Micro-interface enhanced mass transfer lithium carbonate continuous carbonization system

Abstract

The utility model provides a micro-interface enhanced mass transfer lithium carbonate continuous carbonization system, which comprises a configuration kettle and N carbonization kettles which are connected in sequence, the upper part of the configuration kettle is connected with a feed pipe and an exhaust pipe, the side part of the Nth carbonization kettle is connected with a liquid outlet pipe and an air inlet pipe, the configuration kettle is connected with the first carbonization kettle through a feed liquid conveying pipeline, and the carbonization kettles are connected through a gas conveying pipeline; material distribution pipes are arranged in the carbonization kettles, micro-interface strengthening units are arranged in the configuration kettle and the carbonization kettles, and a separation unit is arranged in the Nth carbonization kettle. The micro-interface enhanced mass transfer lithium carbonate continuous carbonization system provided by the utility model realizes continuous carbonization of lithium carbonate, and disperses carbon dioxide gas into nanoscale micro bubbles through the micro-interface enhanced unit, so that the dissolved amount of carbon dioxide is increased, the utilization rate of carbon dioxide is improved, and the energy consumption is reduced. Meanwhile, the lithium carbonate feed liquid is more uniformly contacted with carbon dioxide by combining with the material distribution pipe, so that the reaction efficiency is further improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of lithium carbonate production, and particularly relates to a micro-interface enhanced mass transfer continuous carbonation system for lithium carbonate. Background Art

[0002] As one of the important raw materials for the positive electrode materials of lithium-ion batteries, the demand for lithium carbonate has increased significantly. There are various preparation methods for lithium carbonate, and one of the commonly used methods is to react a lithium carbonate feed liquid with carbon dioxide gas.

[0003] In the prior art, the commonly used production methods can be divided into a single reaction kettle type and a circulating reaction tower type. In the single reaction kettle type, the lithium carbonate feed liquid is injected into the reaction kettle at one time, and carbon dioxide gas is introduced from the bottom of the reaction kettle. After stirring, the two react. After the carbon dioxide is consumed, carbon dioxide is introduced again from the bottom of the reaction kettle, and the above operation is repeated until the reaction is completed. In the circulating reaction tower type, the lithium carbonate feed liquid enters from the top of the tower and leaves from the bottom of the tower, and under the action of a pump, enters the reaction tower again from the top of the tower. At the same time, carbon dioxide is continuously introduced from the bottom of the reaction tower for gas-liquid countercurrent reaction to generate a lithium carbonate carbonation liquid. However, in the above two methods, the solubility of carbon dioxide gas is relatively low, and it is necessary to increase the recycling amount of carbon dioxide, which leads to an increase in energy consumption and a reduction in reaction efficiency. Summary of the Utility Model

[0004] An embodiment of the utility model provides a micro-interface enhanced mass transfer continuous carbonation system for lithium carbonate, which can realize the continuous carbonation of lithium carbonate, increase the dissolution amount of carbon dioxide, improve the utilization rate of carbon dioxide, and improve the reaction efficiency.

[0005] To achieve the above object, the technical solution adopted by the utility model is: to provide a micro-interface enhanced mass transfer continuous carbonation system for lithium carbonate, including a configuration kettle and N carbonation kettles connected in sequence, where N≥2 and N is a positive integer. The upper part of the configuration kettle is connected with a feed pipe and an exhaust pipe. The side part of the Nth carbonation kettle is connected with a liquid outlet pipe and an air inlet pipe, and a cleaning port is arranged at the bottom. The bottom of the configuration kettle and the top of the first carbonation kettle, and the bottom of the carbonation kettle and the top of the next carbonation kettle are respectively connected by a feed liquid conveying pipeline. The top of the carbonation kettle and the side part of the previous carbonation kettle, and the top of the first carbonation kettle and the side part of the configuration kettle are respectively connected by a gas conveying pipeline. Wherein, a cloth pipe connected with the feed liquid conveying pipeline is arranged in the carbonation kettle. A micro-interface enhanced unit for dispersing carbon dioxide gas into tiny bubbles is arranged in both the configuration kettle and the carbonation kettle. The micro-interface enhanced unit is located below the cloth pipe and is connected with the gas conveying pipeline or the air inlet pipe. A separation unit connected with the liquid outlet pipe is arranged in the Nth carbonation kettle, and the separation unit is used for solid-liquid separation of the lithium carbonate carbonation liquid.

