A continuous lithium precipitation device and lithium carbonate production system

Abstract

The present application relates to a continuous lithium precipitation device and a lithium carbonate production system, including a precipitation tower, a first input device arranged in the precipitation tower, an intermittent interceptor arranged in the precipitation tower and located below the first input device, a rotary interceptor arranged in the precipitation tower and located below the intermittent interceptor, a second input device arranged in the precipitation tower, a first recovery pipeline whose input end extends into the precipitation tower and is located on the rotation track of the rotary interceptor, a second recovery pipeline whose input end extends into the precipitation tower and is located below the second input device, and the output end of the first input device faces the bottom of the precipitation tower. The continuous lithium precipitation device and lithium carbonate production system disclosed in the present application generate lithium carbonate crystals by a two-way flow method, and during the generation process, lithium carbonate crystals that meet the particle size requirements are initially filtered out, which can increase the growth rate of the crystals and obtain the uniformity of the crystals without destroying the crystal structure.

Description

Technical Field

[0001] The present application relates to the technical field of industrial production equipment, and in particular to a continuous lithium precipitation device and a lithium carbonate production system. Background Art

[0002] Li2CO3 is the most important lithium salt among lithium compounds and the main raw material for preparing other high-purity lithium compounds and lithium alloys. Therefore, Li2CO3 production is one of the most basic and critical links in the lithium industry. The rapid development of the lithium battery industry in recent years has led to a significant increase in the demand for Li2CO3, the main raw material for producing lithium battery positive electrode materials.

[0003] In the past, the production method of Li2CO3 mostly adopted single-kettle independent operation, which had problems such as large equipment footprint, high labor intensity, low automation, discontinuous process and unstable product properties. This is mainly because each production process is a new process, which requires feeding and process control, and it is difficult to ensure consistency.

[0004] Another method uses two agitators to drive the reaction solution to flow in the tank to achieve continuous precipitation. In this method, the reaction solution needs to circulate, and the shear force generated by the agitator will also destroy the crystal structure and affect the normal growth of the crystal, resulting in a low particle size. In the later filtration process, multi-process combined filtration is required. Summary of the invention

[0005] The present application provides a continuous lithium precipitation device and a lithium carbonate production system, which generate lithium carbonate crystals by a two-way flow method. During the generation process, lithium carbonate crystals that meet the particle size requirements are simultaneously filtered out. This method can increase the growth rate of the crystals and obtain the uniformity of the crystals without destroying the crystal structure.

[0006] The above-mentioned purpose of the present application is achieved through the following technical solutions:

[0007] In a first aspect, the present application provides a continuous lithium deposition device, comprising:

[0008] Sedimentation tower;

[0009] A first input device is arranged in the sedimentation tower, and an output end of the first input device faces the bottom of the sedimentation tower;

[0010] An intermittent interceptor is arranged in the settling tower and below the first input device;

[0011] A rotating interceptor is located in the settling tower and below the intermittent interceptor;

[0012] A second input device is arranged in the sedimentation tower, and an output end of the second input device faces the top of the sedimentation tower;

[0013] A first recovery pipeline, the input end of which extends into the sedimentation tower and is located on the rotation track of the rotary interceptor;

[0014] A second recovery pipeline, the input end of which extends into the sedimentation tower and is located below the second input device;

[0015] The intermittent interceptor and the rotary interceptor are located between the first input device and the second input device.

[0016] In a possible implementation of the first aspect, the intermittent interceptor includes:

[0017] A fixed plate is arranged in the sedimentation tower and fixedly connected to the inner wall of the sedimentation tower;

[0018] First through holes are evenly arranged on the fixing plate around the axis of the fixing plate;

[0019] A rotating plate is rotatably connected to the fixed plate;

[0020] The second through holes are evenly arranged on the rotating plate around the axis of the rotating plate;

[0021] The first driver is arranged on the sedimentation tower, and the driving shaft of the first driver extends into the sedimentation tower and is connected with the rotating plate.

