A method for regenerating an aluminum salt lithium adsorbent

Abstract

The application provides a method for regenerating an aluminum salt lithium adsorbent, and belongs to the technical field of adsorbent regeneration. The method is as follows: a platinum electrode is used as an anode electrode and connected to a positive pole of a power supply, graphite is used as a cathode electrode and connected to a negative pole of the power supply, a dilute acid solution is used as an electrolyte, a diaphragm is arranged in an electrolysis chamber, the diaphragm divides the electrolysis chamber into an anode chamber, a reaction tank and a cathode chamber; an aluminum salt lithium adsorbent to be regenerated is subjected to electrochemical intercalation and activation; and the liquid in the reaction tank is filtered and dried to obtain a regenerated aluminum salt lithium adsorbent. The method combines an electrochemical intercalation method, uses a strong electric field to make harmful high-valence anions in the adsorbent, such as sulfate and carbonate, migrate to the anode and precipitate, and chloride ions in the cathode salt solution migrate and replace the residual high-valence anions in the adsorbent, so that the performance of the adsorbent is recovered, the cost is reduced, the introduction of impurity ions is reduced, water consumption is reduced, the adsorbent is recycled, and the method is green and environmentally friendly.

Description

Technical Field

[0001] This invention belongs to the field of adsorbent regeneration technology, specifically relating to a method for regenerating aluminum salt lithium adsorbents. Background Technology

[0002] Lithium, the lightest metallic element in nature with the lowest electrochemical equivalent and standard electrode potential, is a high-energy-density material. Its reserves are limited and demand is high, earning it the nickname "white oil." Due to its unique physicochemical properties, lithium and its compounds are widely used in ceramics, lubricants, glass, nuclear industry, aerospace, medicine, and lithium batteries. However, constrained by the gradual depletion of hard-rock lithium resources and the energy consumption and environmental issues associated with ore extraction, lithium extraction from salt lakes has become a major development trend.

[0003] Lithium aluminum salt adsorbents have played a crucial role in salt lake mining in various resource endowments both domestically and internationally due to their high selectivity for lithium ions, wide availability of raw materials, mature preparation processes, high versatility, stable performance, and environmental friendliness. The lifespan of these materials is critical to production safety, cost, and efficiency. Salt lake brines, in addition to cations such as sodium, potassium, magnesium, and lithium, are rich in high-valence anions such as sulfate and carbonate. After repeated recycling, the chloride ions coordinated with lithium ions in the adsorbent are replaced by high-valence anions in the brine, primarily carbonate and sulfate, transforming lithium chloride into high-valence lithium salts such as lithium sulfate and lithium carbonate. Because these high-valence lithium salts have stronger binding forces with aluminum hydroxide and resins, the high-valence anions remain trapped in the adsorbent pores, blocking mass transfer channels. This makes it difficult for water washing to effectively remove the anions, leading to a gradual decline in adsorption performance and reduced adsorbent utilization. Therefore, it is necessary to extend or restore the adsorbent's performance.

[0004] Chinese patent CN106140121A discloses a regeneration method for restoring the performance of aluminum salt lithium adsorbents. This method targets aluminum adsorbents with severely diminished adsorption capacity after multiple cycles of use, employing a stepwise soaking process with strong acid, strong alkali, and lithium-containing solutions. While this method is simple and significantly improves the performance of the degraded adsorbent, it suffers from severe acid and alkali corrosion, posing hazards to equipment and the environment. Aluminum-based adsorbents are prone to reacting with acids and alkalis, leading to material loss. Furthermore, the regenerated adsorbent requires excessive water rinsing, increasing water consumption.

[0005] Chinese patent CN104383901A discloses a method for restoring the performance of lithium adsorbents. This method uses aluminum adsorbents damaged by hydrophobic contaminants. After saturation adsorption, the adsorbent is subjected to staged convection with an ammonium salt-containing solution, restoring adsorption performance during the desorption process. This method is feasible for industrial production, and the regeneration process is near neutral, preventing adsorbent loss. However, the introduction of ammonium salts into the desorption solution inevitably increases the complexity of subsequent purification. Furthermore, this method is only effective in removing contaminants formed under weakly alkaline conditions and has no effect on restoring adsorbent performance degradation caused by multivalent anions.

