Automatic battery-grade lithium carbonate alkali preparation system

Abstract

The invention belongs to the technical field of alkali preparation of battery-grade lithium carbonate prepared from salt lake brine, and particularly relates to an automatic alkali preparation system for battery-grade lithium carbonate, which comprises an automatic unpacking device used for opening ton bags; the sodium carbonate preparation device is arranged below the automatic unpacking device, the sodium carbonate preparation device is communicated with a feeding mechanism used for providing pure water and sodium hydroxide into the sodium carbonate preparation device, and the sodium carbonate preparation device is used for receiving the materials in the ton bags and preparing the materials; the automatic filtering part is communicated with the sodium carbonate preparation device and is used for filtering prepared materials; the fine filtration part is communicated with the automatic filtration part and used for performing fine filtration on the filtered materials, the fine filtration part is communicated with a sodium carbonate preparation device, and the unqualified solution and the backwashing water are returned to the sodium carbonate preparation device through the fine filtration part; the finished product tank is communicated with the fine filtration part and is used for receiving the qualified solution. The method has the advantages of high automation degree, low sodium carbonate impurity content and low ton consumption.

Description

Technical Field

[0001] The present invention belongs to the technical field of preparing battery-grade lithium carbonate with soda ash in salt lake brine, and particularly relates to an automated system for preparing battery-grade lithium carbonate with soda ash. Background Art

[0002] In the process of preparing battery-grade lithium carbonate from salt lake lithium extraction, sodium carbonate (soda ash) is used as a lithium precipitation raw material and reacts with the refined lithium chloride solution to form lithium carbonate. Battery-grade lithium carbonate has strict requirements for impurity content. If industrial sodium carbonate containing certain impurities is directly used for lithium precipitation, calcium and magnesium precipitates and other insoluble impurities will be mixed into the lithium carbonate product, resulting in a significant decline in the quality of lithium carbonate and even failing to meet the battery-grade standard.

[0003] Sodium carbonate solution is one of the core raw materials for preparing battery-grade lithium carbonate. Factors such as its impurity content, concentration, temperature, and pH will significantly affect the quality and yield of battery-grade lithium carbonate. Therefore, how to use highly automated means to make the sodium carbonate solution meet the lithium precipitation requirements of battery-grade lithium carbonate is particularly important for improving the quality of preparing battery-grade lithium carbonate from salt lake brine.

[0004] For this reason, an automated system for preparing battery-grade lithium carbonate with soda ash is proposed. Summary of the Invention

[0005] The purpose of the present invention is to provide an automated system for preparing battery-grade lithium carbonate with soda ash to solve the above problems.

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

[0007] An automated system for preparing battery-grade lithium carbonate with soda ash includes:

[0008] An automatic unpacking device for opening the ton bags;

[0009] A soda ash preparation device arranged below the automatic unpacking device. The soda ash preparation device is connected to a feeding mechanism for supplying pure water and sodium hydroxide into the soda ash preparation device. The soda ash preparation device is used to receive the materials in the ton bags and prepare the materials;

[0010] An automatic filtration unit connected to the soda ash preparation device for filtering the prepared materials;

[0011] A fine filtration unit connected to the automatic filtration unit for finely filtering the filtered materials. The fine filtration unit is connected to the soda ash preparation device, and the unqualified solution and backwashing water return to the soda ash preparation device from the fine filtration unit;

[0012] A finished product tank connected to the fine filtration unit for receiving the qualified solution.

[0013] In the automated lithium carbonate for battery-grade alkali preparation system of the present invention, the soda ash preparation device includes:

[0014] The front-stage soda ash preparation kettle, whose feed inlet receives the material in the ton bag, and the front-stage soda ash preparation kettle is communicated with the feeding mechanism;

[0015] The feed inlet of the rear-stage soda ash preparation kettle is communicated with the discharge outlet of the front-stage soda ash preparation kettle, and the discharge outlet of the rear-stage soda ash preparation kettle is communicated with the automatic filtration section and the feed inlet of the front-stage soda ash preparation kettle through a reversing valve;

[0016] Stirring mechanisms are provided in both the front-stage soda ash preparation kettle and the rear-stage soda ash preparation kettle.

