Method and system for filtering and precipitating rare earth dust
By adopting the design of a stirring tank, separation tank and multi-layer overflow structure in the rare earth dust recovery system, the precipitation problem of carbides and adhesives in rare earth dust is solved, and the recycling purity and efficiency are improved.
Patent Information
- Application Number
- CN202510178828.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-18
- Publication Date
- 2025-06-03
AI Technical Summary
In the existing rare earth dust recovery technology, carbides and binders precipitate together with rare earth dust, resulting in a large amount of carbides in the recovered rare earth dust, affecting its purity. In addition, the single-cell structure and disturbance of the precipitation tank cause the rare earth dust to be unable to fully precipitate, and the recycling effect is poor.
A precipitation tank system including a stirring tank, a separation tank and a multi-layer overflow structure is adopted. The mutually bonded floating matter and precipitate are separated by stirring and breaking treatment, and the separation tank is separated while the multi-layer overflow structure improves the precipitation effect.
It significantly improves the precipitation effect and recovery purity of rare earth dust, reduces the precipitation of carbides, and improves the recycling efficiency and economic benefits.
Smart Images
Figure CN120079148A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a post-treatment process for rare earth processing, and more specifically, to a method and system for filtering and precipitating rare earth dust. Background Art
[0002] During the electrolysis process of rare earth powder, not only a large amount of harmful gases are generated, but also some rare earth powder and carbides are discharged in the form of dust along with the harmful gases. Although the amount of rare earth dust discharged with the harmful gases is not large, if these rare earth dusts can be recovered, hundreds of thousands of economic losses can be reduced every year. Therefore, the recovery of rare earth dust is an essential and highly regarded issue in enterprises.
[0003] Currently, mainly a multi-stage spray tower is used to treat harmful gases, and at the same time, the dust is stripped from the gas. The dust will be present in the solution discharged from the spray tower. These solutions will be directly discharged into the sedimentation tank for sedimentation, and then recovered. However, due to the complex electrolysis process, the dust generated contains rare earth dust, carbides, and adhesives of the two. Since the density of carbides is small, they generally float on the water surface. Although direct sedimentation can separate the dust and carbides, the larger carbides and the adhesives of the two will precipitate together with the rare earth dust, resulting in the presence of larger carbides in the recovered rare earth powder, affecting its purity. In addition, the existing sedimentation tank has a structure of multiple single tank bodies, and the discharged solution will continuously disturb it, causing the rare earth dust to be discharged before sufficient sedimentation, resulting in poor recovery effect of rare earth powder. Summary of the Invention
[0004] The technical problem to be solved by the present invention is to provide a method and system for filtering and precipitating rare earth dust, which greatly improves the sedimentation effect, aiming at the deficiencies of the prior art.
[0005] A rare earth dust filtering and precipitating system according to the present invention includes a stirring tank, a separation tank, and a sedimentation tank; the water inlet of the stirring tank is connected to the output end of the spray tower, the water outlet of the stirring tank is connected to the water inlet of the separation tank, a discharge port is provided below the separation tank, a multi-layer overflow structure arranged continuously in the horizontal direction is provided in the sedimentation tank, the innermost layer of the multi-layer overflow structure is provided with a water inlet connected to the discharge port of the separation tank, and the outermost layer of the multi-layer overflow structure is provided with a drain port.
[0006] Preferably, the multi-layer overflow structure includes an inner tank, an outer tank, and a confluence tank; the inner tank is the innermost layer of the multi-layer overflow structure, and a water inlet connected to the discharge port of the separation tank is provided therein; the outer tank is arranged around the inner tank, a first overflow port is provided above the inner tank, the confluence tank is arranged around the outer tank, a second overflow port is provided above the outer tank, and the confluence tank is the outermost layer of the multi-layer overflow structure, and a drain port is provided therein.
[0007] Preferably, the water inlet of the inner pool is arranged at the middle position thereof, and a movable reverse baffle is provided below the water inlet of the inner pool. A water passing hole is provided in the reverse baffle; a throat channel is provided above the water inlet of the inner pool, an upper layer pool body is provided above the throat channel, and the first overflow port is arranged at the top of the upper layer pool body.