[0006] Patent CN115814465A discloses a method for lithium adsorption in a solution containing carbonate and / or sulfate ions. This method uses a weakly acidic, high-concentration salt solution to transform adsorbents with degraded adsorption performance. After transformation, the adsorbent is desorbed and its adsorption performance is restored by rinsing with a low-concentration salt solution or water. However, this method carries a large number of inorganic salt ions into the adsorbent, increasing the complexity of impurity removal in lithium salt production. The transformation and rinsing processes require more than 10 column volumes of water, and the subsequent removal of impurity ions from the water hinders water recycling efficiency. This invention aims to restore adsorbent performance by reacting chemical reagents with pollutants in the adsorbent to unclog pores and increase adsorption sites, and then carrying away the pollutants through water rinsing. However, the use of excessive saturated salt solution also introduces impurities into the adsorbent, which are easily carried into subsequent lithium salt production. The adsorbent recovery process requires excessive water rinsing for impurity removal, increasing water consumption and causing environmental problems. Furthermore, due to the strong binding force between carbonate and sulfate ions and the adsorbent, the effect of water rinsing in carrying away anions is limited, resulting in incomplete restoration of adsorbent performance. Summary of the Invention

[0007] To address the aforementioned problems, this invention provides a method for regenerating lithium aluminum salt adsorbents. This method combines electrochemical intercalation with a strong electric field, causing harmful high-valence anions in the adsorbent, such as sulfate and carbonate ions, to migrate to the anode and precipitate. Similarly, due to the electric field, chloride ions in the cathode salt solution migrate and replace residual high-valence anions in the adsorbent. With appropriate lithium replenishment, the adsorbent's performance is restored, achieving cost reduction, efficiency improvement, reduced introduction of impurity ions, lower water consumption, recycling, and environmental friendliness.

[0008] The technical solution of the present invention is as follows:

[0009] This invention provides a method for regenerating an aluminum salt lithium adsorbent, comprising the following steps:

[0010] Step 1: Set up an electrochemical workstation: Use a platinum electrode as the anode electrode and connect it to the positive terminal of the power supply; use graphite as the cathode electrode and connect it to the negative terminal of the power supply; use a dilute acid solution as the electrolyte; and set up a diaphragm in the electrolysis chamber to divide the electrolysis chamber into an anode chamber, a reaction tank, and a cathode chamber.

[0011] Step 2, Electrochemical Intercalation and Activation: Place the aluminum salt lithium adsorbent to be regenerated in the reaction vessel, connect the DC power supply, and apply 10-50 mA. -2 The current is applied to the adsorbent and the mechanical stirring is continued for 10-20 minutes. Then, an inorganic salt solution is continuously introduced into the cathode chamber for 10-100 minutes. Next, an inorganic calcium salt solution is continuously introduced into the anode chamber for 20-100 minutes. Finally, a lithium chloride solution is continuously introduced into the anode chamber for 4-20 minutes.

[0012] Step 3, tailing treatment: Filter and dry the liquid in the reaction tank to obtain regenerated aluminum salt lithium adsorbent.

[0013] In this invention, the electrolysis chamber is equipped with a diaphragm, which divides the electrolysis chamber into an anode chamber, a reaction tank, and a cathode chamber. A filter screen can also be added while the diaphragm is in place, on the one hand to prevent the adsorbent from contacting the electrode, and on the other hand to facilitate separation and recovery.

[0014] In one specific embodiment of the present invention, the dilute acid in step 1 is selected from at least one of boric acid, phosphoric acid, tartaric acid, oxalic acid, hydrochloric acid, acetic acid, formic acid, nitric acid, and citric acid, and the pH of the dilute acid solution is 3-5.5, preferably 4.5-5.

[0015] Since strong acids and strong bases can react with and dissolve lithium aluminum salt adsorbents, resulting in their loss, and weak bases can also deactivate them, a dilute acid is chosen as the electrolyte in this invention.