[0017] In the automated lithium carbonate for battery-grade alkali preparation system of the present invention, the automatic filtration section includes:

[0018] An automatic filtration device, whose feed inlet is communicated with the front-stage soda ash preparation kettle, the discharge outlet of the automatic filtration device is communicated with the fine filtration section, and the slurry outlet of the automatic filtration device is communicated with the slurry sewage treatment system.

[0019] In the automated lithium carbonate for battery-grade alkali preparation system of the present invention, the fine filtration section includes:

[0020] The first precision filter, whose feed inlet is communicated with the automatic filtration device;

[0021] A precision filtration buffer tank, which is communicated with the qualified solution outlet of the first precision filter;

[0022] The second precision filter, which is communicated with the discharge outlet of the precision filtration buffer tank, and the qualified solution outlet of the second precision filter is communicated with the finished product tank.

[0023] In the automated lithium carbonate for battery-grade alkali preparation system of the present invention, the outlet of the automatic filtration device is communicated with the feed inlet of the sodium carbonate buffer tank, the discharge outlet of the sodium carbonate buffer tank is communicated with the feed inlet of the first precision filter, and the unqualified solution outlet of the second precision filter is communicated with the feed inlet of the sodium carbonate buffer tank.

[0024] In the automated lithium carbonate for battery-grade alkali preparation system of the present invention, both the backwash outlet and the unqualified solution outlet of the first precision filter are communicated with the feed inlet of the filtration slag discharge tank, the backwash outlet of the second precision filter is communicated with the feed inlet of the filtration slag discharge tank, a stirring mechanism is provided in the filtration slag discharge tank, and the discharge outlet of the filtration slag discharge tank is communicated with the rear-stage soda ash preparation kettle.

[0025] In the automated lithium carbonate for battery grade caustic soda dosing system of the present invention, the discharge port of the finished product tank is connected to the feed port of the heat exchanger.

[0026] In the automated lithium carbonate for battery grade caustic soda dosing system of the present invention, the automatic unpacking device includes:

[0027] A lifting assembly, arranged at the upper part of the frame, for lifting the bulk bag;

[0028] An unpacking assembly, arranged in the middle of the frame, for unpacking the bulk bag lifted by the lifting assembly;

[0029] A hopper, arranged below the frame, for receiving the materials dropped from the bulk bag and feeding the materials into the front section soda ash preparation kettle.

[0030] Compared with the prior art, the present invention has the following advantages and technical effects:

[0031] In the present invention, the bulk bag is opened by the automatic unpacking device, and sodium carbonate automatically enters the soda ash preparation device for preparation. After the preparation is completed, it enters the automatic filtration device for filtration. The filtered solution is pumped into the fine filtration section for fine filtration. The qualified solution obtained is fed into the finished product tank for storage. During this process, the unqualified solution and backwash water generated by the fine filtration section are returned to the soda ash preparation device 2 for re-preparation, reducing the waste of raw materials.

[0032] The present invention has the advantages of high automation degree, few impurities in the sodium carbonate solution, and low consumption, enabling good control of the core quality indicators of magnetic foreign objects and metal particles of lithium carbonate for battery grade at the auxiliary material system end, and ensuring the quality of lithium carbonate for battery grade. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings:

[0034] Figure 1 It is a schematic structural diagram of the system of the present invention;

[0035] Figure 2 It is a schematic structural diagram of the automatic disassembly device in the present invention;

[0036] Figure 3 It is a process flow diagram of the present invention;

[0037] Among them, 1. Automatic unpacking device; 11. Lifting component; 12. Unpacking component; 13. Hopper; 2. Soda ash preparation device; 21. Front-stage soda ash preparation kettle; 22. Rear-stage soda ash preparation kettle; 3. Automatic filtration device; 4. Sodium carbonate buffer tank; 5. First precision filter; 6. Filter slag discharge tank; 7. Precision filtration buffer tank; 8. Second precision filter; 9. Finished product tank; 10. Heat exchanger. Detailed implementation manners

[0038] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0039] In order to make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific implementation manners.