[0008] Preferably, the reverse baffle is composed of a plurality of plate bodies, and adjacent two plate bodies are connected by a flexible plate. The plate bodies and the flexible plate are hinged and installed on the inner wall of the inner pool in an inclined downward manner, and limiting blocks are fixed on the inner wall of the inner pool below the plate bodies.
[0009] Preferably, a steam trap is provided at the water inlet of the inner pool.
[0010] Preferably, the steam trap is composed of a connecting section, a steam draining section and a reduced diameter section; the connecting section is connected with the water inlet of the inner pool, the diameter of the connecting section is larger than that of the reduced diameter section, the steam draining section is a diameter-varying pipe section with one end connected to the connecting section and the other end connected to the reduced diameter section, and a plurality of water outlet through holes are formed in both the steam draining section and the reduced diameter section.
[0011] Preferably, the bottom of the inner pool is in a funnel shape, a discharge pipe communicated with the inner cavity thereof is connected below the inner pool, and a valve is installed in the discharge pipe.
[0012] Preferably, a middle baffle is provided in the outer pool to divide the outer pool into a left pool body and a right pool body. A flow channel is provided below the middle baffle, and the left pool body is communicated with the right pool body through the flow channel.
[0013] Preferably, an overflow drain port is provided above the confluence pool.
[0014] A rare earth dust filtration and precipitation method applying the rare earth dust filtration and precipitation device as described above, the method comprising the following steps:
[0015] Step 1: Discharge the solution discharged from the spray tower into a stirring pool and perform stirring treatment in a way of dispersing and stirring to disperse and separate the floating matters and precipitates adhered to each other in the solution;
[0016] Step 2: Discharge the solution after Step 1 into a separation pool to perform static separation on the floating matters and precipitates in the solution;
[0017] Step 3: Take the solution at the bottom of the separation pool and discharge it into a precipitation pool for precipitation treatment.
[0018] Beneficial effects
[0019] The advantages of the present invention are as follows:
[0020] 1. The solution output from the spray tower is discharged into the stirring tank for stirring and dispersing treatment, so as to effectively disperse and separate the floating matter and sediment that are adhered to each other therein. The purpose of doing so can well improve the purity of the sediment filtered out subsequently.
[0021] 2. A separation tank is arranged in the stirring tank and the sedimentation tank, and its purpose is to separate the sediment and floating matter in the solution after stirring and dispersing, to avoid excessive doping in the sediment, and can effectively improve the purity of the rare earth powder precipitated subsequently.
[0022] 3. The sedimentation tank adopts a multi-layer overflow structure of a tank within a tank, which can well precipitate the sediment, thereby separating the sediment from the solution.
[0023] 4. The inner tank of the sedimentation tank adopts the design of a steam trap, a reverse baffle and a throat channel, which can greatly improve the sedimentation effect of the sediment in the solution. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Figure 1 is a schematic structural diagram of the rare earth dust filtration and precipitation system of the present invention;
[0025] Figure 2 is a schematic diagram of the internal structure of the sedimentation tank of the present invention;
[0026] Figure 3 is a schematic top view structure diagram of the reverse baffle of the present invention;
[0027] Figure 4 is a schematic diagram of the internal structure of the steam trap of the present invention.
[0028] Wherein: 1 - stirring tank, 2 - separation tank, 3 - sedimentation tank, 4 - inner tank, 5 - outer tank, 6 - confluence tank, 7 - first overflow port, 8 - second overflow port, 9 - drain port, 10 - throat channel, 11 - upper tank body, 12 - reverse baffle, 13 - steam trap, 14 - limit block, 15 - discharge pipe, 16 - valve, 17 - middle baffle, 18 - flow channel, 19 - connection section, 20 - hydrophobic section, 21 - constriction section, 22 - water outlet through hole, 23 - plate body, 24 - flexible plate, 25 - water passing port. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0029] The following is a further description of the present invention in conjunction with embodiments, but it does not constitute any limitation to the present invention. Any limited modification made by anyone within the scope of the claims of the present invention is still within the scope of the claims of the present invention.
