Regeneration method and regeneration device of aluminum lithium adsorbent

Abstract

The invention discloses a regeneration method and a regeneration device of an aluminum lithium adsorbent, a mixed solution of a buffer solution and an adsorption tail solution is prepared as a regeneration transformation solution, a regeneration transformation area is added in a continuous ion exchange system, and the aluminum adsorbent completes a complete process of adsorption, regeneration transformation and desorption in a cycle period. Compared with the prior art, the method provided by the invention has the advantages that regeneration and transformation of the adsorbent can be completed in normal production operation, carbonate ions in the adsorbent are regularly and efficiently removed, and the original lithium-aluminum layered double hydroxide structure of the adsorbent is maintained, so that the application of the aluminum lithium adsorbent in the carbonate type salt lake is realized.

Description

Technical Field

[0001] The invention belongs to the technical field of adsorbent regeneration, and in particular relates to a regeneration method for an aluminum-based lithium adsorbent. Background Art

[0002] As a key raw material in key areas of energy transformation such as electric vehicles and energy storage, lithium has gradually become a strategic resource in recent years. As the world's largest producer and consumer of lithium batteries, my country's domestic lithium resources were developed relatively late, and the source of lithium depends largely on imported lithium concentrate. As foreign lithium resource-rich countries begin to promote the nationalization of lithium mines, my country must strengthen the development of domestic lithium resources to ensure the security of lithium supply. 80% of my country's lithium resources are concentrated in salt lakes in Qinghai and Tibet. After 20 years of development, the lithium extraction industry in Qinghai Salt Lake has broken through the technical difficulties of extracting lithium from brine with a high magnesium-lithium ratio, and is currently in a period of rapid growth in production capacity. Compared with Qinghai Salt Lake, Tibet Salt Lake has a higher resource endowment, with high lithium content and low magnesium-lithium ratio. At present, more and more companies are joining the team to develop Tibet Salt Lake. According to the main components of salt lake brine, Tibet Salt Lake mainly has three types: carbonate type, sodium sulfate subtype and magnesium sulfate subtype. The main lithium extraction process route currently planned is adsorption coupled membrane method.

[0003] There are currently three mainstream adsorbents for lithium extraction from salt lakes: aluminum-based lithium adsorbents, manganese-based lithium ion sieves, and titanium-based lithium ion sieves. Aluminum-based lithium adsorbents have been commercially applied on a large scale and are generally suitable for salt lake brine with a pH value of 4-8. The dissolution problem of manganese-based lithium ion sieves is relatively serious and is still at the laboratory level. The dissolution of titanium-based lithium ion sieves is relatively low, and pilot experiments have been carried out in many salt lakes in Tibet, but the acid dissolution problem of ion sieves cannot be overcome. The dissolution not only increases the subsequent separation and purification process, but more seriously, it greatly reduces the life of the lithium adsorbent. Manganese-based and titanium-based lithium ion sieves use salt lakes or sulfuric acid as eluents. Since transportation in Tibet is difficult, bipolar membranes need to be added when designing the production line to produce acid and alkali, which increases the complexity of the process route and the investment and operating costs.

[0004] For carbonate-type salt lakes such as Zabuye, the applicant has developed a process route for aluminum-based adsorbent coupled membrane method, using multi-stage nanofiltration water as aluminum-based adsorbent inlet water, and a continuous ion exchange system for continuous lithium adsorption-analysis. However, in actual operation, it was found that even if the adsorbent inlet brine contained only tens of ppm of carbonate ions, after running dozens of cycles, the adsorption and desorption performance of the adsorbent would still show a significant decline. After carbonate ions replace chloride ions to occupy the interlayer space of the layered aluminum-based adsorbent, it is difficult to wash them off with desalted water, resulting in fewer released lithium vacancies and less lithium re-adsorption. Summary of the invention

[0005] In order to solve the problems existing in the above prior art, the present invention provides a regeneration method for an aluminum-based lithium adsorbent, which solves the problem that the adsorption and desorption performance of the aluminum-based lithium adsorbent decreases significantly after dozens of cycles through transformation regeneration.

[0006] Another object of the present invention is to provide a regeneration device for use in the above-mentioned aluminum-based lithium adsorbent regeneration method.