[0006] As another embodiment of the present utility model, stirring units are provided on both the configuration kettle and the carbonization kettle. The stirring unit includes a stirring shaft rotatably connected inside the configuration kettle or the carbonization kettle, a driving member connected above the configuration kettle or the carbonization kettle, and stirring blades connected to the outer periphery of the stirring shaft. The driving member is connected to the stirring shaft and is used to drive the stirring shaft to rotate.

[0007] As another embodiment of the present utility model, the stirring shaft penetrates downward through the micro-interface strengthening unit, and stirring blades are connected to the outer periphery of the stirring shaft and located below the micro-interface strengthening unit. The stirring blades are used to rotate under the drive of the stirring shaft to break up the particles in the lithium carbonate liquid material.

[0008] As another embodiment of the present utility model, the micro-interface strengthening unit includes an intake air coiled pipe connected to the gas delivery pipeline or the intake pipe, and a micro-interface membrane covering the outer periphery of the intake air coiled pipe. Air-permeable holes for the gas to pass through are provided on the peripheral wall of the intake air coiled pipe, and the micro-interface membrane is used to cover the air-permeable holes.

[0009] As another embodiment of the present utility model, the intake air coiled pipe includes an outer ring pipe connected to the gas delivery pipeline or the intake pipe, an inner ring pipe coaxially arranged with the outer ring pipe, and a plurality of branch pipes connected between the outer ring pipe and the inner ring pipe. The inner ring pipe is located on the outer periphery of the stirring shaft, and the air-permeable holes are uniformly distributed on the pipe walls of the outer ring pipe, the inner ring pipe and the branch pipes.

[0010] As another embodiment of the present utility model, the cloth pipe includes a cloth ring pipe connected to the liquid material delivery pipeline, a support sleeve sleeved on the outer periphery of the stirring shaft and coaxially arranged with the cloth ring pipe, and a plurality of cloth branch pipes connected between the cloth ring pipe and the support sleeve. A plurality of first nozzles opening downward are communicated on the peripheral walls of the cloth ring pipe and the cloth branch pipes.

[0011] As another embodiment of the present utility model, the cloth pipe is a spiral material pipe, the spiral material pipe spirally extends downward along the central axis of the stirring shaft, and the spiral radius of the spiral material pipe gradually decreases from top to bottom. A plurality of second nozzles opening downward are communicated on the peripheral wall of the spiral material pipe, and the plurality of second nozzles are arranged at intervals along the spiral direction.

[0012] As another embodiment of the present utility model, the separation unit includes a filter cylinder communicated with the liquid outlet pipe and a filter membrane covering the outer periphery of the filter cylinder. Filter holes for the lithium carbonate carbonization liquid to pass through are provided on the peripheral wall of the filter cylinder, and the filter membrane is used to cover the filter holes.

[0013] As another embodiment of the present utility model, a communicating pipe is connected to the liquid outlet pipe, there are a plurality of separation units, and the liquid outlet ends of the separation units are respectively communicated with the communicating pipe.

[0014] As another embodiment of the present utility model, a pressure controller is provided on the top of the first carbonization kettle, and the pressure controller is used to monitor the carbon dioxide partial pressure in the first carbonization kettle.

[0015] The beneficial effects of the microinterface enhanced mass transfer continuous carbonation system for lithium carbonate provided by the present utility model are as follows: Compared with the prior art, in the microinterface enhanced mass transfer continuous carbonation system for lithium carbonate of the present utility model, raw materials enter the configuration kettle through the feed pipe for the configuration of the lithium carbonate liquor. The configured lithium carbonate liquor flows into each carbonation kettle from top to bottom in sequence through each liquor conveying pipeline. At the same time, carbon dioxide gas is introduced through the gas inlet pipe of the last carbonation kettle and is sequentially introduced into each carbonation kettle and the configuration kettle from bottom to top through each gas conveying pipeline, so that the lithium carbonate liquor undergoes a gas-liquid countercurrent reaction with carbon dioxide gas in the configuration kettle and each carbonation kettle, realizing the continuous carbonation of lithium carbonate, and after the solid-liquid separation of the carbonated liquid of lithium carbonate by the separation unit, it is discharged through the liquid outlet pipe; On this basis, the microinterface enhancement unit can disperse carbon dioxide gas into nano-scale microbubbles, increasing the dissolution amount of carbon dioxide, improving the utilization rate of carbon dioxide, and at the same time combining the cloth pipe in the carbonation kettle to make the contact area between the lithium carbonate liquor and carbon dioxide more uniform, further improving the reaction efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the following drawings 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.