[0016] In one specific embodiment of the present invention, the aluminum-lithium salt adsorbent to be regenerated in step 2 is preferably resin-based aluminum-lithium salt adsorbent particles. The resin-based aluminum-lithium salt adsorbent particles need to be pretreated before being placed in the reaction tank. The specific steps of the pretreatment are as follows: first, drying treatment is performed, then broken or damaged resin-based aluminum-lithium salt adsorbent particles are removed, then deionized water is added, and the particles are dispersed by mechanical stirring at a temperature of 50-80°C. Then, the dispersed solution is filtered, and the solid is transferred to the reaction tank.

[0017] In this invention, the function of using deionized water for dispersion is as follows: Since there are many impurities in the brine, they will be deposited on the surface of the lithium aluminum salt adsorbent during the cyclic adsorption process. Dispersing with deionized water can clean and separate the lithium aluminum salt adsorbent from the impurities, pre-activate the lithium aluminum salt adsorbent, and reduce the number of impurities entering the next stage, thereby affecting the impurity removal process.

[0018] In one specific embodiment of the present invention, the mass ratio of deionized water to resin-based aluminum salt lithium adsorbent particles in step 2 is (1-5):1, preferably 1.5:1, and the mechanical stirring is specifically a dispersion at 200-400 rpm for 2-5 hours; preferably a dispersion at 200 rpm for 2 hours.

[0019] In one specific embodiment of the present invention, the aluminum salt lithium adsorbent in step 2 is a sample whose adsorption capacity has decreased to less than 50% of the initial adsorption capacity after cyclic lithium extraction.

[0020] In one specific embodiment of the present invention, the inorganic salt in step 2 is at least one selected from ammonium chloride, zinc chloride, copper chloride, sodium chloride, potassium chloride, aluminum chloride, magnesium nitrate, sodium nitrate, potassium nitrate, copper nitrate, zinc nitrate, sodium hydrogen phosphate, sodium acetate, sodium oxalate, and sodium citrate. The concentration of the inorganic salt is 0.12-0.5 mol / L, and the flow rate is 1.5-12 mL / min.

[0021] In one specific embodiment of the present invention, the inorganic calcium salt in step 2 is at least one of calcium chloride, calcium nitrate, calcium bromide, calcium iodide, and calcium gluconate, and the concentration of the inorganic calcium salt solution is 0.05-0.20 mol / L, and the flow rate is 1.5-10 mL / min.

[0022] In one specific embodiment of the present invention, the concentration of the lithium chloride solution in step 2 is 0.10-0.60 mol / L, and the flow rate is 4-15 mL / min.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] 1. Under the action of an electric field, high-valence anions such as sulfate and carbonate in the aluminum salt lithium adsorbent migrate to the anode and are precipitated by the inorganic calcium salt introduced into the anode chamber. Chloride ions in the cathode solution also migrate with the electric field, pass through the adsorbent and replace the high-valence anions. Lithium ions introduced into the anode chamber migrate to the adsorbent through the electric field and insert into the adsorbent, so that the interlayer compound of the adsorbent is restored to lithium chloride, thereby achieving the purpose of restoring the performance of the adsorbent.

[0025] 2. This invention reduces the use of inorganic salts and high-concentration acids and alkalis, avoids adsorbent loss and the inclusion of high-content inorganic salt ions, thereby simplifying the subsequent impurity removal process, reducing water consumption, and repeatedly recycling the electrolyte solution, making it green and environmentally friendly. Attached Figure Description

[0026] Figure 1 This is a schematic diagram illustrating the principle of adsorbent performance recovery during the electrolysis process. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the invention 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 merely illustrative and not intended to limit the invention.

[0028] The electrochemical workstation used in the following examples and comparative examples was prepared as follows: a platinum electrode was used as the anode electrode, connected to the positive terminal of the power supply; graphite was used as the cathode electrode, connected to the negative terminal of the power supply; a dilute acid solution was used as the electrolyte; and a diaphragm was installed in the electrolysis chamber, dividing the electrolysis chamber into an anode chamber, a reaction tank, and a cathode chamber. Its working principle diagram is shown below. Figure 1 As shown.

