A method and apparatus for the optimized production of battery grade lithium carbonate from low purity lithium carbonate

Abstract

The application provides a method and equipment for preparing battery-grade lithium carbonate from low-purity lithium carbonate, and relates to the technical field of lithium carbonate preparation, and comprises the following steps: preparing a lithium carbonate suspension, wherein low-purity lithium carbonate powder prepared from lithium-containing substances is added into a certain liquid for dispersion and is placed in a water bath kettle for heating to a certain temperature for standby use; the lithium carbonate powder dispersion liquid comprises deionized water, ultrapure water or ethanol. In the scheme, the required optimized purification suspension is pumped into a mixer, the particle size is controlled through three layers of shearing layers inside the instrument, water washing liquid is pumped into the mixer at the same time, the suspension is sheared and washed with water at the same time, and then the suspension is flowed into a collector through an outlet below for aging, so that the impurities generated by peritectic of the low-purity lithium carbonate are reduced, the crystal growth and morphology optimization are promoted, the soluble impurities are further removed, the particle size distribution is stabilized, the foundation for subsequent solid-liquid separation, drying and purification is laid, and the purpose of continuously preparing battery-grade lithium carbonate from low-purity lithium carbonate is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of lithium carbonate preparation, in particular to a method and device for preparing battery-grade lithium carbonate from low-purity lithium carbonate. BACKGROUND

[0002] Lithium is widely used in chemical raw materials, battery industry, metallurgy, ceramics, national defense, atomic energy, aerospace and other industries. In the battery industry, it is used as an additive for alkaline storage batteries, which can prolong the service life and increase the storage capacity. Battery-grade lithium carbonate is the core raw material for producing ternary lithium battery positive materials.

[0003] Since lithium carbonate is an important raw material for lithium-ion battery positive materials, its purity directly affects the performance of the battery. At present, intermittent precipitation method is mainly used in industry to produce lithium carbonate, which has problems such as low production efficiency, high energy consumption, and unstable product quality. Therefore, a large amount of low-purity lithium carbonate cannot meet the requirements of battery-grade lithium carbonate and standard lithium carbonate. Therefore, it is of great significance to develop an efficient and continuous production method and device for recovering low-purity lithium carbonate to prepare battery-grade lithium carbonate.

[0004] Therefore, it is necessary to provide a method and device for preparing battery-grade lithium carbonate from low-purity lithium carbonate to solve the above technical problems. SUMMARY

[0005] The present application provides a method and device for preparing battery-grade lithium carbonate from low-purity lithium carbonate, which solves the problems of low production efficiency, high energy consumption, and unstable product quality in the prior art.

[0006] To solve the above technical problems, the present application provides a method for preparing battery-grade lithium carbonate from low-purity lithium carbonate, which comprises the following steps:

[0007] S1: Prepare a lithium carbonate suspension, add low-purity lithium carbonate powder prepared from lithium-containing substances to a certain amount of liquid dispersion and place it in a water bath kettle to heat to a certain temperature for standby;

[0008] The lithium carbonate powder dispersion liquid includes deionized water, ultrapure water or ethanol, and the mass ratio of the dispersion liquid to the lithium carbonate powder is 0.5-5;

[0009] S2: Prepare a water washing liquid, take a certain amount of water washing liquid, and place it in a container and heat to a certain temperature in a water bath kettle for standby;

[0010] The water washing liquid includes deionized water, ultrapure water or ethanol, and the main content of low-purity lithium carbonate is 50%-99.5%;

[0011] S3: Shear synchronous water washing;

[0012] Open the micro-tube jet flow high shear mixer and set a certain working speed, pump the lithium carbonate suspension liquid in S1 and the water washing liquid in S2 into the micro-tube jet flow high shear mixer through the peristaltic pump at a certain flow rate to shear control the particle size and simultaneously wash away impurities, collect the lithium carbonate slurry after shearing and washing, and place it in a water bath for stirring and aging for a certain time to obtain the battery-grade lithium carbonate slurry;

[0013] The mixing shear speed is 500-3600 rpm, and the shearing and washing mode includes one-way pumping shearing and circulating pumping shearing.

[0014] The one-way pumping shearing and washing frequency is 1-10 times, and the washing frequency is 2-5 times.

[0015] The circulating pumping shearing and washing cycle time is 0-10 h, and the circulating pumping shearing and washing cycle time is 1-3 h.

[0016] The low-purity lithium carbonate flow rate is 5-100 mL / min, and the water washing liquid flow rate is 1-20 mL / min.

[0017] A device for optimizing the preparation of battery-grade lithium carbonate from low-purity lithium carbonate, characterized by comprising a water bath heating seat, an aging tank, a driving mechanism, a lifting mechanism, and an aging mechanism.

