A precipitation system and precipitation method for rare earth compounds

Abstract

The invention discloses a precipitation system and a precipitation method for rare earth compounds, and relates to the technical field of rare earth resource recovery. The system comprises a dissolving device, a precipitation device, a crystal grain forming device, a static stratification device, a centrifugal dehydration device, a water preparation chamber, a static recovery pool and a control system. By adding a separate crystal grain forming process, high-quality precipitation is facilitated, washing and filtering are easy, and the washing of product chloride ions is facilitated, and the quality is stabilized; the feeding and crystal nucleus growth are more coordinated, and the emulsification phenomenon is effectively solved, and the crystal nucleus material can be automatically returned according to the process requirements; the water preparation chamber is provided, and linkage control is performed for secondary washing, water is saved, and the disadvantage of large washing water consumption is solved; the electric control is reasonable, the dehydration and washing are linked, and the operation is convenient; the whole production process is continuous and smooth, the operation is more simplified, the cost is saved, the energy consumption is reduced, the labor productivity is improved, and the yield is significantly improved.

Description

Technical Field

[0001] The invention relates to the technical field of rare earth resource recovery, and in particular to a precipitation system and a precipitation method for rare earth compounds. Background Art

[0002] In the process of comprehensive recovery of rare earth resources from NdFeB waste, the single rare earth chloride solution obtained through the separation process needs to be converted into a solid compound. Rare earth precipitation mainly includes several methods such as oxalic acid precipitation, ammonium bicarbonate precipitation and sodium carbonate precipitation. Due to the high cost of oxalic acid precipitation, high ammonia nitrogen in ammonium bicarbonate precipitation wastewater, large water volume and complex process of sodium carbonate precipitation, the technical staff has done a lot of work and carried out technical exploration in many aspects according to these situations. At the same time, there are also many new technical research reports, such as continuous precipitation and endpoint control, water recycling, etc. However, these process technologies also have problems such as general quality stability, difficulty in controlling chloride ions, large water usage, easy formation of emulsions in the reaction, difficult and complicated filtration, and great influence of human factors during use. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a precipitation system and a precipitation method for rare earth compounds, which have stable quality, outstanding chlorine radical washing effect, save water, effectively solve the emulsification phenomenon, are easy to operate, and improve labor productivity.

[0004] To achieve the above object, the present invention provides the following solutions:

[0005] The present invention provides a precipitation system for rare earth compounds, comprising a dissolving device, a precipitation device, a grain forming device, a static stratification device, a centrifugal dehydration device, a water preparation chamber, a static recovery tank and a control system, wherein the dissolving device comprises a dissolving tank and a first stirring component arranged in the dissolving tank, the upper part of the dissolving tank is provided with a first ion water inlet and a precipitation agent addition inlet, and the lower part of the dissolving tank is provided with a first reagent outlet and a second reagent outlet; the precipitation device comprises a precipitation tank and a second stirring component arranged in the precipitation tank, the upper part of the precipitation tank is provided with a reagent inlet, a feed liquid inlet and a new crystal seed inlet, the side of the precipitation tank is provided with a precipitation slurry outlet, and the bottom of the precipitation tank is provided with a precipitation slurry discharge port; the grain forming device comprises a molding tank and a third stirring component arranged in the molding tank, the upper part of the molding tank is provided with a precipitation material inlet, a feed liquid inlet and a new crystal seed inlet, the side of the precipitation tank is provided with a precipitation slurry outlet, and the bottom of the precipitation tank is provided with a precipitation slurry discharge port; the grain forming device comprises a molding tank and a third stirring component arranged in the molding tank, the upper part of the molding tank is provided with a precipitation material inlet, and the bottom of the molding tank is provided with a precipitation material outlet. The molding tank is provided with a slurry inlet and a reagent adjustment inlet, a molding slurry outlet is provided at the bottom of the molding tank, and a pH value monitoring sensor is provided in the molding tank; the static stratification device comprises a static stratification tank, a molding slurry inlet is provided at the upper part of the static stratification tank, a supernatant mother liquor discharge port and a seed delivery port are provided on the side of the static stratification tank from top to bottom, and a static stratification slurry outlet is provided at the bottom of the static stratification tank; a static stratification slurry inlet, a second ion water inlet and a centrifugal water inlet are provided at the upper part of the centrifugal dehydration device, and a first centrifugal water outlet and a second centrifugal water outlet are provided at the lower part of the centrifugal dehydration device; a reserve water inlet is provided at the upper part of the water preparation chamber, and a reserve water outlet is provided at the lower part of the water preparation chamber; a first wastewater inlet and a second wastewater inlet are provided at the upper part of one side of the static recovery tank, and a wastewater discharge port is provided at the upper part of the other side of the static recovery tank;

[0006] The first ion water inlet is connected to the ion water source through a first control loop, the first reagent outlet is connected to the reagent inlet through a second control loop, and the second reagent outlet is connected to the reagent adjustment inlet through a third control loop; the liquid inlet is connected to the liquid tank through a fourth control loop, the new seed inlet is connected to the seed delivery port through a fifth control loop, the precipitation slurry outlet is connected to the precipitation slurry inlet through a sixth control loop, and the precipitation slurry discharge port is connected to the precipitation slurry inlet through a seventh control loop; the molding slurry outlet is connected to the molding slurry inlet through an eighth control loop; the supernatant mother liquor discharge port is connected to the first wastewater inlet through a ninth control loop, and the static stratification slurry outlet is connected to the static stratification slurry inlet through a tenth control loop; the second ion water inlet is connected to the ion water source through an eleventh control loop, the centrifugal water inlet is connected to the reserve water outlet through a twelfth control loop, the first centrifugal water outlet is connected to the second wastewater inlet through a thirteenth control loop, and the second centrifugal water outlet is connected to the reserve water inlet through a fourteenth control loop;

[0007] The first stirring component, the second stirring component, the third stirring component, the centrifugal dehydration device, the first control loop, the second control loop, the third control loop, the fourth control loop, the fifth control loop, the sixth control loop, the seventh control loop, the eighth control loop, the ninth control loop, the tenth control loop, the eleventh control loop, the twelfth control loop, the thirteenth control loop, the fourteenth control loop and the pH value monitoring sensor are all connected to the control system.

[0008] Preferably, it also includes a first platform and a second platform arranged on the ground, the upper surface of the second platform is higher than the upper surface of the first platform, the control system includes an electric control cabinet and an auxiliary cabinet, the electric control cabinet, the grain forming device, the centrifugal dehydration device, the water preparation room and the static recovery pool are all arranged on the ground, the auxiliary cabinet, the sedimentation device and the static stratification device are all arranged on the first platform, and the dissolution device is arranged on the second platform.

