Adsorption / desorption device for adsorbing and extracting lithium from salt lake and application of adsorption / desorption device

Abstract

The invention discloses an adsorption / desorption device for salt lake adsorption and lithium extraction and application thereof.The adsorption / desorption device for salt lake adsorption and lithium extraction comprises an adsorption and desorption column, an adsorbent containing area used for containing an adsorbent is arranged in the adsorption and desorption column, and a positive electrode and a negative electrode are oppositely arranged in the adsorbent containing area; the positive electrode and the negative electrode are connected through a direct-current power supply capable of reversing poles, a variable electric field can be formed during pole reversing, and the variable electric field can drive lithium ions to migrate and accelerate desorption of the lithium ions from an adsorbent, so that the lithium ion desorption efficiency is favorably improved, the concentration of the lithium ions in a desorption solution is higher, fresh water is saved, and the service life of the lithium ion battery is prolonged. And time and energy consumption are saved for subsequent concentration of lithium ions. The adsorption / desorption device for adsorbing and extracting lithium in the salt lake is simple in process flow and simple and convenient to operate, can effectively improve the desorption efficiency and save working hours, energy and fresh water, and has practical significance on utilization of lithium resources in the salt lake.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium extraction from salt lakes, and in particular to an adsorption / desorption device for extracting lithium from salt lakes and applications thereof. Background Art

[0002] Lithium metal has a low density (0.534 g / cm 3 ) and strong chemical activity, making it an indispensable key material in modern industry, particularly in high-tech fields. Lithium and its compounds are widely used not only in the atomic energy, aerospace, and defense industries, but also in the civilian industrial sector. They are known as "energy metals" and "the element that propels the world forward."

[0003] Over 70% of the world's industrial lithium reserves are located in salt lake deposits. With the rapid development of the new energy vehicle industry, demand for lithium resources has surged, and salt lake lithium extraction technology has therefore attracted widespread attention. The main salt lake lithium resources are distributed in three major regions: the Andean Plateau of South America (such as Argentina and Chile), western North America (such as the United States), and Central Asia. However, these salt lake regions are generally plagued by poor infrastructure, insufficient energy supply, and scarce freshwater resources, which seriously hinder the commercial development of lithium resources.

[0004] The current industrial applications of lithium extraction technologies from salt lakes mainly include:

[0005] 1) Evaporation crystallization method;

[0006] 2) precipitation method;

[0007] 3) Solvent extraction;

[0008] 4) Adsorption method;

[0009] 5) Calcination method;

[0010] 6) Membrane separation method (nanofiltration, electrodialysis, etc.).

[0011] Among them, the adsorption method enriches lithium ions through selective adsorbents and then uses eluents to separate lithium from other impurities, which has significant advantages: compared with traditional evaporation crystallization and precipitation methods (recovery rate is only 40%-50%), its recovery rate can be increased to more than 90%, and the production cycle is greatly shortened; compared with extraction and calcination methods, it avoids equipment corrosion and environmental pollution problems; in the face of membrane separation technologies (such as nanofiltration and electrodialysis) when dealing with monovalent impurity ions such as K+, the separation efficiency is low and the filter membrane life is short. The adsorption method has higher adsorption efficiency and shows better technical and economic benefits.

[0012] In adsorption systems, aluminum-based adsorbents are highly favored due to their simple process and mature industrial application. However, they still face technical bottlenecks such as low adsorption capacity and low desorption solution concentration, resulting in high energy consumption in the subsequent concentration process.

[0013] Existing technical improvement solutions have limitations. For example, the multi-reaction tank-guide rail system proposed in patent CN110683606A only optimizes the process connection efficiency, but does not improve core problems such as low lithium ion concentration in the desorption liquid and excessive fresh water consumption.

[0014] Therefore, developing an adsorption lithium extraction technology that can effectively increase the concentration of the desorption solution has become a key scientific issue that needs to be urgently solved in the current field of salt lake lithium resource development. Summary of the Invention

[0015] The purpose of the present invention is to provide an adsorption / desorption device for extracting lithium from salt lakes and its application, which is conducive to increasing the concentration of the desorption solution.