[0040] Referring to Figures 1 to 3 , the present invention discloses an automated battery-grade lithium carbonate alkali preparation system, including:

[0041] An automatic unpacking device 1 for opening the ton bags;

[0042] A soda ash preparation device 2 is arranged below the automatic unpacking device 1. The soda ash preparation device 2 is connected to a feeding mechanism for supplying pure water and sodium hydroxide into the soda ash preparation device 2. The soda ash preparation device 2 is used to receive the materials in the ton bags and prepare the materials;

[0043] An automatic filtration unit, which is connected to the soda ash preparation device 2 and is used to filter the prepared materials;

[0044] A fine filtration unit, which is connected to the automatic filtration unit and is used to finely filter the filtered materials. The fine filtration unit is connected to the soda ash preparation device 2. The unqualified solution and backwash water are returned to the soda ash preparation device 2 by the fine filtration unit;

[0045] A finished product tank 9, which is connected to the fine filtration unit and is used to receive the qualified solution.

[0046] In the present invention, the ton bags are opened by the automatic unpacking device 1, and sodium carbonate automatically enters the soda ash preparation device 2 for preparation. After the preparation is completed, it enters the automatic filtration device 3 for filtration. The filtered solution is pumped into the fine filtration unit for fine filtration. The obtained qualified solution is sent into the finished product tank 9 for storage. During this process, the unqualified solution and backwash water generated by the fine filtration unit are returned to the soda ash preparation device 2 for re-preparation, reducing the waste of raw materials.

[0047] The present invention has the advantages of high automation level, few impurities in the sodium carbonate solution, and low consumption, enabling good control of the core quality indicators of battery-grade lithium carbonate, namely magnetic foreign matters and metal particles, at the auxiliary material system end, and ensuring the quality of battery-grade lithium carbonate.

[0048] In an alternative embodiment, the soda ash preparation device 2 includes:

[0049] The front-stage soda ash preparation kettle 21, whose feed inlet receives the materials in the ton bags, is connected to the feeding mechanism;

[0050] The feed inlet of the rear-stage soda ash preparation kettle 22 is connected to the discharge outlet of the front-stage soda ash preparation kettle 21, and the discharge outlet of the rear-stage soda ash preparation kettle 22 is connected to the automatic filtration section and the feed inlet of the front-stage soda ash preparation kettle 21 through a reversing valve;

[0051] Stirring mechanisms are provided in both the front-stage soda ash preparation kettle 21 and the rear-stage soda ash preparation kettle 22.

[0052] In an alternative embodiment, the automatic filtration section includes:

[0053] An automatic filtration device 3, whose feed inlet is connected to the front-stage soda ash preparation kettle 21, the discharge outlet is connected to the fine filtration section, and the slurry outlet is connected to the slurry sewage treatment system.

[0054] The automatic filtration device 3 is a plate and frame filtration device, which can realize automatic feeding, slag discharging, and cleaning, and can automatically start and stop the feed pump according to the feed flow rate and program settings.

[0055] In an alternative embodiment, the fine filtration section includes:

[0056] The first precision filter 5, whose feed inlet is connected to the automatic filtration device 3;

[0057] The precision filtration buffer tank 7, which is connected to the qualified solution outlet of the first precision filter 5;

[0058] The second precision filter 8, which is connected to the discharge outlet of the precision filtration buffer tank 7, and the qualified solution outlet of the second precision filter 8 is connected to the finished product tank 9.

[0059] Both the first precision filter 5 and the second precision filter 8 are automatic backwashing surface filters, with the feeding method being from bottom to top, and they perform full-automatic backwashing according to the set pressure difference or time.

