Device for preparing battery-grade lithium carbonate by continuously depositing lithium

Abstract

The invention relates to the technical field of lithium carbonate preparation, and discloses a device for preparing battery-grade lithium carbonate by continuous lithium deposition, which comprises a bracket and two sets of reaction devices which are arranged on the bracket in bilateral symmetry and are mutually independent and alternately run; wherein the reaction device comprises two reaction kettles which are symmetrically arranged front and back, and a feeding pipe I for conveying a lithium sulfate solution and a feeding pipe II for conveying a sodium carbonate solution are respectively arranged at the upper ends of the reaction kettles in a bilateral symmetry manner. The device for preparing the battery-grade lithium carbonate through continuous lithium precipitation can effectively solve the problems that in the prior art, due to the fact that a traditional intermittent lithium precipitation kettle needs to repeat the processes of discharging, cleaning, feeding and the like after production is finished each time, the production efficiency is low, and the productivity is restricted; and a continuous reaction kettle is difficult to control the feeding uniformity, sulfate radical coating is easily caused to exceed the standard, peritectic is easily caused by lack of speed control precision, the sodium content is caused to exceed the standard, and finally the first-pass yield of the battery-grade lithium carbonate is low.

Description

Technical Field

[0001] This invention relates to the field of lithium carbonate preparation technology, and specifically to an apparatus for the continuous lithium deposition process to prepare battery-grade lithium carbonate. Background Technology

[0002] The lithium precipitation process is a core and critical step in the lithium carbonate production process, and its rationality directly determines production efficiency and product quality.

[0003] Currently, there are certain problems with the lithium deposition process in the industry during production: after the lithium deposition reactor completes a single batch reaction, it is necessary to carry out repetitive operations such as discharging, cleaning, and feeding in sequence. The industry generally adopts an intermittent production mode, which has significant shortcomings: low production efficiency and time-consuming and labor-intensive, which restricts the improvement of production capacity.

[0004] To overcome these bottlenecks and improve production efficiency and product quality, the industry has developed several continuous lithium precipitation reactors. However, in practical applications, these devices still have significant shortcomings in the lithium sulfate solution feeding stage: First, insufficient feeding uniformity easily leads to lithium carbonate crystals coating lithium sulfate, resulting in excessive sulfate content in the product; second, the lack of precision in feeding rate control easily triggers peritectic phenomena, causing the sodium content in the product to exceed standard requirements. These problems directly result in a low first-pass yield of battery-grade lithium carbonate, making it difficult to meet the stringent requirements of downstream industries for battery-grade raw materials. Summary of the Invention

[0005] To address the aforementioned shortcomings of existing technologies, this invention provides an apparatus for the continuous lithium deposition process to prepare battery-grade lithium carbonate. This apparatus effectively solves the problems of traditional intermittent lithium deposition reactors, which require repeated processes of discharging, cleaning, and feeding after each production run, resulting in low production efficiency and limited capacity. Furthermore, continuous reactors struggle to control the uniformity of feeding, easily leading to excessive sulfate coating and insufficient rate control precision, which can cause peritectic reactions and excessive sodium content. Ultimately, these issues result in a low first-pass yield of battery-grade lithium carbonate, failing to meet stringent downstream requirements.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] This invention provides an apparatus for the continuous lithium deposition process to prepare battery-grade lithium carbonate, comprising:

[0008] A support frame, on which two sets of independent and alternately operating reaction devices are symmetrically arranged;

[0009] The reaction device includes two reaction vessels arranged symmetrically front to back. The upper end of the reaction vessels is symmetrically provided with a feed pipe 1 for conveying lithium sulfate solution and a feed pipe 2 for conveying sodium carbonate solution. The lower end of the reaction vessel is provided with a discharge pipe at the center. The reaction vessel is provided with a stirring component to fully mix the lithium sulfate solution and the sodium carbonate solution.

[0010] Among them, the two feed pipes one and two feed pipes two corresponding to the front and rear are respectively connected to the liquid inlet pipe through flanges. The liquid inlet pipe is equipped with an opening and closing component. The lower end of the feed pipe one extends into the reactor and is connected to a dispersion component that makes the lithium sulfate solution uniformly dispersed in the reactor.

[0011] The discharge pipe is equipped with a filter assembly to prevent clogging.