[0022] In a possible implementation of the first aspect, the rotary interceptor includes:

[0023] A rotating shaft is arranged in the sedimentation tower;

[0024] A plurality of sector-shaped interception plates are arranged at intervals on the rotating shaft, and the central angle corresponding to the sector-shaped interception plates is less than 180°;

[0025] Flow holes are evenly distributed on the fan-shaped intercepting plate;

[0026] The second driver is arranged on the sedimentation tower and connected with the rotating shaft.

[0027] In a possible implementation manner of the first aspect, in a direction away from the rotation axis, the sector-shaped intercepting plate is inclined toward a direction close to the bottom of the sedimentation tower.

[0028] In a possible implementation of the first aspect, a recovery tank is provided on one side of the sector-shaped intercepting plate close to the inner wall of the sedimentation tower;

[0029] The input end of the first recovery pipeline is located above the recovery tank.

[0030] In a possible implementation manner of the first aspect, on a plane perpendicular to the axis of the rotating shaft, an overlapping area of ​​projections of two adjacent sector-shaped intercepting plates is smaller than a projection area of ​​the sector-shaped intercepting plates.

[0031] In a possible implementation manner of the first aspect, the first input device includes:

[0032] A telescopic drive, mounted on the settling tower;

[0033] a diversion pipe network, which is mounted on the telescopic drive and is located inside the sedimentation tower;

[0034] Flexible ejectors are evenly distributed on the guide pipe network;

[0035] A first connecting pipe, a first end of which is located outside the sedimentation tower, and a second end of which extends into the sedimentation tower and is connected to the diversion pipe network;

[0036] Among them, the telescopic drive is used to drive the flexible ejector into brief contact with the intermittent interceptor.

[0037] In a possible implementation of the first aspect, the flexible ejector includes:

[0038] A hard connecting pipe, a first end of which is connected to the diversion pipe network;

[0039] a flexible ball connected to the second end of the hard connecting tube;

[0040] The injection holes are evenly distributed on the flexible sphere.

[0041] In a possible implementation manner of the first aspect, an internal circulation module is further included, and the internal circulation module includes:

[0042] An atomizing nozzle module is arranged in the sedimentation tower and above the first input device;

[0043] A second connecting pipe, a first end of which is connected to the bottom of the sedimentation tower, and a second end of which is connected to the atomizing nozzle module;

[0044] The circulation pump is arranged on the second connecting pipeline.

[0045] In a second aspect, the present application provides a lithium carbonate production system, comprising a continuous lithium precipitation device as described in the first aspect and any implementation of the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 It is a structural schematic diagram of a continuous lithium deposition device provided in this application.

[0047] Figure 2 This is a schematic diagram of the growth rate of lithium carbonate crystals provided in this application.

[0048] Figure 3 It is a connection schematic diagram of a fixed plate and a rotating plate provided in the present application.

[0049] Figure 4 It is a structural schematic diagram of a fixing plate provided in this application.

[0050] Figure 5 It is a structural schematic diagram of a rotating plate provided in this application.

[0051] Figure 6 It is a schematic diagram of the principle of a first driver driving a rotating plate to rotate provided in the present application.

[0052] Figure 7 It is a structural schematic diagram of a rotary interceptor provided by the present application.

[0053] Figure 8 It is a structural schematic diagram of the connection between a second recovery pipeline and a second connecting pipeline provided in the present application.

[0054] Fig. 9 It is a structural schematic diagram of a flexible ejector provided in this application.

[0055] In the figure, 1, a sedimentation tower, 2, a first input device, 3, an intermittent interceptor, 4, a rotating interceptor, 5, a second input device, 6, a first recovery pipe, 7, a second recovery pipe, 8, an internal circulation module, 21, a telescopic driver, 22, a flow guide network, 23, a flexible injector, 24, a first connecting pipe, 31, a fixed plate, 32, a first through hole, 33, a rotating plate, 34, a second through hole, 35, a first driver, 41, a rotating shaft, 42, a fan-shaped interceptor plate, 43, a flow hole, 44, a second driver, 45, a recovery tank, 81, an atomizing nozzle module, 82, a second connecting pipe, 83, a circulating pump, 231, a hard connecting pipe, 232, a flexible sphere, 233, a spray hole. DETAILED DESCRIPTION

[0056] The technical solution in this application is further described in detail below in conjunction with the accompanying drawings.