[0016] The present invention is achieved in that:

[0017] In a first aspect, the present invention provides an adsorption / desorption device for extracting lithium from a salt lake, comprising an adsorption / desorption column, wherein the adsorption / desorption column is provided with an adsorbent holding area for holding an adsorbent, wherein a positive electrode and a negative electrode are disposed opposite each other in the adsorbent holding area, and the positive electrode and the negative electrode are connected via a reversible DC power supply;

[0018] The adsorption and desorption column is also provided with a liquid inlet and a liquid outlet, and the adsorbent containing area is located between the liquid inlet and the liquid outlet.

[0019] In an optional embodiment, the material of the positive electrode and the negative electrode is selected from corrosion-resistant conductive materials.

[0020] In an optional embodiment, the material of the positive electrode and the negative electrode is selected from one or an alloy of two or more of gold, platinum, titanium, nickel, and carbon;

[0021] And / or, two or more groups of electrodes are sequentially arranged from the liquid inlet to the liquid outlet, and each group of electrodes includes a positive electrode and a negative electrode.

[0022] In a second aspect, the present invention provides a method for lithium desorption using the adsorption / desorption device described in the aforementioned embodiment, comprising: allowing a desorption liquid to enter the adsorption / desorption column from a liquid inlet, pass through the adsorbent holding area containing a lithium-intercalated adsorbent to desorb lithium, and then exit from a liquid outlet;

[0023] When the desorption liquid passes through the adsorbent containing area, the reversible DC power supply is turned on and the reversal is performed.

[0024] In an optional embodiment, the adsorbent includes at least one of an aluminum-based adsorbent, a manganese-based adsorbent, and a titanium-based adsorbent.

[0025] In an optional embodiment, the reversible DC power supply voltage is 0.1V-220.0V;

[0026] And / or, the reversible DC power supply current is 0.1A-500.0A;

[0027] And / or, the reversible DC power supply is reversed once every 5s-300s.

[0028] In an optional embodiment, the reversible DC power supply voltage is 0.1V-1.5V;

[0029] And / or, the reversible DC power supply current is 10A-50A;

[0030] And / or, the reversible DC power supply is reversed every 30s-100s.

[0031] In an optional embodiment, before the desorption liquid is introduced, pure water is first introduced to rinse the adsorbent.

[0032] In an optional embodiment, when the lithium ion concentration in the desorption liquid leaving the liquid outlet is too low, the desorption liquid is passed into the adsorption desorption column again.

[0033] In an optional embodiment, lithium adsorption is also performed before the desorption liquid is passed into the adsorption column. The lithium adsorption includes: allowing the lithium-containing brine to enter the adsorption desorption column from the liquid inlet, pass through the adsorbent holding area containing the lithium-deficient adsorbent, and then leave from the liquid outlet, so that the lithium-deficient adsorbent is embedded with lithium, thereby completing the lithium adsorption.

[0034] The present invention has the following beneficial effects:

[0035] The positive electrode and negative electrode in the adsorption / desorption device for extracting lithium from salt lakes in the present application are connected by a reversible DC power supply. When the polarity is reversed, a changing electric field can be formed. The changing electric field can drive the migration of lithium ions and accelerate the desorption of lithium ions from the adsorbent, which is conducive to accelerating the desorption efficiency of lithium ions, making the lithium ion concentration in the desorption liquid higher, saving fresh water, and saving time and energy for the subsequent concentration of lithium ions. The process flow of adsorption and desorption using the adsorption / desorption device for extracting lithium from salt lakes in the present application is simple and easy to operate, can effectively improve the desorption efficiency, save work hours, energy and fresh water, and has practical significance for the utilization of salt lake lithium resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0037] Figure 1 This is a schematic diagram of the structure of the adsorption / desorption device for lithium extraction from salt lakes in Example 1.

[0038] Diagram: 1-reversible DC power supply; 2-wire; 3-liquid inlet; 4-adsorption and desorption column; 5-electrode; 6-adsorbent; 7-liquid outlet. DETAILED DESCRIPTION

[0039] To make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer are used. Where the manufacturer of the reagents or instruments is not specified, they are all conventional products that can be purchased commercially.

