A lithium extraction and purification device

Abstract

The application relates to the technical field of lithium extraction, and discloses a lithium extraction and purification device, which comprises a lithium extraction centrifuge, a filter press and a reflux pipeline assembly. The lithium extraction centrifuge is connected with a light phase outlet, a light phase inlet, a heavy phase outlet and a heavy phase inlet. The filter press is provided with a liquid inlet and a liquid outlet. The heavy phase outlet is connected with the liquid inlet through a pipeline. The liquid outlet is connected with the reflux pipeline assembly through a flange. The reflux pipeline assembly comprises a precipitation pipeline, a first control valve, a filter pipeline and a second control valve. The liquid outlet, the precipitation pipeline, the first control valve and the heavy phase inlet form a reflux pipeline system. The liquid outlet, the precipitation pipeline, the filter pipeline and the second control valve form a discharge pipeline system. A lithium concentration sensor is arranged in the liquid outlet. The lithium content of the purified raffinate is monitored in real time through the online lithium concentration sensor, and the lithium-rich filtrate is automatically refluxed to the centrifuge for secondary extraction, so that a closed-loop recovery system is formed, and the loss of lithium is reduced.

Description

Technical Field

[0001] This invention relates to the field of lithium extraction technology, specifically to a lithium extraction and purification device. Background Technology

[0002] Solvent extraction is one of the key technologies for extracting and purifying lithium from salt lake brines or ore leachates. Centrifugal extractors, as the core equipment, have become the preferred choice for modern lithium extraction plants due to their efficient mixing and rapid separation capabilities, especially in processing brines with high magnesium-to-lithium ratios. Their basic working principle involves using a motor to drive a high-speed rotating drum, which thoroughly mixes and transfers the organic extractant phase (light phase) and the brine phase (heavy phase) of different densities within the drum. This allows lithium ions to selectively transfer to the organic phase, and the powerful centrifugal force then rapidly separates the two phases, achieving both lithium extraction and impurity removal.

[0003] However, in actual operation, the raffinate (waste brine) discharged from the heavy phase outlet of the centrifuge may still contain a certain concentration of lithium ions. This is usually caused by factors such as extraction reaction equilibrium limitations, insufficient stage efficiency, or fluctuations in feed concentration. Directly discharging or sending this raffinate to subsequent treatment will result in the loss of lithium resources and reduce the recovery rate and economic benefits of the entire production line.

[0004] Currently, the conventional solution to this problem is to use a multi-stage countercurrent extraction process, which involves connecting multiple centrifuges in series and allowing the raffinate to be repeatedly extracted in subsequent stages. While effective, this method significantly increases equipment investment, floor space requirements, and energy consumption. Summary of the Invention

[0005] (a) Technical problems to be solved

[0006] To address the shortcomings of existing technologies, this application provides a lithium extraction and purification device.

[0007] (II) Technical Solution

[0008] To solve the above problems, this application provides the following technical solution: a lithium extraction and purification device, including a lithium extraction centrifuge, a filter press and a reflux pipeline assembly, wherein the lithium extraction centrifuge is connected to a light phase outlet, a light phase inlet, a heavy phase outlet and a heavy phase inlet, the filter press is provided with a liquid inlet and a liquid outlet, the heavy phase outlet and the liquid inlet are connected by a pipeline, and the liquid outlet is connected to the reflux pipeline assembly by a flange;

[0009] The reflux pipeline assembly includes a sedimentation pipe, a first control valve, a filter pipe, and a second control valve. One end of the sedimentation pipe is connected to the outlet via a flange, and the other end of the sedimentation pipe is connected to the first control valve via a flange. The other end of the first control valve is connected to the heavy phase inlet via a pipe. The outlet, sedimentation pipe, first control valve, and heavy phase inlet form a reflux pipeline system. A filter pipe is connected in the middle of the sedimentation pipe, and a second control valve is installed at the lower end of the filter pipe. The outlet, sedimentation pipe, filter pipe, and second control valve form a discharge pipeline system.