[0029] Example 1

[0030] Granulated aluminum salt lithium adsorbent A was selected, packed into a column, and its initial adsorption and desorption capacities were determined. After continuous lithium extraction in brine containing high-valence anions, when its adsorption capacity decreased to less than 50% of the initial capacity, it was removed from the adsorption column, dried, and sieved to remove the detached adsorbent powder and binder. The adsorbent on the sieve was collected for performance recovery experiments.

[0031] The main ionic composition of the brine used in the experiment:

[0032]

[0033] The collected adsorbent was dispersed in 1.5 times its own weight of deionized water and heated to 50°C and mechanically stirred at 200 rpm for 2 hours.

[0034] The uniformly dispersed adsorbent was filtered, and the solid was transferred to an electrolytic cell, mixed with electrolyte, and the pH was adjusted to 5.5. The mixture was then slowly stirred at 80 rpm, and a DC power supply was connected with a constant current of 10 mA. -2 The process was continued for 10 minutes, with a continuous flow of 0.15 mol / L sodium chloride solution into the cathode chamber at a flow rate of 1.5 mL / min for 100 minutes.

[0035] A 0.05 mol / L calcium chloride solution was continuously introduced into the anode chamber at a flow rate of 3.0 mL / min for 40 min. Then, a 0.20 mol / L LiCl solution was continuously added into the anode chamber at a flow rate of 15 mL / min for 4 min.

[0036] The adsorbent was filtered, collected, dried, and then packed into a column to determine the adsorption-desorption capacity. The precipitate in the anode chamber was filtered, and the electrolyte was reused in subsequent processes.

[0037] Example 2

[0038] Granulated aluminum salt lithium adsorbent B was selected, packed into a column, and its initial adsorption and desorption capacities were determined. After continuous lithium extraction in brine containing high-valence anions, when its adsorption capacity decreased to less than 50% of the initial capacity, it was removed from the adsorption column, dried, and sieved to remove the adsorbent powder and binder. The adsorbent on the sieve was collected for performance recovery experiments.

[0039] The main ionic composition of the brine used in the experiment:

[0040]

[0041] The collected adsorbent was dispersed in 1.0 times its own weight of deionized water and heated to 60°C and mechanically stirred at 300 rpm for 2 hours.

[0042] The uniformly dispersed adsorbent was filtered, and the solid was transferred to an electrolytic cell, mixed with electrolyte, and the pH was adjusted to 4.5. The mixture was then slowly stirred at 80 rpm, and a DC power supply was connected with a constant current of 50 mA. -2 The process was continued for 20 minutes, with a 0.20 mol / L mixed solution of sodium chloride, sodium nitrate and potassium chloride continuously passed through the cathode chamber at a flow rate of 12 mL / min for 10 minutes.

[0043] A 0.2 mol / L calcium nitrate solution was continuously introduced into the anode chamber at a flow rate of 2 mL / min for 60 min. Then, a 0.10 mol / L LiCl solution was continuously added into the anode chamber at a flow rate of 4 mL / min for 20 min.

[0044] The adsorbent was filtered, collected, dried, and then packed into a column to determine the adsorption-desorption capacity. The precipitate in the anode chamber was filtered, and the electrolyte was reused in subsequent processes.

[0045] Example 3

[0046] Granulated aluminum salt lithium adsorbent C was selected, packed into a column, and its initial adsorption and desorption capacities were determined. After continuous lithium extraction in brine containing high-valence anions, when its adsorption capacity decreased to less than 50% of the initial capacity, it was removed from the adsorption column, dried, and sieved to remove the adsorbent powder and binder. The adsorbent on the sieve was collected for performance recovery experiments.

[0047] The main ionic composition of the brine used in the experiment:

[0048]

[0049] The collected adsorbent was dispersed in 1.5 times its own weight of deionized water and heated to 70°C and mechanically stirred at 300 rpm for 2 hours.

[0050] The uniformly dispersed adsorbent was filtered, and the solid was transferred to an electrolytic cell, mixed with electrolyte, and the pH was adjusted to 4.0. The mixture was then stirred slowly at 80 rpm, and a DC power supply was connected with a constant current of 20 mA. -2 The process was continued for 20 minutes, with a 0.12 mol / L mixed solution of aluminum chloride, magnesium nitrate, sodium nitrate, and potassium nitrate continuously passed through the cathode chamber at a flow rate of 3.5 mL / min for 50 minutes.