[0040] An embodiment of the present invention provides an adsorption / desorption device for extracting lithium from a salt lake, comprising an adsorption / desorption column, wherein the adsorption / desorption column is provided with an adsorbent holding area for holding an adsorbent 6, wherein a positive electrode 5 and a negative electrode 5 are disposed opposite each other in the adsorbent holding area, and the positive electrode 5 and the negative electrode 5 are connected via a reversible DC power supply 1;

[0041] The adsorption and desorption column is further provided with a liquid inlet 3 and a liquid outlet 7 , and the adsorbent containing area is located between the liquid inlet 3 and the liquid outlet 7 .

[0042] The positive electrode 5 and the negative electrode 5 in the adsorption / desorption device for extracting lithium from salt lakes in the present application are connected by a reversible DC power supply 1. The reversible DC power supply 1 can adjust the power supply voltage, voltage and control the reversal cycle. A changing electric field can be formed during reversal. The changing electric field can drive the migration of lithium ions and accelerate the desorption of lithium ions from the adsorbent 6, which is conducive to accelerating the desorption efficiency of lithium ions, making the lithium ion concentration in the desorption liquid higher, saving fresh water, and saving time and energy for the subsequent concentration of lithium ions. The process flow of adsorption and desorption using the adsorption / desorption device for extracting lithium from salt lakes in the present application is simple and easy to operate, can effectively improve the desorption efficiency, save working hours, energy and fresh water, and has practical significance for the utilization of salt lake lithium resources.

[0043] It should be noted that the adsorption column is usually a container for containing adsorbents, and its specific shape is not limited, and it can be cylindrical, serpentine, etc.; the liquid inlet and liquid outlet are only required to be arranged at both ends of the adsorbent containing area, so that the brine or desorption liquid can enter from the liquid inlet and leave from the liquid outlet after passing through the adsorbent containing area. Under normal circumstances, the liquid inlet can be arranged above the adsorption and analysis column, and the liquid outlet can be arranged below the adsorption and analysis column; or the liquid inlet can be arranged below the adsorption and analysis column, and the liquid outlet can be arranged above the adsorption and analysis column.

[0044] In an optional embodiment, the material of the positive electrode and the negative electrode is selected from corrosion-resistant conductive materials.

[0045] In an optional embodiment, the material of the positive electrode 5 and the negative electrode 5 is selected from one or an alloy of two or more of gold, platinum, titanium, nickel, and carbon, preferably a titanium electrode 5. These materials have good corrosion resistance and conductivity, which is conducive to extending service life, reducing energy consumption, and reducing the introduction of impurities.

[0046] In an optional embodiment, two or more groups of electrodes 5 are sequentially arranged from the liquid inlet 3 to the liquid outlet 7 , and each group of electrodes 5 includes a positive electrode 5 and a negative electrode 5 .

[0047] The number and arrangement of the electrodes 5 can be selected according to the size of the adsorption column. In some embodiments, the electrodes 5 can also be arranged in 3, 4 or more groups so that the adsorbent in the adsorption column is evenly covered by the changing electric field.

[0048] An embodiment of the present invention further provides a method for lithium desorption using the adsorption / desorption device described in the aforementioned embodiment, comprising: allowing a desorption liquid to enter the adsorption / desorption column from a liquid inlet 3, pass through the adsorbent containing area containing a lithium-intercalated adsorbent to desorb lithium, and then exit from a liquid outlet;

[0049] While the desorption liquid passes through the adsorbent containing area, the reversible DC power supply 1 is connected and the reversal is performed.

[0050] The lithium desorption method of the present application can effectively improve the efficiency of the desorption process of adsorbent 6, reduce the desorption time, increase the desorption concentration, avoid accelerating the desorption by increasing the desorption solution temperature, and help reduce energy consumption. In some embodiments, the brine flow rate through the column during the desorption step can be 1BV / h-3BV / h.

[0051] In an optional embodiment, the adsorbent 6 is selected from at least one of aluminum-based adsorbents, manganese-based adsorbents, and titanium-based adsorbents.