[0007] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions:

[0008] A method for regenerating an aluminum-based lithium adsorbent comprises the following steps:

[0009] In a continuous ion exchange system loaded with aluminum-based lithium adsorbent, the adsorbent enters the adsorption zone for lithium adsorption, passes through the adsorption zone and then enters the regeneration transformation zone for regeneration transformation, and after regeneration transformation, it successively enters the elution zone and the analysis zone for elution and analysis, and finally passes through the top material zone for material-liquid replacement, and then re-enters the adsorption zone to start a new cycle of lithium extraction; wherein the regeneration transformation zone uses a mixture of a buffer solution and the adsorption zone adsorption tail liquid as the regeneration transformation liquid.

[0010] In the present invention, the adsorption tail liquid is the tail brine produced after the adsorbent adsorbs lithium in the adsorption zone. When the adsorbent works normally, the adsorption tail liquid is a lithium-poor brine, in which the lithium content is generally 0-15% of the lithium content of the feed brine in the adsorption zone, for example 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, etc.

[0011] In a specific embodiment, the continuous ion exchange system is a continuous ion exchange system with more than 10 columns, for example, a 20-column system, a 30-column system or a system of other customized numbers, such as a 12-column system, a 36-column system, a 48-column system, etc., but not limited thereto, preferably any one of a 20-column system and a 30-column system.

[0012] In a specific embodiment, the feed brine in the adsorption zone is one or more stages of produced water after carbonate-type raw brine is treated by nanofiltration membrane.

[0013] In a specific embodiment, the total carbonate content in the brine fed to the adsorption zone is less than 2000 ppm, for example, 1900 ppm, 1800 ppm, 1700 ppm, 1600 ppm, 1500 ppm, 1400 ppm, 1300 ppm, 1200 ppm, 1100 ppm, 1000 ppm, 900 ppm, 800 ppm, 700 ppm, 600 ppm, 500 ppm, 400 ppm, 300 ppm, 200 ppm, 100 ppm, etc., and preferably less than 1000 ppm.

[0014] In a specific embodiment, the pH range of the regeneration transformation solution is 3-6.5, such as 4, 4.5, 5, 5.5, 6, etc., preferably 4-5.5.

[0015] In a specific embodiment, the buffer pair type of the buffer solution in the regeneration transformation liquid is selected from any one of sodium dihydrogen phosphate-disodium hydrogen phosphate, potassium dihydrogen phosphate-dipotassium hydrogen phosphate, potassium dihydrogen phosphate-disodium hydrogen phosphate, sodium dihydrogen phosphate-dinopotassium hydrogen phosphate, citric acid-disodium hydrogen phosphate, citric acid-sodium citrate, acetic acid-sodium acetate, glycine-hydrochloric acid, phthalic acid-hydrochloric acid and imidazole-hydrochloric acid, preferably any one of citric acid-disodium hydrogen phosphate, citric acid-sodium citrate and acetic acid-sodium acetate.

[0016] In a specific embodiment, the total concentration of the buffer pair of the buffer solution in the regeneration transformation solution is 0.05-0.25 mol / L, for example, 0.1 mol / L, 0.12 mol / L, 0.15 mol / L, 0.18 mol / L, 0.2 mol / L, 0.23 mol / L, 0.25 mol / L, etc.

[0017] In a specific embodiment, the volume ratio of the buffer solution in the regeneration transformation solution to the adsorption tail liquid is 5:5-9:1, for example, 5:5, 6:4, 7:3, 8:2, 9:1, etc., preferably 6:4-8:2.

[0018] In a specific embodiment, the flow direction of the material in the regeneration transformation zone is in the upper part and out the lower part, and the flow rate is 5-25BV / h, for example, 6BV / h, 7BV / h, 8BV / h, 9BV / h, 10BV / h, 12BV / h, 13BV / h, 15BV / h, 18BV / h, 20BV / h, 22BV / h, 24BV / h, etc.

[0019] In a specific embodiment, the rotation interval of the continuous ion exchange system is 5-20 min / step, for example, 6 min / step, 7 min / step, 8 min / step, 10 min / step, 12 min / step, 15 min / step, 16 min / step, 18 min / step, 20 min / step, etc.