[0051] A 0.10 mol / L calcium bromide solution was continuously introduced into the anode chamber at a flow rate of 10 mL / min for 20 min. Then, a 0.60 mol / L LiCl solution was continuously added into the anode chamber at a flow rate of 7.0 mL / min for 10 min.

[0052] The adsorbent was filtered, collected, dried, and then packed into a column to determine its adsorption capacity. The precipitate in the anode chamber was filtered, and the electrolyte was reused in subsequent processes.

[0053] Example 4

[0054] Granulated aluminum salt lithium adsorbent D was selected, packed into a column, and its initial adsorption and desorption capacities were determined. After continuous lithium extraction in brine containing high-valence anions, when its adsorption capacity decreased to less than 50% of the initial capacity, it was removed from the adsorption column, dried, and sieved to remove the detached adsorbent powder and binder. The adsorbent on the sieve was collected for performance recovery experiments.

[0055] The main ionic composition of the brine used in the experiment:

[0056]

[0057] The collected adsorbent was dispersed in 5 times its own weight of deionized water and heated to 80°C and mechanically stirred at 400 rpm for 5 hours.

[0058] The uniformly dispersed adsorbent was filtered, and the solid was transferred to an electrolytic cell, mixed with electrolyte, and the pH was adjusted to 3. The mixture was then slowly stirred at 80 rpm, and a DC power supply was connected with a constant current of 40 mA. -2 The process was continued for 15 minutes, with a 0.5 mol / L mixed solution of sodium chloride, zinc chloride, and sodium citrate continuously passed through the cathode chamber at a flow rate of 2.5 mL / min for 80 minutes.

[0059] A 0.05 mol / L calcium gluconate solution was continuously introduced into the anode chamber at a flow rate of 1.5 mL / min for 100 min. Then, a 0.10 mol / L LiCl solution was continuously added into the anode chamber at a flow rate of 6 mL / min for 15 min.

[0060] The adsorbent was filtered, collected, dried, and then packed into a column to determine its adsorption capacity. The precipitate in the anode chamber was filtered, and the electrolyte was reused in subsequent processes.

[0061] Comparative Example 1

[0062] The difference from Example 1 is that no inorganic salt solution is added to the cathode.

[0063] Comparative Example 2

[0064] The difference from Example 1 is that no inorganic calcium salt solution is added to the anode.

[0065] Comparative Example 3

[0066] The difference from Example 1 is that no inorganic salt solution is added to the cathode, and no inorganic calcium salt and lithium chloride solution is added to the anode.

[0067] Comparative Example 4

[0068] The difference from Example 1 is that this is a sample with no degradation in adsorption performance, and it is the first adsorption.

[0069] Comparative Example 5

[0070] The difference from Example 2 is that this is a sample with no degradation in adsorption performance, and it is the first adsorption.

[0071] Comparative Example 6

[0072] The difference from Example 3 is that this is a sample with no degradation in adsorption performance, and it is the first adsorption.

[0073] Comparative Example 7

[0074] The difference from Example 4 is that this is a sample with no degradation in adsorption performance, and it is the first adsorption.

[0075] Comparative Example 8

[0076] The difference from Example 1 is that after the cyclic adsorption experiment, the sample whose adsorption capacity decreased to less than 50% of the initial capacity was not subjected to a performance recovery experiment.

[0077] Comparative Example 9

[0078] The difference from Example 2 is that after the cyclic adsorption experiment, the sample whose adsorption capacity decreased to less than 50% of the initial capacity was not subjected to a performance recovery experiment.

[0079] Comparative Example 10

[0080] The difference from Example 3 is that after the cyclic adsorption experiment, the sample whose adsorption capacity decreased to less than 50% of the initial capacity was not subjected to a performance recovery experiment.

[0081] Comparative Example 11

[0082] The difference from Example 4 is that after the cyclic adsorption experiment, the sample whose adsorption capacity decreased to less than 50% of the initial capacity was not subjected to a performance recovery experiment.