[0009] Preferably, the first stirring assembly includes a first motor and a first stirring paddle, the first stirring paddle is arranged in the dissolution tank, and the first motor is connected to the first stirring paddle; the first control loop includes a first pipeline and a first solenoid valve arranged on the first pipeline; the second control loop includes a second pipeline and a second solenoid valve and a spray flowmeter arranged on the second pipeline in sequence; the third control loop includes a third pipeline and a third solenoid valve, a reagent replenishing box and a fourth solenoid valve arranged on the third pipeline in sequence, and a reagent flowmeter is arranged at the outlet of the reagent replenishing box; the first motor, the first solenoid valve, the second solenoid valve, the third solenoid valve, the fourth solenoid valve, the spray flowmeter and the reagent flowmeter are all connected to the auxiliary cabinet.

[0010] Preferably, a temperature sensor is provided in the sedimentation tank, and a heating device is provided outside the sedimentation tank; the second stirring assembly includes a second motor, a second stirring paddle and a first reduction gearbox, the second stirring paddle is provided in the sedimentation tank, and the second motor is connected to the second stirring paddle through the first reduction gearbox; the fourth control loop includes a fourth pipeline and a fifth solenoid valve provided on the fourth pipeline; the sixth control loop includes a sixth pipeline and a sixth solenoid valve provided on the sixth pipeline; the seventh control loop includes a seventh pipeline and a seventh solenoid valve provided on the seventh pipeline; the temperature sensor, the heating device, the second motor, the fifth solenoid valve, the sixth solenoid valve and the seventh solenoid valve are all connected to the auxiliary cabinet.

[0011] Preferably, the third stirring assembly includes a third motor, a third stirring paddle and a second reduction gearbox, the third stirring paddle is arranged in the molding tank, and the third motor is connected to the third stirring paddle through the second reduction gearbox; the eighth control loop includes an eighth pipeline and an eighth solenoid valve and a first liquid pump which are sequentially arranged on the eighth pipeline; the third motor, the eighth solenoid valve and the first liquid pump are all connected to the auxiliary cabinet.

[0012] Preferably, the fifth control loop includes a fifth pipeline and a ninth solenoid valve and a second liquid-feeding pump sequentially arranged on the fifth pipeline; the ninth control loop includes a ninth pipeline and a tenth solenoid valve arranged on the ninth pipeline; the tenth control loop includes a tenth pipeline and an eleventh solenoid valve arranged on the tenth pipeline; the ninth solenoid valve and the second liquid-feeding pump are both connected to the auxiliary cabinet, and the tenth solenoid valve and the eleventh solenoid valve are both connected to the electric control cabinet.

[0013] Preferably, the centrifugal dehydration device includes a bracket, a centrifugal dehydration shell, a grid inner liner and a fourth motor, the centrifugal dehydration shell is arranged on the bracket, the grid inner liner is arranged in the centrifugal dehydration shell, and the fourth motor is used to drive the grid inner liner to rotate; the eleventh control circuit includes an eleventh pipeline and a twelfth solenoid valve arranged on the eleventh pipeline; the twelfth control circuit includes a twelfth pipeline and a thirteenth solenoid valve and a water pump arranged on the twelfth pipeline in sequence; the thirteenth control circuit includes a thirteenth pipeline and a fourteenth solenoid valve arranged on the thirteenth pipeline; the fourteenth control circuit includes a fourteenth pipeline and a fifteenth solenoid valve arranged on the fourteenth pipeline; the fourth motor, the water pump, the twelfth solenoid valve, the thirteenth solenoid valve, the fourteenth solenoid valve and the fifteenth solenoid valve are all connected to the electric control cabinet.

[0014] Preferably, a plurality of first partition walls and a plurality of second partition walls are respectively arranged on both sides of the inner wall of the static recovery pool, a first recess is formed between the first partition wall and the static recovery pool, a second recess is formed between the second partition wall and the static recovery pool, the plurality of first partition walls and the plurality of second partition walls are arranged at intervals, the plurality of first recesses and the plurality of second recesses are arranged at intervals and connected in sequence, and the height of the first partition wall is the same as the height of the second partition wall.

[0015] The present invention also provides a precipitation method based on the precipitation system of the rare earth compound, comprising the following steps:

[0016] Step 1: adding a precipitant into the dissolving tank through the precipitant adding port, and opening the first control loop through the control system, and then adding ionized water into the dissolving tank through the first ionized water inlet, and stirring through the first stirring component to prepare a precipitant solution;

[0017] Step 2: opening the fourth control loop through the control system, and then adding the feed liquid into the precipitation tank through the feed liquid inlet, opening the second control loop to add the precipitant solution in the dissolving device into the precipitation tank through the reagent inlet, and stirring through the second stirring component;

[0018] Step 3: Open the sixth control loop through the control system, add the slurry in the precipitation device into the molding tank, stir it through the third stirring assembly, take out part of the slurry in the precipitation device and test the solid-liquid ratio and the content of rare earth in the supernatant mother liquor, the pH value monitoring sensor transmits the measured pH value in the molding tank to the control system, when the pH value is <6.2-6.8 or the content of rare earth in the supernatant mother liquor is >0.1g / L, the control system opens the third control loop, and then replenishes the precipitant solution in the dissolving device into the molding tank;

[0019] Step 4: opening the eighth control loop through the control system, and then adding the slurry in the grain forming device into the static stratification tank; when the solid-liquid ratio reaches 0.1 to 1:1, opening the ninth control loop through the control system to discharge the supernatant into the static recovery tank; after the discharge is completed, opening the tenth control loop to discharge the slurry in the static stratification device into the centrifugal dehydration device for dehydration;

[0020] Step 5, opening the twelfth control loop through the control system, and then adding the water in the water preparation chamber to the centrifugal dehydration device for the first washing, opening the thirteenth control loop so that the washing water is placed in the static recovery pool; then opening the eleventh control loop so that the ionized water enters the centrifugal dehydration device for the second washing, opening the fourteenth control loop so that the washing water enters the water preparation chamber for the first washing of the next batch; after the second washing is completed, the washed rare earth compound is put into a packaging bag;

[0021] Step six, repeat the above steps one to five to carry out the precipitation process of the second tank of liquid; after 48 to 96 hours, open the seventh control loop through the control system, and then discharge all the slurry in the precipitation device from the bottom to the grain forming device; open the fifth control loop, return part of the slurry in the static stratification device to the precipitation device as new seeds, and repeat the subsequent precipitation operation; at the same time, open the tenth control loop, so that the static stratification device discharges the remaining slurry from the bottom to the centrifugal dehydration device, and repeat the above rare earth compound precipitation process.