[0052] In an optional embodiment, the voltage of the reversible DC power supply 1 is 0.1V-220.0V, for example, 0.1V, 24.5V, 48.9V, 73.3V, 97.7V, 122.1V, 146.5V, 170.9V, 195.3V, 219.7V, 220.0V. Preferably, the voltage of the reversible DC power supply 1 is 0.1V-1.5V; the voltage provides a driving force for the migration of lithium ions. If the voltage is too small, it is not conducive to the improvement of the desorption efficiency and the concentration of the analytical solution. If the voltage is too large, the analytical solution may be electrolyzed to generate gas, causing a safety hazard.

[0053] In an optional embodiment, the current of the reversible DC power supply 1 is 0.1A-500.0A, for example, 0.1A, 55.6A, 111.1A, 166.6A, 222.1A, 277.6A, 333.1A, 388.6A, 444.1A, 499.6A, 500.0A. Preferably, the current of the reversible DC power supply 1 is 10A-50A; a smaller power supply is conducive to reducing energy consumption.

[0054] In an optional embodiment, the reversible DC power supply 1 is reversed once every 5s-300s, for example, 5s, 37.8s, 70.6s, 103.4s, 136.2s, 169.0s, 201.8s, 234.6s, 267.4s, 300s. Preferably, the reversible DC power supply 1 is reversed once every 30s-100s. If the reversal frequency is too high, the lithium ions will continue to shake in place, which will lead to a decrease in the desorption rate; if the reversal frequency is too low, the lithium ion concentration in the solution will decrease, and the lithium recovery rate will decrease.

[0055] In an optional embodiment, before the desorption liquid is introduced, pure water is first introduced to rinse the adsorbent 6 to reduce the amount of lithium-containing brine adhering to the adsorbent 6 and reduce the introduction of impurities. In some embodiments, the brine flow rate through the column during the rinsing step can be 5BV / h-15BV / h.

[0056] In an optional embodiment, when the lithium ion concentration in the desorption liquid leaving the liquid outlet 7 is too low, it is passed into the adsorption desorption column again to increase the concentration of lithium ions in the desorption liquid, which is beneficial to reduce the energy consumption of subsequent concentration of the desorption liquid.

[0057] In an optional embodiment, lithium adsorption is also performed before the desorption liquid is passed into the adsorption column. The lithium adsorption includes: allowing the lithium-containing brine to enter the adsorption desorption column from the liquid inlet, pass through the adsorbent holding area containing the lithium-deficient adsorbent, and then leave from the liquid outlet, so that the lithium-deficient adsorbent is embedded with lithium, thereby completing the lithium adsorption.

[0058] When the lithium-containing brine passes through the lithium-deficient adsorbent 6 in the adsorbent holding area, the lithium ions in the lithium-containing brine can be adsorbed to obtain a lithium-intercalated adsorbent, thereby realizing the extraction of lithium ions.

[0059] It should be noted that the adsorbent 6 in the present application is first activated before lithium adsorption; during adsorption, the flow rate of the lithium-containing brine is related to the amount of adsorbent 6 contained in the adsorption and analysis column 4 and the residence time of the brine in the adsorbent containing area. In theory, the more adsorbent 6 is used in the adsorption and analysis column 4, the longer the brine stays in the adsorbent containing area, and the lower the lithium ion concentration in the brine, the faster the brine inlet rate can be. In some embodiments, the brine flow rate through the column in the adsorption step can be 2BV / h-6BV / h.

[0060] The features and properties of the present invention are further described in detail below in conjunction with the examples. The lithium adsorbent 6 involved in each example and comparative example is LiCl·2Al(OH) 3· nH2O. The composition of salt lake brine is shown in Table 1. The lithium, calcium, potassium, sodium, magnesium, boron and sulfate are determined by inductively coupled plasma atomic emission spectrometry (ICP-OES), and the chloride ion is determined by argentometric method.