[0030] Embodiment 1
[0031] Refer to Figures 1-4, A rare earth dust filtration and precipitation system of the present invention includes a stirring tank 1, a separation tank 2 and a precipitation tank 3. The water inlet of the stirring tank 1 is connected to the output end of the spray tower, which inputs the solution output by the spray tower and stirs and disperses these solutions. Specifically, a plurality of staggered stirring rods are arranged on the stirring shaft in the stirring tank 1, and the solution is discharged from above the stirring rods and directly discharged onto the stirring rods. The rotating stirring shaft can stir and disperse the falling solution through the stirring rods, so as to effectively disperse and separate the floating substances and precipitates that are adhered to each other therein. The purpose of doing this is to well improve the purity of the subsequent filtered precipitate, that is, rare earth dust. And the solution after passing through the stirring rods will be discharged.
[0032] The water outlet of the stirring tank 1 is connected to the water inlet of the separation tank 2, so as to input the solution that has been stirred and dispersed into the separation tank 2 for separation treatment. Among them, the separation tank 2 is a tank with a relatively large volume, and its main function is to separate the floating substances and precipitates in the solution. It should be noted that the floating substances are mainly carbon particles / carbon ash, which are generated during the electrolysis process and are sucked out by the dust collection system together with the rare earth dust. Therefore, in the separation tank 2 for the solution after stirring and dispersing, the floating substances and precipitates therein are quickly separated, the floating substances float on the water surface, and the precipitates are in the water. In order to better separate them, the water inlet of the separation tank 2 in this embodiment is located in the middle position, so that the floating substances and precipitates can be quickly separated. A discharge port is provided below the separation tank 2 to discharge the solution containing precipitates into the precipitation tank 3.
[0033] A multi-layer overflow structure arranged continuously in the horizontal direction is provided in the precipitation tank 3. The innermost layer of the multi-layer overflow structure is provided with a water inlet connected to the discharge port of the separation tank 2, and the outermost layer of the multi-layer overflow structure is provided with a drain port. Through such a design, the precipitates can be well precipitated, so as to separate them from the solution.
[0034] In this embodiment, the multi-layer overflow structure includes an inner tank 4, an outer tank 5 and a confluence tank 6. The inner tank 4 is the innermost side of the multi-layer overflow structure, and a water inlet connected to the discharge port of the separation tank 2 is provided therein. The outer tank 5 is arranged around the inner tank 4. A first overflow port 7 is provided above the inner tank 4. The confluence tank 6 is arranged around the outer tank 5. A second overflow port 8 is provided above the outer tank 5. The confluence tank 6 is the outermost layer of the multi-layer overflow structure, and a drain port is provided therein. An overflow drain port 9 is provided above the confluence tank 6. Among them, using the top edges of the inner tank 4 and the outer tank 5 as the overflow ports can increase the overflow area, which is beneficial to the deceleration and stable flow of the water body. And the overflow drain port 9 is arranged on one side of the confluence tank 6 for discharging the solution from the precipitation tank 3. Although the confluence tank 6 is not used as the main precipitation tank body, it still has a certain precipitation function and can further collect the precipitates remaining in the solution.
[0035] The solution discharged from the separation tank 2 is first discharged into the inner tank 4, and then overflows through the outer tank and the confluence tank 6 respectively, that is, it precipitates in a multi-precipitation structure by overflowing, which can effectively ensure the slowness of the water body during the flow process, making the flow of the water body relatively stable, facilitating the precipitation of sediments. At the same time, precipitation can occur in all three tanks, maximizing the precipitation of sediments, greatly reducing the loss of rare earth dust, and improving the economic benefits of recovery.
[0036] Regarding the inner tank 4, its water inlet is set at the middle position, and its water outlet direction is perpendicular to the axis direction of the inner tank 4, which is beneficial to the precipitation of sediments and also avoids the influence of sediment agitation when the water enters from the bottom. Further, a water eliminator 13 is provided at the water inlet of the inner tank 4, and its function is to slow down the discharged solution.
