ALUMINUM-BASED LITHIUM ION-SIEVE (LIS), AND PREPARATION METHOD AND USE THEREOF

Abstract

Disclosed are an aluminum-based lithium ion-sieve (LIS), and a preparation method and use thereof. The aluminum-based LIS is Li.sub.2SO.sub.4.Math.2Al(OH).sub.3.Math.nH.sub.2O coated with Al(OH).sub.3, where n is 1 to 4. The preparation method includes: reacting an aluminum salt and a lithium salt with an alkali to obtain an adsorbent intermediate LiOH.Math.2Al(OH).sub.3.Math.nH.sub.2O; using a dilute sulfuric acid to obtain an aluminum-based lithium adsorbent Li.sub.2SO.sub.4.Math.2Al(OH).sub.3.Math.nH.sub.2O; and filtering out and washing the adsorbent, mixing the adsorbent with a metaaluminate, and adjusting a pH to obtain the Li.sub.2SO.sub.4.Math.2Al(OH).sub.3.Math.nH.sub.2O coated with Al(OH).sub.3. The aluminum-based LIS of the present disclosure has the advantages of high adsorption capacity and prominent stability, and can be used to efficiently recover low-concentration lithium in industrial wastewater. Moreover, the LIS is coated with aluminum hydroxide, which can effectively protect the structure from being corroded.

Claims

1. An aluminum-based lithium ion-sieve (LIS), wherein the aluminum-based LIS is Li.sub.2SO.sub.4.Math.2Al(OH).sub.3.Math.nH.sub.2O coated with Al(OH).sub.3, wherein n is 1 to 4; and a preparation method of the aluminum-based LIS comprises the following steps: (1) dissolving an aluminum salt in water, and subjecting a resulting solution to dispersion; and adding a lithium salt, heating, and adjusting a pH to higher than 7.0 to obtain an aluminum-based lithium adsorbent intermediate (LiOH.Math.2Al(OH).sub.3.Math.nH.sub.2O), wherein n is 1 to 4; (2) adjusting a pH of the aluminum-based lithium adsorbent intermediate obtained in step (1) to lower than 7.0, and filtering a resulting mixture to obtain a filter cake, which is an aluminum-based lithium adsorbent (Li.sub.2SO.sub.4.Math.2Al(OH).sub.3.Math.nH.sub.2O); and (3) washing the aluminum-based lithium adsorbent obtained in step (2), and mixing the aluminum-based lithium adsorbent with a metaaluminate solution; adjusting a pH, and filtering a resulting mixture to obtain a filter cake; and drying and grinding the filter cake to obtain the aluminum-based LIS.

2. The aluminum-based LIS according to claim 1, wherein the aluminum salt in step (1) is at least one from the group consisting of aluminum sulfate, aluminum chloride, aluminum nitrate, and sodium metaaluminate.

3. The aluminum-based LIS according to claim 1, wherein the lithium salt in step (1) is at least one from the group consisting of lithium hydroxide, lithium sulfate, lithium chloride, and lithium nitrate.

4. The aluminum-based LIS according to claim 1, wherein the pH is adjusted to 9.0 to 11.0 in step (1); and the reaction is conducted at 30° C. to 100° C. for 1 h to 72 h in step (1).

5. The aluminum-based LIS according to claim 1, wherein the pH is adjusted to higher than 7.0 with at least one solution from the group consisting of a sodium hydroxide solution, a lithium hydroxide solution, a sodium carbonate solution, a sodium bicarbonate solution, and ammonia water in step (1).

6. The aluminum-based LIS according to claim 1, wherein in step (2), the pH is adjusted to lower than 7.0 with at least one from the group consisting of a sulfuric acid solution, a sulfate-containing salt solution, and a mixed solution of the sulfuric acid and salt solutions; the sulfuric acid solution has a concentration of 0.5 mol/L to 2 mol/L; and the sulfate-containing salt solution is at least one from the group consisting of an aluminum sulfate solution, a nickel sulfate solution, a cobalt sulfate solution, a manganese sulfate solution, a ferric sulfate solution, and a ferrous sulfate solution; and the mixed solution of the sulfuric acid and salt solutions is at least one from the group consisting of a mixed solution of sulfuric acid and ferric chloride solutions and a mixed solution of sulfuric acid and ferrous chloride solutions.