[0010] A lithium concentration sensor is installed in the outlet. The lithium concentration sensor is used to detect the lithium concentration in the filtrate. If the lithium concentration exceeds a set threshold, it is transported to a lithium extraction centrifuge through a reflux pipeline system for secondary extraction. If the lithium concentration does not exceed the set threshold, the filtrate is discharged through a discharge pipeline system.

[0011] Preferably, the lithium extraction centrifuge includes an extraction cylinder and a motor. The light phase outlet, light phase inlet, heavy phase outlet, and heavy phase inlet are all connected to the interior of the extraction cylinder. The motor is used to drive the internal drum to rotate, thereby separating the mixture inside the extraction cylinder.

[0012] Preferably, the light phase inlet is used to deliver the extractant into the extraction cylinder, and the heavy phase inlet is used to deliver the brine to be extracted into the extraction cylinder. The brine and extractant are mixed and separated by the rotation of the drum inside the extraction cylinder. The separated organic phase containing lithium is discharged through the light phase outlet, and the waste liquid containing impurities is discharged through the heavy phase outlet.

[0013] Preferably, the purification device further includes a PLC control box, and the motor, filter press, lithium concentration sensor, first control valve and second control valve are electrically connected to the PLC control box to control the coordinated operation of each component.

[0014] Preferably, the sedimentation tube is U-shaped, and the filter tube is located in the middle of the sedimentation tube to divide the sedimentation tube into left and right parts, and is connected to the two parts respectively.

[0015] Preferably, the filter tube is provided with a filter screen cylinder inside, which is used to filter impurities in the filtrate. The top of the filter screen cylinder is provided with a cover plate, which is fixedly installed on the top of the filter tube by bolts, so as to facilitate the removal of the filter screen cylinder from the filter tube for cleaning or replacement.

[0016] Preferably, the bottom of the extraction cylinder is provided with a drain port for discharging filter residue.

[0017] (III) Beneficial Effects

[0018] Compared with the prior art, this application provides a lithium extraction and purification device, which has the following beneficial effects:

[0019] 1. This lithium extraction and purification device uses an online lithium concentration sensor to monitor the lithium content of the purified raffinate in real time, and automatically recirculates the lithium-rich filtrate to a centrifuge for secondary extraction, forming an intelligent closed-loop recovery system. This reduces lithium loss.

[0020] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0021] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0022] Figure 1 This is a schematic diagram of the structure of a lithium extraction and purification device according to this application;

[0023] Figure 2 This is a schematic diagram of the lithium extraction centrifuge used in this application;

[0024] Figure 3 This is a schematic diagram of the reflux pipe assembly of this application.

[0025] Reference numerals: 100, Lithium extraction centrifuge; 101, Extraction cylinder; 102, Motor; 103, Light phase outlet; 104, Light phase inlet; 105, Heavy phase outlet; 106, Heavy phase inlet; 107, Drain outlet; 200, PLC control box; 300, Filter press; 301, Liquid inlet; 302, Liquid outlet; 303, Lithium concentration sensor; 400, Reflux pipeline assembly; 401, Sedimentation tube; 402, First control valve; 403, Filter tube; 404, Second control valve; 405, Cover plate; 406, Filter screen cylinder. Detailed Implementation

[0026] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0027] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise stated, "multiple" means two or more. Furthermore, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0028] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0029] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0030] Please see Figures 1-3 This application provides a new technical solution: a lithium extraction and purification device, including a lithium extraction centrifuge 100, a filter press 300, and a reflux pipeline assembly 400. The lithium extraction centrifuge 100 is connected to a light phase outlet 103, a light phase inlet 104, a heavy phase outlet 105, and a heavy phase inlet 106. The filter press 300 is provided with a liquid inlet 301 and a liquid outlet 302. The heavy phase outlet 105 is connected to the liquid inlet 301 through a pipeline. The liquid outlet 302 is connected to the reflux pipeline assembly 400 through a flange.