[0017] Figure 1 It is a schematic structural diagram of the microinterface enhanced mass transfer continuous carbonation system for lithium carbonate provided by the embodiment of the present utility model;

[0018] Figure 2 It is a schematic structural diagram of the configuration kettle provided by the embodiment of the present utility model;

[0019] Figure 3 It is a schematic structural diagram of the Nth carbonation kettle provided by the embodiment of the present utility model;

[0020] Figure 4 It is a top view structural diagram of the microinterface enhancement unit provided by the embodiment of the present utility model;

[0021] Figure 5 It is a schematic structural diagram of the cloth pipe provided by the embodiment of the present utility model;

[0022] Figure 6 It is a schematic structural diagram of another embodiment of the cloth pipe provided by the embodiment of the present utility model;

[0023] Figure 7 It is a schematic structural diagram of the separation unit and the connecting pipe provided by the embodiment of the present utility model.

[0024] Among them, each reference numeral in the figure:

[0025] 1. Configuration kettle; 11. Feed pipe; 12. Exhaust pipe; 2. Carbonization kettle; 21. Liquid discharge pipe; 22. Gas inlet pipe; 23. Cleaning port; 3. Liquid material conveying pipeline; 31. Feed pump; 4. Gas conveying pipeline; 5. Cloth pipe; 51. Cloth loop pipe; 52. Cloth branch pipe; 53. Support sleeve; 54. First spray head; 55. Spiral material pipe; 56. Second spray head; 6. Microinterface strengthening unit; 61. Intake air coil; 611. Vent hole; 612. Outer ring pipe; 613. Inner ring pipe; 614. Branch pipe; 7. Separation unit; 71. Filter cartridge; 711. Filter hole; 72. Filter membrane; 8. Stirring unit; 81. Stirring shaft; 82. Stirring paddle; 83. Driving part; 84. Stirring blade; 9. Connecting pipe. Specific implementation manners

[0026] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model.

[0027] It should be noted that when an element is referred to as being "disposed on" another element, it can be directly on the other element or indirectly on the other element. It should be understood that the orientation or positional relationship indicated by terms such as "length", "width", "upper", "lower", "front", "rear", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, 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 thus cannot be understood as a limitation to the present invention. Terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or several of such features. In the description of the present invention, the meaning of "a plurality" and "several" is two or more unless otherwise specifically defined.

[0028] Please refer to Figures 1 to 7, the continuous carbonization system of lithium carbonate with enhanced mass transfer through micro-interfaces provided by the present utility model will be described. The continuous carbonization system of lithium carbonate with enhanced mass transfer through micro-interfaces includes a configuration kettle 1 and N carbonization kettles 2 connected in sequence, where N≥2 and N is a positive integer. The upper part of the configuration kettle 1 is connected with a feed pipe 11 and an exhaust pipe 12. The side part of the Nth carbonization kettle 2 is connected with a liquid outlet pipe 21 and an air inlet pipe 22, and a cleaning port 23 is provided at the bottom. The bottom of the configuration kettle 1 and the top of the first carbonization kettle 2, as well as the bottom of the carbonization kettle 2 and the top of the subsequent carbonization kettle 2, are respectively connected by a liquid material conveying pipeline 3. The top of the carbonization kettle 2 and the side part of the previous carbonization kettle 2, as well as the top of the first carbonization kettle 2 and the side part of the configuration kettle 1, are respectively connected by a gas conveying pipeline 4. Among them, a cloth pipe 5 connected to the liquid material conveying pipeline 3 is provided in the carbonization kettle 2. Micro-interface strengthening units 6 for dispersing carbon dioxide gas into tiny bubbles are provided in both the configuration kettle 1 and the carbonization kettle 2. The micro-interface strengthening unit 6 is located below the cloth pipe 5 and is connected to the gas conveying pipeline 4 or the air inlet pipe 22. A separation unit 7 connected to the liquid outlet pipe 21 is provided in the Nth carbonization kettle 2, and the separation unit 7 is used for solid-liquid separation of the carbonized liquid of lithium carbonate.