[0018] The aging tank is installed on the inner wall of the water bath heating seat, the top of the aging tank is sealingly installed with a top plate, the top of the top plate is fixedly provided with a mounting cover, and the upper and lower positions of the aging tank are respectively fixedly provided with a feeding pipe and a discharging pipe.

[0019] The driving mechanism comprises a first mounting bracket and a motor, the first mounting bracket is installed on the top of the mounting cover, the motor is installed on the upper surface of the first mounting bracket through bolts, the output shaft key groove of the motor is connected with a driving gear, one side of the driving gear is meshingly connected with a driven gear, the key groove at the axis of the driving gear and above the top plate is connected with a ratchet wheel, and the outer wall of the ratchet wheel is meshingly connected with a ratchet belt wheel.

[0020] The lifting mechanism comprises a second mounting bracket and an electric cylinder, the second mounting bracket is installed on the top of the mounting cover and on one side of the first mounting bracket, the electric cylinder is installed on the top of the second mounting bracket, a middle plate is fixedly arranged in the middle of the second mounting bracket, a limiting turntable is rotatably connected in the middle plate, a key rod is connected with the key groove at the axis of the limiting turntable, a positioning disc is fixedly arranged on the top end of the key rod, an adapter turntable is rotatably installed on the output end of the electric cylinder, and a reset spring is sleeved on the outer wall of the key rod.

[0021] The aging mechanism includes a hollow tube and an auxiliary tube, the hollow tube is connected to the axis of the driven gear, the auxiliary tube is fixed to the outer wall of the hollow tube, a sealing box is installed outside the hollow tube, a linkage rod is fixed to the inner wall of the sealing box and the outer wall of the key rod, guide wheels are rotatably connected to the left and right ends of the linkage rod, rotating shafts are rotatably connected to the inner wall of the sealing box and the left and right sides of the linkage rod, stirring plates are installed outside the rotating shafts through bolts, linkage plates are connected to the axis of the rotating shafts, and notches are formed in the inner part of the linkage plates.

[0022] Preferably, the driving gear and the driven gear are rotatably connected to the installation cover at the axis, and the ratchet and the toothed belt wheel are rotatably connected to the top plate.

[0023] Preferably, the reset spring is fixedly connected to the positioning disc and the limiting turntable at the upper and lower ends, and the top of the positioning disc is in contact with the bottom of the connecting turntable.

[0024] Preferably, the key rod penetrates through the inside of the limiting turntable and the hollow tube, and the key rod extends to the entire inside of the hollow tube, the auxiliary tube is in an "L" type structure, the linkage rod is in a "Z" type structure, and the guide wheels are embedded in the notches.

[0025] Preferably, it further includes a cleaning mechanism.

[0026] A driven belt wheel is rotatably connected to the inner part of the installation cover at the top end of the top plate, and the outer walls of the driven belt wheel and the toothed belt wheel are sleeved with a belt.

[0027] The cleaning mechanism includes a sleeve and a connecting rod, the sleeve is fixed to the bottom end of the driven belt wheel, the connecting rod is fixed to the outer wall of the sleeve, a positioning ring is fixed to the inner wall of the aging tank, an inner tooth ring is fixed to the bottom of the positioning ring, a rotating frame is installed at the bottom end of the connecting rod through bolts, a rotating gear is rotatably connected to the bottom of the rotating frame, a cleaning rotating plate is fixed to the axis of the rotating gear, and an arc-shaped sliding block is slidably connected to the inner part of the positioning ring.

[0028] Preferably, the hollow tube penetrates through the inside of the sleeve and the driven belt wheel without contacting the sleeve and the driven belt wheel, and the rotating gear and the inner tooth ring are in meshing.

[0029] Preferably, the arc-shaped sliding block and the rotating frame are fixedly connected, and the outer wall of the cleaning rotating plate is in contact with the inner wall of the aging tank.

[0030] Preferably, a limiting sleeve is fixed to the inner part of the hollow tube and the outer wall of the key rod, a through hole is formed in the inner part of the limiting sleeve, the through hole is connected to the port of the auxiliary tube, an L-shaped hole is formed in the inner part of the key rod, and a hose is sealingly installed at the outlet end of the L-shaped hole.

[0031] Compared with the related art, the method and the device for preparing battery-grade lithium carbonate from low-purity lithium carbonate provided by the application have the following beneficial effects:

[0032] The required optimized purification suspension is pumped into the mixer to control the particle size through three layers of shearing layers inside the instrument, and water washing liquid is pumped into the mixer at the same time to shear and synchronously wash the suspension, and then the suspension is flowed into the collector through the lower outlet to age, reduce the impurities of low-purity lithium carbonate due to peritectic, promote crystal growth and morphology optimization, further remove soluble impurities, stabilize the particle size distribution, lay a foundation for subsequent solid-liquid separation, drying and purification, and thus achieve the purpose of continuously preparing battery-grade lithium carbonate from low-purity lithium carbonate. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the application, and for those skilled in the art, other drawings can also be obtained from the structures shown in the drawings without creative labor.