[0031] The reflux pipeline assembly 400 includes a sedimentation pipe 401, a first control valve 402, a filter pipe 403, and a second control valve 404. One end of the sedimentation pipe 401 is connected to the outlet 302 via a flange, and the other end of the sedimentation pipe 401 is connected to the first control valve 402 via a flange. The other end of the first control valve 402 is connected to the heavy phase inlet 106 via a pipeline. The outlet 302, sedimentation pipe 401, first control valve 402, and heavy phase inlet 106 form a reflux pipeline system. A filter pipe 403 is connected in the middle of the sedimentation pipe 401, and the second control valve 404 is installed at the lower end of the filter pipe 403. The outlet 302, sedimentation pipe 401, filter pipe 403, and second control valve 404 form a discharge pipeline system.

[0032] A lithium concentration sensor 303 is installed in the outlet 302. The lithium concentration sensor 303 is used to detect the lithium concentration in the filtrate. If the lithium concentration exceeds a set threshold, it is transported to the lithium extraction centrifuge 100 through the reflux pipeline system for secondary extraction. If the lithium concentration does not exceed the set threshold, the filtrate is discharged through the discharge pipeline system.

[0033] The brine and extractant are mixed and separated by a lithium extraction centrifuge 100. The extractant is introduced into the light phase inlet 104, and the brine to be extracted is introduced into the heavy phase inlet 106. The extraction and separation are completed under the action of centrifugal force. The waste liquid containing impurities is discharged from the heavy phase outlet 105 and enters the filter press 300 for filtration and purification. When the filtrate after filtration flows out through the outlet 302, the lithium concentration is detected by the lithium concentration sensor 303. When the concentration exceeds the set threshold, the PLC controls the first control valve 402 to open and the second control valve 404 to close. The filtrate returns to the heavy phase inlet 106 through the sedimentation pipe 401 and the reflux pipe for secondary extraction. When the concentration does not exceed the set threshold, the second control valve 404 opens and the first control valve 402 closes. The filtrate is discharged from the system through the filter pipe 403.

[0034] In this embodiment, the filter press 300 is an XMYZ100 / 1000-U type plate and frame filter press with a working pressure of 0.6-1.2MPa; the lithium extraction centrifuge 100 is a CWL-M type centrifugal extractor; the first control valve 402 and the second control valve 404 are electric ball valves.

[0035] It achieves integrated operation of lithium extraction and purification, adopts a dual-pipeline system design, and can automatically switch processes according to lithium concentration through real-time lithium concentration monitoring and automatic reflux control, which improves operational flexibility and reduces lithium loss.

[0036] In some embodiments, the lithium extraction centrifuge 100 includes an extraction cylinder 101 and a motor 102. The light phase outlet 103, light phase inlet 104, heavy phase outlet 105 and heavy phase inlet 106 are all connected to the interior of the extraction cylinder 101. The motor 102 is used to drive the internal drum of the motor 102 to rotate, so that the mixture inside the extraction cylinder 101 is separated.

[0037] The core of the lithium extraction centrifuge 100 consists of the extraction cylinder 101 and the drive motor 102. The motor 102 drives the internal drum to rotate at high speed (2000-5000 r / min), ensuring that the extractant and brine entering from the light phase inlet 104 and the heavy phase inlet 106 are fully mixed and contacted under centrifugal force, completing the extraction reaction. Simultaneously, utilizing the density difference between the two phases, rapid separation is achieved under the action of the centrifugal force field. The separated two phases are discharged from the corresponding light phase outlet 103 and heavy phase outlet 105, respectively.

[0038] In some embodiments, the light phase inlet 104 is used to deliver the extractant into the extraction cylinder 101, and the heavy phase inlet 106 is used to deliver the brine to be extracted into the extraction cylinder 101. The brine and extractant are mixed and separated by the rotation of the drum inside the extraction cylinder 101. The separated organic phase containing lithium is discharged through the light phase outlet 103, and the waste liquid containing impurities is discharged through the heavy phase outlet 105.

