected to the cathode rod and communicates with the cavity, while the other end is connected to the inside of the housing. The mold is located inside the box at the lower part of the outlet of pipe A; Negative pressure device and pipeline B; the negative pressure device is connected to the inside of the box through pipeline B. It is also equipped with a lifting device for driving the cathode rod to move up and down.

[0009] Furthermore, the receiver is a molybdenum pot, which is fixedly installed at the bottom of the molten salt electrolysis cell.

[0010] Furthermore, the upper part of the mouth is designed with a trumpet-shaped structure; The valve structure includes a valve body that is adapted to the shape of the bell mouth structure. A guide post is fixedly connected to the upper part of the valve body. A mounting seat is sleeved on the outside of the guide post. The mounting seat is located in the cavity and connected to the inner wall of the cathode rod. The mounting seat is provided with a flow groove. A spring is sleeved on the guide post between the mounting seat and the valve body.

[0011] Furthermore, the spring is a ceramic spring.

[0012] Furthermore, a cylindrical cavity is provided at the lower part of the flared structure; A column is fixedly installed at the lower part of the valve body, which slides with the cylindrical cavity, and the lower part of the column extends to the outside of the cathode rod.

[0013] Furthermore, the upper part of the cavity is designed with a frustum structure.

[0014] Furthermore, the side wall of the box has an opening, and the box at the opening is equipped with a sealed door.

[0015] Furthermore, the negative pressure device is a vacuum pump.

[0016] The beneficial effects of this invention are as follows: The valve structure is opened by the suction of the negative pressure device, and the liquid metal is drawn into the pipeline A through the inlet and cavity, and then into the mold. This greatly shortens the furnace exit time, improves the efficiency of electrolytic production, reduces the downtime of the electrolytic cell, reduces the heat loss of the electrolytic cell, improves the current efficiency, and greatly reduces manual operation and unnecessary risks. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the planar structure of the present invention; Figure 2 This is a schematic diagram of the cathode rod and valve structure of the present invention; Figure 3 This is a schematic diagram of the cross-sectional structure of the cathode rod of the present invention; Figure 4 This is a three-dimensional schematic diagram of the valve structure of the present invention; Figure 5 This is a schematic diagram of the internal structure of the box of the present invention; In the picture: 1. Molten salt electrolytic cell; 2. Receiver; 3. Cathode rod; 4. Cavity; 5. Mouth; 51. Trumpet-shaped structure; 52. Cylindrical cavity; 6. Valve structure; 61. Valve body; 62. Guide column; 63. Mounting base; 64. Flow channel; 65. Spring; 7. Lifting device; 8. Pipeline A; 9. Box; 10. Mold; 11. Negative pressure device; 12. Column; 13. Sealing door; 14. Pipeline B; 15. Support plate; 16. Vacuum motor; 17. Lead screw. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will now be described in further detail with reference to the accompanying drawings and the following embodiments, so that the public can better understand the implementation method of this invention. The specific implementation scheme of this invention is as follows: Example 1 A liquid metal collection system for a rare earth molten salt electrolysis furnace, characterized in that it includes a molten salt electrolysis cell 1, a receiver 2 at the bottom of the molten salt electrolysis cell 1, a cathode rod 3 inside the molten salt electrolysis cell 1 above the receiver 2, a cavity 4 inside the cathode rod 3, an opening 5 at the lower end of the cathode rod 3, the cavity 4 being connected to the outside through the opening 5, a valve structure 6 for sealing the opening 5 being installed inside the cavity 4, the upper part of the cavity 4 extending to the outer surface of the cathode rod 3, one end of a pipe A8 being connected to the cathode rod 3 and communicating with the cavity 4, the other end being connected to the inside of a housing 9, a mold 10 being installed inside the housing 9, the mold 10 being located below the outlet of pipe A8, and the inside of the housing 9 being connected to a negative pressure device 11 through pipe B14. The connection is established by evacuating the chamber 9 through the negative pressure device 11, creating a negative pressure inside the cavity 4. Under the action of the negative pressure, the valve structure 6 moves downward, opening the port 5. The liquid metal collected in the receiver 2 flows into the mold 10 inside the chamber 9 through the port 5, the cavity 4, and the pipeline A8 under the action of the air pressure difference. After the metal collection is completed, the negative pressure device 11 is closed, the valve structure 6 loses the negative pressure suction and resets, resealing the port 5. The entire collection process only requires moving the cathode rod 3 downward to insert it into the receiver 2 to absorb the metal, which greatly shortens the furnace operation time, improves the electrolysis production efficiency, reduces the downtime of the electrolytic cell, reduces the heat loss of the electrolytic cell, improves the current efficiency, and greatly reduces manual operation, reducing unnecessary risks.