[0037] Specifically, the water eliminator 13 is composed of a connecting section 19, a water eliminating section 20 and a reduced diameter section 21. Among them, the connecting section 19 is connected to the water inlet of the inner tank 4, the diameter of the connecting section 19 is larger than the diameter of the reduced diameter section 21, the water eliminating section 20 is a pipe section with a gradually changing diameter with one end connected to the connecting section 19 and the other end connected to the reduced diameter section 21, and a plurality of water outlet through holes 22 are provided in both the water eliminating section 20 and the reduced diameter section 21. When the solution is discharged into the water eliminating section 20 through the water inlet and the connecting section 19 of the inner tank 4, the solution will be discharged from the water outlet through holes 22, enabling the solution to be evenly discharged into the inner tank 4 in a small flow rate, achieving a better speed reduction effect. The gradual change in the diameter of the water eliminating section 20 is designed to adapt to the continuous reduction of the solution during the discharge process, and can prevent the accumulation of sediments in the solution in the water eliminator 13.
[0038] As the main sedimentation tank body in the sedimentation tank 3, the inner tank 4 has more sediments than other tank bodies. In order to better carry out sedimentation and avoid the phenomenon of sediment backflow in the inner tank 4, a movable reverse baffle 12 is provided below the water inlet of the inner tank 4 in this embodiment, and a water passing hole 25 is provided in the reverse baffle 12. Through the guiding action of the reverse baffle 12, the sediments can be effectively guided to the lower part of the inner tank 4; and through its blocking action, the phenomenon of sediment backflow in the inner tank 4 can be effectively avoided.
[0039] Specifically, the reverse baffle 12 consists of multiple plate bodies 23, and adjacent plate bodies 23 are connected by a flexible plate 24. The plate bodies 23 and the flexible plate 24 are hinged and installed on the inner wall of the inner pool 4 in an inclined downward manner. Limiting blocks 14 are fixed on the inner wall of the inner pool 4 below the plate bodies 23. When the solution flows towards the bottom of the inner pool 4 and / or the sediment precipitates on the upper surface of the reverse baffle 12, the solution and / or the sediment will, under the guiding action of the inclined reverse baffle 12, enter the inner pool 4 below it through its water passing opening 25. If there is a reverse flow phenomenon at the bottom of the inner pool 4, the reverse baffle 12 swings upward, but it will not swing too much under the limiting action of the limiting blocks 14, so as to block the reverse flow, thereby greatly reducing the phenomenon of sediment flowing back with the solution.
[0040] In this embodiment, a throat channel 10 is provided above the water inlet of the inner pool 4, an upper layer pool body 11 is provided above the throat channel 10, and the first overflow port 7 is arranged at the top of the upper layer pool body 11. Such a design can better precipitate the sediment in the solution by blocking the solution. The bottom of the inner pool 4 is funnel-shaped, and a discharge pipe 15 communicating with its inner cavity is connected below the inner pool 4, and a valve 16 is installed in the discharge pipe 15 to facilitate the discharge of the sediment in the inner pool 4.
[0041] Regarding the outer pool 5, a central baffle 17 is provided therein to divide the outer pool 5 into a left pool body and a right pool body. A flow channel 18 is provided below the central baffle 17, and the left pool body is connected to the right pool body through the flow channel 18. Through such a design, the flow path of the solution can be increased, and the precipitation effect can be improved.
[0042] Embodiment 2
[0043] A rare earth dust filtration and precipitation method using the above rare earth dust filtration and precipitation device, the method comprising the following steps:
[0044] Step 1: Discharge the solution discharged from the spray tower into the stirring tank 1 and perform stirring treatment in a way of dispersing and stirring to disperse and separate the floating substances and sediments adhered to each other in the solution. Specifically, the way of dispersing and stirring is mainly: discharging the solution from above the stirring rod of the stirring tank 1 and directly discharging it onto the stirring rod, and the rotating stirring rod stirs and disperses the falling solution, so as to effectively disperse and separate the floating substances and sediments adhered to each other therein.
[0045] Step 2: Discharge the solution after Step 1 into the separation tank 2 to statically separate the floating substances and sediments in the solution.
[0046] Step 3: Take the solution at the bottom of the separation tank 2 and discharge it into the sedimentation tank 3 for sedimentation treatment. Through sedimentation in three tanks and by adopting the way of overflowing and discharging the solution, the sediment in the solution can be well precipitated and separated.
[0047] The above are only the preferred embodiments of the present invention. It should be noted that for those skilled in the art, without departing from the structure of the present invention, several modifications and improvements can be made, which will not affect the implementation effect of the present invention and the practicability of the patent.