[0022] Compared with the prior art, the present invention has achieved the following technical effects:

[0023] The rare earth compound precipitation system and precipitation method provided by the present invention include a dissolving device, a precipitation device, a crystal grain forming device, a static stratification device, a centrifugal dehydration device, a water preparation chamber, a static recovery pool and a control system. By adding a separate crystal grain forming process, it is beneficial to high-quality precipitation, easy to wash and filter, and beneficial to the washing of product chloride ions and stable quality; the feeding and crystal nucleus growth are more coordinated, the emulsification phenomenon is effectively solved, and the crystal nucleus material can be automatically returned according to the process requirements; the water preparation chamber is provided to carry out linkage control of secondary washing, save water, and solve the disadvantage of large washing water consumption; the electronic control is reasonable, the dehydration and washing are linked, and the operation is convenient; the whole production process is continuous and smooth, the operation is more simplified, the cost is saved, the energy consumption is reduced, the labor productivity is improved, and the yield is significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 A schematic diagram of the structure of a precipitation system for rare earth compounds provided by the present invention;

[0026] Figure 2 A schematic diagram of the structure of a dissolving device in a precipitation system of a rare earth compound provided by the present invention;

[0027] Figure 3 A schematic diagram of the structure of a precipitation device in a precipitation system for rare earth compounds provided by the present invention;

[0028] Figure 4 A schematic structural diagram of a grain forming device in a precipitation system of a rare earth compound provided by the present invention;

[0029] Figure 5 A schematic diagram of the structure of a static stratification device in a precipitation system of a rare earth compound provided by the present invention;

[0030] Figure 6 A schematic diagram of the structure of a centrifugal dehydration device in a precipitation system of a rare earth compound provided by the present invention;

[0031] Figure 7 A schematic diagram of the structure of a water preparation chamber in a precipitation system for rare earth compounds provided by the present invention;

[0032] Figure 8 A front view of a static recovery tank in a precipitation system for rare earth compounds provided by the present invention;

[0033] Fig. 9 A top view of a static recovery tank in a precipitation system for rare earth compounds provided by the present invention;

[0034] Fig.10 A platform distribution diagram of a precipitation system for rare earth compounds provided by the present invention;

[0035] Fig.11 An electrically controlled distribution diagram of a precipitation system for rare earth compounds provided by the present invention;

[0036] Fig.12 An electrical control diagram of a first motor, a first liquid feed pump, and a second liquid feed pump in a precipitation system for rare earth compounds provided by the present invention;

[0037] Fig.13 An electrical control diagram of the second motor, the third motor, the fourth motor and the water pump in the precipitation system of the rare earth compound provided by the present invention;

[0038] Fig.14 The present invention provides an electrical control diagram of multiple electromagnetic valves in the precipitation system of rare earth compounds.

[0039] Description of reference numerals: 1. Electric control cabinet; 2. Auxiliary cabinet; 3. Dissolving device; 31. Dissolving tank; 32. First stirring paddle; 4. Sedimentation device; 41. Sedimentation tank; 42. Second stirring paddle; 5. Grain forming device; 51. Forming tank; 52. Third stirring paddle; 6. Standing stratification device; 61. Standing stratification tank; 7. Centrifugal dehydration device; 71. Bracket; 72. Centrifugal dehydration shell; 73. Grid liner; 8. Water preparation chamber; 9. Standing recovery pool; 91, first partition wall; 92, second partition wall; 93, first wastewater inlet; 94, second wastewater inlet; 95, wastewater outlet; 10, ion water source; 11, first pipeline; 12, second pipeline; 13, third pipeline; 14, fourth pipeline; 15, fifth pipeline; 16, sixth pipeline; 17, seventh pipeline; 18, eighth pipeline; 19, ninth pipeline; 20, tenth pipeline; 21, eleventh pipeline; 22, twelfth pipeline; 23, the thirteenth pipeline; 24, the fourteenth pipeline; 25, the spray flow meter; 26, the reagent replenishment box; 4-2PY1, the first solenoid valve; 4-2PY3, the second solenoid valve; 4-2PY2, the third solenoid valve; 4-4PY1, the fourth solenoid valve; 4-3PY3, the fifth solenoid valve; 4-3PY1, the sixth solenoid valve; 4-3PY2, the seventh solenoid valve; 4-PY2, the eighth solenoid valve; 4-5PY2, the ninth solenoid valve; 4- 5PY3, the tenth solenoid valve; 4-5PY1, the eleventh solenoid valve; 1PY, the twelfth solenoid valve; 4-7PY, the thirteenth solenoid valve; 4-6PY1, the fourteenth solenoid valve; 4-6PY2, the fifteenth solenoid valve; 3-2M, the first motor; 7-3M, the second motor; 11-4M1, the third motor; 18-6M, the fourth motor; 13-4M2, the first liquid pump; 15-5M, the second liquid pump; 21-7M, the water pump. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] The purpose of the present invention is to provide a precipitation system and a precipitation method for rare earth compounds, which have stable quality, outstanding chlorine radical washing effect, save water, effectively solve the emulsification phenomenon, are easy to operate, and improve labor productivity.

[0042] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0043] like Figure 1-Figure 9 As shown, this embodiment provides a precipitation system for rare earth compounds, including a dissolving device 3, a precipitation device 4, a grain forming device 5, a static stratification device 6, a centrifugal dehydration device 7, a water preparation chamber 8, a static recovery tank 9 and a control system, wherein the dissolving device 3 includes a dissolving tank 31 and a first stirring component arranged in the dissolving tank 31, the dissolving tank 31 is provided with a first ion water inlet and a precipitant addition inlet at the top, and the dissolving tank 31 is provided with a first reagent outlet and a second reagent outlet at the bottom; the precipitation device 4 includes a precipitation tank 41 and a second stirring component arranged in the precipitation tank 41, the precipitation tank 41 is provided with a reagent inlet, a liquid inlet and a new seed inlet at the top, the precipitation tank 41 is provided with a precipitation slurry outlet on the side, and the precipitation tank 41 is provided with a precipitation slurry discharge port at the bottom; the grain forming device 5 includes a molding tank 51 and a third stirring component arranged in the molding tank 51, the molding tank 51 is provided with a The top of the molding tank 51 is provided with a precipitation slurry inlet and a reagent adjustment inlet, the bottom of the molding tank 51 is provided with a molding slurry outlet, and the molding tank 51 is provided with a pH monitoring sensor; the static stratification device 6 includes a static stratification tank 61, the upper part of the static stratification tank 61 is provided with a molding slurry inlet, the side of the static stratification tank 61 is provided with a supernatant mother liquor discharge port and a seed delivery port from top to bottom, and the bottom of the static stratification tank 61 is provided with a static stratification slurry outlet; the upper part of the centrifugal dehydration device 7 is provided with a static stratification slurry inlet, a second ion water inlet and a centrifugal water inlet, and the lower part of the centrifugal dehydration device 7 is provided with a first centrifugal water outlet and a second centrifugal water outlet; the upper part of the water preparation chamber 8 is provided with a water preparation inlet, and the lower part of the water preparation chamber 8 is provided with a water preparation outlet; the upper part of one side of the static recovery tank 9 is provided with a first wastewater inlet 93 and a second wastewater inlet 94, and the upper part of the other side of the static recovery tank 9 is provided with a wastewater discharge port 95.