[0039] The light phase inlet 104 feeds an organic extractant (such as a phosphate ester extractant) into the extraction cylinder 101, while the heavy phase inlet 106 introduces the brine to be extracted. Under the high-speed rotation of the drum driven by the motor 102, the two liquid phases are fully mixed, and the extractant selectively combines with lithium ions in the brine to form a complex. Under the action of centrifugal force, the organic phase containing lithium (light phase) and the aqueous phase containing impurities (heavy phase) are separated. The organic phase is discharged from the upper light phase outlet 103 for subsequent treatment, while the waste liquid containing impurities is discharged from the heavy phase outlet 105 and enters the filter press 300.

[0040] In some embodiments, the purification device further includes a PLC control box 200, wherein the motor 102, filter press 300, lithium concentration sensor 303, first control valve 402 and second control valve 404 are electrically connected to the PLC control box 200 to control the coordinated operation of the components.

[0041] In this embodiment, the PLC control box 200 uses a Siemens S7-1200 or Mitsubishi FX5 series PLC. It receives the detection signal from the lithium concentration sensor 303 and automatically controls the opening and closing states of the first control valve 402 and the second control valve 404 according to a preset concentration threshold. Simultaneously, the PLC system coordinates and controls the speed of the motor 102 and the operating status of the filter press 300, achieving synchronous operation between the various devices.

[0042] In some embodiments, the sedimentation tube 401 is arranged in a "U" shape, and the filter tube 403 is disposed in the middle of the sedimentation tube 401 to divide the sedimentation tube 401 into left and right parts, and is connected to the two parts respectively.

[0043] The U-shaped sedimentation tube 401 utilizes gravity to allow suspended particles in the filtrate to settle naturally, extending the residence time of the filtrate in the tube and improving the sedimentation effect. The filter tube 403 is located in the middle of the sedimentation tube 401, dividing it into left and right sections. The right section receives the filtrate from the filter press and performs initial sedimentation, while the left section connects to the return pipe. When filtrate needs to be discharged, the liquid is further filtered through the filter tube 403 and then discharged through the second control valve 404, ensuring the purity of the discharged liquid.

[0044] In some embodiments, a filter cylinder 406 is provided inside the filter tube 403. The filter cylinder 406 is used to filter impurities in the filtrate. A cover plate 405 is provided on the top of the filter cylinder 406. The cover plate 405 is fixedly installed on the top of the filter tube 403 by bolts, which facilitates the removal of the filter cylinder 406 from the filter tube 403 for cleaning or replacement.

[0045] In this embodiment, the filter cylinder 406 is cylindrical, with a porous filtration structure at the bottom and sides.

[0046] The filter screen 406 inside the filter tube 403 filters the filtrate passing through the sedimentation tube 401, trapping tiny particulate impurities and ensuring the purity of the discharged or returned liquid. The cover plate 405 on the top of the filter screen 406 is fixed to the filter tube 403 with bolts. When the filter screen 406 is clogged or needs to be replaced, the cover plate 405 can be easily removed to take out the filter screen 406 for cleaning or replacement, ensuring that the filtration effect is always good.

[0047] In some embodiments, a drain port 107 is provided at the bottom of the extraction cylinder 101 for discharging filter residue. During long-term operation, a certain amount of filter residue and sediment will accumulate at the bottom of the extraction cylinder 101. If these substances are not removed in time, they will affect the operating efficiency and separation effect of the centrifuge. The drain port 107 at the bottom of the extraction cylinder 101 can be opened periodically to discharge these filter residues and sediments during shutdown, keeping the inside of the extraction cylinder clean and ensuring continuous and efficient operation of the equipment.