[0061] Table 1

[0062]

[0063] Example 1

[0064] This embodiment provides an adsorption / desorption device for extracting lithium from salt lakes, such as Figure 1 As shown, it includes an adsorption and desorption column, wherein the adsorption and desorption column is provided with an adsorbent containing area for containing an adsorbent 6, wherein a positive electrode 5 and a negative electrode 5 are oppositely arranged in the adsorbent containing area, and the positive electrode 5 and the negative electrode 5 are both connected to the reversible DC power supply 1 through a wire 2;

[0065] The adsorption and desorption column is further provided with a liquid inlet 3 and a liquid outlet 7 , and the adsorbent containing area is located between the liquid inlet 3 and the liquid outlet 7 .

[0066] Example 2

[0067] This embodiment provides a method for lithium adsorption and desorption using the adsorption / desorption device in Example 1, which specifically includes the following steps:

[0068] Adsorption: Prepare a Φ30*600 adsorption column and fill it with 250cm 3 (201g) activated lithium adsorbent 6, 2.5L salt lake brine at a flow rate of 4BV / h was passed through the column to adsorb lithium, the adsorption tail liquid after passing through the column was collected and stirred evenly, and a mixed sample of the tail liquid was taken for testing.

[0069] Rinse: Use pure water to pass through the column at a flow rate of 10BV / h, the rinsing liquid volume is 500ml, collect the rinsing liquid through the column and stir it evenly, take the mixed sample for testing.

[0070] Desorption: Use pure water as the desorption liquid and flow it through the column at a flow rate of 2 BV / h. The desorption liquid volume is 1.2 L. Turn on the reversible DC power supply controller 1 and control the voltage to 1.2 ± 0.1 V and the current to 20 ± 0.5 A. Reverse the polarity every 60 seconds. Collect the desorption liquid after the column, stir it evenly, and take a mixed sample for testing.

[0071] Example 3:

[0072] This embodiment provides a method for lithium adsorption and desorption using the adsorption / desorption device in Example 1. The difference from Example 2 is that the voltage of the controller of the reversible DC power supply 1 is reduced. The method specifically includes the following steps:

[0073] Adsorption: Prepare a Φ30*600 adsorption column and fill it with 250cm 3 (201g) activated lithium adsorbent 6, 2.5L raw salt lake brine was passed through the column at a flow rate of 4BV / h to adsorb lithium, the adsorption tail liquid after passing through the column was collected and stirred evenly, and a mixed sample of the tail liquid was taken for testing.

[0074] Rinse: Use pure water to pass through the column at a flow rate of 10BV / h, the rinsing liquid volume is 500ml, collect the rinsing liquid through the column and stir it evenly, take the mixed sample for testing.

[0075] Desorption: Use pure water as the desorption liquid and flow it through the column at a flow rate of 2 BV / h. The desorption liquid volume is 1.2 L. Turn on the reversible DC power supply controller 1 and control the voltage to 0.8 ± 0.1 V and the current to 20 ± 0.5 A. Reverse the polarity every 60 seconds. Collect the desorption liquid after the column, stir it evenly, and take a mixed sample for testing.

[0076] Example 4:

[0077] This embodiment provides a method for lithium adsorption and desorption using the adsorption / desorption device in Example 1. The method differs from Example 2 mainly in that the reversal frequency of the controller of the reversible DC power supply 1 is increased. The method specifically includes the following steps:

[0078] Adsorption: Prepare a Φ30*600 adsorption column and fill it with 250cm 3 (201g) activated lithium adsorbent 6, 2.5L raw salt lake brine was passed through the column at a flow rate of 4BV / h to adsorb lithium, the adsorption tail liquid after passing through the column was collected and stirred evenly, and a mixed sample of the tail liquid was taken for testing.

[0079] Rinse: Use pure water to pass through the column at a flow rate of 10BV / h, the rinsing liquid volume is 500ml, collect the rinsing liquid through the column and stir it evenly, take the mixed sample for testing.

[0080] Desorption: Use pure water as the desorption liquid and flow it through the column at a flow rate of 2 BV / h. The desorption liquid volume is 1.2 L. Turn on the reversible DC power supply controller 1 and control the voltage to 1.2 ± 0.1 V and the current to 20 ± 0.5 A. Reverse the polarity every 30 seconds. Collect the desorption liquid after the column, stir it evenly, and take a mixed sample for testing.