[0034] Figure 1 The best structure schematic diagram provided by the application is shown in the following figure:

[0035] Figure 2 The cross-sectional structure schematic diagram of the aging tank, the top plate and the mounting cover provided by the application is shown in the following figure:

[0036] Figure 3 The cross-sectional structure schematic diagram of the aging tank, the top plate and the mounting cover provided by the application is shown in the following figure: Figure 2 The bottom view structure schematic diagram is shown in the following figure:

[0037] Figure 4 The bottom view structure schematic diagram is shown in the following figure: Figure 2 The structure schematic diagram of the driving mechanism and the lifting mechanism is shown in the following figure:

[0038] Figure 5 The cross-sectional structure schematic diagram of the lifting mechanism is shown in the following figure: Figure 4 The cross-sectional structure schematic diagram of the lifting mechanism is shown in the following figure:

[0039] Figure 6 The enlarged structure schematic diagram at A is shown in the following figure: Figure 5 The enlarged structure schematic diagram at A is shown in the following figure:

[0040] Figure 7 The cross-sectional structure schematic diagram of the aging mechanism is shown in the following figure: Figure 2 The cross-sectional structure schematic diagram of the aging mechanism is shown in the following figure:

[0041] Figure 8 The cross-sectional structure schematic diagram of the aging mechanism is shown in the following figure: Figure 7 The enlarged structure schematic diagram at B is shown in the following figure:

[0042] Figure 9 The enlarged structure schematic diagram at B is shown in the following figure: Figure 7The linkage rod drives the stirring plate to rotate in the working state of the linkage turnover in the process of the linkage rod descending.

[0043] Figure 10 The profile structure schematic diagram of the linkage rod, the hollow pipe, the auxiliary pipe and the limiting sleeve provided by the present application is shown.

[0044] Figure 11 The Figure 2 The cleaning mechanism structure schematic diagram is shown.

[0045] Figure 12 The Figure 11 The detailed connection structure schematic diagram of the arc-shaped sliding block and the rotating frame is shown.

[0046] Explanation of reference numerals:

[0047] 1, water bath heating seat;

[0048] 2, aging tank, 3, top plate, 4, mounting cover;

[0049] 5, driving mechanism, 51, first mounting frame, 52, motor, 53, driving gear, 54, ratchet wheel, 55, ratchet belt pulley, 56, driven pulley, 57, belt, 58, driven gear;

[0050] 6, lifting mechanism, 61, second mounting frame, 62, electric cylinder, 63, middle plate, 64, limiting turntable, 65, linkage rod, 66, positioning disc, 67, connecting turntable, 68, reset spring;

[0051] 7, aging mechanism, 71, stirring plate, 72, auxiliary pipe, 73, hollow pipe, 74, sealing box, 75, linkage rod, 76, guide wheel, 77, rotating shaft, 78, linkage plate, 79, notch, 710, limiting sleeve, 711, through hole;

[0052] 8, cleaning mechanism, 81, positioning ring, 82, cleaning turnplate, 83, sleeve, 84, connecting rod, 85, rotating frame, 86, rotating gear, 87, inner tooth ring, 88, arc-shaped sliding block;

[0053] 9, feeding pipe, 10, discharging pipe;

[0054] 11, middle hole, 12, hose. DETAILED DESCRIPTION

[0055] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0056] The application provides a method and equipment for preparing battery-grade lithium carbonate from low-purity lithium carbonate.

[0057] First embodiment:

[0058] A method for preparing battery-grade lithium carbonate from low-purity lithium carbonate, comprising the following steps:

[0059] S1: preparing a lithium carbonate suspension, wherein low-purity lithium carbonate powder prepared from lithium-containing substances is added into a certain liquid for dispersion and placed in a water bath kettle for heating to a certain temperature for standby;

[0060] The lithium carbonate powder dispersion liquid comprises deionized water, ultrapure water or ethanol, and the mass ratio of the dispersion liquid to the lithium carbonate powder is 0.5-5;

[0061] S2: preparing a water washing liquid, wherein a certain amount of the water washing liquid is taken, filled into a container and placed in a water bath kettle for heating to a certain temperature for standby;

[0062] The water washing liquid comprises deionized water, ultrapure water or ethanol, and the low-purity lithium carbonate has a main content of 50%-99.5%;

[0063] S3: synchronous water washing by shearing;

[0064] The micro-pipe jet flow high-shear mixer is opened and set to a certain working speed, the lithium carbonate suspension in S1 and the water washing liquid in S2 are pumped into the micro-pipe jet flow high-shear mixer at a certain flow rate through a peristaltic pump for shearing control of particle size and synchronous water washing for removing impurities, the lithium carbonate slurry after shearing and water washing is collected and placed in a water bath kettle for water bath stirring and aging for a certain time, and then battery-grade lithium carbonate slurry can be obtained;

[0065] The shearing speed of the mixing shearer is 500-3600 rpm, and the shearing and water washing mode comprises one-way pumping shearing and circulating pumping shearing;

[0066] The one-way pumping shearing and water washing frequency is 1-10 times, and the water washing frequency is 2-5 times;

[0067] The circulating pumping shearing and water washing cycle time is 0-10 h, and the circulating pumping shearing and water washing cycle time is 1-3 h;

[0068] The flow rate of the low-purity lithium carbonate is 5-100 mL / min, and the flow rate of the water washing liquid is 1-20 mL / min.