[0012] Furthermore, the dispersion component includes multiple concentric nested annular tubes with uniformly varying diameters. Adjacent annular tubes are connected by flanges, and the outermost annular tube is connected to the feed pipe and fixedly connected to the inner wall of the reactor via a short rod.

[0013] Furthermore, the annular tube has micropores uniformly and continuously formed on its peripheral wall and at a lower position.

[0014] Furthermore, the stirring assembly includes a stirring shaft rotatably mounted on the reactor and driven by a drive motor. Multiple spiral plates are uniformly fixedly mounted on the stirring shaft, and stirring blades are fixedly mounted on the stirring shaft between two adjacent spiral plates.

[0015] Furthermore, the filtration assembly includes a filter plate, which is fixedly connected inside the discharge pipe and rotatably connected to the stirring shaft. A cleaning module is connected to the filter plate to prevent large particles from accumulating on the filter plate.

[0016] Furthermore, the cleaning module includes a vortex plate, which is disposed above the filter plate and fixedly connected to the stirring shaft, and a baffle is fixedly connected to the inner circumferential wall of the discharge pipe.

[0017] Furthermore, the stop is annular with a chamfer on the upper end near the center, and an elliptical groove on the lower end of the stop.

[0018] Furthermore, the opening and closing assembly includes a central rod controlled by a servo motor. The central rod is coaxially arranged in the inlet pipe. A ring seat corresponding to the flange on the inlet pipe is symmetrically fixedly connected to the central rod via a connecting plate. The ring seat is rotatably connected to the inlet pipe, and a through groove is provided on the peripheral wall of the ring seat. The through grooves on the two ring seats in the same inlet pipe are staggered.

[0019] The technical solution provided by this invention has the following advantages compared with the prior art:

[0020] 1. This device uses two independent reaction units on the left and right sides to operate alternately. The two reaction vessels inside each unit can seamlessly switch between feeding, reaction, discharging and cleaning processes through opening and closing components. This avoids the process interruptions caused by repeated discharging, cleaning and feeding in traditional intermittent equipment, so that the equipment is always in an effective working state, significantly improving equipment utilization and overall production capacity.

[0021] 2. The lithium sulfate solution is uniformly dispersed into the reactor through a dispersion component consisting of concentric nested ring tubes and micropores, avoiding lithium sulfate coating problems caused by excessively high local concentrations. At the same time, the flow control valve and pressure gauge on the feed pipeline precisely regulate the ratio of the two solutions, and the servo motor of the opening and closing component provides precise control to ensure a stable reaction ratio. This effectively solves the industry pain points of excessive sulfate coating and excessive sodium content, and improves the first-pass yield of battery-grade lithium carbonate.

[0022] 3. The spiral plate of the stirring assembly promotes longitudinal circulation of the solution, while the stirring blades achieve transverse shearing and stirring. The two work together to break the concentration gradient of the solution, enhance the mass transfer effect, and ensure that the lithium sulfate solution and sodium carbonate solution are uniformly mixed throughout the entire range. This avoids crystal defects caused by violent local reactions, allowing the precipitation reaction to proceed fully and stably, and further improving the purity of the product. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present invention;

[0025] Figure 2 This is a schematic diagram of the reaction apparatus according to an embodiment of the present invention;

[0026] Figure 3 This is a schematic diagram of the structure of the liquid inlet pipe and the opening and closing assembly according to an embodiment of the present invention;

[0027] Figure 4 This is a schematic diagram of the reactor structure from a first-view perspective after being cut open according to an embodiment of the present invention;

[0028] Figure 5 This is a schematic diagram of the reactor structure from a second perspective after being cut open according to an embodiment of the present invention;

[0029] Figure 6 This is a schematic diagram of the structure of the filtering component according to an embodiment of the present invention;

[0030] Figure 7 This is a schematic diagram of the planar structure of the cleaning module in an embodiment of the present invention.

[0031] The labels in the diagram represent: 1. Support; 2. Reaction device; 21. Reactor; 211. Feed pipe one; 212. Feed pipe two; 22. Discharge pipe; 23. Stirring assembly; 231. Stirring shaft; 232. Spiral plate; 233. Stirring blade; 24. Liquid inlet pipe; 25. Opening and closing assembly; 251. Central rod; 252. Annular seat; 2521. Through groove; 26. Dispersion assembly; 261. Ring pipe; 262. Short rod; 263. Micropore; 27. Filter assembly; 271. Filter plate; 272. Cleaning module; 2721. Vortex plate; 2722. Baffle; 2723. Elliptical groove. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0033] The present invention will be further described below with reference to embodiments.