[0029] In the continuous carbonization system of lithium carbonate with enhanced mass transfer through micro-interfaces provided in this embodiment, compared with the prior art, the raw materials enter the configuration kettle 1 through the feed pipe 11 for the configuration of the lithium carbonate liquid material. The configured lithium carbonate liquid material flows into each carbonization kettle 2 from top to bottom in sequence through each liquid material conveying pipeline 3. At the same time, carbon dioxide gas is introduced through the air inlet pipe 22 of the last carbonization kettle 2 and is passed into each carbonization kettle 2 and the configuration kettle 1 from bottom to top in sequence through each gas conveying pipeline 4, so that the lithium carbonate liquid material undergoes a gas-liquid countercurrent reaction with carbon dioxide gas in the configuration kettle 1 and each carbonization kettle 2, realizing the continuous carbonization of lithium carbonate. After solid-liquid separation of the carbonized liquid of lithium carbonate by the separation unit 7, it is discharged through the liquid outlet pipe 21. On this basis, the micro-interface strengthening unit 6 can disperse carbon dioxide gas into nano-scale tiny bubbles, increasing the dissolution amount of carbon dioxide and improving the utilization rate of carbon dioxide. At the same time, combined with the cloth pipe 5 in the carbonization kettle 2, the contact area between the lithium carbonate liquid material and carbon dioxide is made more uniform, further improving the reaction efficiency.

[0030] In this embodiment, there are 3 carbonization kettles 2, and each liquid material conveying pipeline 3 and each gas conveying pipeline 4 connect the preparation kettle 1 and the 3 carbonization kettles 2 in series. Various raw materials of the lithium carbonate liquid material enter from the feed pipe 11 and the liquid material is prepared in the preparation kettle 1 (the liquid-solid ratio of the lithium carbonate liquid material is 15:1 to 40:1). The bottom of the preparation kettle 1 is connected to the top of the first carbonization kettle 2 through the liquid material conveying pipeline 3. The bottom of the first carbonization kettle 2 is connected to the top of the second carbonization kettle 2 through a liquid material conveying pipeline 3. The bottom of the second carbonization kettle 2 is connected to the top of the third carbonization kettle 2 through a liquid material conveying pipeline 3, so that the lithium carbonate liquid material flows from top to bottom in each carbonization kettle 2. At the same time, carbon dioxide gas enters the third carbonization kettle 2 from the air inlet pipe 22. The top of the third carbonization kettle 2 is connected to the lower side of the second carbonization kettle 2 through a gas conveying pipeline 4. The top of the second carbonization kettle 2 is connected to the lower side of the first carbonization kettle 2 through a gas conveying pipeline 4. The top of the first carbonization kettle 2 is connected to the lower side of the preparation kettle 1 through the gas conveying pipeline 4. Finally, the unreacted carbon dioxide gas is discharged through the exhaust pipe 12 on the preparation kettle 1. After continuous carbonization reaction, a carbonized liquid of lithium carbonate is obtained in the third carbonization kettle 2. The solid-liquid separation of the carbonized liquid of lithium carbonate is carried out by the separation unit 7 in the third carbonization kettle 2 to obtain a clarified carbonized liquid of lithium carbonate, and finally the carbonized liquid of lithium carbonate is led out through the liquid outlet pipe 21 and sent to the next process. The unreacted lithium carbonate particles in the carbonized liquid of lithium carbonate are intercepted in the third carbonization kettle 2 and continue to carry out the carbonization reaction.

[0031] It should be noted that during the above carbonization process, the cleaning port 23 of the third carbonization kettle 2 is in a normally closed state and is only opened after the reaction ends to clean the remaining residue particles of the reaction. Each liquid material conveying pipeline 3 is provided with a feeding pump 31 to realize the series flow of the lithium carbonate liquid material. At the same time, the feeding pump 31 can increase the conveying pressure of the lithium carbonate liquid material and avoid pipeline blockage.

[0032] As a specific implementation manner of the microinterface enhanced mass transfer lithium carbonate continuous carbonization system provided by the present utility model, refer to Figures 1 to 3 , both the preparation kettle 1 and the carbonization kettle 2 are provided with a stirring unit 8. The stirring unit 8 includes a stirring shaft 81 rotatably connected in the preparation kettle 1 or the carbonization kettle 2, a driving member 83 connected above the preparation kettle 1 or the carbonization kettle 2, and stirring blades 82 connected to the outer periphery of the stirring shaft 81. The driving member 83 is connected to the stirring shaft 81 and is used to drive the stirring shaft 81 to rotate.