[0069] The lithium-containing substances in step S1 are one or more of lithium ore, lithium residue, lithium-containing waste liquid and waste lithium battery material;

[0070] The lithium ore is one or more of spodumene, lepidolite, petalite and amblygonite;

[0071] The present embodiment

[0072] The required optimization purification suspension is pumped into the mixer, the particle size is controlled by the three shear layers inside the instrument, and water washing liquid is pumped into the mixer at the same time to shear and synchronize the water washing of the suspension, and then flows into the collector through the lower outlet to age, reduce the impurities of low-purity lithium carbonate due to peritectic, promote crystal growth and morphology optimization, further remove soluble impurities, stabilize particle size distribution, lay a foundation for subsequent solid-liquid separation, drying and purification, and achieve the purpose of optimizing the continuous preparation of battery-grade lithium carbonate from low-purity lithium carbonate.

[0073] The second embodiment is:

[0074] Please refer to Figures 1 to 9 A device for optimizing the preparation of battery-grade lithium carbonate from low-purity lithium carbonate, comprising: a water bath heating seat 1, an aging tank 2, a driving mechanism 5, a lifting mechanism 6, and an aging mechanism 7.

[0075] The aging tank 2 is installed on the inner wall of the water bath heating seat 1, the top of the aging tank 2 is sealingly installed with a top plate 3, the top of the top plate 3 is fixedly provided with a mounting cover 4, and the upper and lower positions of the aging tank 2 are respectively fixedly provided with a feeding pipe 9 and a discharge pipe 10.

[0076] The driving mechanism 5 comprises a first mounting frame 51 and a motor 52, the first mounting frame 51 is installed on the top of the mounting cover 4, the motor 52 is installed on the upper surface of the first mounting frame 51 through bolts, the output shaft key groove of the motor 52 is connected with a driving gear 53, one side of the driving gear 53 is meshingly connected with a driven gear 58, the shaft center of the driving gear 53 and above the top plate 3 is key-groove connected with a ratchet wheel 54, and the outer wall of the ratchet wheel 54 is meshingly connected with a ratchet belt wheel 55.

[0077] The shaft centers of the driving gear 53 and the driven gear 58 are respectively rotationally connected with the mounting cover 4, and the ratchet wheel 54 and the ratchet belt wheel 55 are respectively rotationally connected with the top plate 3.

[0078] Please refer to Figure 2 and Figure 4 The motor 52 can preferably rotate in both directions, and when the user starts the motor 52 to rotate clockwise, the driving gear 53 and the ratchet wheel 54 can be synchronously driven to rotate clockwise. Since the outer wall of the ratchet wheel 54 and the ratchet belt wheel 55 are meshingly connected, when the ratchet wheel 54 rotates clockwise, it will avoid the ratchet belt wheel 55, so that when the motor 52 rotates clockwise, only the driving gear 53 can be driven to rotate.

[0079] The lifting mechanism 6 comprises a second mounting frame 61 and an electric cylinder 62, the second mounting frame 61 is mounted on the top of the mounting cover 4 and located on one side of the first mounting frame 51, the electric cylinder 62 is mounted on the top of the second mounting frame 61, a middle plate 63 is fixedly arranged in the middle of the second mounting frame 61, a limiting turntable 64 is rotatably connected inside the middle plate 63, a key rod 65 is connected with the key groove of the shaft of the limiting turntable 64, a positioning disc 66 is fixedly arranged at the top end of the key rod 65, an adapter turntable 67 is rotatably mounted at the output end of the electric cylinder 62, a reset spring 68 is sleeved on the outer wall of the key rod 65;

[0080] The aging mechanism 7 comprises a hollow pipe 73 and an auxiliary pipe 72, the hollow pipe 73 is connected with the shaft of the driven gear 58 through the key groove, the auxiliary pipe 72 is fixedly arranged on the outer wall of the hollow pipe 73, a sealing box 74 is mounted on the outside of the hollow pipe 73, a linkage rod 75 is fixedly arranged inside the sealing box 74 and located on the outer wall of the key rod 65, a guide wheel 76 is rotatably connected at the left and right ends of the linkage rod 75, a rotating shaft 77 is rotatably connected inside the sealing box 74 and located on the left and right sides of the linkage rod 75, a stirring plate 71 is mounted on the outside of the rotating shaft 77 through bolts, a linkage plate 78 is connected with the key groove of the shaft of the rotating shaft 77, and a notch 79 is formed in the inside of the linkage plate 78.