[0048] Working Principle: In the operation of a lithium extraction and purification device, the brine to be extracted from the salt lake is pumped into the extraction cylinder 101 through the heavy phase inlet 106, while the organic extractant is pumped in through the light phase inlet 104. The two materials meet inside the extraction cylinder 101. The PLC-controlled motor 102 starts, driving the drum to rotate at high speed, generating centrifugal force to fully mix the brine and extractant. The lithium-containing organic phase (light phase), due to its lower density, is pushed to the outside of the drum and discharged from the upper light phase outlet 103, entering the subsequent back-extraction process. The aqueous phase (heavy phase), containing impurities, accumulates in the center of the drum due to its higher density and is discharged from the lower heavy phase outlet 105. The waste liquid discharged from port 105 is transported through a pipeline to the inlet 301 of the filter press 300. The PLC controls the filter press to start. Under the pressure of 0.8MPa, the clear liquid in the waste liquid enters the outlet 302 through the filter cloth. Solid impurities (such as mud and silicon slag) are intercepted to form a filter cake. The PLC receives the detection data from the lithium concentration sensor 303 and controls the second control valve 404 to close and the first control valve 402 to open. The clear liquid enters the U-shaped sedimentation tube 401. In the sedimentation tube, the preliminarily purified clear liquid returns to the heavy phase inlet 106 of the lithium extraction centrifuge 100 through the first control valve 402 for secondary extraction.

[0049] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0050] Although embodiments of this application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A lithium extraction and purification device, comprising a lithium extraction centrifuge, a filter press, and a reflux pipeline assembly, characterized in that, The lithium extraction centrifuge is connected to a light phase outlet, a light phase inlet, a heavy phase outlet, and a heavy phase inlet. The filter press is provided with a liquid inlet and a liquid outlet. The heavy phase outlet and the liquid inlet are connected by a pipe. The liquid outlet is connected to a reflux pipe assembly by a flange. The reflux pipeline assembly includes a sedimentation pipe, a first control valve, a filter pipe, and a second control valve. One end of the sedimentation pipe is connected to the outlet via a flange, and the other end of the sedimentation pipe is connected to the first control valve via a flange. The other end of the first control valve is connected to the heavy phase inlet via a pipe. The outlet, sedimentation pipe, first control valve, and heavy phase inlet form a reflux pipeline system. A filter pipe is connected in the middle of the sedimentation pipe, and a second control valve is installed at the lower end of the filter pipe. The outlet, sedimentation pipe, filter pipe, and second control valve form a discharge pipeline system. A lithium concentration sensor is installed in the outlet. The lithium concentration sensor is used to detect the lithium concentration in the filtrate. If the lithium concentration exceeds a set threshold, it is transported to a lithium extraction centrifuge through a reflux pipeline system for secondary extraction. If the lithium concentration does not exceed the set threshold, the filtrate is discharged through a discharge pipeline system.

2. The lithium extraction and purification device according to claim 1, characterized in that, The lithium extraction centrifuge includes an extraction cylinder and a motor. The light phase outlet, light phase inlet, heavy phase outlet, and heavy phase inlet are all connected to the interior of the extraction cylinder. The motor is used to drive the internal drum to rotate, thereby separating the mixture inside the extraction cylinder.

3. The lithium extraction and purification device according to claim 2, characterized in that, The light phase inlet is used to deliver the extractant into the extraction cylinder, and the heavy phase inlet is used to deliver the brine to be extracted into the extraction cylinder. The brine and extractant are mixed and separated by the rotation of the drum inside the extraction cylinder. The separated organic phase containing lithium is discharged through the light phase outlet, and the waste liquid containing impurities is discharged through the heavy phase outlet.

4. The lithium extraction and purification device according to claim 2, characterized in that, The purification device also includes a PLC control box. The motor, filter press, lithium concentration sensor, first control valve and second control valve are electrically connected to the PLC control box to control the coordinated operation of the components.

5. The lithium extraction and purification device according to claim 1, characterized in that, The sedimentation tube is U-shaped, and the filter tube is located in the middle of the sedimentation tube to divide the sedimentation tube into left and right parts, and is connected to the two parts respectively.

6. The lithium extraction and purification device according to claim 5, characterized in that, The filter tube contains a filter screen, which is used to filter impurities in the filtrate. The top of the filter screen is covered with a cover plate, which is fixed to the top of the filter tube with bolts, so that the filter screen can be removed from the filter tube for cleaning or replacement.

7. The lithium extraction and purification device according to claim 2, characterized in that, The bottom of the extraction cylinder is provided with a drain port, which is used to discharge filter residue.

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