[0081] Example 5:

[0082] This embodiment provides a method for lithium adsorption and desorption using the adsorption / desorption device in Example 1. The method differs from Example 2 mainly in that the current of the controller of the reversible DC power supply 1 is different. The method specifically includes the following steps:

[0083] Adsorption: Prepare a Φ30*600 adsorption column and fill it with 250cm 3 (201g) activated lithium adsorbent 6, 2.5L raw salt lake brine was passed through the column at a flow rate of 4BV / h to adsorb lithium, the adsorption tail liquid after passing through the column was collected and stirred evenly, and a mixed sample of the tail liquid was taken for testing.

[0084] Rinse: Use pure water to pass through the column at a flow rate of 10BV / h, the rinsing liquid volume is 500ml, collect the rinsing liquid through the column and stir it evenly, take the mixed sample for testing.

[0085] Desorption: Use pure water as the desorption liquid, flow through the column at a flow rate of 2 BV / h. The desorption liquid volume is 1.2 L. Turn on the reversible DC power supply controller 1, control the voltage to 1.2 ± 0.1 V, and the current to 10 ± 0.5 A. Reverse the polarity every 30 seconds. Collect the desorption liquid after the column, stir it evenly, and take a mixed sample for testing.

[0086] Example 6

[0087] This embodiment provides a method for lithium adsorption and desorption using the adsorption / desorption device in Example 1. The difference from Example 2 is mainly that the conditions of the desorption step are different. Specifically, the method includes the following steps:

[0088] Adsorption: Prepare a Φ30*600 adsorption column and fill it with 250cm 3 (201g) activated lithium adsorbent 6, 2.5L salt lake brine at a flow rate of 4BV / h was passed through the column to adsorb lithium, the adsorption tail liquid after passing through the column was collected and stirred evenly, and a mixed sample of the tail liquid was taken for testing.

[0089] Rinse: Use pure water to pass through the column at a flow rate of 10BV / h, the rinsing liquid volume is 500ml, collect the rinsing liquid through the column and stir it evenly, take the mixed sample for testing.

[0090] Desorption: Use pure water as the desorption liquid and flow it through the column at a flow rate of 2 BV / h. The desorption liquid volume is 1.2 L. Turn on the reversible DC power supply controller 1 and control the voltage to 1.5 ± 0.1 V and the current to 40 ± 0.5 A. Reverse the polarity every 100 seconds. Collect the desorption liquid after the column, stir it evenly, and take a mixed sample for testing.

[0091] Example 7

[0092] This embodiment provides a method for lithium adsorption and desorption using the adsorption / desorption device in Example 1. The difference from Example 2 is mainly that the conditions of the desorption step are different. Specifically, the method includes the following steps:

[0093] Adsorption: Prepare a Φ30*600 adsorption column and fill it with 250cm 3 (201g) activated lithium adsorbent 6, 2.5L salt lake brine at a flow rate of 4BV / h was passed through the column to adsorb lithium, the adsorption tail liquid after passing through the column was collected and stirred evenly, and a mixed sample of the tail liquid was taken for testing.

[0094] Rinse: Use pure water to pass through the column at a flow rate of 10BV / h, the rinsing liquid volume is 500ml, collect the rinsing liquid through the column and stir it evenly, take the mixed sample for testing.

[0095] Desorption: Use pure water as the desorption liquid and flow it through the column at a flow rate of 2 BV / h. The desorption liquid volume is 1.2 L. Turn on the reversible DC power supply controller 1 and control the voltage to 0.5 ± 0.1 V and the current to 20 ± 0.5 A. Reverse the polarity every 30 seconds. Collect the desorption liquid after the column, stir it evenly, and take a mixed sample for testing.

[0096] Comparative Example 1:

[0097] This embodiment provides a method for lithium adsorption and desorption using the adsorption / desorption device in Example 1. The method differs from Example 1 only in that the reversible DC power supply 1 controller is not turned on in the desorption step. The method specifically includes the following steps:

[0098] Adsorption: Prepare a Φ30*600 adsorption column and fill it with 250cm 3 (201g) activated lithium adsorbent 6, 2.5L raw salt lake brine was passed through the column at a flow rate of 4BV / h to adsorb lithium, the adsorption tail liquid after passing through the column was collected and stirred evenly, and a mixed sample of the tail liquid was taken for testing.