[0081] Please refer to Figure 4 : when the driving gear 53 rotates clockwise, the transmission control driven gear 58 rotates counterclockwise, and when the driven gear 58 rotates counterclockwise, the hollow pipe 73 and the key rod 65 inside can be synchronously rotated;

[0082] When the key rod 65 rotates, the user can start the electric cylinder 62 to drive the adapter turntable 67 to descend, and when the adapter turntable 67 descends, it contacts the positioning disc 66 to control the key rod 65 to descend along the vertical direction of the limiting turntable 64, at this time the reset spring 68 is in a compressed state, and when the key rod 65 descends, the key rod 65 can descend along the vertical direction of the hollow pipe 73.

[0083] Please refer to Figure 5 and Figure 6 : it can be understood that, since the driven gear 58, the hollow pipe 73 and the key rod 65 are connected with each other through the key groove, when the driven gear 58 rotates, the hollow pipe 73 and the key rod 65 can be connected and rotated, and when the key rod 65 ascends or descends along the vertical direction of the hollow pipe 73, it will not cause interference;

[0084] At the same time, when the key rod 65 rotates downward, the rotation of the limiting turntable 64 cooperates with the contact rotation of the adapter turntable 67 and the positioning disc 66 to avoid the rotation interference of the key rod 65, and at the same time, the rotation load of the key rod 65 can be reduced, so that the key rod 65 can stably rotate.

[0085] The upper and lower ends of the reset spring 68 are fixedly connected with the positioning disc 66 and the limiting turntable 64 respectively, and the top of the positioning disc 66 is in contact with the bottom of the connecting turntable 67.

[0086] The key rod 65 penetrates the limiting turntable 64 and the hollow tube 73, and the key rod 65 extends into the entire hollow tube 73, the auxiliary tube 72 is in an L-shaped structure, the linkage rod 75 is in a Z-shaped structure, and the guide wheel 76 is embedded in the notch 79.

[0087] Please refer to Figure 7 and Figure 8 : When the lithium carbonate slurry is in the initial aging stage, the hollow tube 73 rotates to drive the sealing box 74 to rotate, and synchronously drives the two horizontal stirring plates 71 to rotate horizontally.

[0088] Please refer to Figure 8 and Figure 9 : When the lithium carbonate slurry is in the later aging stage, the user controls the key rod 65 to descend, the key rod 65 linkage controls the linkage rod 75 to drive the two guide wheels 76 to descend, and when the guide wheels 76 descend, the force can be controlled by the corresponding notches 79 to control the two linkage plates 78 to control the corresponding rotating shafts 77 to drive the two stirring plates 71 to rotate clockwise and counterclockwise, and finally realize the angle switching of the stirring plates 71, which is convenient for the rotation and stirring of the lithium carbonate slurry in the later aging stage.

[0089] The third embodiment

[0090] Compared with the traditional lithium carbonate slurry aging design, the driving mechanism 5 and the aging mechanism 7 are linked and operated, when the lithium carbonate slurry is in the initial aging stage, the stirring plate 71 is horizontally arranged, the core advantage of horizontal rotation stirring is to maximize the radial shear force, which can produce a "horizontal strong shear effect" on the slurry, and can break the small agglomerated particles formed in real time, avoiding the formation of "hard agglomeration" due to the sedimentation of particles.

[0091] When the lithium carbonate slurry is in the later aging stage, the user can control the stirring plate 71 to switch to the inclined state by operating the lifting mechanism 6, adjust the angle of the stirring plate 71 to increase, and the flow field changes from "single radial flow" to "radial shear combined with axial circulation" composite flow field, and when the stirring plate 71 rotates, it will drive the slurry to flip up and down along the axial direction, ensuring that the slurry concentration, temperature and shear force in the whole area of the aging tank 2 are uniform, and all lithium carbonate particles are in the same "crystal growth environment", avoiding local supersaturation or undersaturation, and finally obtaining more concentrated crystals, reducing the loss of subsequent classification process.

[0092] The third embodiment

[0093] Please refer to Figure 4 , Figure 11 andFigure 12 Further comprising a cleaning mechanism 8;

[0094] A driven pulley 56 is rotatably connected to the top end of the top plate 3 and inside the mounting cover 4, and the outer wall of the driven pulley 56 and the ratchet pulley 55 is sleeved with a belt 57.

[0095] The cleaning mechanism 8 comprises a sleeve 83 and a connecting rod 84, the sleeve 83 is fixedly arranged at the bottom end of the driven pulley 56, the connecting rod 84 is fixedly arranged at the outer wall of the sleeve 83, the inner wall of the aging tank 2 is fixedly arranged with a positioning ring 81, the bottom of the positioning ring 81 is fixedly arranged with an inner tooth ring 87, the bottom of the rotating frame 85 is rotatably connected with a rotating gear 86, the rotating gear 86 is fixedly arranged at the axis of the rotating frame 85, and the inner wall of the positioning ring 81 is slidably connected with an arc-shaped sliding block 88.