[0044] The first ion water inlet is connected to the ion water source 10 through the first control loop, the first reagent outlet is connected to the reagent inlet through the second control loop, and the second reagent outlet is connected to the reagent adjustment inlet through the third control loop; the liquid inlet is connected to the liquid tank through the fourth control loop, the new seed inlet is connected to the seed delivery port through the fifth control loop, the precipitation slurry outlet is connected to the precipitation slurry inlet through the sixth control loop, and the precipitation slurry discharge port is connected to the precipitation slurry inlet through the seventh control loop; the molding slurry outlet is connected to the molding slurry inlet through the eighth control loop; the supernatant mother liquor discharge port is connected to the first wastewater inlet 93 through the ninth control loop, and the static stratification slurry outlet is connected to the static stratification slurry inlet through the tenth control loop; the second ion water inlet is connected to the ion water source 10 through the eleventh control loop, the centrifugal water inlet is connected to the reserve water outlet through the twelfth control loop, the first centrifugal water outlet is connected to the second wastewater inlet 94 through the thirteenth control loop, and the second centrifugal water outlet is connected to the reserve water inlet through the fourteenth control loop. The first stirring component, the second stirring component, the third stirring component, the centrifugal dehydration device 7, the first control loop, the second control loop, the third control loop, the fourth control loop, the fifth control loop, the sixth control loop, the seventh control loop, the eighth control loop, the ninth control loop, the tenth control loop, the eleventh control loop, the twelfth control loop, the thirteenth control loop, the fourteenth control loop and the pH value monitoring sensor are all connected to the control system.

[0045] During operation, the second stirring component is turned on, the feed liquid is added to the precipitation tank 41, and then the prepared precipitant is sprayed and added to the precipitation device 4; after the precipitation is completed, the slurry is discharged into the crystal grain forming device 5, and after the forming is completed, the qualified feed liquid is sent to the static stratification device 6 for stratification; after stratification, the supernatant mother liquor is discharged to the static recovery tank 9; the slurry enters the centrifugal dehydration device 7 through the tenth control loop, and the first washing is carried out using the standby water chamber washing water linkage control, and the washing water enters the static recovery tank 9; then the second washing is linked and controlled using ion clean water, and the washing water enters the standby water chamber 8, and is used for the next batch of washing. According to the process requirements, within a certain period of time, all the slurry in the precipitation tank 41 is discharged from the bottom, and part of the slurry in the static stratification device 6 is returned to the precipitation tank 41 as a new crystal nucleus. At the same time, the static stratification tank 61 is emptied from the bottom of the remaining slurry to the centrifugal dehydration device 7.

[0046] It can be seen that a separate crystal forming process is added in this embodiment, which is conducive to high-quality precipitation, and is easy to wash and filter, which is conducive to the washing of product chloride and stable quality; the feeding and crystal nucleus growth are more coordinated, the emulsification phenomenon is effectively solved, and the crystal nucleus material can be automatically returned according to the process requirements; a water preparation chamber 8 is provided to carry out linkage control of secondary washing, save water, and solve the disadvantage of large amount of washing water; the electronic control is reasonable, the dehydration and washing are linked, and the operation is convenient; the whole production process is continuous and smooth, the operation is more simplified, the cost is saved, the energy consumption is reduced, the labor productivity is improved, and the yield is significantly improved.

[0047] like Fig.10 and Fig.11 As shown, in this embodiment, the first platform and the second platform are also arranged on the ground, the upper surface of the second platform is higher than the upper surface of the first platform, the control system includes an electric control cabinet 1 and an auxiliary cabinet 2, the electric control cabinet 1, the grain forming device 5, the centrifugal dehydration device 7, the water preparation chamber 8 and the static recovery pool 9 are all arranged on the ground, the auxiliary cabinet 2, the sedimentation device 4 and the static stratification device 6 are all arranged on the first platform, and the dissolution device 3 is arranged on the second platform. The ground, the first platform and the second platform form a three-layer ladder shape, so that the dissolution device 3, the sedimentation device 4, the grain forming device 5, the static stratification device 6, the centrifugal dehydration device 7, the water preparation chamber 8 and the static recovery pool 9 are reasonably distributed, and the electric control cabinet 1 is arranged on the ground to control the devices on the ground; the auxiliary cabinet 2 is arranged on the first platform to control the devices on the first platform and the second platform, so that the relevant devices are easy to control.

[0048] like Figure 2As shown, the first stirring assembly includes a first motor 3-2M and a first stirring paddle 32, the first stirring paddle 32 is arranged in the dissolution tank 31, and the first motor 3-2M is connected to the first stirring paddle 32; the first control loop includes a first pipeline 11 and a first solenoid valve 4-2PY1 arranged on the first pipeline 11, and the first ion water inlet and the ion water source 10 are connected through the first pipeline 11; the second control loop includes a second pipeline 12 and a second solenoid valve 4-2PY3 and a spray flowmeter 25 arranged on the second pipeline 12 in sequence, and the first reagent outlet and the reagent inlet are connected through the first solenoid valve 4-2PY1. The second pipeline 12 is connected; the third control loop includes a third pipeline 13 and a third solenoid valve 4-2PY2, a reagent replenishing box 26 and a fourth solenoid valve 4-4PY1 which are sequentially arranged on the third pipeline 13, a reagent flow meter is arranged at the outlet of the reagent replenishing box 26, and the second reagent outlet and the reagent regulating inlet are connected through the third pipeline 13; the first motor 3-2M, the first solenoid valve 4-2PY1, the second solenoid valve 4-2PY3, the third solenoid valve 4-2PY2, the fourth solenoid valve 4-4PY1, the spray flow meter 25 and the reagent flow meter are all connected to the auxiliary cabinet 2. When working, the first solenoid valve 4-2PY1 is opened through the auxiliary cabinet 2 to input the required ionized water or the clean water arranged by the process from the first ionized water inlet, and the precipitant is added from the precipitant adding inlet according to the process formula, and the first motor 3-2M is opened through the auxiliary cabinet 2 to drive the first stirring paddle 32 to stir the liquid in the dissolving tank 31, and the standard precipitant solution is configured to be used when the rare earth compound is precipitated.