[0034] Example:

[0035] Please see Figure 1 - Figure 7 The present invention provides a technical solution:

[0036] An apparatus for the continuous lithium deposition process to prepare battery-grade lithium carbonate, comprising:

[0037] Support 1, on which two sets of independent and alternately operating reaction devices 2 are symmetrically arranged;

[0038] The reaction device 2 includes two reaction vessels 21 arranged symmetrically front to back. The upper end of the reaction vessel 21 is symmetrically provided with a feed pipe 211 for conveying lithium sulfate solution and a feed pipe 212 for conveying sodium carbonate solution. The lower end of the reaction vessel 21 is provided with a discharge pipe 22 at the center. The reaction vessel 21 is provided with a stirring assembly 23 to fully mix the lithium sulfate solution and the sodium carbonate solution.

[0039] The two feed pipes 211 and 212 are connected to the liquid inlet pipe 24 by flanges. The liquid inlet pipe 24 is equipped with an opening and closing component 25. The lower end of the feed pipe 211 extends into the reactor 21 and is connected to a dispersion component 26 that uniformly disperses the lithium sulfate solution into the reactor 21. The discharge pipe 22 is equipped with a filter component 27 to prevent clogging.

[0040] Specifically, traditional intermittent lithium deposition reactors 21 require repeated processes such as unloading, reactor cleaning, and refeeding after each production cycle, resulting in interrupted production processes and low equipment utilization, which severely restricts capacity improvement. On the other hand, existing continuous lithium deposition reactors 21 lack precise feeding distribution and dispersion control mechanisms, making it difficult to ensure uniform feeding. This can easily lead to lithium carbonate crystals coating lithium sulfate, resulting in excessive sulfate content in the product. Furthermore, insufficient reaction rate control precision can easily induce peritectic reactions, causing excessive sodium content. Ultimately, this results in a low first-pass yield of battery-grade lithium carbonate products, making it difficult to meet the stringent quality requirements of downstream lithium battery production.

[0041] To solve the above-mentioned technical problems, the present invention makes targeted improvements to the structure and operation mode of the traditional lithium deposition reactor 21. The specific workflow is as follows: In the initial stage of operation, the left reaction device 2 is controlled to enter the operation state, the right reaction device 2 is in the standby state, and preparatory procedures such as equipment preheating and pipeline purging and unblocking are completed (for ease of subsequent explanation, the two reactors 21 in the left reaction device 2 will be referred to as reactor A and reactor B, and the two reactors 21 in the right reaction device 2 will be referred to as reactor C and reactor D).

[0042] During operation, lithium sulfate solution and sodium carbonate solution are first simultaneously introduced into the left-side reaction device 2 through inlet pipe 24. During the initial feed, under the drive control of the opening / closing component 25, inlet pipes 211 and 212 corresponding to reactor A are both open, while inlet pipes 211 and 212 corresponding to reactor B are closed. In this state, the lithium sulfate solution and sodium carbonate solution transported by inlet pipe 24 are precisely injected into reactor A through inlet pipes 211 and 212, respectively. Both inlet pipes 211 and 212 are equipped with external flow control valves and external pressure gauges, enabling real-time monitoring and precise control of the sodium carbonate solution's feed flow rate and pressure. This ensures that the feed volume ratio of sodium carbonate solution to lithium sulfate solution is precisely controlled at 8:12, guaranteeing the accuracy of the reaction ratio and laying the foundation for the subsequent preparation of high-purity lithium carbonate.

[0043] Sodium carbonate solution is fed into reactor A through feed pipe 212 and falls directly to the bottom of the reactor. Lithium sulfate solution is fed into dispersion component 26 through feed pipe 211 and is evenly dispersed into sodium carbonate solution by the diversion effect of dispersion component 26. This achieves uniform contact and mixing of the two reaction solutions, avoids the phenomenon of lithium carbonate crystals coating lithium sulfate due to excessive local solution concentration, effectively reduces the sulfate impurity content in the product, and improves the product quality of battery-grade lithium carbonate.