7. The aluminum-based LIS according to claim 1, wherein in step (3), the pH is adjusted to 3.5 to 11.0; and the pH is adjusted with at least one solution from the group consisting of a sodium hydroxide solution, a lithium hydroxide solution, a sodium carbonate solution, a sodium bicarbonate solution, ammonia water, an aluminum sulfate solution, a nickel sulfate solution, a cobalt sulfate solution, a manganese sulfate solution, a permanganic acid solution, a ferric sulfate solution, a ferrous sulfate solution, a ferric chloride solution, and a ferrous chloride solution.

8. The aluminum-based LIS according to claim 1, wherein the metaaluminate in step (3) is at least one from the group consisting of sodium metaaluminate and potassium metaaluminate.

9. A method for treating industrial wastewater with the aluminum-based LIS according to claim 1, comprising the following steps: (1) packing the aluminum-based LIS into a resin column, adding industrial wastewater, and conducting ion adsorption to obtain a post-adsorption solution and an aluminum-based LIS under adsorption saturation; and (2) subjecting the aluminum-based LIS under adsorption saturation to counter-current washing and then to counter-current desorption to obtain a pure lithium solution.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0039] FIG. 1 is a process flow diagram of Example 1 of the present disclosure; and

[0040] FIG. 2 is an X-ray diffraction (XRD) pattern of the aluminum-based LIS of Example 1 of the present disclosure.

DETAILED DESCRIPTION

[0041] In order to have a thorough understanding of the present disclosure, preferred experimental schemes of the present disclosure are described below with reference to examples to further illustrate the characteristics and advantages of the present disclosure. Any change or modification made without departing from the subject of the present disclosure can be understood by those skilled in the art. The protection scope of the present disclosure is determined by the claims.

[0042] If no specific conditions are specified in the examples of the present disclosure, conventional conditions or the conditions recommended by a manufacturer will be adopted. All of the raw materials, reagents, or the like which are not specified with manufacturers are conventional commercially-available products.

Example 1

[0043] An aluminum-based LIS was provided in this example, which was Li.sub.2SO.sub.4.Math.2Al(OH).sub.3.Math.nH.sub.2O coated with Al(OH).sub.3.

[0044] A preparation method of the aluminum-based LIS in this example included the following steps:

[0045] (1) 36 g of LiOH was weighed and dissolved in 200 ml of deionized water, then 360 g of Al.sub.2(SO.sub.4).sub.3 was added, and a resulting mixture was thoroughly mixed for 60 min by ultrasonic treatment; and the mixture was heated to 80° C. in a water bath, and a pH was adjusted to 10.0 with sodium hydroxide to obtain an aluminum-based lithium adsorbent intermediate (LiOH.Math.2Al(OH).sub.3.Math.nH.sub.2O);

[0046] (2) a pH of the aluminum-based lithium adsorbent intermediate obtained in step (1) was adjusted to 4 with 0.5 mol/L dilute sulfuric acid; after reaction was completed, aging was conducted for 4 h; a resulting system was filtered, and a resulting filter cake was washed 2 to 3 times to obtain an aluminum-based lithium adsorbent (Li.sub.2SO.sub.4.Math.2Al(OH).sub.3.Math.nH.sub.2O); and

[0047] (3) the aluminum-based lithium adsorbent obtained in step (2) was filtered out by suction filtration and washed; 100 g of NaAlO.sub.2 was weighed and dissolved in 500 ml of water, a resulting solution was mixed with the aluminum-based lithium adsorbent, and a pH was adjusted to 10.0; and a resulting mixture was filtered, and a resulting filter cake was collected, dried at 80° C. for 24 h, and ground to obtain the aluminum-based lithium adsorbent (Li.sub.2SO.sub.4.Math.2Al(OH).sub.3.Math.nH.sub.2O coated with Al(OH).sub.3).

[0048] A method for treating industrial wastewater with the aluminum-based LIS was provided, including the following steps:

[0049] (1) 50 g of the aluminum-based LIS was packed into a resin column, and then strongly-alkaline industrial wastewater (with a pH of 13, Li.sup.+ content) was added for ion adsorption; and the column was placed in a thermostatic water bath and the solution was stirred for 60 min to obtain a post-adsorption solution and an aluminum-based LIS under adsorption saturation; where the Li.sup.+ content in wastewater was determined by ICP before and after adsorption, and the pH was determined by a smart pH meter before and after adsorption; and

[0050] (2) the aluminum-based LIS under adsorption saturation was subjected to counter-current washing and then to counter-current desorption to obtain a pure lithium solution.

[0051] As determined above, the aluminum-based LIS exhibited an adsorption capacity of 2.7 mg/g for Li.sup.+, and the solution had a pH of 13 before adsorption and a pH of 8 after adsorption, indicating significant reduction in pH.