[0019] Specifically, receiver 2 is a molybdenum pot, which is fixedly installed at the bottom of molten salt electrolysis cell 1. This fixes the molybdenum pot to the bottom of the furnace, preventing it from being frequently lifted out. This avoids stress fatigue of the molybdenum pot during hot and cold cycles, while also reducing oxidation loss from contact with air at high temperatures, thus extending the service life of the molybdenum pot.

[0020] It should be noted that the upper part of the opening 5 is provided with a flared structure 51, and the valve structure 6 includes a valve body 61 that is adapted to the shape of the flared structure 51. The enlarged structure of the flared opening can increase the inlet area of ​​the liquid metal entering the cavity 4 and reduce the flow resistance. At the same time, the valve body 61 with the adapted shape can achieve a better fit and sealing effect, preventing the liquid metal from accidentally flowing into the cavity when not collected, and improving the sealing performance of the entire valve structure 6.

[0021] A guide post 62 is fixedly connected to the upper part of the valve body 61. A mounting seat 63 is slidably sleeved on the outside of the guide post 62. The mounting seat 63 is set in the cavity 4 and fixed or threadedly connected to the inner side wall of the cathode rod 3. The mounting seat 63 is provided with a flow groove 64 to facilitate the passage of liquid metal through the mounting seat 63. A spring 65 is sleeved on the guide post 62 between the mounting seat 63 and the valve body 61. The spring 65 pushes the valve body 61 to press against the flared structure 51 for sealing. When a negative pressure is formed in the cavity 4, the valve body 61 moves upward against the spring 65, driving the guide post 62 to slide upward along the mounting seat 63, so that the valve body 61 is separated from the flared structure 51, and the opening 5 opens to collect the liquid metal. The structure is simple and reliable, and the valve structure can be automatically opened and closed without additional power.

[0022] Furthermore, spring 65 is a ceramic spring, which can adapt to the high-temperature environment inside cavity 4.

[0023] It should be noted that the lower part of the flared structure 51 has a cylindrical cavity 52, and the lower part of the valve body 61 is fixedly provided with a column 12 that slides with the cylindrical cavity 52 with a clearance, and the lower part of the column 12 extends to the outside of the cathode rod 3. The above design can avoid the absorption of electrolyte.

[0024] The valve body 61, guide post 62, mounting base 63 and post 12 can all be made of molybdenum.

[0025] The upper part of the cavity 4 is set in a frustum structure 41, and the diameter of the frustum structure gradually decreases from top to bottom. This structure can guide and gather the liquid metal flowing in the cavity, making it easier for the liquid metal to gather along the side wall of the cavity 4 into the channel, and then flow into the pipe A from the channel, reducing the residue of liquid metal in the cavity.

[0026] It should be noted that one end of the channel is connected to the upper end of the frustum structure 41, and the other end extends to the upper end face of the cathode rod 3. A connecting joint is fixedly installed on the upper end face of the cathode rod 3 outside the channel. The connecting joint is plugged into and plugged into the pipeline A8. The pipeline A8 can be a molybdenum tube.

[0027] Specifically, the side wall of the box 9 has an opening, and the box 9 at the opening is equipped with a sealing door 13. The operator can open the sealing door 9 to take out the cooled metal ingot, while maintaining the overall sealing performance of the box and ensuring that the negative pressure collection process is stable.