[0044] During the feeding stage and throughout the entire reaction process, the stirring component 23 continuously rotates at a preset speed to shear and stir the mixed solution in the reactor, further enhancing the mass transfer effect between solutions, improving mixing uniformity, and ensuring that the precipitation reaction proceeds fully and stably. After the solution in reactor A reaches the preset liquid level, the opening and closing component 25 is activated, closing the corresponding feed pipe 1 211 and feed pipe 212 for reactor A, while simultaneously opening the corresponding feed pipe 1 211 and feed pipe 212 for reactor B. The lithium sulfate solution and sodium carbonate solution delivered by the liquid inlet pipe 24 of the left reaction device 2 are seamlessly switched and injected into reactor B until the preset liquid level gauge in reactor B shows that the liquid level has reached the specified height. At this point, the left liquid inlet pipe 24 stops feeding, thereby achieving seamless and continuous feeding in the left reaction device 2, eliminating the waiting time of the feeding process, and significantly improving the overall production efficiency of the device.

[0045] Lithium sulfate solution and sodium carbonate solution undergo a metathesis precipitation reaction in reactor 21 to generate lithium precipitate slurry with lithium carbonate crystals as the solid phase. After the reaction reaches the preset time, the discharge pipe 22 at the bottom of reactor A is opened to discharge the lithium precipitate slurry to the subsequent aging tank for aging, centrifugation, drying, pulverization, and other subsequent refining processes. To prevent large solid particles in the lithium precipitate slurry from forming a bridging effect and causing blockage in the discharge pipe 22, a filter assembly 27 is installed in the discharge pipe 22. This filter assembly 27 can effectively block large solid particles. At the same time, in conjunction with the stirring assembly 23, the rotation direction and speed of the stirring blades are adjusted during the discharge stage to move the large solid particles deposited in the reactor to the edge of the filter assembly 27 for crushing and refining. This transforms the large solid particles into small particles that can pass through the filter assembly 27, thereby maximizing the recovery of lithium carbonate crystals and unreacted raw materials and reducing material loss and production costs.

[0046] At the same time that reactor A completes the reaction and starts the discharge process, the feeding process of the right-side reaction device 2 is started simultaneously. That is, lithium sulfate solution and sodium carbonate solution are introduced into reactor C through the liquid inlet pipe 24 of the right-side reaction device 2. After the feed into reactor C reaches the preset liquid level, the opening and closing component 25 switches the feeding path and then seamlessly injects lithium sulfate solution and sodium carbonate solution into reactor D. During this period, reactor A, which has completed the discharge, is simultaneously cleaned by high-pressure water washing, purging and other cleaning operations to ensure the cleanliness of the reactor body and avoid residual materials from contaminating the next batch of reaction.

[0047] When the cleaning operation of reactor A is completed, the precipitation reaction in reactor B is just finished and the discharge process is started. At this time, lithium sulfate solution and sodium carbonate solution are introduced into reactor A again through the liquid inlet pipe 24 of the left reaction device 2. The left reaction device 2 enters the cycle operation mode of "reaming and discharging from reactor B + feeding and reacting from reactor A". When the discharge process of reactor B is started, the precipitation reaction in reactor C is completed. Then the discharge and cleaning process of reactor C is started. At this time, reactor D is still in a continuous reaction state. After the reaction in reactor D is completed, the discharge and cleaning process of reactor D is started. At the same time, reactor C is cleaned and a new round of feeding and reacting is started. The right reaction device 2 enters the cycle operation mode of "reaming and discharging from reactor C + feeding and reacting from reactor D".

[0048] The above-mentioned operating mode design can achieve the following technical effects: when the left reaction device 2 is in the process state of "discharge + cleaning", the right reaction device 2 must be in the process state of "feeding + reaction"; when the right reaction device 2 is in the process state of "discharge + cleaning", the left reaction device 2 must be in the process state of "feeding + reaction"; the entire cycle of "feeding, reaction, discharge, and cleaning" of a single reactor 21 is completely coupled and matched with the process cycle of the corresponding reactor 21 of another set of reaction devices 2, ensuring that the entire set of devices always operates without interruption, and ultimately realizing continuous operation of lithium deposition production, greatly improving production efficiency and product first-pass yield.

[0049] The dispersion component 26 includes multiple concentric nested annular tubes 261 with uniformly varying diameters. Adjacent annular tubes 261 are connected by flanges. The outermost annular tube 261 is connected to the feed pipe 211 and fixedly connected to the inner wall of the reactor 21 by a short rod 262. Micropores 263 are uniformly opened through the annular tubes 261 at the lower part of their circumference.