[0033] In this embodiment, the driving member 83 can be a servo motor. The rotation of the driving member 83 drives the stirring shaft 81 to rotate, so that the stirring blades 82 play a role in stirring the lithium carbonate liquid. The stirring unit 8 in the configuration kettle 1 can promote the mixing of various raw materials to accelerate the configuration process of the lithium carbonate liquid. During the carbonization reaction process, effective stirring is carried out through the stirring unit 8 to promote the dissolution rate of carbon dioxide in the lithium carbonate liquid and accelerate the reaction rate. On the other hand, stirring can ensure the uniform distribution of carbon dioxide in the lithium carbonate liquid and avoid incomplete reaction caused by too high local concentration.

[0034] As a specific implementation manner of the microinterface enhanced mass transfer lithium carbonate continuous carbonization system provided by the present utility model, refer to Figures 1 to 3 , the stirring shaft 81 penetrates downward through the microinterface strengthening unit 6, and stirring blades 84 are connected to the outer periphery of the stirring shaft 81 and located below the microinterface strengthening unit 6. The stirring blades 84 are used to rotate under the drive of the stirring shaft 81 to break up the particles in the lithium carbonate liquid.

[0035] In this embodiment, during the carbonization reaction process, there may be unreacted precipitates in the lithium carbonate liquid, and these precipitates will agglomerate into blocky particles and sink below the microinterface strengthening unit 6. By arranging the stirring blades 84 on the stirring shaft 81, the stirring blades 84 rotate synchronously with the stirring shaft 81 to cut and break up the above-mentioned precipitate particles, ensuring that the lithium carbonate liquid can fully react and avoiding waste of raw materials.

[0036] As a specific implementation manner of the microinterface enhanced mass transfer lithium carbonate continuous carbonization system provided by the present utility model, refer to Figure 4 , the microinterface strengthening unit 6 includes an intake air coil 61 connected to the gas delivery pipeline 4 or the intake pipe 22 and a microinterface membrane (not shown in the figure) covering the outer periphery of the intake air coil 61. Air permeable holes 611 for gas to pass through are provided on the peripheral wall of the intake air coil 61, and the microinterface membrane is used to cover the air permeable holes 611.

[0037] In this embodiment, carbon dioxide gas enters the intake air coil 61 in the corresponding kettle body from the intake pipe 22 or the gas delivery pipeline 4 and escapes through the air permeable holes 611 on the peripheral wall of the intake air coil 61. Since the microinterface membrane covers the outside of the air permeable holes 611 and the microinterface membrane has tiny pores, when carbon dioxide escapes from the air permeable holes 611 and enters the lithium carbonate liquid through the pores on the microinterface membrane, it is forced to be dispersed into a large number of tiny bubbles, thereby enhancing the solubility of carbon dioxide and improving the utilization rate of carbon dioxide.

[0038] Specifically, the microinterface membrane adopts a metal powder sintered metal membrane or a metal powder powder mesh composite membrane. The pore size accuracy of the microinterface membrane is 0.05 - 10 μm, and the distribution amount of carbon dioxide is 3 - 60 m³ / h.

[0039] As a specific embodiment of the micro-interface enhanced mass transfer lithium carbonate continuous carbonization system provided by the present utility model, refer to Figure 4 , the intake air coil 61 includes an outer ring pipe 612 connected to the gas delivery pipe 4 or the intake pipe 22, an inner ring pipe 613 coaxially arranged with the outer ring pipe 612, and a plurality of branch pipes 614 connected between the outer ring pipe 612 and the inner ring pipe 613. The inner ring pipe 613 is located on the outer periphery of the stirring shaft 81, and the air permeation holes 611 are uniformly arranged on the pipe walls of the outer ring pipe 612, the inner ring pipe 613, and the branch pipes 614.

[0040] In this embodiment, by setting the intake air coil 61 as a structure of an outer ring pipe 612, an inner ring pipe 613, and a plurality of branch pipes 614, on the one hand, the distribution area of carbon dioxide gas is increased, and on the other hand, the inner ring pipe 613 is located on the outer periphery of the stirring shaft 81 and will not interfere with the stirring action of the stirring unit 8.