[0057] This application discloses a continuous lithium deposition device, see Figure 1 In some examples, the continuous lithium precipitation equipment disclosed in the present application includes a precipitation tower 1, a first input device 2, an intermittent interceptor 3, a rotating interceptor 4, a second input device 5, a first recovery pipeline 6 and a second recovery pipeline 7.

[0058] The first input device 2 is located in the sedimentation tower 1, and the output end of the first input device 2 is toward the bottom of the sedimentation tower 1. The second input device 5 is also located in the sedimentation tower 1, and the output end of the second input device 5 is toward the top of the sedimentation tower 1. The first input device 2 and the second input device 5 have the same function of transporting raw materials into the sedimentation tower 1. The difference lies in the types of raw materials transported.

[0059] The raw materials here refer to solutions, including sodium carbonate solutions and lithium-containing solutions.

[0060] The first input device 2 and the second input device 5 respectively transport a raw material into the precipitation tower 1, and the first raw material flows from top to bottom in the precipitation tower 1, and the second raw material flows from bottom to top in the precipitation tower 1. The two raw materials react during the flow process and generate lithium carbonate crystals.

[0061] The solution flowing from bottom to top has a faster flow speed, first reaches the top of the liquid surface in the sedimentation tower 1, then diffuses to the surroundings, and then flows from top to bottom in the sedimentation tower 1 with the second solution. This method can achieve full mixing of the two solutions.

[0062] The lithium carbonate crystals formed at the beginning are small in size, but as time goes by, the volume of the lithium carbonate crystals will gradually increase. The lithium carbonate crystals with qualified particle size are recovered by the intermittent interceptor 3 and the rotary interceptor 4, and sent to the subsequent process for separation and drying to obtain lithium carbonate products.

[0063] After the lithium carbonate crystals appearing in the precipitation tower 1 grow to a certain extent, they begin to move from top to bottom in the precipitation tower 1 and fall onto the rotary interceptor 4 or the bottom of the precipitation tower 1. The lithium carbonate crystals falling on the rotary interceptor 4 are recovered by the first recovery pipe 6, and the lithium carbonate crystals falling at the bottom of the precipitation tower 1 are recovered by the second recovery pipe 7.

[0064] There are two issues that need to be stated here. The first issue is about the formation of small lithium carbonate crystals, which requires a relatively stable environment. The second issue is that the growth rate of lithium carbonate crystals includes an ascending section and a descending section, so it is necessary to take them out when the particle size is appropriate to obtain the highest possible output rate. The growth rate curve of lithium carbonate crystals is shown in Figure 2 shown.

[0065] The solution to the first problem is the intermittent interceptor 3, which is located in the sedimentation tower 1 and below the first input device 2. The function of the intermittent interceptor 3 is to create a stable zone below the first input device 2, and the existence of the stable zone is intermittent.

[0066] When the stable zone exists, the area above the intermittent interceptor 3 is almost in a static state. This environment is conducive to the initial formation of lithium carbonate crystals. When small lithium carbonate crystals begin to appear on a large scale, the stable zone disappears. At this time, the small lithium carbonate crystals begin to grow gradually and move toward the bottom of the precipitation tower 1.

[0067] In addition, the concentration of the second raw material in the stable zone will increase at this time, which is conducive to the rapid and large-scale formation of small-particle lithium carbonate crystals.

[0068] pass Figure 4 and Figure 5It can be seen that there is a channel in the middle of the intermittent interceptor 3. When the stable zone exists, the channel can enable the second raw material to continuously enter the stable zone.

[0069] The second problem is solved by the rotary interceptor 4. Most of the lithium carbonate crystals that meet the particle size requirements are recovered by the rotary interceptor 4, and a small number of lithium carbonate crystals that meet the particle size requirements will fall to the bottom of the precipitation tower 1.