[0083] Cyclic adsorption-desorption experiments: For each example and comparative sample packed into the column, the peristaltic pump speed was adjusted, and a bottom-in, top-out method was used. The brine from Example 1 was passed through the adsorption column at a rate of 2-15 column volumes per hour. The tail liquid was collected. Similarly, 1.5-5 column volumes of water were used to desorb the saturated adsorbent, and the eluent was collected. This cycle was repeated. The Li+ content in the solution before and after adsorption was determined by atomic absorption spectrometry, and the adsorption and desorption capacities were calculated using the following formulas:

[0084] Q = (Co - Ct)V / m

[0085] Where Q represents the adsorption or desorption capacity, Co represents the initial Li+ concentration in the solution, Ct represents the concentration of the solution after adsorption, V is the solution volume, and m is the adsorbent mass.

[0086] The adsorption-desorption capacity of Examples 1-4 and Comparative Examples 1-11 was measured, and the decrease rate of adsorption-desorption capacity after 50 cycles of adsorption-desorption experiment was measured, as shown in Table 1.

[0087] Table 1. Desorption / desorption capacity determination of Examples 1-4 and Comparative Examples 1-11, and determination of the rate of decrease in adsorption / desorption capacity after 50 cycles of adsorption / desorption experiments.

[0088]

[0089]

[0090] As shown in Table 1, the adsorbents recovered using the methods in Examples 1-4 exhibit high adsorption and desorption capacities and cycling stability. Examples 1-4 and Comparative Examples 4-7 demonstrate that the adsorption and desorption capacities can be restored to over 85% of their initial values ​​after the recovery experiments. Examples 1-4 and Comparative Examples 8-11 show that the adsorbents recovered through the performance restoration experiments exhibit less and more stable adsorption and desorption capacity decay, while the adsorbents with degraded performance show more drastic subsequent capacity decay, significantly reducing material utilization efficiency. Examples 1-4 and Comparative Examples 1-3 demonstrate that the addition of chloride-containing inorganic salts improves adsorbent performance recovery, and soluble calcium salts are effective in removing high-valence anions. The combination of these two methods avoids secondary contamination of the adsorbent by high-valence anions.

[0091] Table 2. Adsorbent composition before and after performance recovery of adsorbent A

[0092]

[0093] As can be seen from Table 2, after the cyclic adsorption experiment, chloride ions in adsorbent A were replaced by sulfate ions, resulting in a decrease in chloride ion content and a significant increase in sulfate ions, leading to a decrease in adsorption capacity. However, after the performance recovery experiment, the elemental composition of the adsorbent was close to the original composition, indicating a good recovery effect.

[0094] Table 3. Adsorbent composition before and after performance recovery of adsorbent B

[0095]

[0096]

[0097] As can be seen from Table 3, after the cyclic adsorption experiment, chloride ions in adsorbent B were replaced by sulfate and carbonate ions, resulting in a decrease in chloride ion content and a significant increase in sulfate and carbonate ions, leading to a decrease in adsorption capacity. However, after the performance recovery experiment, the elemental composition of the adsorbent was close to the original composition, indicating a good recovery effect.

[0098] Table 4. Adsorbent composition before and after performance recovery of adsorbent C

[0099]

[0100] As can be seen from Table 4, after the cyclic adsorption experiment, chloride ions in adsorbent C were replaced by sulfate and carbonate ions, resulting in a decrease in chloride ion content and a significant increase in sulfate and carbonate ions, leading to a decrease in adsorption capacity. However, after the performance recovery experiment, the elemental composition of the adsorbent was close to the original composition, indicating a good recovery effect.

[0101] Table 5. Adsorbent composition before and after performance recovery of adsorbent D

[0102]

[0103] As can be seen from Table 5, after the cyclic adsorption experiment, chloride ions in adsorbent D were replaced by sulfate and carbonate ions, resulting in a decrease in chloride ion content and a significant increase in sulfate and carbonate ions, leading to a decrease in adsorption capacity. However, after the performance recovery experiment, the elemental composition of the adsorbent was close to the original composition, indicating a good recovery effect.