[0041] As a specific embodiment of the micro-interface enhanced mass transfer lithium carbonate continuous carbonization system provided by the present utility model, refer to Figure 5 , the cloth pipe 5 includes a cloth ring pipe 51 connected to the liquid delivery pipe 3, a support sleeve 53 sleeved on the outer periphery of the stirring shaft 81 and coaxially arranged with the cloth ring pipe 51, and a plurality of cloth branch pipes 52 connected between the cloth ring pipe 51 and the support sleeve 53. A plurality of first nozzles 54 with downward openings are communicated on the peripheral walls of the cloth ring pipe 51 and the cloth branch pipes 52.

[0042] In this embodiment, the cloth ring pipe 51 is horizontally arranged inside the kettle body of the carbonization kettle 2, and the discharge end of the liquid delivery pipe 3 extends into the kettle body of the carbonization kettle 2 and is communicated with the cloth ring pipe 51. The support sleeve 53 is sleeved on the outer periphery of the stirring shaft 81 and will not affect the rotation of the stirring shaft 81. Further, a bearing or other supporting members can be added between the support sleeve 53 and the stirring shaft 81 to increase the stability of the stirring shaft 81 and the cloth ring pipe 51. A plurality of cloth branch pipes 52 are divergently connected between the support sleeve 53 and the cloth ring pipe 51, and a plurality of first nozzles 54 with downward openings are uniformly arranged on the cloth ring pipe 51 and the cloth branch pipes 52. The lithium carbonate liquid material enters the cloth ring pipe 51 and a plurality of cloth branch pipes 52 from the liquid delivery pipe 3 and is sprinkled into the interior of the kettle body of the carbonization kettle 2 through the first nozzles 54, increasing the distribution area of the lithium carbonate liquid material and making the distribution of the lithium carbonate liquid material more uniform, which is helpful for the balanced progress of the carbonization reaction.

[0043] As a specific embodiment of the micro-interface enhanced mass transfer lithium carbonate continuous carbonization system provided by the present utility model, refer to Figure 6, the cloth tube 5 is a spiral material tube 55. The spiral material tube 55 spirally extends downward along the central axis of the stirring shaft 81, and the spiral radius of the spiral material tube 55 gradually decreases from top to bottom. A plurality of second nozzles 56 opening downward are communicated with the peripheral wall of the spiral material tube 55, and the plurality of second nozzles 56 are arranged at intervals along the spiral direction.

[0044] In this embodiment, while the spiral material tube 55 spirally extends downward, the spiral radius gradually shrinks, similar to the shape of a tower spring, so that the spiral material tube 55 forms a spiral shape from a top view angle. The second nozzles 56 are arranged at intervals along the spiral direction of the spiral material tube 55. Through the above settings, the lithium carbonate liquid material can be sprayed out from the second nozzles 56 at different positions at different heights, ensuring that the lithium carbonate liquid material can be evenly distributed in the kettle body space of the carbonization kettle 2 during the descending process, avoiding the situation of local supersaturation or over-dilution, and ensuring the uniformity and high efficiency of the carbonization reaction.

[0045] Specifically, the stirring shaft 81 is located on the spiral center line of the spiral material tube 55, and the rotation of the stirring shaft 81 will not cause position interference with the spiral material tube 55.

[0046] As a specific implementation manner of the micro-interface enhanced mass transfer lithium carbonate continuous carbonization system provided by the present utility model, refer to Figure 7 , the separation unit 7 includes a filter cylinder 71 communicated with the liquid outlet pipe 21 and a filter membrane 72 coated on the outer periphery of the filter cylinder 71. Filter holes 711 for the lithium carbonate carbonization liquid to pass through are provided on the peripheral wall of the filter cylinder 71, and the filter membrane 72 is used to cover the filter holes 711.

[0047] In this embodiment, in the last carbonization kettle 2, the carbonization liquid of the continuously carbonized lithium carbonate is subjected to solid-liquid separation through the filtration of the filter membrane 72, so that the clarified lithium carbonate carbonization liquid enters the cylinder body of the filter cylinder 71 through the filter holes 711, and then is discharged through the liquid outlet pipe 21. When the separation unit 7 performs the above solid-liquid separation, the pressure in the last carbonization kettle 2 is used as the separation driving force, and the back pressure of the filtered liquid is controlled to keep the filtration pressure difference at 0-200 kPa.