[0070] The input end of the first recovery pipe 6 extends into the sedimentation tower 1 and is located on the rotation track of the rotary interceptor 4, and its function is to absorb the lithium carbonate crystals that meet the particle size requirements on the rotary interceptor 4 by negative pressure; the input end of the second recovery pipe 7 extends into the sedimentation tower 1 and is located below the second input device 5, and its function is to absorb the lithium carbonate crystals that meet the particle size requirements on the bottom of the sedimentation tower 1 by negative pressure.

[0071] The intermittent interceptor 3 and the rotary interceptor 4 are located between the first input device 2 and the second input device 5 . There are multiple rotary interceptors 4 , which are spaced apart in the height direction of the sedimentation tower 1 .

[0072] For some examples, see Figure 1 , Figures 3 to 6 The intermittent interceptor 3 includes a fixed plate 31, a rotating plate 33 and a first driver 35. The fixed plate 31 is fixed in the sedimentation tower 1 and fixedly connected to the inner wall of the sedimentation tower 1. The rotating plate 33 is rotatably connected to the fixed plate 31. The first driver 35 is fixedly installed on the sedimentation tower 1. The driving shaft of the driver 35 extends into the sedimentation tower 1 and is connected to the rotating plate 33.

[0073] The fixed plate 31 and the rotating plate 33 are connected via a bearing.

[0074] In some possible implementations, the first driver 35 uses a telescopic driver, such as a pneumatic cylinder or an electric cylinder. This is because the rotation amount of the rotating plate 33 is limited, and the telescopic amount of the telescopic driver can meet the rotation requirement of the rotating plate 33 .

[0075] like Figure 6 As shown, the telescopic rod of the first driver 35 extends into the arc-shaped sliding groove on the rotating plate 33 in the sedimentation tower 1. When the telescopic rod of the first driver 35 is extended or shortened, it can drive the rotating plate 33 to rotate.

[0076] The first through holes 32 are evenly arranged on the fixed plate 31 around the axis of the fixed plate 31, and the second through holes 34 are evenly arranged on the rotating plate 33 around the axis of the rotating plate 33. When the first through holes 32 are connected with the corresponding second through holes 34, the intermittent interceptor 3 is in an open state, otherwise the intermittent interceptor 3 is in a closed state.

[0077] For some examples, see Figure 1 and Figure 7 The rotary interceptor 4 includes a rotary shaft 41, a fan-shaped interception plate 42 and a second driver 44. The rotary shaft 41 is arranged in the sedimentation tower 1, and the rotary shaft 41 is connected to the sedimentation tower 1 in a rotary connection.

[0078] There are multiple fan-shaped intercepting plates 42 , which are arranged at intervals on the rotating shaft 41 . When passing through, the central angle of the fan-shaped intercepting plates 42 is required to be less than 180°. The fan-shaped intercepting plates 42 are also evenly distributed with flow holes 43 .

[0079] The second driver 44 is disposed on the sedimentation tower 1 and connected to the rotating shaft 41 .

[0080] In some possible implementations, the second driver 44 includes a motor and a reducer, and the second driver 44 is located outside the sedimentation tower 1 .

[0081] In some possible implementations, the fan-shaped intercepting plate 42 is inclined toward the bottom of the sedimentation tower 1 in a direction away from the rotating shaft 41 , so that the sodium carbonate crystals on the fan-shaped intercepting plate 42 can move to the edge of the fan-shaped intercepting plate 42 .

[0082] In some possible implementations, a recovery tank 45 is provided on one side of the sector-shaped intercepting plate 42 close to the inner wall of the precipitation tower 1 , and the purpose of the recovery tank 45 is to temporarily store the collected sodium carbonate crystals.

[0083] In some possible implementations, on a plane perpendicular to the axis of the rotating shaft 41 , the overlapping area of ​​the projections of two adjacent fan-shaped intercepting plates 42 is smaller than the projection area of ​​the fan-shaped intercepting plates 42 , in order to avoid complete overlap of the two adjacent fan-shaped intercepting plates 42 , which would result in a decrease in the interception efficiency of the fan-shaped intercepting plates 42 .