[0104] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for regenerating an aluminum salt lithium adsorbent, characterized in that, Includes the following steps: Step 1: Set up an electrochemical workstation: Use a platinum electrode as the anode electrode and connect it to the positive terminal of the power supply; use graphite as the cathode electrode and connect it to the negative terminal of the power supply; use a dilute acid solution as the electrolyte; and set up a diaphragm in the electrolysis chamber to divide the electrolysis chamber into an anode chamber, a reaction tank, and a cathode chamber. Step 2, Electrochemical Intercalation and Activation: Place the aluminum salt lithium adsorbent to be regenerated in the reaction vessel, connect the DC power supply, and apply 10-50 mA. -2 The current is applied to the adsorbent and the mechanical stirring is continued for 10-20 minutes. Then, a salt solution is continuously introduced into the cathode chamber for 10-100 minutes. Next, a calcium salt solution is continuously introduced into the anode chamber for 20-100 minutes. Finally, a lithium chloride solution is continuously introduced into the anode chamber for 4-20 minutes. The salt is at least one selected from ammonium chloride, zinc chloride, copper chloride, sodium chloride, potassium chloride, aluminum chloride, magnesium nitrate, sodium nitrate, potassium nitrate, copper nitrate, zinc nitrate, sodium hydrogen phosphate, sodium acetate, sodium oxalate, and sodium citrate; the calcium salt is at least one selected from calcium chloride, calcium nitrate, calcium bromide, calcium iodide, and calcium gluconate. Step 3, tailing treatment: Filter and dry the liquid in the reaction tank to obtain regenerated aluminum salt lithium adsorbent.

2. The method for regenerating an aluminum salt lithium adsorbent according to claim 1, characterized in that, The dilute acid mentioned in step 1 is selected from at least one of boric acid, phosphoric acid, tartaric acid, oxalic acid, hydrochloric acid, acetic acid, formic acid, nitric acid, and citric acid, and the pH of the dilute acid solution is 3-5.

5.

3. The method for regenerating an aluminum salt lithium adsorbent according to claim 2, characterized in that, The pH of the dilute acid solution is 4.5-5.

4. The method for regenerating an aluminum salt lithium adsorbent according to claim 1, characterized in that, The lithium aluminum salt adsorbent to be regenerated in step 2 is resin-based lithium aluminum salt adsorbent particles. The resin-based lithium aluminum salt adsorbent particles need to be pretreated before being placed in the reaction tank. The specific steps of the pretreatment are as follows: first, drying is performed, then broken or damaged resin-based lithium aluminum salt adsorbent particles are removed, then deionized water is added, and the particles are dispersed by mechanical stirring at a temperature of 50-80℃. Then, the dispersed solution is filtered, and the solid is transferred to the reaction tank.

5. The method for regenerating an aluminum salt lithium adsorbent according to claim 4, characterized in that, In step 2, the mass ratio of deionized water to the resin-based aluminum salt lithium adsorbent particles is (1-5):1, and the mechanical stirring is specifically a dispersion at 200-400 rpm for 2-5 hours.

6. The method for regenerating an aluminum salt lithium adsorbent according to claim 5, characterized in that, In step 2, the mass ratio of deionized water to the resin-based aluminum salt lithium adsorbent particles is 1.5:1, and the mechanical stirring is specifically a dispersion at 200 rpm for 2 hours.

7. The method for regenerating an aluminum salt lithium adsorbent according to claim 1, characterized in that, The aluminum salt lithium adsorbent mentioned in step 2 is a sample whose adsorption capacity has decreased to less than 50% of the initial adsorption capacity after cyclic lithium extraction.

8. The method for regenerating an aluminum salt lithium adsorbent according to claim 1, characterized in that, In step 2, the concentration of the salt solution is 0.12-0.5 mol / L, and the flow rate is 1.5-12 mL / min.

9. The method for regenerating an aluminum salt lithium adsorbent according to claim 1, characterized in that, In step 2, the concentration of the calcium salt solution is 0.05-0.20 mol / L, and the flow rate is 1.5-10 mL / min.

10. The method for regenerating an aluminum salt lithium adsorbent according to claim 1, characterized in that, The lithium chloride solution in step 2 has a concentration of 0.10-0.60 mol / L and a flow rate of 4-15 mL / min.

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