[0049] like Figure 3As shown, a temperature sensor is provided in the sedimentation tank 41 for monitoring the temperature of the sedimentation slurry, and a heating device is provided outside the sedimentation tank 41; the second stirring assembly includes a second motor 7-3M, a second stirring paddle 42 and a first reduction gearbox, the second stirring paddle 42 is provided in the sedimentation tank 41, and the second motor 7-3M is connected to the second stirring paddle 42 through the first reduction gearbox; specifically, the sedimentation tank 41 is a cylindrical tank body with an inverted cone-shaped bottom, and an operating platform is provided in the middle and upper part of the sedimentation tank 41. The fourth control loop includes a fourth pipeline 14 and a fifth solenoid valve 4-3PY3 arranged on the fourth pipeline 14, and the liquid inlet is connected to the liquid tank through the fourth pipeline 14; the sixth control loop includes a sixth pipeline 16 and a sixth solenoid valve 4-3PY1 arranged on the sixth pipeline 16, and the sedimentation slurry outlet is connected to the sedimentation slurry inlet through the sixth pipeline 16; the seventh control loop includes a seventh pipeline 17 and a seventh solenoid valve 4-3PY2 arranged on the seventh pipeline 17, and the sedimentation slurry discharge port is connected to the sedimentation slurry inlet through the seventh pipeline 17; the temperature sensor, the heating device, the second motor 7-3M, the fifth solenoid valve 4-3PY3, the sixth solenoid valve 4-3PY1 and the seventh solenoid valve 4-3PY2 are all connected to the auxiliary cabinet 2. During operation, the fifth solenoid valve 4-3PY3 is opened through the auxiliary cabinet 2, so that the slurry enters the precipitation tank 41 from the slurry inlet to reach the specified amount, and then the second solenoid valve 4-2PY3 is opened to add the precipitant solution in the dissolution tank 31, and it is accurately added in a spraying manner through the spray flowmeter 25. At the same time, the auxiliary cabinet 2 turns on the second motor 7-3M to drive the second stirring paddle 42 through the first reduction gearbox to stir the liquid in the precipitation tank 41; after the precipitant solution is added to reach the specified amount, the sixth solenoid valve 4-3PY1 is opened, and the slurry is discharged to the grain forming device 5 through the side outlet of the precipitation tank 41; after the production process has been carried out for a certain period of time, the seventh solenoid valve 4-3PY2 is opened again, and all the slurry is discharged to the grain forming device 5 through the bottom outlet of the precipitation tank 41, and replaced with new crystal seeds.

[0050] like Figure 4As shown, the third stirring assembly includes a third motor 11-4M1, a third stirring paddle 52 and a second reduction box. The third stirring paddle 52 is arranged in the molding tank 51, and the third motor 11-4M1 is connected to the third stirring paddle 52 through the second reduction box; specifically, the molding tank 51 is a cylindrical tank body with an inverted cone at the bottom. The eighth control loop includes an eighth pipeline 18 and an eighth solenoid valve 4-PY2 and a first liquid feed pump 13-4M2 which are sequentially arranged on the eighth pipeline 18. The molding slurry outlet is connected to the molding slurry inlet through the eighth pipeline 18; the third motor 11-4M1, the eighth solenoid valve 4-PY2 and the first liquid feed pump 13-4M2 are all connected to the auxiliary cabinet 2. Open the sixth solenoid valve 4-3PY1, discharge the precipitation slurry into the molding tank 51 through the precipitation slurry inlet, take out part of the precipitation slurry according to the process requirements, observe the precipitation situation, test the solid-liquid ratio of the precipitation slurry and the content of rare earth in the supernatant mother liquor, if the rare earth content does not meet the requirements or the pH is not enough, use the reagent replenishment box 26 for adjustment, that is, open the third solenoid valve 4-2PY2 and the fourth solenoid valve 4-4PY1 through the auxiliary cabinet 2, so that the precipitant solution in the dissolving tank 31 passes through the third pipeline 13 and is accurately added to the molding tank 51 through the reagent flowmeter, so that the precipitated rare earth compound grains grow fully and meet the process requirements. Specifically, when the pH value is <6.2-6.8, if the rare earth content is >0.1g / L, the amount of reagent is insufficient, open the third solenoid valve 4-2PY2 and the fourth solenoid valve 4-4PY1 to add the precipitant solution to reach the specified value range until the rare earth content is <0.1g / L.

[0051] like Figure 5As shown, the static stratification tank 61 is a cylindrical tank body with an inverted cone-shaped bottom, the fifth control loop includes a fifth pipeline 15 and a ninth solenoid valve 4-5PY2 and a second liquid pump 15-5M sequentially arranged on the fifth pipeline 15, the new seed inlet is connected to the seed delivery port through the fifth pipeline 15, and the seed delivery port is arranged at the middle and lower part of the side of the static stratification tank 61; the ninth control loop includes a ninth pipeline 19 and a tenth solenoid valve 4-5PY3 arranged on the ninth pipeline 19, and the supernatant mother liquid discharge port is connected to the first waste The water inlet 93 is connected through the ninth pipeline 19, and the supernatant mother liquor discharge port is arranged at the upper middle part of the side of the static stratification tank 61; the tenth control loop includes the tenth pipeline 20 and the eleventh solenoid valve 4-5PY1 arranged on the tenth pipeline 20, and the static stratification slurry outlet is connected to the static stratification slurry inlet through the tenth pipeline 20; the ninth solenoid valve 4-5PY2 and the second liquid pump 15-5M are both connected to the auxiliary cabinet 2, and the tenth solenoid valve 4-5PY3 and the eleventh solenoid valve 4-5PY1 are both connected to the electric control cabinet 1. During operation, when the slurry in the molding tank 51 meets the process requirements, the auxiliary cabinet 2 opens the eighth solenoid valve 4-PY2 and the first liquid pump 13-4M2 to allow the slurry to enter the static stratification tank 61 through the eighth pipeline 18, so that the mother liquor wastewater and the precipitated rare earth compounds are stratified. When the solid-liquid ratio reaches 0.1-1:1, the electric control cabinet 1 opens the tenth solenoid valve 4-5PY3 to discharge the supernatant mother liquor into the static recovery tank 9. After the discharge, the electric control cabinet 1 opens the eleventh solenoid valve 4-5PY1 to discharge the slurry to the centrifugal dehydration device 7 for dehydration; according to the process requirements, part of the slurry is transferred back to the sedimentation tank 41 in real time for use as a new crystal seed for precipitation. Specifically, the ninth solenoid valve 4-5PY2 and the second liquid pump 15-5M are opened by the auxiliary cabinet 2.

[0052] like Figure 6 and Figure 7As shown, the centrifugal dehydration device 7 includes a bracket 71, a centrifugal dehydration shell 72, a grid liner 73 and a fourth motor 18-6M, the centrifugal dehydration shell 72 is arranged on the bracket 71, the grid liner 73 is arranged in the centrifugal dehydration shell 72, and the fourth motor 18-6M is used to drive the grid liner 73 to rotate; the eleventh control loop includes an eleventh pipeline 21 and a twelfth solenoid valve 1PY arranged on the eleventh pipeline 21, and the second ion water inlet is connected to the ion water source 10 through the eleventh pipeline 21; the twelfth control loop includes a twelfth pipeline 22 and a thirteenth solenoid valve 4-7PY and a water pump 21-7M arranged on the twelfth pipeline 22 in sequence, and the centrifugal water inlet is connected to the spare The water outlet is connected through the twelfth pipeline 22; the thirteenth control circuit includes the thirteenth pipeline 23 and the fourteenth solenoid valve 4-6PY1 arranged on the thirteenth pipeline 23, the first centrifugal water outlet is connected to the second wastewater inlet 94 through the thirteenth pipeline 23; the fourteenth control circuit includes the fourteenth pipeline 24 and the fifteenth solenoid valve 4-6PY2 arranged on the fourteenth pipeline 24, the second centrifugal water outlet is connected to the standby water inlet through the fourteenth pipeline 24; the fourth motor 18-6M, the water pump 21-7M, the twelfth solenoid valve 1PY, the thirteenth solenoid valve 4-7PY, the fourteenth solenoid valve 4-6PY1 and the fifteenth solenoid valve 4-6PY2 are all connected to the electric control cabinet 1. When working, the electric control cabinet 1 opens the eleventh solenoid valve 4-5PY1 to allow the slurry in the static stratification tank 61 to enter the grid liner 73, and when rotating at high speed, the water is thrown out to achieve the purpose of dehydrating the material. The thirteenth solenoid valve 4-7PY and the water pump 21-7M are opened through the electric control cabinet 1 to pump the water in the water preparation chamber 8 into the centrifugal dehydration device 7 for the first water washing, and then the fourteenth solenoid valve 4-6PY1 is opened to allow the washing water to flow out from the first centrifugal water outlet and enter the static recovery tank 9; after the first washing, the twelfth solenoid valve 1PY is opened through the electric control cabinet 1, and the ionized water enters the centrifugal dehydration device 7 for the second water washing, and then the fifteenth solenoid valve 4-6PY2 is opened to allow the washing water to enter the water preparation chamber 8 from the second centrifugal water outlet for use in the first washing of the next batch, thereby achieving water saving.