[0060] In an alternative embodiment, the outlet of the automatic filtration device 3 is connected to the feed inlet of the sodium carbonate buffer tank 4, the discharge outlet of the sodium carbonate buffer tank 4 is connected to the feed inlet of the first precision filter 5, and the unqualified solution outlet of the second precision filter 8 is connected to the feed inlet of the sodium carbonate buffer tank 4.

[0061] In an alternative solution, the backwash outlet and the unqualified solution outlet of the first precision filter 5 are both communicated with the feed inlet of the filter residue tank 6, the backwash outlet of the second precision filter 8 is communicated with the feed inlet of the filter residue tank 6, a stirring mechanism is arranged in the filter residue tank 6, and the discharge outlet of the filter residue tank 6 is communicated with the subsequent soda ash preparation kettle 22.

[0062] In an alternative solution, the discharge outlet of the finished product tank 9 is communicated with the feed inlet of the heat exchanger 10.

[0063] In an alternative solution, the automatic unpacking device 1 includes:

[0064] A lifting assembly 11, arranged at the upper part of the frame, for lifting the ton bag;

[0065] The lifting assembly 11 is selected as an electric hoist;

[0066] An unpacking assembly 12, arranged in the middle of the frame, for unpacking the ton bag lifted by the lifting assembly 11;

[0067] A hopper 13, arranged below the frame, for receiving the materials falling from the ton bag and feeding the materials into the previous soda ash preparation kettle 21.

[0068] One specific example:

[0069] The sodium carbonate is in ton packages, and the sodium carbonate produced in the salt lake area is purchased. The calcium and magnesium contents in the sodium carbonate produced in the salt lake area are relatively high.

[0070] The main content of the sodium carbonate raw material is 99.24%, the content of the impurity calcium element is 0.0018%, the content of the impurity magnesium element is 0.0071%, as well as magnetic foreign impurities and sediment, etc. The calcium and magnesium element contents being lower than 0.02% can meet the production raw material conditions and are allowed to enter the refining process. The sodium carbonate mainly provides carbonate ions for the production of battery-grade lithium carbonate. The carbonate ions react with lithium ions to form lithium carbonate, and the finished lithium carbonate is separated according to different solubilities.

[0071] The dry-packed sodium carbonate is placed at a designated position. The hook of the lifting assembly 11 hooks the ton bag, and the execution program is operated on the control panel. The sodium carbonate is automatically placed on the unpacking assembly 12. A cutting device is arranged on the unpacking assembly 12 to cut the ton bag from top to bottom. The sodium carbonate falls into the hopper 13. The lifting assembly 11 is moved to recycle the discarded ton bag. The valve below the hopper 13 is opened, and the sodium carbonate enters the soda ash preparation device 2;

[0072] The soda ash preparation device 2 is divided into a front-stage soda ash preparation kettle group and a rear-stage soda ash preparation kettle group. The front-stage soda ash preparation kettle group includes at least two parallel front-stage soda ash preparation kettles 21, and the rear-stage soda ash preparation kettle group includes at least two parallel rear-stage soda ash preparation kettles 22. Soda ash enters the front-stage soda ash preparation kettle 21, and at the same time, purified water and purified sodium hydroxide are introduced into the front-stage soda ash preparation kettle 21 in a preset proportion through a feeding mechanism. At the same time, the materials are stirred by a stirring mechanism for the first-stage preparation. Then, the sodium carbonate solution is pumped into the rear-stage soda ash preparation kettle 22, and the materials are stirred by the stirring mechanism for the second-stage preparation;

[0073] The soda ash is in powder form. Under the surface tension of water and the adsorption between soda ash particles, the soda ash powder will agglomerate together, forming an agglomeration phenomenon. Setting the rear-stage soda ash preparation kettle 22 for the second-stage preparation can effectively reduce the occurrence of the agglomeration phenomenon;