TABLE-US-00001 TABLE 1 Li.sup.+ concentration pH Industrial wastewater 325 mg/L 13 Post-adsorption solution  50 mg/L 8 Pure lithium solution 536 mg/L 6.5 Adsorption capacity of the 2.7 mg/g aluminum-based LIS for Li.sup.+

[0052] It can be seen from Table 1 that the adsorbent showed high adsorption to Li in industrial wastewater; the pure lithium solution could be enriched to more than 500 mg/L through the counter-current desorption; and the Al(OH).sub.3 shell protected the aluminum-based adsorbent itself from being corroded during the adsorption process.

[0053] FIG. 1 is a process flow diagram of Example 1 of the present disclosure. It can be seen from FIG. 1 that a lithium salt and an aluminum salt react with an alkali for adjusting pH, a dilute sulfuric acid is used to obtain an aluminum-based lithium adsorbent, and finally the aluminum-based lithium adsorbent is mixed with a metaaluminate to obtain the aluminum-based LIS coated with Al(OH).sub.3, and the aluminum salt can also supplemented by reverse-adjusting a pH of the post-adsorption solution.

Example 2

[0054] An aluminum-based LIS was provided in this example, which was Li.sub.2SO.sub.4.Math.2Al(OH).sub.3.Math.nH.sub.2O coated with Al(OH).sub.3.

[0055] A preparation method of the aluminum-based LIS in this example included the following steps:

[0056] (1) 48 g of LiOH was weighed and dissolved in 200 ml of deionized water, then 180 g of Al(OH).sub.3 was added, and a resulting mixture was thoroughly mixed for 120 min by ultrasonic treatment; and the mixture was heated to 60° C. in a water bath, and a pH was adjusted to 10.0 with sodium hydroxide to obtain an aluminum-based lithium adsorbent intermediate (LiOH.Math.2Al(OH).sub.3.Math.nH.sub.2O);

[0057] (2) a pH of the aluminum-based lithium adsorbent intermediate obtained in step (1) was adjusted to 4 with 0.5 mol/L dilute sulfuric acid; after reaction was completed, aging was conducted for 6 h; a resulting system was filtered, and a resulting filter cake was collected to obtain an aluminum-based lithium adsorbent (Li.sub.2SO.sub.4.Math.2Al(OH).sub.3.Math.nH.sub.2O); and

[0058] (3) the aluminum-based lithium adsorbent obtained in step (2) was washed 2 to 3 times; 300 g of NaAlO.sub.2 was weighed and dissolved in 500 ml of water, a resulting solution was subjected to ultrasonic dispersion for 30 min and then mixed with the aluminum-based lithium adsorbent, and a pH was adjusted to 8.0; and a resulting mixture was filtered, and a resulting filter cake was collected, dried at 80° C. for 24 h, and ground to obtain the aluminum-based lithium adsorbent (Li.sub.2SO.sub.4.Math.2Al(OH).sub.3.Math.nH.sub.2O coated with Al(OH).sub.3).

[0059] A method for treating industrial wastewater with the aluminum-based LIS was provided, including the following steps:

[0060] (1) 50 g of the aluminum-based LIS was packed into a resin column, and then strongly-alkaline industrial wastewater (with a pH of 12) was added for ion adsorption; and the column was placed in a thermostatic water bath and the solution was stirred for 60 min to obtain a post-adsorption solution and an aluminum-based LIS under adsorption saturation; where the Li.sup.+ content in wastewater was determined by ICP before and after adsorption, and the pH was determined by a smart pH meter before and after adsorption; and

[0061] (2) the aluminum-based LIS under adsorption saturation was subjected to counter-current washing and then to counter-current desorption to obtain a pure lithium solution.

[0062] As determined above, the aluminum-based LIS exhibited an adsorption capacity of 2.1 mg/g for Li.sup.+, and the solution had a pH of 12 before adsorption and a pH of 7.5 after adsorption, indicating significant reduction in pH.

TABLE-US-00002 TABLE 2 Li.sup.+ concentration pH Industrial wastewater 257 mg/L 12 Post-adsorption solution  41 mg/L 7.5 Pure lithium solution 424 mg/L 6.3 Adsorption capacity of the 2.1 mg/g aluminum-based LIS for Li.sup.+

[0063] It can be seen from Table 2 that the adsorbent showed high adsorption to Li in industrial wastewater; and the Al(OH).sub.3 shell protected the aluminum-based adsorbent itself from being corroded during the adsorption process.

Example 3

[0064] An aluminum-based LIS was provided in this example, which was Li.sub.2SO.sub.4.Math.2Al(OH).sub.3.Math.nH.sub.2O coated with Al(OH).sub.3, where the n was 1 to 4.