[0084] The input end of the first recovery pipe 6 is located above the recovery tank 45. When the recovery tank 45 passes through the input end of the first recovery pipe 6, the first recovery pipe 6 absorbs the sodium carbonate crystals temporarily stored in the recovery tank 45 by negative pressure.

[0085] For some examples, see Figure 1 The first input device 2 includes a telescopic drive 21, a guide pipe network 22, a flexible ejector 23 and a first connecting pipe 24. The telescopic drive 21 is fixedly mounted on the sedimentation tower 1. The guide pipe network 22 is mounted on the telescopic drive 21 and is located inside the sedimentation tower 1. The flexible ejectors 23 are evenly distributed on the guide pipe network 22. The first end of the first connecting pipe 24 is located outside the sedimentation tower 1, and the second end extends into the sedimentation tower 1 and is connected to the guide pipe network 22.

[0086] The first material enters the flexible ejector 23 through the first connecting pipe 24 and the flow guiding pipe network 22 , and is then uniformly ejected into the interior of the sedimentation tower 1 .

[0087] It is explained here that, considering the limited injection speed of the flexible injector 23, the flexible injector 23 may be blocked, and the reason for the blockage is that sodium carbonate crystals are generated at the injection hole 233 of the flexible injector 23. In order to solve this problem, the present application uses a telescopic driver 21 to drive the guide pipe network 22 and the flexible injector 23 to contact the intermittent interceptor 3 briefly.

[0088] The brief contact can force the flexible injector 23 to deform, thereby clearing the injection hole 233 .

[0089] The flexible injector 23 includes a hard connecting tube 231 and a flexible sphere 232. The first end of the hard connecting tube 231 is connected to the guide pipe network 22, and the second end is connected to the flexible sphere 232. The flexible sphere 232 is evenly distributed with injection holes 233. Fig. 9 shown.

[0090] For some examples, see Figure 1 An internal circulation module 8 is also added, which includes an atomizing nozzle module 81, a second connecting pipe 82 and a circulating pump 83. The atomizing nozzle module 81 is located in the sedimentation tower 1 and above the first input device 2. The first end of the second connecting pipe 82 is connected to the bottom of the sedimentation tower 1, and the second end is connected to the atomizing nozzle module 81. The circulating pump 83 is arranged on the second connecting pipe 82.

[0091] The atomizing nozzle module 81, the second connecting pipe 82 and the sedimentation tower 1 form a loop.

[0092] The function of the internal circulation module 8 is to drive the circulation of materials in the sedimentation tower 1, so as to improve the utilization rate of the materials.

[0093] When the internal circulation module 8 is used, the second recovery pipe 7 needs to be transferred to the second connecting pipe 82, such as Figure 8 As shown, a filter is added at the connection between the second recovery pipeline 7 and the second connecting pipeline 82 to intercept sodium carbonate crystals that meet the particle size requirements.

[0094] The present application also discloses a lithium carbonate production system, including any one of the continuous lithium precipitation devices described above.

[0095] The lithium carbonate production system is mainly composed of a batching system (sodium carbonate solution, lithium-containing solution), the continuous lithium precipitation equipment disclosed in the present application, a precipitation tank, a separation tank and a drying system. The sodium carbonate solution and the lithium-containing solution enter the continuous lithium precipitation equipment for reaction, and the generated lithium carbonate crystals enter the precipitation tank for preliminary precipitation, and then enter the separation tank for dehydration and separation, at which time wet lithium carbonate is obtained. The wet lithium carbonate enters the drying system for drying to obtain a finished lithium carbonate product.