[0020] On the other hand, a regeneration device suitable for the aforementioned aluminum-based lithium adsorbent regeneration method comprises a feed system, including functional areas of an adsorption zone, a regeneration transformation zone, a leaching zone, a decomposition zone, and a top-feeding zone, an ion exchange column, and a power system; wherein the feed system provides the required liquid feed and / or receives the corresponding discharge for the adsorption zone, the regeneration transformation zone, the leaching zone, the decomposition zone, and the top-feeding zone;

[0021] The adsorption zone, regeneration transformation zone, elution zone, analysis zone, and top material zone are arranged adjacent to each other in sequence to form a closed loop of functional zones;

[0022] The adsorption zone is used for the lithium adsorption of salt lake brine by aluminum-based lithium adsorbent;

[0023] The regeneration and transformation zone is used for regenerating and transforming the lithium adsorbent after passing through the adsorption zone;

[0024] The elution zone is used for eluting the lithium adsorbent after passing through the regeneration transformation zone;

[0025] The decomposition zone is used for decomposing the lithium adsorbent after passing through the elution zone;

[0026] The top material zone is used for liquid replacement of the lithium adsorbent after passing through the desorption zone;

[0027] The power system drives the ion exchange columns arranged in a circle to perform periodic cyclic switching in the adsorption zone, regeneration transformation zone, elution zone, analysis zone, and top material zone.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] The regeneration method of the aluminum-based lithium adsorbent provided by the present invention uses a mixed solution of a buffer solution and an adsorption tail liquid as a regeneration transformation liquid, which has the characteristics of high proton content and high pH value compared to low-concentration conventional acids, thereby having the advantages of high regeneration efficiency and stable regeneration effect. The buffer in the regeneration transformation liquid provides the protons required for decarbonation, and the adsorption tail liquid provides the interlayer chloride ions required for transformation. The continuous and stable pH value of the regeneration transformation liquid inhibits the dissolution of the main structure of the double hydroxide of the aluminum-based lithium adsorbent and maintains the structural stability of the core components of the adsorbent.

[0030] The present invention integrates the regeneration transformation process into a conventional continuous ion exchange system, realizing the continuous closed-loop application of the adsorbent from adsorption to regeneration to analysis, which can be scaled up to continuous production, allowing the aluminum-based lithium adsorbent to be smoothly applied to carbonate salt lakes. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The figure is a schematic flow chart of the regeneration method of the aluminum-based lithium adsorbent of the present invention.

[0032] Figure 2 It is a schematic diagram of the functional area distribution of the regeneration device of the aluminum-based lithium adsorbent of the present invention. DETAILED DESCRIPTION

[0033] In order to better understand the technical solution of the present invention, the following embodiments will further illustrate the solution provided by the present invention, but the present invention is not limited to the listed embodiments, and should also include any other known changes within the scope of the claims of the present invention.

[0034] like Figure 1 , Figure 2 As shown, the 20-column continuous ion exchange system can be correspondingly divided into an adsorption zone, a regeneration (transformation) zone, a leaching zone, a decomposition zone, and a top-feeding zone, wherein the 20 ion exchange columns are arranged in a circle, and the adsorption zone, the regeneration and transformation zone (referred to as the "regeneration zone"), the leaching zone, the decomposition zone, and the top-feeding zone are also arranged in a circle. During operation, the power system drives the ion exchange columns to rotate, thereby realizing the periodic switching of the ion exchange columns in different functional zones; the feeding system provides the required feed liquid feed and / or receives the corresponding discharge for the adsorption zone, the regeneration and transformation zone, the leaching zone, the decomposition zone, and the top-feeding zone, for example, the adsorption zone feed is supplied with salt lake brine filtered by a nanofiltration membrane, and part of the adsorption tail liquid is sent to the regeneration and transformation zone to be prepared with a buffer solution into a regeneration and transformation liquid, and supplied to the regeneration and transformation zone; the leaching zone supplies desalted water or a decomposition liquid for elution, and the decomposition zone supplies desalted water for decomposition of the lithium adsorbent, etc. Typically, the column on a continuous ion exchange system rotates and steps every few minutes, for example, 5-20 minutes / step, that is, it moves one step in the circumferential direction every 5-20 minutes, thereby entering different functional areas in turn for adsorption, regeneration, elution, analysis and feed-liquid replacement.