[0053] like Figure 8 and Fig. 9As shown, a plurality of first partition walls 91 and a plurality of second partition walls 92 are respectively arranged on both sides of the inner wall of the static recovery pool 9, a first concave channel is formed between the first partition wall 91 and the static recovery pool 9, a second concave channel is formed between the second partition wall 92 and the static recovery pool 9, the plurality of first partition walls 91 and the plurality of second partition walls 92 are arranged at intervals, the plurality of first concave channels and the plurality of second concave channels are arranged at intervals and connected in sequence, the plurality of first concave channels and the plurality of second concave channels in this embodiment form a plurality of folding channels, and the washing wastewater can effectively recover the filtered products by passing through the plurality of folding channels, and the height of the first partition wall 91 is the same as the height of the second partition wall 92. Specifically, the static recovery pool 9 is arranged under the ground with a depth of 1.5 meters. In the present embodiment, two first partition walls 91 and one second partition wall 92 are arranged to form a first concave on the left, a second concave and a first concave on the right which are connected in sequence. The first wastewater inlet 93 and the second wastewater inlet 94 are arranged at an end away from the first concave on the left, and the wastewater discharge port 95 is arranged at an end away from the first concave on the right, and the wastewater is sent to the environmental protection workshop through the wastewater discharge port 95 for comprehensive treatment.

[0054] like Figure 12-14 As shown, the start and stop of the first motor 3-2M, the second motor 7-3M and the third motor 11-4M1, specifically, the knob switch ST / ST1 / ST2 rotates clockwise, its normally open point closes, the inverter receives the signal to work, and the first motor 3-2M, the second motor 7-3M and the third motor 11-4M1 work; the knob switch ST / ST1 / ST2 rotates counterclockwise, its normally open point recovers from the closed state to the normally open state, the inverter loses the signal and stops working, and the first motor 3-2M, the second motor 7-3M and the third motor 11-4M1 stop working.

[0055] The first liquid pump 13-4M2, the second liquid pump 15-5M, the water pump 21-7M and the fourth motor 18-6M are started and stopped. Specifically, the start button SB22 / SB33 / SA22 / SA44 is pressed, and the intermediate relay KA / KA1 / KA2 / KA3 is energized and self-locked, and its normally open point KA / KA1 / KA2 / KA3 is closed and self-locked. The normally open solenoid valve is energized and sucked, specifically, the fourteenth solenoid valve 4-6PY1, the thirteenth solenoid valve 4-7PY / the ninth solenoid valve 4-5PY2 / the thirteenth solenoid valve 4-7PY / the eleventh solenoid valve 4-5PY1 are opened, and at the same time, the time relay KT1 / KT2 / KT3 / KT4 works, delays for 3s, the time relay normally open point KT1 / KT2 / KT3 / KT4 is closed, and the AC contactor KM1 / KM2 / KM3 / KM4 is sucked and self-locked. The intermediate relay stops working, the first liquid pump 13-4M2, the second liquid pump 15-5M, the water pump 21-7M and the fourth motor 18-6M start, and the indicator light is on. Press the stop button SB11 / SB3 / SA11 / SA33, the intermediate relay KA / KA1 / KA2 / KA3 loses power and disconnects, the normally open point KA / KA1 / KA2 / KA3 recovers from the closed state to the normally open state, and the normally open solenoid valve recovers from the power failure to the normally closed state. Specifically, the fourteenth solenoid valve 4-6PY1, the thirteenth solenoid valve 4-7PY / the ninth solenoid valve 4-5PY2 / the thirteenth solenoid valve 4-7PY / the eleventh solenoid valve 4-5PY1 are closed, the AC contactor KM1 / KM2 / KM3 / KM4 is disconnected, the first liquid pump 13-4M2, the second liquid pump 15-5M, the water pump 21-7M and the fourth motor 18-6M stop working, and the indicator light is off.

[0056] In this embodiment, multiple solenoid valves are opened and closed, specifically, the rotary buttons SA01 / SA02 / SA03 / SA04 / SA05 / SA06 / SA07 / SA08 / SA09 / SA10 are rotated clockwise, their normally open points are closed, and the normally closed solenoid valves are opened, specifically, the eighth solenoid valve 4-PY2 / the third solenoid valve 4-2PY2 / the second solenoid valve 4-2PY3 / the fifth solenoid valve 4-3PY3 / the sixth solenoid valve 4-3PY1 / the seventh solenoid valve 4-3PY2 / the fourth solenoid valve 4-4PY1 / the tenth solenoid valve 4-5PY3 / the fourteenth solenoid valve 4-6PY1 / the fifteenth solenoid valve 4-6PY2 are energized to open. When the rotary button is rotated counterclockwise, its normally open point is restored to disconnection, and the normally closed solenoid valve is disconnected. Specifically, the eighth solenoid valve 4-PY2 / the third solenoid valve 4-2PY2 / the second solenoid valve 4-2PY3 / the fifth solenoid valve 4-3PY3 / the sixth solenoid valve 4-3PY1 / the seventh solenoid valve 4-3PY2 / the fourth solenoid valve 4-4PY1 / the tenth solenoid valve 4-5PY3 / the fourteenth solenoid valve 4-6PY1 / the fifteenth solenoid valve 4-6PY2 lose power and disconnect.

[0057] This embodiment also provides a precipitation method based on a precipitation system of a rare earth compound, comprising the following steps:

[0058] Step 1: add precipitant to the dissolution tank 31 from the precipitant adding port, and open the first control loop through the control system, and then add ionized water to the dissolution tank 31 through the first ionized water inlet, and stir through the first stirring component to prepare a precipitant solution; specifically, prepare 1.3-1.8 mol / L precipitant solution according to process requirements, control the temperature at 25-50°C, the precipitant is sodium carbonate, oxalic acid, etc., and stir evenly for precipitation.