[0096] The embodiments of this specific implementation method are all preferred embodiments of the present application, and are not intended to limit the protection scope of the present application. Therefore, all equivalent changes made based on the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A continuous lithium precipitation device, characterized in that: include: Sedimentation tower (1); A first input device (2) is arranged in the sedimentation tower (1), and an output end of the first input device (2) faces the bottom of the sedimentation tower (1); An intermittent interceptor (3) is arranged in the sedimentation tower (1) and is located below the first input device (2); A rotating interceptor (4) is arranged in the sedimentation tower (1) and is located below the intermittent interceptor (3); A second input device (5) is arranged in the sedimentation tower (1), and an output end of the second input device (5) faces the top of the sedimentation tower (1); A first recovery pipe (6), the input end of which extends into the sedimentation tower (1) and is located on the rotation track of the rotary interceptor (4); A second recovery pipe (7), the input end of which extends into the sedimentation tower (1) and is located below the second input device (5); Wherein, the intermittent interceptor (3) and the rotary interceptor (4) are located between the first input device (2) and the second input device (5); The intermittent interceptor (3) comprises: A fixed plate (31) is disposed in the sedimentation tower (1) and fixedly connected to the inner wall of the sedimentation tower (1); First through holes (32) are evenly arranged on the fixing plate (31) around the axis of the fixing plate (31); A rotating plate (33) is rotatably connected to the fixed plate (31); Second through holes (34) are evenly arranged on the rotating plate (33) around the axis of the rotating plate (33); A first driver (35) is arranged on the sedimentation tower (1), and a driving shaft of the first driver (35) extends into the sedimentation tower (1) and is connected to the rotating plate (33); The rotary interceptor (4) comprises: A rotating shaft (41) is disposed in the sedimentation tower (1); A plurality of sector-shaped intercepting plates (42) are arranged at intervals on the rotating shaft (41), and the central angle corresponding to the sector-shaped intercepting plates (42) is less than 180°; Flow holes (43) are evenly distributed on the fan-shaped intercepting plate (42); The second driver (44) is arranged on the sedimentation tower (1) and connected to the rotating shaft (41).

2. The continuous lithium precipitation equipment according to claim 1, characterized in that: In a direction away from the rotation axis (41), the sector-shaped intercepting plate (42) is inclined toward a direction close to the bottom of the sedimentation tower (1).

3. The continuous lithium precipitation equipment according to claim 2, characterized in that: A recovery tank (45) is provided on one side of the sector-shaped intercepting plate (42) close to the inner wall of the sedimentation tower (1); The input end of the first recovery pipe (6) is located above the recovery tank (45).

4. The continuous lithium precipitation equipment according to claim 2, characterized in that: On a plane perpendicular to the axis of the rotating shaft (41), the overlapping area of ​​the projections of two adjacent sector-shaped intercepting plates (42) is smaller than the projection area of ​​the sector-shaped intercepting plates (42).

5. The continuous lithium precipitation equipment according to claim 1, characterized in that: The first input device (2) comprises: A telescopic driver (21) is provided on the sedimentation tower (1); A flow guide pipe network (22) is provided on the telescopic driver (21) and is located inside the sedimentation tower (1); Flexible ejectors (23) are evenly distributed on the flow guiding pipe network (22); A first connecting pipe (24), a first end of which is located outside the sedimentation tower (1), and a second end of which extends into the sedimentation tower (1) and is connected to the flow guide pipe network (22); The telescopic driver (21) is used to drive the flexible ejector (23) to briefly contact the intermittent interceptor (3).

6. The continuous lithium precipitation equipment according to claim 5, characterized in that: The flexible ejector (23) comprises: A hard connecting pipe (231), a first end of which is connected to the flow guiding pipe network (22); A flexible sphere (232) connected to the second end of the hard connecting tube (231); The injection holes (233) are evenly distributed on the flexible sphere (232).

7. The continuous lithium deposition equipment according to claim 1, characterized in that: It also includes an internal circulation module (8), which includes: An atomizing nozzle module (81) is arranged in the sedimentation tower (1) and located above the first input device (2); A second connecting pipe (82), a first end of which is connected to the bottom of the sedimentation tower (1), and a second end of which is connected to the atomizing nozzle module (81); The circulation pump (83) is arranged on the second connecting pipeline (82).

8. A lithium carbonate production system, characterized in that: Comprising the continuous lithium deposition equipment as described in any one of claims 1 to 7.

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