[0035] In the present invention, the continuous ion exchange system is a continuous ion exchange system commonly used in the field of lithium extraction from salt lakes, such as Xiamen Fumei's FM-Sep-20025 continuous ion exchange system, which includes an adsorption zone, a elution zone, a decomposition zone, and a top material zone. The present invention only adds a regeneration transformation zone between the adsorption zone and the elution zone, and the regeneration transformation zone uses a mixed solution of a buffer solution and the adsorption zone adsorption tail liquid as the regeneration transformation liquid.

[0036] The buffer pair of the buffer solution in the regeneration transformation liquid is selected from any one of sodium dihydrogen phosphate-disodium hydrogen phosphate, potassium dihydrogen phosphate-dipotassium hydrogen phosphate, potassium dihydrogen phosphate-disodium hydrogen phosphate, sodium dihydrogen phosphate-dipotassium hydrogen phosphate, citric acid-disodium hydrogen phosphate, citric acid-sodium citrate, acetic acid-sodium acetate, glycine-hydrochloric acid, phthalic acid-hydrochloric acid and imidazole-hydrochloric acid, preferably any one of citric acid-disodium hydrogen phosphate, citric acid-sodium citrate and acetic acid-sodium acetate. The total concentration of the buffer pair of the buffer solution in the regeneration transformation liquid is 0.05-0.25 mol / L.

[0037] Among them, the adsorption tail liquid in the adsorption zone is the tail brine produced after the adsorbent adsorbs lithium in the adsorption zone. When the adsorbent works normally, the adsorption tail liquid is a lithium-poor brine, and the lithium content in it is greatly lower than the lithium content in the feed brine entering the adsorption zone, generally 0-15% of the lithium content of the feed brine in the adsorption zone.

[0038] In the present invention, the adsorption tail liquid in the adsorption zone is mixed with the buffer solution to form a regeneration transformation liquid and then enters the regeneration transformation zone. In the present invention, unless otherwise specified, reference may be made to the prior art, such as Xiamen Fumei's FM-Sep-20025 continuous ion exchange system, including the zoning of each functional zone, the series and parallel relationship of each ion exchange column, the feeding system supplying or receiving the feed liquid, the operation of the power system, etc., all of which may refer to the prior art.

[0039] In the regeneration method of the aluminum-based lithium adsorbent of the present invention, the aluminum-based lithium adsorbent first enters the adsorption zone for lithium adsorption, then enters the regeneration transformation zone for regeneration transformation after lithium adsorption in the adsorption zone, and then enters the elution zone for elution and the analysis zone for analysis in turn, and finally passes through the top material zone for material-liquid replacement, and then the obtained aluminum-based lithium adsorbent re-enters the adsorption zone to start a new cycle of lithium extraction.

[0040] The present invention is further illustrated by the following examples, but the scope of the present invention is not limited thereto.

[0041] The main devices and raw material sources used in the following examples are as follows:

[0042] Single column 500mL*30 columns / 20 columns continuous ion exchange system, Xiamen Fumei Technology Co., Ltd.

[0043] Aluminum-based lithium adsorbent, a spherical aluminum-based lithium adsorbent product, can be prepared through Example 1 in patent CN117258747B.

[0044] Determination of lithium content in the analytical solution: After the analytical solution was diluted with 1% nitric acid, its lithium content was determined by inductively coupled plasma optical emission spectrometry (ICP-OES).

[0045] Example 1

[0046] A single column 500mL*30 column continuous ion exchange system is used. The raw brine is the secondary nanofiltration water produced by Zabuye original brine, and its composition is as follows (except for the lithium content of the adsorption tail liquid which is lower than 50mg / L, the other compositions are similar to it):

[0047] Li Na K Mg Ca B <![CDATA[Cl - ]]> <![CDATA[SO4 2- ]]> <![CDATA[CO3 2- ]]> mg / L g / L g / L mg / L mg / L mg / L g / L mg / L mg / L 705 89 25 - - 94 156 - 350

[0048] Prepare buffer solution: 100L of 0.2mol / L sodium dihydrogen phosphate solution: weigh 3.12kg of sodium dihydrogen phosphate dihydrate and dissolve it in 100L of water; 100L of 0.2mol / L disodium hydrogen phosphate solution: weigh 7.16kg of disodium hydrogen phosphate dodecahydrate and dissolve it in 100L of water.