[0096] Please refer to Figure 4 : During the operation of the second embodiment, if the user starts the motor 52 to rotate counterclockwise, the ratchet 54 will rotate counterclockwise to affect the counterclockwise rotation of the control ratchet pulley 55, and the belt 57 controls the counterclockwise rotation of the driven pulley 56, and the driven pulley 56 rotates counterclockwise to synchronously drive the sleeve 83 to control the revolution of the connecting rod 84.

[0097] Please refer to Figure 11 and Figure 12 : The connecting rod 84 can control the rotating frame 85 to control the revolution of the rotating gear 86 and the cleaning rotating plate 82 along the axis of the positioning ring 81 and abutting the inner wall of the aging tank 2, and when the rotating gear 86 revolves, the rotating gear 86 and the inner tooth ring 87 form meshing rotation transmission to drive the cleaning rotating plate 82 to rotate.

[0098] The hollow pipe 73 penetrates through the inside of the sleeve 83 and the driven pulley 56 and does not contact the sleeve 83 and the driven pulley 56, and the rotating gear 86 and the inner tooth ring 87 are meshed with each other.

[0099] Please refer to Figure 12 : It can be understood that when the rotating frame 85 rotates by the arc-shaped sliding block 88 to link the rotating movement in the positioning ring 81, the overall rotation stability of the rotating frame 85 can be ensured.

[0100] Please refer to Figure 4 : Since the hollow pipe 73 penetrates through the inside of the driven pulley 56 and the sleeve 83, the rotation of the hollow pipe 73 and the sleeve 83 is independent, which can avoid interference.

[0101] The embodiment

[0102] Lithium carbonate slurry in the aging stage (especially high concentration, constant temperature and low speed stirring scene), easy to form hard scale layer on the tank wall because of the following reasons;

[0103] The temperature difference between the inner wall of the aging tank 2 and the main body of the slurry is small (such as the tank wall is heated first when heated in water bath, the local supersaturation of the slurry is increased, and the crystals are preferentially precipitated and attached), the small particles in the slurry are settled due to gravity or weak flow field, and gradually accumulate to form dense fouling. The cleaning mechanism 8 can remove the fouling on the inner wall of the aging tank 2, and avoid secondary pollution and particle size fluctuation;

[0104] At the same time, the cleaning rotating plate 82 can form a self-rotating motion in the process of revolution, activate the dead zone flow field, and drive the static slurry near the tank wall to move when self-rotating, so that the "concentration, temperature and particle dispersion state" of the whole tank slurry tend to be consistent, avoiding the fluctuation of crystallization quality caused by local difference. At the same time, the cleaning rotating plate 82 rotates to drive the slurry near the tank wall to flow, continuously update the static slurry of the thermal boundary layer, quickly transfer heat to the main body, shorten the temperature control response time, and ensure that the whole tank crystallization environment is consistent.

[0105] Fourth embodiment:

[0106] Please refer to Figure 7 , Figure 8 and Figure 10 , the arc-shaped sliding block 88 and the rotating frame 85 are fixedly connected, and the outer wall of the cleaning rotating plate 82 is in contact with the inner wall of the aging tank 2.

[0107] The hollow pipe 73 is internally and externally provided with a limiting sleeve 710, the limiting sleeve 710 is internally provided with a through hole 711, the through hole 711 is in communication with the port of the auxiliary pipe 72, the key rod 65 is internally provided with an L-shaped hole 11, and the outlet end of the hole 11 is sealingly installed with a hose 12.

[0108] Preferably, the outside of the hose 12 can be externally provided with an inert gas storage tank, and inert gas can be introduced into the hose 12.

[0109] Please refer to Figure 7 and Figure 8 : during the working process of the first embodiment, when the key rod 65 descends, the key rod 65 synchronously descends along the vertical direction of the limiting sleeve 710;

[0110] Please refer to Figure 10When the key lever 65 is lowered, the bottom end of the middle hole 11 inside the key lever 65 will be in communication with the through hole 711 inside the limiting sleeve 710, at this time, the middle hole 11, the through hole 711 and the auxiliary pipe 72 are in communication, the user injects inert gas through the hose 12, the gas can move downward through the middle hole 11, pass through the through hole 711 and finally be discharged into the inside of the aging tank 2 from the auxiliary pipe 72, the outlet position of the auxiliary pipe 72 can be provided with a one-way valve to avoid the lithium carbonate slurry in the aging tank 2 from flowing back to the auxiliary pipe 72.