[0050] Specifically, the lithium sulfate solution introduced through the feed pipe 211 first enters the outermost annular pipe 261 under the drive of the feed pressure, and then flows sequentially into each of the inner annular pipes 261 through the flange connecting channel between adjacent annular pipes 261. In one possible embodiment, the pore diameter of the micropores 263 on each annular pipe 261 is 0.5mm-1mm, and the pore spacing is 8mm-10mm. The design of these pore diameter and pore spacing parameters allows the lithium sulfate solution to be uniformly sprayed into the sodium carbonate solution in the reactor 21 in the form of a fine liquid stream, achieving uniform distribution of the lithium sulfate solution throughout the sodium carbonate solution. This effectively avoids the phenomenon of lithium carbonate crystals coating lithium sulfate caused by a sudden increase in local solution concentration, while ensuring that the two reaction solutions form a uniform mixing system in the initial contact stage, providing a guarantee for the full progress of the subsequent precipitation reaction, thereby improving the purity and first-pass yield of battery-grade lithium carbonate products.

[0051] The stirring assembly 23 includes a stirring shaft 231 that is rotatably mounted on the reactor 21 and driven by a drive motor. Multiple spiral plates 232 are uniformly fixedly mounted on the stirring shaft 231, and stirring blades 233 are fixedly mounted on the stirring shaft 231 between two adjacent spiral plates 232.

[0052] The filter assembly 27 includes a filter plate 271, which is fixedly connected inside the discharge pipe 22 and rotatably connected to the stirring shaft 231. A cleaning module 272 is connected to the filter plate 271 to prevent large particles from accumulating on the filter plate 271. The cleaning module 272 includes a vortex plate 2721, which is disposed above the filter plate 271 and fixedly connected to the stirring shaft 231. A baffle 2722 is fixedly connected to the inner peripheral wall of the discharge pipe 22. The baffle 2722 is annular and has a chamfer on the side of its upper end near the center. An elliptical groove 2723 is provided at the lower end of the baffle 2722.

[0053] Specifically, after the drive motor starts, the output torque drives the stirring shaft 231 to rotate at a constant speed, which in turn drives the spiral plate 232 and stirring blade 233 on the shaft to rotate synchronously. When the spiral plate 232 rotates, it generates an axial thrust, which can promote the upward flow of the mixed solution in the lower part of the reaction vessel 21, realizing the longitudinal circulation of the solution in the vessel. When the stirring blade 233 rotates, it generates a transverse shearing and stirring effect on the surrounding solution. The synergistic effect of longitudinal circulation and transverse stirring can break the local concentration gradient of the solution, so that the lithium sulfate solution and sodium carbonate solution can quickly form a uniform mixed system, ensuring that the precipitation reaction proceeds stably and fully throughout the entire range, effectively avoiding the crystal coating or peritectic formation problem caused by violent local reactions, and improving product purity.

[0054] Meanwhile, as the stirring shaft 231 rotates, it synchronously drives the coaxially connected vortex plate 2721 to rotate. The spiral structure of the vortex plate 2721 generates radial thrust when rotating, which can continuously sweep large solid particles blocked by the filter plate 271 along the surface of the filter plate 271 towards the edge area of ​​the discharge pipe 22. The guide chamfer at the upper end of the baffle 2722 can guide the large particles swept towards the edge, preventing the particles from accumulating at the angle between the baffle 2722 and the inner wall of the discharge pipe 22. The elliptical groove 2723 at the lower end of the baffle 2722 forms a periodic extrusion fit with the outermost end of the vortex plate 2721. As the vortex plate 2721 rotates, its outer end will periodically embed into the elliptical groove 2723, generating extrusion crushing force on the large solid particles entering the groove, breaking the large particles into small particles that can pass through the pores of the filter plate 271. This effectively prevents the interruption of discharge caused by the blockage of the filter plate 271, maximizes the recovery of lithium carbonate crystals and unreacted raw materials, and reduces material loss and production costs.

[0055] The opening and closing assembly 25 includes a central rod 251 controlled by a servo motor. The central rod 251 is coaxially arranged in the liquid inlet pipe 24. The central rod 251 is symmetrically fixedly connected to an annular seat 252 corresponding to the flange on the liquid inlet pipe 24 via a connecting plate. The annular seat 252 is rotatably connected to the liquid inlet pipe 24, and a through groove 2521 is provided on the peripheral wall of the annular seat 252. The through grooves 2521 on the two annular seats 252 in the same liquid inlet pipe 24 are staggered.