[0049] The regeneration transformation liquid composition of pH 6.4: 66.2L of 0.2mol / L sodium dihydrogen phosphate solution, 23.8L of 0.2mol / L sodium dihydrogen phosphate solution, and 10L of adsorption tail liquid.

[0050] The 30-column continuous ion exchange system is divided into the following zones: 18 columns in the adsorption zone, 1 column in the regeneration and transformation zone, 4 columns in the elution zone, 6 columns in the desorption zone, and 1 column in the top feed zone. The rotation interval is 10 min / step, and the flow rate in the regeneration and transformation zone is 2.5 L / h (5 BV / h).

[0051] The continuous ion exchange system was operated for 5 cycles, and samples were taken in each cycle to determine the lithium content in the analytical solution.

[0052] Example 2

[0053] A single column 500mL*30 column continuous ion exchange system is used. The raw brine is the first-level nanofiltration water produced by Zabuye original brine, and its composition is as follows (except for the lithium content of the adsorption tail liquid which is lower than 50mg / L, the other compositions are similar to it):

[0054] Li Na K Mg Ca B <![CDATA[Cl - ]]> <![CDATA[SO4 2- ]]> <![CDATA[CO3 2- ]]> mg / L g / L g / L mg / L mg / L mg / L g / L mg / L mg / L 721 90 28 - - 183 161 - 1920

[0055] Prepare buffer solution: 100L of 0.1mol / L citric acid solution: weigh 2.10kg of citric acid monohydrate and dissolve it in 100L of water; 100L of 0.1mol / L sodium citrate solution: weigh 2.94kg of trisodium citrate dihydrate and dissolve it in 100L of water.

[0056] The regeneration transformation solution of pH 4.0 is composed of: 41.3 L of 0.1 mol / L citric acid solution, 28.7 L of 0.1 mol / L sodium citrate solution, and 30 L of adsorption tail liquid.

[0057] The 30-column continuous ion exchange system is divided into the following zones: 18 columns in the adsorption zone, 1 column in the regeneration and transformation zone, 4 columns in the elution zone, 6 columns in the desorption zone, and 1 column in the top feed zone. The rotation interval is 15 min / step, and the flow rate in the regeneration and transformation zone is 4 L / h (8 BV / h).

[0058] The continuous ion exchange system was operated for 5 cycles, and samples were taken in each cycle to determine the lithium content in the analytical solution.

[0059] Example 3

[0060] A single column 500mL*20 column continuous ion exchange system was used. The raw brine was the secondary nanofiltration water produced by Zabuye original brine, and its composition was as follows (except for the lithium content of the adsorption tail liquid which was lower than 50mg / L, the other compositions were similar to it):

[0061] Li Na K Mg Ca B <![CDATA[Cl - ]]> <![CDATA[SO4 2- ]]> <![CDATA[CO3 2- ]]> mg / L g / L g / L mg / L mg / L mg / L g / L mg / L mg / L 700 89 25 - - 101 155 - 980

[0062] Prepare buffer solution: 100L of 0.3mol / L acetic acid solution: weigh 1.80kg of glacial acetic acid and dissolve it in 100L of water; 100L of 0.3mol / L sodium acetate solution: weigh 4.08kg of sodium acetate trihydrate and dissolve it in 100L of water.

[0063] The regeneration transformation liquid composition of pH 4.8: 32.8 L of 0.3 mol / L acetic acid solution, 47.2 L of 0.3 mol / L sodium acetate solution, and 20 L of adsorption tail liquid.

[0064] The 20-column continuous ion exchange system is divided into the following sections: 12 columns in the adsorption zone, 1 column in the regeneration and transformation zone, 2 columns in the elution zone, 4 columns in the desorption zone, and 1 column in the top feed zone. The rotation interval is 10 min / step, and the flow rate in the regeneration and transformation zone is 4.5 L / h (9 BV / h).

[0065] The continuous ion exchange system was operated for 5 cycles, and samples were taken in each cycle to determine the lithium content in the analytical solution.