[0074] When the preparation amount is too large, the soda ash is still not completely dissolved in the rear-stage soda ash preparation kettle 22. In this case, the changeover valve is adjusted to connect the discharge port of the rear-stage soda ash preparation kettle 22 with the feed port of the front-stage soda ash preparation kettle 21, and the materials circulate between the front-stage soda ash preparation kettle 21 and the rear-stage soda ash preparation kettle 22 until the soda ash is fully dissolved;

[0075] The sodium carbonate solution first enters the automatic filtering device 3, and completes the full-automatic feeding, slag discharging, and cleaning work according to the set time. When the feeding flow rate decreases by 25%, the pumping work stops automatically, and then the slag discharging and cleaning work are completed automatically. The slag enters the slag slurry sewage treatment system through the slag slurry port, and the filtered sodium carbonate solution enters the sodium carbonate buffer tank 4. The automatic filtering device 3 is signal-connected to the liquid level gauge in the sodium carbonate buffer tank 4, and the feeding speed of the sodium carbonate buffer tank 4 is controlled according to the liquid level of the solution in the sodium carbonate buffer tank 4;

[0076] The sodium carbonate solution in the sodium carbonate buffer tank 4 is pumped into the first precision filter 5. The feeding mode of the first precision filter 5 is from bottom to top. The sodium carbonate solution is filtered in the first precision filter 5 under the action of pressure. The qualified solution flows out from the top of the first precision filter 5 and enters the precision filtering buffer tank 7. The first precision filter 5 stops feeding every two hours for pure water backwashing, and the backwashing time is 2 minutes. The backwashing water is introduced into the filtering slag discharging tank 6, and the materials in the filtering slag discharging tank 6 are sent into the rear-stage soda ash preparation kettle 22;

[0077] Among them, a conductivity sensor is arranged at the outlet of the first precision filter 5. When the conductivity exceeds 20% of the set value, an alarm is given. The conductivity sensor is signal-connected to the feeding pump of the first precision filter 5. When an alarm is found, the bypass of the first precision filter 5 is opened, and the unqualified solution is all discharged into the filtering slag discharging tank 6;

[0078] The preliminarily qualified solution in the precision filtration buffer tank 7 enters the second precision filter 8. The filtration principle of the second precision filter 8 is the same as that of the first precision filter 5. The qualified solution flows out from the top of the second precision filter 8 and enters the finished product tank 9. The second precision filter 8 stops feeding every 1 hour and automatically starts pure water backwashing for 1 minute. The backwashing water enters the filtration slag discharge tank 6.

[0079] A stirring mechanism is arranged in the filtration slag discharge tank 6 for stirring and mixing the materials from different sources, and then the materials in the filtration slag discharge tank 6 are pumped into the subsequent soda ash preparation kettle 22 for further purification.

[0080] Among them, a conductivity sensor is arranged at the outlet of the second precision filter 8. When the conductivity exceeds 10% of the set value, an alarm is given. The conductivity sensor is signal-connected to the feed pump of the second precision filter 8. When an alarm is detected, the bypass of the second precision filter 8 is opened, and the unqualified solution is all discharged into the sodium carbonate buffer tank 4 and re-enters the first precision filter 5 for further precision filtration.

[0081] The qualified solution in the finished product tank 9 undergoes heat exchange through the heat exchanger 10 and then enters the lithium precipitation process to prepare battery-grade lithium carbonate.

[0082] The automated battery-grade lithium carbonate alkali preparation system of the present invention has the advantages of high automation, low sodium carbonate impurities, and low unit consumption. The present invention can well control the core quality indicators of magnetic foreign matters and metal particles of battery-grade lithium carbonate at the auxiliary material system end, ensuring the quality of battery-grade lithium carbonate.