[0099] Rinse: Use pure water to flow through the column at a flow rate of 10BV / h, the rinsing liquid volume is 250ml, collect the rinsing liquid through the column and stir it evenly, take the mixed sample for testing.

[0100] Desorption: Use pure water as the desorption liquid, and desorb at a flow rate of 2BV / h. The volume of the desorption liquid is 1.2L. Collect the desorption liquid that has passed through the column and stir it evenly, and take a mixed sample for testing.

[0101] Comparative Example 2:

[0102] This embodiment provides a method for lithium adsorption and desorption using the adsorption / desorption device in Example 1. The only difference from Example 1 is that the desorption step does not involve polarity reversal.

[0103] The results of testing the compositions of the mixed samples obtained in the above embodiments and comparative examples are shown in Table 2.

[0104] Table 2

[0105]

[0106]

[0107]

[0108] It can be seen from Table 2 that under the conditions where other parameters are the same, the electric field generated by the inversion is more conducive to increasing the concentration of lithium ions in the analytical solution and the recovery efficiency is higher.

[0109] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. An adsorption / desorption device for extracting lithium from salt lakes, characterized in that: The adsorption desorption column comprises an adsorption desorption column, wherein an adsorbent containing area for containing adsorbent is provided in the adsorbent containing area, a positive electrode and a negative electrode are oppositely arranged in the adsorbent containing area, and the positive electrode and the negative electrode are connected via a reversible DC power supply; The adsorption and desorption column is also provided with a liquid inlet and a liquid outlet, and the adsorbent containing area is located between the liquid inlet and the liquid outlet.

2. The adsorption / desorption device for extracting lithium from salt lakes according to claim 1, characterized in that: The material of the positive electrode and the negative electrode is selected from corrosion-resistant conductive materials; And / or, two or more groups of electrodes are sequentially arranged from the liquid inlet to the liquid outlet, and each group of electrodes includes a positive electrode and a negative electrode.

3. The adsorption / desorption device for extracting lithium from salt lakes according to claim 2, characterized in that: The material of the positive electrode and the negative electrode is selected from one of gold, platinum, titanium, nickel, carbon, or an alloy composed of two or more thereof.

4. A method for lithium desorption using the adsorption / desorption device according to any one of claims 1 to 3, characterized in that: include: The desorption liquid enters the adsorption desorption column from the liquid inlet, passes through the adsorbent containing area containing the lithium-intercalated adsorbent to desorb lithium, and then leaves the adsorption column from the liquid outlet; When the desorption liquid passes through the adsorbent containing area, the reversible DC power supply is turned on and the reversal is performed.

5. The method for lithium desorption according to claim 4, wherein The adsorbent includes at least one of an aluminum-based adsorbent, a manganese-based adsorbent, and a titanium-based adsorbent.

6. The method for lithium desorption according to claim 4, wherein The reversible DC power supply voltage is 0.1V-220.0V; And / or, the reversible DC power supply current is 0.1A-500.0A; And / or, the reversible DC power supply is reversed once every 5s-300s.

7. The method for lithium desorption according to claim 6, wherein The reversible DC power supply voltage is 0.1V-1.5V; And / or, the reversible DC power supply current is 10A-50A; And / or, the reversible DC power supply is reversed every 30s-100s.

8. The method for lithium desorption according to claim 4, wherein Before the desorption liquid is introduced, pure water is introduced to rinse the adsorbent.

9. The method for lithium desorption according to claim 4, wherein When the lithium ion concentration in the desorption liquid leaving the liquid outlet is too low, the desorption liquid is passed into the adsorption desorption column again.

10. The method for lithium desorption according to claim 4, wherein Before the desorption liquid is passed into the adsorption column, lithium adsorption is also performed. The lithium adsorption includes: allowing the lithium-containing brine to enter the adsorption desorption column from the liquid inlet, pass through the adsorbent holding area containing the lithium-deficient adsorbent, and then leave from the liquid outlet, so that the lithium-deficient adsorbent is intercalated with lithium, thereby completing the lithium adsorption.

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