[0028] The negative pressure device 11 specifically employs a vacuum pump, which can stably provide the negative pressure suction required to collect liquid metal.

[0029] It is also equipped with a lifting device 7 for driving the cathode rod 3 to move up and down. The lifting device 7 is existing technology, such as the cathode lifting device of rare earth molten salt electrolysis furnace with application number CN202421084505.6 of our company.

[0030] It should be noted that pipe A8 extends into the housing 9, and a sealing ring is installed at the connection between the two to reduce air leakage into the housing 9 and ensure stable negative pressure inside the housing. The lifting device 7 is fixedly connected to the side of pipe A8 near the cathode rod 3 by a clamp. When the lifting device 7 moves the cathode rod 3, pipe A8 can also move up and down accordingly, and at the same time, pipe A8 can slide relative to the housing 9.

[0031] The working principle and process of Embodiment 1 of the present invention are as follows: During operation, the molten salt electrolysis process proceeds normally. Under the action of electrolysis, the liquid metal is deposited on the cathode rod 3 and gradually gathers and falls into the bottom molybdenum pot 2. When it is necessary to collect the metal, it is only necessary to turn on the lifting device 7 to move the cathode rod 3 downward, so that the lower end of the cathode rod 3 is inserted into the liquid metal in the receiver 2. Then, the negative pressure device 11 is turned on to draw the inside of the box 9 and the cavity 4 to a vacuum through the pipeline B14, thereby forming a negative pressure inside. The valve body 61 moves upward against the elastic force of the ceramic spring 65 and disengages from the flared structure 51. The opening 5 opens, and the liquid metal in the molybdenum pot 2 flows into the mold 10 in the box 9 through the opening 5, the cavity 4, and the pipeline A8 under the action of the air pressure difference.

[0032] After the mold 10 has collected a sufficient amount of liquid metal, the negative pressure device 11 is turned off, the sealing door 13 is opened, the negative pressure inside the cavity 4 disappears, the ceramic spring 65 pushes the valve body 61 and the column 12 to reset downwards, re-attach the sealing horn structure and the cylindrical cavity 52, close the opening 5, and then the lifting device drives the cathode rod 3 to reset back to the electrolysis position.

[0033] Example 2 Since one mold 10 cannot meet the load-bearing capacity of liquid metal, the negative pressure device 11 needs to be stopped multiple times, the sealing door 13 needs to be opened, the mold 10 needs to be switched, and the collection operation needs to be carried out again. The entire collection process is interrupted, which will prolong the operation time and require the vacuuming operation of the box 9 to be carried out again, reducing the operation efficiency.

[0034] To solve the above technical problems, a slide is provided inside the housing 9. The slide is equipped with a tray 15 by sliding. At least two molds 10 are placed on the upper surface of the tray 15. A power mechanism is also provided to drive the tray 15. The power mechanism can drive the tray 15 to move different molds 10 below the outlet of the pipeline A8, and can also drive the tray 15 to the opening. The opening is opened on the upper surface of the housing 9 on the side of the outlet of the pipeline A8.

[0035] Specifically, the power mechanism includes a vacuum motor 16, and a lead screw 17 is fixedly connected to the output shaft of the vacuum motor 16. The lead screw 17 is connected to the support plate 15 by a thread, and the support plate 15 is slidably engaged with the slide rail. The vacuum motor 16 drives the lead screw 17 to rotate, which in turn drives the support plate 15 to move horizontally along the slide rail.

[0036] The enclosure 9 is equipped with a transparent window, which is located on the side of the enclosure 9 to facilitate observation of the interior.

[0037] The beneficial effects are as follows: the mold 10 can be switched via the power mechanism without opening the sealed door 13, eliminating the need to repeatedly start and stop the negative pressure device and repeatedly vacuum, further shortening the operation time and improving the collection efficiency. Simultaneously, the opening is located at the top of the box 9, making it convenient for workers to retrieve the cooled finished metal ingots, making the operation more convenient and safer. The remaining structures and beneficial effects of this embodiment are consistent with Embodiment 1, and will not be repeated here.