[0066] Example 4

[0067] A single column 500mL*30 column continuous ion exchange system is used. The raw brine is the first-level nanofiltration water produced by Zabuye original brine, and its composition is as follows (except for the lithium content of the adsorption tail liquid which is lower than 50mg / L, the other compositions are similar to it):

[0068] Li Na K Mg Ca B <![CDATA[Cl - ]]> <![CDATA[SO4 2- ]]> <![CDATA[CO3 2- ]]> mg / L g / L g / L mg / L mg / L mg / L g / L mg / L mg / L 728 90 28 - - 176 163 - 1540

[0069] Prepare buffer solution: 100L of 0.1mol / L citric acid solution: weigh 2.10kg of citric acid monohydrate and dissolve it in 100L of water; 100L of 0.2mol / L disodium hydrogen phosphate solution: weigh 3.56kg of disodium hydrogen phosphate dihydrate and dissolve it in 100L of water.

[0070] The regeneration transformation solution with pH 5.4 is composed of: 22.1L of 0.1mol / L citric acid solution, 27.9L of 0.2mol / L disodium hydrogen phosphate solution, and 50L of adsorption tail liquid.

[0071] The 30-column continuous ion exchange system is divided into the following zones: 18 columns in the adsorption zone, 1 column in the regeneration and transformation zone, 4 columns in the elution zone, 6 columns in the desorption zone, and 1 column in the top feed zone. The rotation interval is 5 min / step, and the flow rate in the regeneration and transformation zone is 12.5 L / h (25 BV / h).

[0072] The continuous ion exchange system was operated for 5 cycles, and samples were taken in each cycle to determine the lithium content in the analytical solution.

[0073] Example 5

[0074] A single column 500mL*20 column continuous ion exchange system was used. The raw brine was the secondary nanofiltration water produced by Zabuye original brine, and its composition was as follows (except for the lithium content of the adsorption tail liquid which was lower than 50mg / L, the other compositions were similar to it):

[0075] Li Na K Mg Ca B <![CDATA[Cl - ]]> <![CDATA[SO4 2- ]]> <![CDATA[CO3 2- <!-- 5 -->]]> mg / L g / L g / L mg / L mg / L mg / L g / L mg / L mg / L 710 89 25 - - 97 156 - 760

[0076] Prepare buffer solution: 100L of 0.2mol / L potassium hydrogen phthalate solution: weigh 4.08kg of sodium dihydrogen phosphate dihydrate and dissolve it in 100L of water; 100L of 0.2mol / L hydrochloric acid solution: measure 1.67L of industrial hydrochloric acid and dissolve it in 100L of water.

[0077] The regeneration transformation liquid composition of pH 3.0: 8L of 0.2mol / L potassium hydrogen phthalate solution, 20L of 0.2mol / L hydrochloric acid solution, 32L of desalted water, and 40L of adsorption tail liquid.

[0078] The 20-column continuous ion exchange system is divided into the following zones: 12 columns in the adsorption zone, 1 column in the regeneration and transformation zone, 2 columns in the elution zone, 4 columns in the desorption zone, and 1 column in the top feed zone. The rotation interval is 20 min / step, and the flow rate in the regeneration and transformation zone is 3 L / h (6 BV / h).

[0079] The continuous ion exchange system was operated for 5 cycles, and samples were taken in each cycle to determine the lithium content in the analytical solution.

[0080] Comparative Example 1

[0081] A single column 500mL*30 column continuous ion exchange system is used. The raw brine is the secondary nanofiltration water produced by Zabuye original brine, and its composition is as follows (except for the lithium content of the adsorption tail liquid which is lower than 50mg / L, the other compositions are similar to it):

[0082] Li Na K Mg Ca B <![CDATA[Cl - ]]> <![CDATA[SO4 2- ]]> <![CDATA[CO3 2- ]]> mg / L g / L g / L mg / L mg / L mg / L g / L mg / L mg / L 705 89 25 - - 94 156 - 350

[0083] The 30-column continuous ion exchange system is divided into the following sections: 18 columns in the adsorption zone, 5 columns in the elution zone, 6 columns in the desorption zone, and 1 column in the top feed zone. The rotation interval is 10 min / step.

[0084] The continuous ion exchange system was operated for 5 cycles, and samples were taken in each cycle to determine the lithium content in the analytical solution.