[0083] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0084] The above-described embodiments are only descriptions of the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. An automated alkali preparation system for battery-grade lithium carbonate, characterized in that Including: An automatic unpacking device (1) for opening the ton bags; A soda ash preparation device (2) arranged below the automatic unpacking device (1). The soda ash preparation device (2) is connected to a feeding mechanism for supplying pure water and sodium hydroxide into the soda ash preparation device (2). The soda ash preparation device (2) is used to receive the materials in the ton bags and prepare the materials; An automatic filtration section, connected to the soda ash preparation device (2), for filtering the prepared materials; A fine filtration section, connected to the automatic filtration section, for finely filtering the filtered materials. The fine filtration section is connected to the soda ash preparation device (2). The unqualified solution and the backwashing water are returned from the fine filtration section to the soda ash preparation device (2); A finished product tank (9), connected to the fine filtration section, for receiving the qualified solution.

2. The automated lithium carbonate battery-grade alkali preparation system according to claim 1, characterized in that, The soda ash preparation device (2) includes: A front-stage soda ash preparation kettle (21) whose feed inlet receives the materials in the ton bags. The front-stage soda ash preparation kettle (21) is connected to the feeding mechanism; The feed inlet of the rear-stage soda ash preparation kettle (22) is connected to the discharge outlet of the front-stage soda ash preparation kettle (21). The discharge outlet of the rear-stage soda ash preparation kettle (22) is connected to the automatic filtration section and the feed inlet of the front-stage soda ash preparation kettle (21) through a reversing valve; Stirring mechanisms are arranged in both the front-stage soda ash preparation kettle (21) and the rear-stage soda ash preparation kettle (22).

3. An automated lithium carbonate for battery grade alkali preparation system according to claim 2, characterized in that, The automatic filtration section includes: An automatic filtration device (3) whose feed inlet is connected to the front-stage soda ash preparation kettle (21). The discharge outlet of the automatic filtration device (3) is connected to the fine filtration section. The slurry outlet of the automatic filtration device (3) is connected to a slurry sewage treatment system.

4. An automated lithium carbonate for battery grade alkali preparation system according to claim 3, characterized in that, The fine filtration section includes: A first precision filter (5) whose feed inlet is connected to the automatic filtration device (3); A precision filtration buffer tank (7), connected to the qualified solution outlet of the first precision filter (5); A second precision filter (8), connected to the discharge outlet of the precision filtration buffer tank (7). The qualified solution outlet of the second precision filter (8) is connected to the finished product tank (9).

5. An automated lithium carbonate for battery grade alkali preparation system according to claim 4, characterized in that, The outlet of the automatic filtration device (3) is connected to the feed inlet of a sodium carbonate buffer tank (4). The discharge outlet of the sodium carbonate buffer tank (4) is connected to the feed inlet of the first precision filter (5). The unqualified solution outlet of the second precision filter (8) is connected to the feed inlet of the sodium carbonate buffer tank (4).

6. An automated lithium carbonate for battery grade alkali preparation system according to claim 5, characterized in that, The backwashing outlet and the unqualified solution outlet of the first precision filter (5) are both connected to the feed inlet of a filtration slag discharge tank (6). The backwashing outlet of the second precision filter (8) is connected to the feed inlet of the filtration slag discharge tank (6). A stirring mechanism is arranged in the filtration slag discharge tank (6). The discharge outlet of the filtration slag discharge tank (6) is connected to the rear-stage soda ash preparation kettle (22).

7. An automated lithium carbonate battery-grade alkali preparation system according to claim 1, wherein, The discharge outlet of the finished product tank (9) is connected to the feed inlet of a heat exchanger (10).

8. An automated lithium carbonate alkali preparation system for battery grade according to claim 2, characterized in that, The automatic unpacking device (1) includes: A lifting assembly (11) arranged at the upper part of the frame for lifting the ton bags; Unpacking component (12), which is arranged in the middle of the rack and is used for unpacking the bulk bag lifted by the lifting component (11); Hopper (13), which is arranged below the rack and is used for receiving the materials falling from the bulk bag and feeding the materials into the front-end soda ash preparation kettle (21).

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