[0038] The working principle and process of Embodiment 2 of the present invention are as follows: The loading status of mold 10 can be observed through the transparent window. When the first mold 10 is full, the vacuum motor 16 is started. The vacuum motor 16 drives the lead screw 17 to rotate. Since the lead screw 17 is threadedly connected to the support plate 15, it drives the support plate 15 to move along the slide, moving the next empty mold 10 to below the outlet of pipeline A8, and continuing the collection operation.

[0039] The full mold 10 can be moved to the opening position with the pallet 15, and the operator can take out the full mold 10 and replace it with a special clamp.

[0040] In the description of this invention, it should be understood that the terms "center," "upper," "lower," "left," "right," "front," "rear," "lower left," "upper right," "outer," "clockwise," and "counterclockwise," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the scope of protection of this invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Although the invention has been described according to a limited number of embodiments, those skilled in the art should understand from the above description that other embodiments are conceived within the scope of the invention described herein.

Claims

1. A liquid metal collection system for a rare earth molten salt electrolysis furnace, characterized in that, include: Molten salt electrolyzer (1); Receiver (2), which is located at the bottom of the molten salt electrolysis cell (1); Cathode rod (3), which is set in the molten salt electrolysis cell (1) above the receiver (2); Cavity (4), which is located inside cathode rod (3); The opening (5) is located on the lower end face of the cathode rod (3), and the cavity (4) is connected to the outside through the opening (5); A valve structure (6) for sealing the opening (5) is provided inside the cavity (4); Pipeline A (8) and box (9). One end of pipeline A (8) is connected to the cathode rod (3) and communicates with the cavity (4), and the other end is connected to the inside of the box (9). Mold (10), mold (10) is set inside box (9); Negative pressure device (11) and pipeline B (14). Negative pressure device (11) is connected to the inside of box (9) through pipeline B (14). It is also equipped with a lifting device (7) for driving the cathode rod (3) to move up and down.

2. The rare earth molten salt electrolysis furnace liquid metal collection system according to claim 1, characterized in that: The receiver (2) is a molybdenum pot, which is fixedly installed at the bottom of the molten salt electrolysis tank (1).

3. The liquid metal collection system for a rare earth molten salt electrolysis furnace according to claim 1, characterized in that: The upper part of the mouth (5) is set in a trumpet-shaped structure (51); The valve structure (6) includes a valve body (61) that is adapted to the shape of the bell mouth structure (51). A guide post (62) is fixedly connected to the upper part of the valve body (61). A mounting seat (63) is sleeved on the outside of the guide post (62). The mounting seat (63) is located in the cavity (4) and connected to the inner side wall of the cathode rod (3). A flow groove (64) is provided on the mounting seat (63). A spring (65) is sleeved on the guide post (62) between the mounting seat (63) and the valve body (61).

4. The liquid metal collection system for a rare earth molten salt electrolysis furnace according to claim 3, characterized in that: The spring (65) is a ceramic spring.

5. The liquid metal collection system for a rare earth molten salt electrolysis furnace according to claim 3, characterized in that: The lower part of the flared structure (51) has a cylindrical cavity (52); A column (12) is fixedly installed at the lower part of the valve body (61) and slides with the cylindrical cavity (52) with clearance, and the lower part of the column (12) extends to the outside of the cathode rod (3).

6. The liquid metal collection system for a rare earth molten salt electrolytic furnace according to claim 1, characterized in that: The upper part of the cavity (4) is set in a frustum structure (41).

7. The liquid metal collection system for a rare earth molten salt electrolysis furnace according to claim 1, characterized in that: The side wall of the box (9) has an opening, and the box (9) at the opening is equipped with a sealing door (13).

8. The liquid metal collection system for a rare earth molten salt electrolysis furnace according to claim 1, characterized in that: The negative pressure device (11) is a vacuum pump.

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