[0085] Comparative Example 2

[0086] A single column 500mL*30 column continuous ion exchange system is used. The raw brine is the secondary nanofiltration water produced by Zabuye original brine, and its composition is as follows (except for the lithium content of the adsorption tail liquid which is lower than 50mg / L, the other compositions are similar to it):

[0087] Li Na K Mg Ca B <![CDATA[Cl - ]]> <![CDATA[SO4 2- ]]> <![CDATA[CO3 2- ]]> mg / L g / L g / L mg / L mg / L mg / L g / L mg / L mg / L 705 89 25 - - 94 156 - 350

[0088] Prepare buffer solution: 100L of 0.2mol / L sodium dihydrogen phosphate solution: weigh 3.12kg of sodium dihydrogen phosphate dihydrate and dissolve it in 100L of water; 100L of 0.2mol / L disodium hydrogen phosphate solution: weigh 7.16kg of disodium hydrogen phosphate dodecahydrate and dissolve it in 100L of water.

[0089] The composition of the regeneration transformation solution at pH 6.4: 73.5 L of 0.2 mol / L sodium dihydrogen phosphate solution and 26.5 L of 0.2 mol / L sodium dihydrogen phosphate solution.

[0090] The 30-column continuous ion exchange system is divided into the following zones: 18 columns in the adsorption zone, 1 column in the regeneration and transformation zone, 4 columns in the elution zone, 6 columns in the desorption zone, and 1 column in the top feed zone. The rotation interval is 10 min / step, and the flow rate in the regeneration and transformation zone is 2.5 L / h (5 BV / h).

[0091] The continuous ion exchange system was operated for 5 cycles, and samples were taken in each cycle to determine the lithium content in the analytical solution.

[0092] Comparative Example 3

[0093] A single column 500mL*30 column continuous ion exchange system is used. The raw brine is the secondary nanofiltration water produced by Zabuye original brine, and its composition is as follows (except for the lithium content of the adsorption tail liquid which is lower than 50mg / L, the other compositions are similar to it):

[0094] Li Na K Mg Ca B <![CDATA[Cl - ]]> <![CDATA[SO4 2- ]]> <![CDATA[CO3 2- ]]> mg / L g / L g / L mg / L mg / L mg / L g / L mg / L mg / L 705 89 25 - - 94 156 - 350

[0095] The regeneration transformation liquid is the adsorption tail liquid produced in the adsorption zone.

[0096] The 30-column continuous ion exchange system is divided into the following zones: 18 columns in the adsorption zone, 1 column in the regeneration and transformation zone, 4 columns in the elution zone, 6 columns in the desorption zone, and 1 column in the top feed zone. The rotation interval is 10 min / step, and the flow rate in the regeneration and transformation zone is 2.5 L / h (5 BV / h).

[0097] The continuous ion exchange system was operated for 5 cycles, and samples were taken in each cycle to determine the lithium content in the analytical solution.

[0098] Table 1 Lithium content in the analytical solution during multiple cycles (mg / L)

[0099]

[0100]

[0101] From the above results, it can be seen that after the regeneration step is added to the continuous desorption / ionization system of Examples 1 to 5, the adsorbent can be efficiently and losslessly regenerated while working normally, so that it can operate stably in a carbonate salt lake; while in Comparative Example 1, due to the lack of a regeneration step, as carbonate ions gradually accumulate in the adsorbent, the number of sites for the adsorbent to play a lithium extraction role becomes fewer and fewer, so that after 5 cycles, nearly 90% of the performance has been lost; the regeneration transformation liquid of Comparative Example 2 only includes a buffer solution, and there is no adsorption tail liquid to provide the monovalent anions required for ion exchange, so the effect of removing carbonate ions is very weak, the residual carbonate ions in the adsorbent will continue to accumulate, and the performance of the adsorbent will continue to decay; the regeneration transformation liquid of Comparative Example 3 only includes the adsorption tail liquid generated in the adsorption zone, and the high concentration salt can only remove part of the carbonate ions, and cannot eradicate the carbonate ions adsorbed in each cycle, so the final result is similar to Comparative Examples 1 and 2.

[0102] It is easy to understand that the above embodiments are only examples for clear explanation and do not mean that the present invention is limited thereto. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from this are still within the protection scope of the present invention.