[0111] The embodiment

[0112] During the process of aging the lithium carbonate slurry, the inert gas is introduced to have the degassing and impurity removal effects, the inert gas bubbles introduced are equivalent to "gas carriers" and can contact and "carry" the dissolved air and volatile impurities in the slurry to the liquid surface to escape, at the same time, the flow field disturbance can be strengthened, the "local dead zone" can be eliminated, the slurry uniformity can be improved, the slow flow of the slurry in the dead zone can be avoided, the small crystals cannot be effectively dissolved, the growth of the large crystals is limited, the "particle size bimodal distribution" condition is avoided, and the local supersaturation abnormality in the dead zone is avoided.

[0113] Please refer to Figures 1 to 12 The working principle of the method and the device for preparing battery-grade lithium carbonate from low-purity lithium carbonate provided by the application is as follows:

[0114] Step S1, aging of the lithium carbonate slurry;

[0115] The user adds the lithium carbonate slurry to be treated to the inside of the aging tank 2 through the discharge pipe 9, and starts the water bath heating seat 1 to heat and warm up the inside of the aging tank 2.

[0116] When the lithium carbonate slurry is in the initial aging stage, the stirring plate 71 is horizontally arranged, the hollow pipe 73 rotates to drive the sealing box 74 to rotate, and the two horizontal stirring plates 71 are simultaneously driven to rotate in the horizontal direction.

[0117] When the lithium carbonate slurry is in the later aging stage, the user controls the key lever 65 to be lowered, the key lever 65 drives the two guide wheels 76 to be lowered through linkage, the guide wheels 76 are lowered to be controlled by the corresponding notches 79 to drive the two linkage plates 78 to control the two stirring plates 71 to rotate clockwise and counterclockwise through the corresponding rotating shafts 77, and finally the angle of the stirring plate 71 is switched, so that the lithium carbonate slurry is conveniently rotated and stirred in the later aging stage.

[0118] Step S2, the aging and the cleaning of the inner wall are simultaneously performed.

[0119] When the user starts the motor 52 to rotate anticlockwise, the ratchet wheel 54 rotates anticlockwise, which affects the control ratchet gear 55 to rotate anticlockwise, and the belt 57 controls the driven pulley 56 to rotate anticlockwise, and the driven pulley 56 rotates anticlockwise, which synchronously drives the sleeve 83 to rotate around the connecting rod 84;

[0120] The connecting rod 84 controls the rotating frame 85 to control the rotating gear 86 and the cleaning rotating plate 82 to rotate around the axis of the positioning ring 81 and fit the inner wall of the aging tank 2, and when the rotating gear 86 rotates around, the rotating gear 86 and the inner tooth ring 87 form meshing rotation transmission, which drives the cleaning rotating plate 82 to rotate, and the cleaning rotating plate 82 rotates around and rotates, which rotates the aging tank 2 to clean the inner wall.

[0121] The above is only the preferred embodiment of the present application, and does not limit the patent scope of the present application, and any equivalent structural transformation, direct / indirect application in other related technical fields within the concept of the present application, and the content of the present application are included in the patent protection scope of the present application.