[0059] Step 2: Open the fourth control loop through the control system, and then add the feed liquid to the precipitation tank 41 through the feed liquid inlet, open the second control loop to add the precipitant solution in the dissolving device 3 to the precipitation tank 41 through the reagent inlet, and stir through the second stirring component; specifically, put the 1.0-1.5mol / L content of the feed liquid into the precipitation tank 41 to reach the required process quantity of 1.5-4.0 cubic meters, keep the feed liquid temperature at 25-50°C, add the precipitant solution in the dissolving device 3 at a rate of 6-12L / hr, and add the precipitant solution in the dissolving device 3 through a flow meter with a plurality of small holes in the L-shaped tube in the form of a spray to ensure that there is no excessive concentration locally, so that the reaction proceeds evenly. When the temperature of the slurry in the precipitation tank 41 is less than 25-50°C, the auxiliary cabinet 2 automatically starts the heating device to make the temperature of the slurry in the precipitation tank 41 reach 25-50°C. After adding the specified amount, stir for another 30 minutes.

[0060] Step three, open the sixth control loop through the control system, and then add the slurry in the precipitation device 4 into the molding tank 51, and stir it through the third stirring component, take out part of the slurry in the precipitation device 4 and test the solid-liquid ratio and the content of rare earth in the supernatant mother liquor, the pH value monitoring sensor transmits the measured pH value in the molding tank 51 to the control system, when the pH value is <6.2~6.8 or the content of rare earth in the supernatant mother liquor is >0.1g / L, the control system opens the third control loop, and then replenishes the precipitant solution in the dissolution device 3 into the molding tank 51.

[0061] Step 4: Open the eighth control loop through the control system, and then add the slurry in the grain forming device 5 into the static stratification tank 61. When the solid-liquid ratio reaches 0.1-1:1, open the ninth control loop through the control system to discharge the supernatant into the static recovery tank 9. After the discharge is completed, open the tenth control loop to discharge the slurry in the static stratification device 6 into the centrifugal dehydration device 7 for dehydration.

[0062] Step 5, open the twelfth control loop through the control system, and then add the water in the water preparation chamber 8 into the centrifugal dehydration device 7 for the first washing, open the thirteenth control loop to allow the washing water to stand in the recovery pool 9; then open the eleventh control loop to allow the ionized water to enter the centrifugal dehydration device 7 for the second washing, open the fourteenth control loop to allow the washing water to enter the water preparation chamber 8 for the first washing of the next batch; after the second washing is completed, the washed rare earth compounds are put into packaging bags.

[0063] Step 6. Repeat the above steps 1 to 5 to carry out the precipitation process of the second tank of liquid; after 48 to 96 hours, open the seventh control loop through the control system, and then discharge all the slurry in the precipitation device 4 from the bottom to the grain forming device 5; open the fifth control loop, return part of the slurry in the static stratification device 6 to the precipitation device 4 as a new seed, and repeat the subsequent precipitation operation; at the same time, open the tenth control loop, so that the static stratification device 6 discharges the remaining slurry from the bottom to the centrifugal dehydration device 7, and repeats the above rare earth compound precipitation process.

[0064] The present specification uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A precipitation system for rare earth compounds, characterized in that: The invention comprises a dissolving device, a settling device, a grain forming device, a static stratification device, a centrifugal dehydration device, a water preparation chamber, a static recovery tank and a control system. The dissolving device comprises a dissolving tank and a first stirring assembly arranged in the dissolving tank, the upper part of the dissolving tank is provided with a first ion water inlet and a precipitant addition inlet, and the lower part of the dissolving tank is provided with a first reagent outlet and a second reagent outlet; the settling device comprises a settling tank and a second stirring assembly arranged in the settling tank, the upper part of the settling tank is provided with a reagent inlet, a liquid inlet and a new seed inlet, the side of the settling tank is provided with a precipitation slurry outlet, and the bottom of the settling tank is provided with a precipitation slurry discharge port; the grain forming device comprises a forming tank and a third stirring assembly arranged in the forming tank, the upper part of the forming tank is provided with a precipitation slurry inlet and a reagent adjustment inlet The molding tank is provided with a molding slurry outlet at the bottom, and a pH value monitoring sensor is provided in the molding tank; the static stratification device comprises a static stratification tank, the upper part of the static stratification tank is provided with a molding slurry inlet, the side of the static stratification tank is provided with a supernatant mother liquor discharge port and a seed delivery port from top to bottom, and the bottom of the static stratification tank is provided with a static stratification slurry outlet; the upper part of the centrifugal dehydration device is provided with a static stratification slurry inlet, a second ion water inlet and a centrifugal water inlet, and the lower part of the centrifugal dehydration device is provided with a first centrifugal water outlet and a second centrifugal water outlet; the upper part of the water preparation chamber is provided with a water preparation inlet, and the lower part of the water preparation chamber is provided with a water preparation outlet; the upper part of one side of the static recovery tank is provided with a first wastewater inlet and a second wastewater inlet, and the upper part of the other side of the static recovery tank is provided with a wastewater discharge port; The first ion water inlet is connected to the ion water source through a first control loop, the first reagent outlet is connected to the reagent inlet through a second control loop, and the second reagent outlet is connected to the reagent adjustment inlet through a third control loop; the liquid inlet is connected to the liquid tank through a fourth control loop, the new seed inlet is connected to the seed delivery port through a fifth control loop, the precipitation slurry outlet is connected to the precipitation slurry inlet through a sixth control loop, and the precipitation slurry discharge port is connected to the precipitation slurry inlet through a seventh control loop; the molding slurry outlet is connected to the molding slurry inlet through an eighth control loop; the supernatant mother liquor discharge port is connected to the first wastewater inlet through a ninth control loop, and the static stratification slurry outlet is connected to the static stratification slurry inlet through a tenth control loop; the second ion water inlet is connected to the ion water source through an eleventh control loop, the centrifugal water inlet is connected to the reserve water outlet through a twelfth control loop, the first centrifugal water outlet is connected to the second wastewater inlet through a thirteenth control loop, and the second centrifugal water outlet is connected to the reserve water inlet through a fourteenth control loop; The first stirring component, the second stirring component, the third stirring component, the centrifugal dehydration device, the first control loop, the second control loop, the third control loop, the fourth control loop, the fifth control loop, the sixth control loop, the seventh control loop, the eighth control loop, the ninth control loop, the tenth control loop, the eleventh control loop, the twelfth control loop, the thirteenth control loop, the fourteenth control loop and the pH value monitoring sensor are all connected to the control system.

2. The precipitation system of rare earth compounds according to claim 1, characterized in that: It also includes a first platform and a second platform arranged on the ground, the upper surface of the second platform is higher than the upper surface of the first platform, the control system includes an electric control cabinet and an auxiliary cabinet, the electric control cabinet, the grain forming device, the centrifugal dehydration device, the water preparation room and the static recovery pool are all arranged on the ground, the auxiliary cabinet, the sedimentation device and the static stratification device are all arranged on the first platform, and the dissolution device is arranged on the second platform.