Claims

1. A method for regenerating an aluminum-based lithium adsorbent, characterized in that: The following steps are involved: In a continuous ion exchange system loaded with aluminum-based lithium adsorbent, the adsorbent enters the adsorption zone for lithium adsorption, passes through the adsorption zone and then enters the regeneration transformation zone for regeneration transformation, and after regeneration transformation, it successively enters the elution zone and the analysis zone for elution and analysis, and finally passes through the top material zone for material-liquid replacement, and then re-enters the adsorption zone to start a new cycle of lithium extraction; wherein the regeneration transformation zone uses a mixture of a buffer solution and the adsorption zone adsorption tail liquid as the regeneration transformation liquid.

2. The method for regenerating an aluminum-based lithium adsorbent according to claim 1, characterized in that: The continuous ion exchange system is a continuous ion exchange system having more than 10 columns, preferably any one of a 20-column system and a 30-column system.

3. The method for regenerating an aluminum-based lithium adsorbent according to claim 1, characterized in that: The feed brine of the adsorption zone is the primary or multi-stage produced water after carbonate-type raw brine is treated by nanofiltration membrane; Preferably, the total carbonate content in the brine fed to the adsorption zone is less than 2000 ppm, preferably less than 1000 ppm.

4. The method for regenerating an aluminum-based lithium adsorbent according to claim 1, characterized in that: The pH range of the regeneration transformation liquid is 3-6.5, preferably 4-5.

5.

5. The method for regenerating an aluminum-based lithium adsorbent according to claim 1 or 4, characterized in that: The buffer pair of the buffer solution in the regeneration transformation liquid is selected from any one of sodium dihydrogen phosphate-disodium hydrogen phosphate, potassium dihydrogen phosphate-dipotassium hydrogen phosphate, potassium dihydrogen phosphate-disodium hydrogen phosphate, sodium dihydrogen phosphate-dipotassium hydrogen phosphate, citric acid-disodium hydrogen phosphate, citric acid-sodium citrate, acetic acid-sodium acetate, glycine-hydrochloric acid, phthalic acid-hydrochloric acid and imidazole-hydrochloric acid.

6. The method for regenerating an aluminum-based lithium adsorbent according to claim 5, characterized in that: The total concentration of the buffer pair of the buffer solution in the regeneration transformation solution is 0.05-0.25 mol / L.

7. The method for regenerating an aluminum-based lithium adsorbent according to claim 1, characterized in that: The volume ratio of the buffer solution in the regeneration transformation solution to the adsorption tail liquid is 5:5-9:1, preferably 6:4-8:

2.

8. The method for regenerating an aluminum-based lithium adsorbent according to claim 1, characterized in that: The flow direction of the material in the regeneration transformation zone is upward in and downward out, and the flow rate is 5-25BV / h.

9. The method for regenerating an aluminum-based lithium adsorbent according to claim 1, characterized in that: The rotation interval of the continuous ion exchange system is 5-20min / step.

10. A regeneration device suitable for the aluminum-based lithium adsorbent regeneration method according to any one of claims 1 to 9, characterized in that: It includes a feeding system, including functional areas of an adsorption zone, a regeneration transformation zone, a leaching zone, a decomposition zone, and a top-feeding zone, an ion exchange column, and a power system; wherein the feeding system provides the required liquid feed and / or receives the corresponding discharge for the adsorption zone, the regeneration transformation zone, the leaching zone, the decomposition zone, and the top-feeding zone; The adsorption zone, regeneration transformation zone, elution zone, analysis zone, and top material zone are arranged adjacent to each other in sequence to form a closed loop of functional zones; The adsorption zone is used for the lithium adsorption of salt lake brine by aluminum-based lithium adsorbent; The regeneration and transformation zone is used for regenerating and transforming the lithium adsorbent after passing through the adsorption zone; The elution zone is used for eluting the lithium adsorbent after passing through the regeneration transformation zone; The decomposition zone is used for decomposing the lithium adsorbent after passing through the elution zone; The top material zone is used for liquid replacement of the lithium adsorbent after passing through the desorption zone; The power system drives the ion exchange columns arranged in a circle to perform periodic cyclic switching in the adsorption zone, regeneration transformation zone, elution zone, analysis zone, and top material zone.

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