[0048] Specifically, the structure of the filter membrane 72 can adopt a wedge-shaped mesh filter element, a sintered metal felt filter element, a sintered metal powder filter element or a composite filter element of a sintered metal wire mesh and powder, which can effectively remove the suspended particles in the lithium carbonate carbonization liquid.

[0049] Furthermore, the setting of the filter cartridge 71 provides support for the installation of the filter membrane 72. The filter membrane 72 is laid on the outer periphery of the filter cartridge 71, which facilitates the installation and cleaning operations and avoids the accumulation of suspended particles in the filter holes 711 causing blockage. When too many suspended particles accumulate on the surface area of the filter membrane 72, resulting in a decrease in filtration efficiency or an increase in pressure difference, the flux can be restored by means of pulse backwashing. The backwashing pressure is the partial pressure of carbon dioxide in the last carbonization kettle 2 plus 500 kpa (g).

[0050] As a specific implementation manner of the microinterface enhanced mass transfer lithium carbonate continuous carbonization system provided by the present utility model, refer to Figure 7 , the liquid outlet pipe 21 is connected with a connecting pipe 9. There are multiple separation units 7, and the liquid outlet ends of the multiple separation units 7 are respectively communicated with the connecting pipe 9.

[0051] In this embodiment, the solid-liquid separation of the lithium carbonate carbonization liquid is carried out simultaneously by multiple separation units 7, improving the solid-liquid separation effect. The clarified lithium carbonate carbonization liquid filtered by the multiple separation units 7 is respectively collected into the connecting pipe 9 through the filter cartridges 71, and finally uniformly discharged by the liquid outlet pipe 21.

[0052] Specifically, the connecting pipe 9 is horizontally arranged, the multiple separation units 7 are arranged in the up-down direction, and the upper end of the filter cartridge 71 penetrates through the peripheral wall of the connecting pipe 9 to realize the connection between the separation unit 7 and the connecting pipe 9, facilitating the lithium carbonate carbonization liquid to enter the connecting pipe 9 under the push of the separation pressure and be discharged by the liquid outlet pipe 21.

[0053] As a specific implementation manner of the microinterface enhanced mass transfer lithium carbonate continuous carbonization system provided by the present utility model, refer to Figure 1 , a pressure controller (not shown in the figure) is provided at the top of the first carbonization kettle 2, and the pressure controller is used to monitor the partial pressure of carbon dioxide in the first carbonization kettle 2.

[0054] In this embodiment, by controlling the partial pressure of carbon dioxide in the first carbonization kettle 2, the partial pressures of carbon dioxide in the remaining carbonization kettles 2 are controlled in a chained manner; when the pressure controller detects that the partial pressure of carbon dioxide in the first carbonization kettle 2 exceeds the preset value, the first carbonization kettle 2 discharges carbon dioxide to the preparation kettle 1 through the gas transmission pipeline 4. The preparation kettle 1 is an atmospheric pressure container, and the undissolved carbon dioxide gas is discharged from the exhaust pipe 12 of the preparation kettle 1 to the subsequent gas treatment unit. When the pressure controller detects that the partial pressure of carbon dioxide in the first carbonization kettle 2 is lower than the preset value, carbon dioxide gas can be supplemented through the three-way joint provided on the gas transmission pipeline 4 to increase the partial pressures of carbon dioxide in the carbonization kettles 2.

[0055] The above are only the preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A continuous carbonation system for lithium carbonate with enhanced mass transfer through micro-interfaces, characterized in that, It includes a configuration kettle and N carbonization kettles connected in sequence, where N≥2 and N is a positive integer. The upper part of the configuration kettle is connected with a feed pipe and an exhaust pipe. The side part of the Nth carbonization kettle is connected with a liquid outlet pipe and an air inlet pipe, and a cleaning port is provided at the bottom. The bottom of the configuration kettle and the top of the first carbonization kettle, and the bottom of the carbonization kettle and the top of the next carbonization kettle are respectively connected by a liquid conveying pipeline. The top of the carbonization kettle and the side part of the previous carbonization kettle, and the top of the first carbonization kettle and the side part of the configuration kettle are respectively connected by a gas conveying pipeline; Among them, a cloth pipe connected to the liquid conveying pipeline is arranged in the carbonization kettle. Micro-interface strengthening units for dispersing carbon dioxide gas into tiny bubbles are arranged in both the configuration kettle and the carbonization kettle. The micro-interface strengthening unit is located below the cloth pipe and is connected to the gas conveying pipeline or the air inlet pipe. A separation unit connected to the liquid outlet pipe is arranged in the Nth carbonization kettle, and the separation unit is used for solid-liquid separation of the carbonized liquid of lithium carbonate.