3. The precipitation system of rare earth compounds according to claim 2, characterized in that: The first stirring component includes a first motor and a first stirring paddle, the first stirring paddle is arranged in the dissolution tank, and the first motor is connected to the first stirring paddle; the first control circuit includes a first pipeline and a first solenoid valve arranged on the first pipeline; the second control circuit includes a second pipeline and a second solenoid valve and a spray flowmeter arranged on the second pipeline in sequence; the third control circuit includes a third pipeline and a third solenoid valve, a reagent replenishing box and a fourth solenoid valve arranged on the third pipeline in sequence, and a reagent flowmeter is arranged at the outlet of the reagent replenishing box; the first motor, the first solenoid valve, the second solenoid valve, the third solenoid valve, the fourth solenoid valve, the spray flowmeter and the reagent flowmeter are all connected to the auxiliary cabinet.

4. The precipitation system of rare earth compounds according to claim 2, characterized in that: A temperature sensor is provided in the sedimentation tank, and a heating device is provided outside the sedimentation tank; the second stirring assembly includes a second motor, a second stirring paddle and a first reduction gearbox, the second stirring paddle is provided in the sedimentation tank, and the second motor is connected to the second stirring paddle through the first reduction gearbox; the fourth control loop includes a fourth pipeline and a fifth solenoid valve provided on the fourth pipeline; the sixth control loop includes a sixth pipeline and a sixth solenoid valve provided on the sixth pipeline; the seventh control loop includes a seventh pipeline and a seventh solenoid valve provided on the seventh pipeline; the temperature sensor, the heating device, the second motor, the fifth solenoid valve, the sixth solenoid valve and the seventh solenoid valve are all connected to the auxiliary cabinet.

5. The precipitation system of rare earth compounds according to claim 2, characterized in that: The third stirring assembly includes a third motor, a third stirring paddle and a second reduction gearbox, the third stirring paddle is arranged in the molding tank, and the third motor is connected to the third stirring paddle through the second reduction gearbox; the eighth control loop includes an eighth pipeline and an eighth solenoid valve and a first liquid pump which are sequentially arranged on the eighth pipeline; the third motor, the eighth solenoid valve and the first liquid pump are all connected to the auxiliary cabinet.

6. The precipitation system of rare earth compounds according to claim 2, characterized in that: The fifth control loop includes a fifth pipeline and a ninth solenoid valve and a second liquid-feeding pump sequentially arranged on the fifth pipeline; the ninth control loop includes a ninth pipeline and a tenth solenoid valve arranged on the ninth pipeline; the tenth control loop includes a tenth pipeline and an eleventh solenoid valve arranged on the tenth pipeline; the ninth solenoid valve and the second liquid-feeding pump are both connected to the auxiliary cabinet, and the tenth solenoid valve and the eleventh solenoid valve are both connected to the electric control cabinet.

7. The precipitation system of rare earth compounds according to claim 2, characterized in that: The centrifugal dehydration device includes a bracket, a centrifugal dehydration shell, a grid liner and a fourth motor, the centrifugal dehydration shell is arranged on the bracket, the grid liner is arranged in the centrifugal dehydration shell, and the fourth motor is used to drive the grid liner to rotate; the eleventh control circuit includes an eleventh pipeline and a twelfth solenoid valve arranged on the eleventh pipeline; the twelfth control circuit includes a twelfth pipeline and a thirteenth solenoid valve and a water pump arranged on the twelfth pipeline in sequence; the thirteenth control circuit includes a thirteenth pipeline and a fourteenth solenoid valve arranged on the thirteenth pipeline; the fourteenth control circuit includes a fourteenth pipeline and a fifteenth solenoid valve arranged on the fourteenth pipeline; the fourth motor, the water pump, the twelfth solenoid valve, the thirteenth solenoid valve, the fourteenth solenoid valve and the fifteenth solenoid valve are all connected to the electric control cabinet.

8. The precipitation system of rare earth compounds according to claim 1, characterized in that: A plurality of first partition walls and a plurality of second partition walls are respectively arranged on both sides of the inner wall of the static recovery pool, a first recess is formed between the first partition wall and the static recovery pool, a second recess is formed between the second partition wall and the static recovery pool, the plurality of first partition walls and the plurality of second partition walls are arranged at intervals, the plurality of first recesses and the plurality of second recesses are arranged at intervals and connected in sequence, and the height of the first partition wall is the same as the height of the second partition wall.

9. A precipitation method based on the precipitation system of the rare earth compound according to any one of claims 1 to 8, characterized in that: The following steps are involved: Step 1: adding a precipitant into the dissolving tank through the precipitant adding port, and opening the first control loop through the control system, and then adding ionized water into the dissolving tank through the first ionized water inlet, and stirring through the first stirring component to prepare a precipitant solution; Step 2: opening the fourth control loop through the control system, and then adding the feed liquid into the precipitation tank through the feed liquid inlet, opening the second control loop to add the precipitant solution in the dissolving device into the precipitation tank through the reagent inlet, and stirring through the second stirring component; Step 3: Open the sixth control loop through the control system, add the slurry in the precipitation device into the molding tank, stir it through the third stirring assembly, take out part of the slurry in the precipitation device and test the solid-liquid ratio and the content of rare earth in the supernatant mother liquor, the pH value monitoring sensor transmits the measured pH value in the molding tank to the control system, when the pH value is <6.2-6.8 or the content of rare earth in the supernatant mother liquor is >0.1g / L, the control system opens the third control loop, and then replenishes the precipitant solution in the dissolving device into the molding tank; Step 4: opening the eighth control loop through the control system, and then adding the slurry in the grain forming device into the static stratification tank; when the solid-liquid ratio reaches 0.1 to 1:1, opening the ninth control loop through the control system to discharge the supernatant into the static recovery tank; after the discharge is completed, opening the tenth control loop to discharge the slurry in the static stratification device into the centrifugal dehydration device for dehydration; Step 5, opening the twelfth control loop through the control system, and then adding the water in the water preparation chamber to the centrifugal dehydration device for the first washing, opening the thirteenth control loop so that the washing water is placed in the static recovery pool; then opening the eleventh control loop so that the ionized water enters the centrifugal dehydration device for the second washing, and opening the fourteenth control loop so that the washing water enters the water preparation chamber for the first washing of the next batch; After the second washing is completed, the washed rare earth compound is put into a packaging bag; Step six, repeat the above steps one to five to carry out the precipitation process of the second tank of liquid; after 48 to 96 hours, open the seventh control loop through the control system, and then discharge all the slurry in the precipitation device from the bottom to the grain forming device; open the fifth control loop, return part of the slurry in the static stratification device to the precipitation device as new seeds, and repeat the subsequent precipitation operation; at the same time, open the tenth control loop, so that the static stratification device discharges the remaining slurry from the bottom to the centrifugal dehydration device, and repeat the above rare earth compound precipitation process.

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