[0065] A preparation method of the aluminum-based LIS in this example included the following steps:

[0066] (1) 21 g of LiCl was weighed and dissolved in 200 ml of deionized water, then 210 g of Al(NO.sub.3).sub.3 was added, and a resulting mixture was thoroughly mixed for 30 min by ultrasonic treatment; the mixture was heated to 90° C. in a water bath, and a pH was adjusted to 12 with sodium hydroxide; and a resulting mixture was stirred for 12 h at a stirring rate of 120 rpm to obtain an aluminum-based lithium adsorbent intermediate (LiOH.Math.2Al(OH).sub.3.Math.nH.sub.2O);

[0067] (2) a pH of the aluminum-based lithium adsorbent intermediate obtained in step (1) was adjusted to 4 with 0.5 mol/L dilute sulfuric acid; after reaction was completed, aging was conducted for 6 h; a resulting system was filtered, and a resulting filter cake was collected to obtain an aluminum-based lithium adsorbent (Li.sub.2SO.sub.4.Math.2Al(OH).sub.3.Math.nH.sub.2O); and

[0068] (3) the aluminum-based lithium adsorbent obtained in step (2) was washed 2 to 3 times; 300 g of NaAlO.sub.2 was weighed and dissolved in 500 ml of water, a resulting solution was mixed with the aluminum-based lithium adsorbent; a resulting mixture was subjected to ultrasonic dispersion for 30 min, and a pH was adjusted to 6.0; and a resulting mixture was filtered, and a resulting filter cake was collected, dried at 80° C. for 24 h, and ground to obtain the aluminum-based lithium adsorbent (Li.sub.2SO.sub.4.Math.2Al(OH).sub.3.Math.nH.sub.2O coated with Al(OH).sub.3).

[0069] A method for treating industrial wastewater with the aluminum-based LIS was provided, including the following steps:

[0070] (1) 50 g of the aluminum-based LIS was packed into a resin column, and then strongly-alkaline industrial wastewater (with a pH of 13) was added for ion adsorption; and the column was placed in a thermostatic water bath and the solution was stirred for 60 min to obtain a post-adsorption solution and an aluminum-based LIS under adsorption saturation; where the Li.sup.+ content in wastewater was determined by ICP before and after adsorption, and the pH was determined by a smart pH meter before and after adsorption; and

[0071] (2) the aluminum-based LIS under adsorption saturation was subjected to counter-current washing and then to counter-current desorption to obtain a pure lithium solution.

[0072] As determined above, the aluminum-based LIS exhibited an adsorption capacity of 2.3 mg/g for Li.sup.+, and the solution had a pH of 13 before adsorption and a pH of 8.5 after adsorption, indicating significant reduction in pH.

TABLE-US-00003 TABLE 3 Li.sup.+ concentration pH Industrial wastewater 431 mg/L 13 Post-adsorption solution 196 mg/L 8.5 Pure lithium solution 579 mg/L 6 Adsorption capacity of the 2.3 mg/g aluminum-based LIS for Li.sup.+

[0073] It can be seen from Table 3 that the adsorbent showed high adsorption to Li in industrial wastewater; the pure lithium solution could be enriched to more than 500 mg/L through multiple counter-current desorption; and the Al(OH).sub.3 shell protected the aluminum-based adsorbent itself from being corroded during the adsorption process.

[0074] FIG. 2 shows the XRD result of the product. It can be seen that the peak intensity of Al(OH).sub.3 was stronger than that of the adsorbent; and the absorption peak of aluminum hydroxide in the prepared product covered the absorption peak of the lithium-ion adsorbent, indicating that an aluminum-based lithium-ion adsorbent coated with aluminum hydroxide was synthesized.

[0075] The aluminum-based LIS and a preparation method and use thereof provided in the present disclosure are described in detail above, and specific examples are used herein to illustrate the principle and implementation of the present disclosure. The examples are illustrated above merely to help understand the method and core ideas thereof (including the optimal mode) of the present disclosure and allow any person skilled in the art to practice the present disclosure, including manufacturing and using any device or system and implementing any combined method. It should be noted that several improvements and modifications may be made by persons of ordinary skill in the art without departing from the principle of the present disclosure, and these improvements and modifications should also fall within the protection scope of the present disclosure. The protection scope of the present disclosure is defined by the claims and may encompass other examples that those skilled in the art can think of. If these other examples have structural elements that are not different from the literal expression in the claims or include equivalent structural elements that are not substantially different from the literal expression in the claims, they should also be included in the scope of the claims.