2. The micro-interface enhanced mass transfer continuous lithium carbonate carbonization system according to claim 1, characterized in that, Stirring units are arranged on both the configuration kettle and the carbonization kettle. The stirring unit includes a stirring shaft rotatably connected in the configuration kettle or the carbonization kettle, a driving member connected above the configuration kettle or the carbonization kettle, and stirring blades connected to the outer periphery of the stirring shaft. The driving member is connected to the stirring shaft and is used to drive the stirring shaft to rotate.

3. The micro-interface enhanced mass transfer lithium carbonate continuous carbonization system according to claim 2, characterized in that, The stirring shaft penetrates downward through the micro-interface strengthening unit, and stirring blades located below the micro-interface strengthening unit are connected to the outer periphery of the stirring shaft. The stirring blades are used to rotate under the drive of the stirring shaft to break up the particles in the lithium carbonate liquid.

4. The micro-interface enhanced mass transfer lithium carbonate continuous carbonization system according to claim 2, characterized in that, The micro-interface strengthening unit includes an air inlet coil connected to the gas conveying pipeline or the air inlet pipe and a micro-interface membrane covering the outer periphery of the air inlet coil. Air permeable holes for gas to pass through are provided on the peripheral wall of the air inlet coil, and the micro-interface membrane is used to cover the air permeable holes.

5. The micro-interface enhanced mass transfer continuous carbonation system for lithium carbonate according to claim 4, wherein The air inlet coil includes an outer ring pipe connected to the gas conveying pipeline or the air inlet pipe, an inner ring pipe coaxially arranged with the outer ring pipe, and a plurality of branch pipes connected between the outer ring pipe and the inner ring pipe. The inner ring pipe is located on the outer periphery of the stirring shaft, and the air permeable holes are uniformly arranged on the pipe walls of the outer ring pipe, the inner ring pipe and the branch pipes.

6. The micro-interface enhanced mass transfer continuous lithium carbonate carbonization system according to claim 2, characterized in that, The cloth pipe includes a cloth ring pipe connected to the liquid conveying pipeline, a support sleeve sleeved on the outer periphery of the stirring shaft and coaxially arranged with the cloth ring pipe, and a plurality of cloth branch pipes connected between the cloth ring pipe and the support sleeve. A number of first nozzles opening downward are communicated on the peripheral walls of the cloth ring pipe and the cloth branch pipes.

7. The microinterface enhanced mass transfer continuous carbonation system for lithium carbonate according to claim 2, characterized in that, The cloth pipe is a spiral feed pipe, the spiral feed pipe spirally extends downward along the central axis of the stirring shaft, and the spiral radius of the spiral feed pipe gradually decreases from top to bottom. A plurality of second nozzles opening downward are communicated on the peripheral wall of the spiral feed pipe, and the plurality of second nozzles are arranged at intervals along the spiral direction.

8. The micro-interface enhanced mass transfer lithium carbonate continuous carbonization system according to claim 1, characterized in that The separation unit includes a filter cartridge communicated with the liquid outlet pipe and a filter membrane covering the outer periphery of the filter cartridge. Filter holes for the lithium carbonate carbonization liquid to pass through are provided on the peripheral wall of the filter cartridge, and the filter membrane is used to cover the filter holes.

9. The microinterface enhanced mass transfer lithium carbonate continuous carbonization system according to claim 8, wherein The liquid outlet pipe is connected with a communicating pipe. There are multiple separation units, and the liquid outlet ends of the separation units are respectively communicated with the communicating pipe.

10. The microinterface enhanced mass transfer continuous carbonation system for lithium carbonate according to claim 1, wherein A pressure controller is provided at the top of the first carbonization kettle, and the pressure controller is used to monitor the partial pressure of carbon dioxide in the first carbonization kettle.

Images