Claims
1. A rare earth dust filtration and sedimentation system, characterized in that: The invention comprises a stirring tank (1), a separation tank (2) and a sedimentation tank (3); the water inlet of the stirring tank (1) is connected to the output end of a spray tower, the water outlet of the stirring tank (1) is connected to the water inlet of the separation tank (2), a discharge outlet is provided below the separation tank (2), and a multi-layer overflow structure continuously arranged in a horizontal direction is provided in the sedimentation tank (3), the innermost layer of the multi-layer overflow structure is provided with a water inlet connected to the discharge outlet of the separation tank (2), and the outermost layer of the multi-layer overflow structure is provided with a discharge outlet.
2. A rare earth dust filtration and sedimentation system according to claim 1, characterized in that: The multi-layer overflow structure comprises an inner pool (4), an outer pool (5) and a confluence pool (6); the inner pool (4) is the innermost side of the multi-layer overflow structure, and is provided with a water inlet connected to the discharge outlet of the separation pool (2); the outer pool (5) is arranged around the inner pool (4), and a first overflow outlet (7) is provided above the inner pool (4); the confluence pool (6) is arranged around the outer pool (5), and a second overflow outlet (8) is provided above the outer pool (5); the confluence pool (6) is the outermost layer of the multi-layer overflow structure, and is provided with a discharge outlet.
3. A rare earth dust filtration and sedimentation system according to claim 2, characterized in that: The water inlet of the inner pool (4) is arranged in the middle thereof, and a movable reverse baffle (12) is arranged below the water inlet of the inner pool (4), and a water outlet (25) is arranged in the reverse baffle (12); a throat channel (10) is arranged above the water inlet of the inner pool (4), and an upper pool body (11) is arranged above the throat channel (10), and the first overflow port (7) is arranged at the top of the upper pool body (11).
4. A rare earth dust filtration and sedimentation system according to claim 3, characterized in that: The reverse blocking piece (12) is composed of a plurality of plate bodies (23), two adjacent plate bodies (23) are connected by a flexible plate (24), the plate bodies (23) and the flexible plates (24) are hingedly installed on the inner wall of the inner pool (4) in an inclined downward manner, and a limiting block (14) is fixed on the inner wall of the inner pool (4) below the plate bodies (23).
5. A rare earth dust filtering and sedimentation system according to claim 3, characterized in that: A steam trap (13) is provided at the water inlet of the inner pool (4).
6. A rare earth dust filtration and sedimentation system according to claim 5, characterized in that: The steam trap (13) is composed of a connecting section (19), a hydrophobic section (20) and a constricted section (21); the connecting section (19) is connected to the water inlet of the inner pool (4); the diameter of the connecting section (19) is larger than the diameter of the constricted section (21); the hydrophobic section (20) is a pipe section with a gradually changing diameter, one end of which is connected to the connecting section (19) and the other end of which is connected to the constricted section (21); and a plurality of water outlet holes (22) are provided in the hydrophobic section (20) and the constricted section (21).
7. A rare earth dust filtration and sedimentation system according to claim 3, characterized in that: The bottom of the inner pool (4) is funnel-shaped, and a discharge pipe (15) communicating with the inner cavity of the inner pool (4) is connected below the inner pool (4), and a valve (16) is installed in the discharge pipe (15).
8. A rare earth dust filtering and sedimentation system according to claim 2, characterized in that: A central baffle (17) is provided in the outer pool (5) to separate the outer pool (5) into a left pool body and a right pool body. A flow channel (18) is provided below the central baffle (17), and the left pool body is connected to the right pool body through the flow channel (18).
9. A rare earth dust filtering and sedimentation system according to claim 2, characterized in that: An overflow drain outlet (9) is provided above the confluence pool (6).
10. A rare earth dust filtering and sedimentation method using the rare earth dust filtering and sedimentation device according to any one of claims 1 to 9, characterized in that: The method comprises the following steps: Step 1, discharging the solution discharged from the spray tower into a stirring tank (1) and stirring the solution in a dispersing and stirring manner to disperse and separate floating objects and sediments adhering to each other in the solution; Step 2, discharging the solution after step 1 into a separation tank (2) to statically separate the floating matter and sediment in the solution; Step 3: Take the solution at the bottom of the separation tank (2) and discharge it into the sedimentation tank (3) for sedimentation treatment.