[0056] Specifically, taking the opening and closing control of the left reaction device 2 as an example, in the initial state, the servo motor drives the central rod 251 to maintain a specific rotation angle, so that the through grooves 2521 on the two annular seats 252 are misaligned with the flange interface on the liquid inlet pipe 24. At this time, the feed pipes 1 211 and 212 corresponding to the A and B reactors are in a closed state.

[0057] When feeding is required, the servo motor drives the center rod 251 to rotate at a preset angle, causing the two annular seats 252 to rotate synchronously. This makes the through groove 2521 on one of the annular seats 252 precisely aligned and connected with the feed pipe 1 211 and feed pipe 212 corresponding to reactor A. Since the through grooves 2521 of the two annular seats 252 are staggered, the through groove 2521 of the annular seat 252 corresponding to reactor B is still staggered and closed with the feed pipe 1 211 and feed pipe 212 of reactor B. The material then flows precisely into reactor A through the through groove 2521 from the liquid inlet pipe 24.

[0058] Once the liquid level in reactor A reaches the preset height, the servo motor drives the central rod 251 to rotate again by a preset angle, causing the two annular seats 252 to rotate synchronously. This switches the channel 2521 corresponding to reactor A to a staggered closed state, while simultaneously rotating the channel 2521 corresponding to reactor B to a position aligned and connected with the feed pipe 1 211 and feed pipe 212 of reactor B. The material then seamlessly flows into reactor B, thus achieving uninterrupted alternating feeding between reactors A and B in the left-side reaction device 2. This feeding control method, through precise angle adjustment of the servo motor, ensures a high degree of consistency in the material feeding sequence and ratio, avoiding reaction stability issues caused by feeding interruptions or ratio fluctuations, thereby ensuring the uniformity of lithium carbonate product quality.

[0059] In addition, in one possible implementation, an identical opening and closing assembly 25 can be added between the liquid inlet pipes 24 of the two sets of reaction devices 2 and connected by a connecting pipe. This design can realize the material exchange and cyclic allocation between the two sets of reaction devices 2, further improving the material consistency and continuous operation cyclic adaptation performance of the whole device. The above effects are predictable, so no additional drawings or textual descriptions are provided in this application.

[0060] It is worth noting that the above-mentioned apparatus for continuous lithium deposition to prepare battery-grade lithium carbonate also has the following advantages:

[0061] Advantage 1: This device adopts two independent reaction devices 2 that operate alternately. The two reaction vessels 21 inside each device seamlessly switch between feeding, reaction, discharging and cleaning processes through the opening and closing components 25. This avoids the process interruption caused by repeated discharging, cleaning and feeding in traditional intermittent equipment, so that the equipment is always in an effective working state, which significantly improves the equipment utilization rate and overall production capacity.

[0062] Advantage 2: The lithium sulfate solution is uniformly dispersed into the reaction vessel 21 through the dispersion component 26, which consists of concentric nested ring pipes 261 and micropores 263, avoiding the problem of lithium sulfate coating caused by excessive local concentration. At the same time, the flow control valve and pressure gauge on the feed pipeline precisely regulate the ratio of the two solutions, and the servo motor of the opening and closing component 25 provides precise control to ensure a stable reaction ratio. This effectively solves the industry pain points of excessive sulfate coating and excessive sodium content, and improves the first-pass yield of battery-grade lithium carbonate.

[0063] Thirdly, the spiral plate 232 of the stirring component 23 promotes the longitudinal circulation of the solution, and the stirring blade 233 achieves transverse shearing and stirring. The two work together to break the concentration gradient of the solution, enhance the mass transfer effect, ensure that the lithium sulfate solution and sodium carbonate solution are uniformly mixed throughout the entire range, avoid crystal defects caused by violent local reactions, and make the precipitation reaction fully and stably proceed, further improving the purity of the product.

[0064] Fourthly, the filter plate 271 inside the discharge pipe 22 blocks large particles, and the vortex plate 2721 driven by the stirring shaft 231 sweeps the particles to the edge. The chamfer of the baffle 2722 plays a guiding role. Its elliptical groove 2723 and the vortex plate 2721 form a squeezing and crushing combination, which not only prevents the pipeline blockage caused by large particles bridging and ensures smooth discharge, but also allows large particles to be crushed and recycled, minimizing material loss and reducing production energy consumption and costs.