Claims

1. A method of optimizing the production of battery grade lithium carbonate from low purity lithium carbonate, characterized in that, The method comprises the following steps: S1: preparing a lithium carbonate suspension, a low-purity lithium carbonate powder prepared from a lithium-containing material is added into a certain liquid dispersion and placed in a water bath kettle for heating to a certain temperature for standby; The lithium carbonate powder dispersion liquid comprises deionized water, ultrapure water or ethanol, and the mass ratio of the dispersion liquid to the lithium carbonate powder is 0.5-5; S2: preparing a water washing liquid, a certain amount of water washing liquid is taken and placed in a container and heated to a certain temperature in a water bath kettle for standby; The water washing liquid comprises deionized water, ultrapure water or ethanol, and the low-purity lithium carbonate mainly contains 50%-99.5%; S3: synchronous water washing by shearing; A micro-tube jet flow high-shear mixer is opened and set to a certain working speed, and the lithium carbonate suspension in S1 and the water washing liquid in S2 are pumped into the micro-tube jet flow high-shear mixer at a certain flow rate by a peristaltic pump to control the particle size by shearing and simultaneously remove impurities by water washing, the lithium carbonate slurry after shearing and water washing is collected and placed in a water bath kettle for water bath stirring and aging for a certain time to obtain a battery-grade lithium carbonate slurry; The shearing speed of the mixing shearer is 500-3600 rpm, and the shearing and water washing mode comprises one-way pumping shearing and circulating pumping shearing; The one-way pumping shearing and water washing is performed 1-10 times; The circulating pumping shearing and water washing cycle time is 1-3 h; The flow rate of the low-purity lithium carbonate is 5-100 mL / min, and the flow rate of the water washing liquid is 1-20 mL / min; A low-purity lithium carbonate preparation method for optimizing the preparation of battery-grade lithium carbonate needs to use a low-purity lithium carbonate preparation device for optimizing the preparation of battery-grade lithium carbonate, which comprises a water bath heating seat, an aging tank, a driving mechanism, a lifting mechanism and an aging mechanism; The aging tank is installed on the inner wall of the water bath heating seat, a top plate is sealingly installed on the top of the aging tank, an installation cover is fixedly arranged on the top of the top plate, and an upper feeding pipe and a discharge pipe are fixedly arranged on the upper and lower positions of the aging tank, respectively; The driving mechanism comprises a first mounting frame and a motor, the first mounting frame is installed on the top of the installation cover, the motor is installed on the upper surface of the first mounting frame through bolts, a driving gear is connected to the output shaft key groove of the motor, a driven gear is meshingly connected to one side of the driving gear, a ratchet wheel is key-groove-connected to the axis of the driving gear and above the top plate, and a ratchet belt pulley is meshingly connected to the outer wall of the ratchet wheel; The lifting mechanism comprises a second mounting frame and an electric cylinder, the second mounting frame is installed on the top of the installation cover and on one side of the first mounting frame, the electric cylinder is installed on the top of the second mounting frame, a middle plate is fixedly arranged in the middle of the second mounting frame, a limiting turntable is rotatably connected in the middle plate, a key rod is key-groove-connected to the axis of the limiting turntable, a positioning disc is fixedly arranged on the top end of the key rod, an adapter turntable is rotatably installed on the output end of the electric cylinder, and a reset spring is sleeved on the outer wall of the key rod; The aging mechanism includes a hollow tube and an auxiliary tube, the hollow tube is connected to the axis of the driven gear, the auxiliary tube is fixed to the outer wall of the hollow tube, a sealing box is installed outside the hollow tube, a linkage rod is fixed inside the sealing box and located outside the key rod, guide wheels are rotatably connected to the left and right ends of the linkage rod, rotating shafts are rotatably connected inside the sealing box and located on the left and right sides of the linkage rod, stirring plates are installed outside the rotating shafts through bolts, linkage plates are connected to the axes of the rotating shafts, and notches are formed in the linkage plates.

2. A process for the optimized production of battery grade lithium carbonate from low purity lithium carbonate as claimed in claim 1 wherein, The driving gear and the driven gear are rotatably connected to the mounting cover at the axes thereof, and the ratchet wheel and the toothed belt wheel are rotatably connected to the top plate.

3. A process for the optimized production of battery grade lithium carbonate from low purity lithium carbonate as claimed in claim 1 wherein, The reset spring is fixedly connected to the positioning disc and the limiting turntable at the upper and lower ends thereof, and the top of the positioning disc is in contact with the bottom of the linking turntable.

4. A process for the optimized production of battery grade lithium carbonate from low purity lithium carbonate as claimed in claim 1 wherein, The key rod penetrates through the limiting turntable and the hollow tube, and extends into the entire hollow tube, the auxiliary tube has an "L" type structure, the linkage rod has a "Z" type structure, and the guide wheels are embedded in the notches.

5. A process for the optimized production of battery grade lithium carbonate from low purity lithium carbonate as claimed in claim 1 wherein, It also includes a cleaning mechanism; A driven belt wheel is rotatably connected to the mounting cover at the top end of the top plate and inside the mounting cover, and the driven belt wheel and the toothed belt wheel are sleeved with a belt. The cleaning mechanism includes a sleeve and a connecting rod, the sleeve is fixed to the bottom end of the driven belt wheel, the connecting rod is fixed to the outer wall of the sleeve, a positioning ring is fixed to the inner wall of the aging tank, an inner tooth ring is fixed to the bottom of the positioning ring, a rotating frame is installed at the bottom end of the connecting rod through bolts, a rotating gear is rotatably connected to the bottom of the rotating frame, a cleaning rotating plate is fixed to the axis of the rotating gear, and an arc-shaped sliding block is slidably connected to the inside of the positioning ring.

6. A process for the optimized production of battery grade lithium carbonate from low purity lithium carbonate as claimed in claim 5 wherein, The hollow tube penetrates through the sleeve and the driven belt wheel and does not contact the sleeve and the driven belt wheel, and the rotating gear and the inner tooth ring are in meshing engagement.

7. A process for the optimized production of battery grade lithium carbonate from low purity lithium carbonate as claimed in claim 5 wherein, The arc-shaped sliding block and the rotating frame are fixedly connected, and the outer wall of the cleaning rotating plate is in contact with the inner wall of the aging tank.

8. A process for the optimized production of battery grade lithium carbonate from low purity lithium carbonate as claimed in claim 1 wherein, A limiting sleeve is fixed to the inside of the hollow tube and located outside the key rod, a through hole is formed in the limiting sleeve, the through hole is in communication with the port of the auxiliary tube, an L-shaped hole is formed in the key rod, and a hose is sealingly installed at the outlet end of the L-shaped hole.

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