[0065] Advantage 5: The opening and closing assembly 25 precisely controls the rotation angle of the central rod 251 and the annular seat 252 through a servo motor. It uses the staggered through slot 2521 to achieve seamless switching of feeding between different reactors 21, ensuring that the feeding sequence and material flow of each reactor 21 are highly consistent. This avoids differences in reaction stability caused by feeding fluctuations, ensures the uniformity of lithium carbonate product quality in multiple batches, and meets the stringent requirements of downstream industries.

[0066] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the protection scope of the technical solutions of the embodiments of the present invention.

Claims

1. An apparatus for the continuous lithium deposition process to prepare battery-grade lithium carbonate, characterized in that, include: Support (1), and two sets of independent and alternately operating reaction devices (2) are symmetrically arranged on the support (1); The reaction device (2) includes two reaction vessels (21) arranged symmetrically front to back. The upper end of the reaction vessel (21) is symmetrically provided with a feed pipe (211) for conveying lithium sulfate solution and a feed pipe (212) for conveying sodium carbonate solution. The lower end of the reaction vessel (21) is provided with a discharge pipe (22). The reaction vessel (21) is provided with a stirring assembly (23) to fully mix the lithium sulfate solution and the sodium carbonate solution. Among them, the two feed pipes 1 (211) and the two feed pipes 2 (212) corresponding to the front and rear are connected to the liquid inlet pipe (24) through flanges. The liquid inlet pipe (24) is equipped with an opening and closing component (25). The lower end of the feed pipe 1 (211) extends into the reactor (21) and is connected to a dispersion component (26) that makes the lithium sulfate solution uniformly dispersed in the reactor (21). The discharge pipe (22) is equipped with a filter assembly (27) to prevent clogging.

2. The apparatus for continuous lithium deposition to prepare battery-grade lithium carbonate according to claim 1, characterized in that: The dispersion component (26) includes multiple concentric nested ring tubes (261) with uniformly varying diameters. Adjacent ring tubes (261) are connected by flanges. The outermost ring tube (261) is connected to the feed pipe (211) and fixedly connected to the inner wall of the reactor (21) by a short rod (262).

3. The apparatus for continuous lithium deposition to prepare battery-grade lithium carbonate according to claim 2, characterized in that: The lower part of the peripheral wall of the ring tube (261) is provided with micropores (263).

4. The apparatus for continuous lithium deposition to prepare battery-grade lithium carbonate according to claim 1, characterized in that: The stirring assembly (23) includes a stirring shaft (231) that is rotatably mounted on the reactor (21) and driven by a drive motor. Multiple spiral plates (232) are uniformly fixedly mounted on the stirring shaft (231), and stirring blades (233) are fixedly mounted on the stirring shaft (231) between two adjacent spiral plates (232).

5. The apparatus for continuous lithium deposition to prepare battery-grade lithium carbonate according to claim 4, characterized in that: The filter assembly (27) includes a filter plate (271), which is fixedly connected inside the discharge pipe (22) and rotatably connected to the stirring shaft (231). A cleaning module (272) is connected to the filter plate (271) to prevent large particles from accumulating on the filter plate (271).

6. The apparatus for continuous lithium deposition to prepare battery-grade lithium carbonate according to claim 5, characterized in that: The cleaning module (272) includes a vortex plate (2721), which is disposed above the filter plate (271) and fixedly connected to the stirring shaft (231). A baffle (2722) is fixedly connected to the inner circumferential wall of the discharge pipe (22).

7. The apparatus for continuous lithium deposition to prepare battery-grade lithium carbonate according to claim 6, characterized in that: The stop (2722) is annular and has a chamfer on the side of its upper end near the center. The lower end of the stop (2722) has an elliptical groove (2723).

8. The apparatus for continuous lithium deposition to prepare battery-grade lithium carbonate according to claim 1, characterized in that: The opening and closing assembly (25) includes a central rod (251) controlled by a servo motor. The central rod (251) is coaxially arranged in the liquid inlet pipe (24). The central rod (251) is symmetrically fixed with an annular seat (252) corresponding to the flange on the liquid inlet pipe (24) by a connecting plate. The annular seat (252) is rotatably connected to the liquid inlet pipe (24), and a through groove (2521) is provided on the peripheral wall of the annular seat (252). The through grooves (2521) on the two annular seats (252) in the same liquid inlet pipe (24) are staggered.

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