A lithium-ion adsorption material, a preparation method thereof, a lithium extraction system, and a lithium extraction method

Abstract

The present invention relates to the field of lithium ion adsorption. Specifically, it relates to a lithium ion adsorption material, a preparation method thereof, a lithium extraction system and a lithium extraction method. The preparation method of the lithium ion adsorption material comprises the following steps: dissolving and uniformly mixing a lithium ion sieve and a polymer to obtain a spinning solution; performing electrospinning on the spinning solution to obtain the lithium ion adsorption material; the mass ratio of the lithium ion sieve to the polymer is (5-10):(24-40). The preparation method of the lithium ion adsorption material has a simple preparation method, and the prepared lithium ion adsorption material has excellent adsorption performance.

Description

Technical Field

[0001] The present invention relates to the field of lithium ion adsorption, and in particular, to a lithium ion adsorption material, a preparation method thereof, a lithium extraction system and a lithium extraction method. Background Art

[0002] Lithium is the lightest known metal. In the field of light alloys, it is used to manufacture light alloys and wear-resistant alloys, and has the characteristics of low density, strong corrosion resistance, large elastic modulus, high specific toughness, and high damage resistance. It is an ideal lightweight material with high weight reduction benefits. Lithium and its compounds are widely used in various fields of the national economy. They not only play an important role in traditional consumption fields such as glass, ceramics, lubricants, etc., but also promote the development of high-tech fields such as lithium batteries, nuclear energy, aerospace, etc., and are known as "the new energy of the 21st century". In recent years, with the development of high-tech industries, the market demand for lithium has increased sharply. The lithium resources on land can no longer meet the social demand for lithium, and lithium extraction from liquid lithium resources has attracted more and more attention. Most of the lithium ion sieves prepared at present are in powder form. Although they have good adsorption performance, their fluidity and permeability are very poor, which is not conducive to industrial application. Researchers at home and abroad have carried out a large amount of research work on the shaping of lithium ion sieves.

[0003] Granular ion sieves are generally formed by physical calcination or by using polymer materials for bonding. The lithium ion sieves formed by physical calcination are easy to break and have poor stability; direct bonding mostly uses high molecular compounds as binders and is formed into granular adsorbents by a phase inversion process. However, since most of the added binders are organic substances, their hydrophilicity is poor, resulting in a decrease in the lithium exchange rate of the granular lithium ion sieves and a decrease in the lithium adsorption capacity compared with the powder ion sieves. Membrane-type ion sieves are prepared by adding ion sieves to a casting solution and then scraping to form a film. The mechanical strength and chemical stability of the membrane-type adsorbent are both good, and the dissolution loss rate in seawater is very small, which is suitable for mass production and continuous operation; however, the polymer masks some active sites of the ion sieves, resulting in a decrease in the lithium adsorption capacity compared with the powder ion sieves. The nanofiber mat-type adsorbent prepared by electrospinning technology can well retain the adsorption sites of the lithium ion sieve, and at the same time improve and solve the problems of its permeability and difficulty in shaping, and has become the focus of development at home and abroad.

[0004] The electrospinning process is mainly divided into four parts: the base region, jetting, stretching, and collection. The interface between the tip of the needle and the ejected solution is called the base region. First, a jet flows out from the tip of the needle to form a cone called the Taylor cone, and the shape of the Taylor cone depends on the surface tension of the liquid and the force of the electric field. Subsequently, the ejected thin stream is stretched and refined at a very high magnification under the action of the electric field force and moves towards the receiving substrate. During this process, as the solvent volatilizes or the melt solidifies, the fibers finally land on a collecting device with opposite charges or grounded. This continuous process is jetting, stretching, and collection. The running trajectory of the fibers in the air is non-linear, so a flocculent or reticular micro / nano fiber or non-woven fiber membrane material is obtained on the receiving device. The fiber membrane prepared by the electrospinning technology has the advantages of diverse materials, high aspect ratio, high porosity, high specific surface area, uniform structure, etc. Secondly, the method is simple and can achieve large-scale preparation.

[0005] In view of this, the present invention is specifically proposed. Summary of the Invention

[0006] One aspect of the present invention relates to a preparation method of a lithium ion adsorption material, comprising the following steps:

[0007] Dissolve and mix uniformly a lithium ion sieve and a polymer to obtain a spinning solution; perform electrospinning on the spinning solution to obtain the lithium ion adsorption material;

[0008] The mass ratio of the lithium ion sieve to the polymer is (5 - 10):(24 - 40).

[0009] The preparation method of the lithium ion adsorption material is simple, and the prepared lithium ion adsorption material has excellent adsorption performance.

[0010] Another aspect of the present invention further relates to the lithium ion adsorption material prepared by the preparation method of the lithium ion adsorption material;

[0011] Preferably, the thickness of the lithium ion adsorption material is 0.5 - 1 cm.

[0012] The lithium ion adsorption material meets the use conditions of the lithium extraction process from salt lakes, is not easy to lose, has a high lithium ion adsorption capacity, and high permeability.

[0013] Another aspect of the present invention further relates to a lithium extraction system, comprising: an adsorption unit, a salt lake brine storage device, and a hydrochloric acid storage device;

[0014] A number of adsorption columns are arranged in the adsorption unit; the lithium ion adsorption material is attached to the inner side wall of the adsorption column;

[0015] The liquid outlet of the salt lake brine storage device is connected to the liquid inlet of the adsorption column; the liquid outlet of the hydrochloric acid storage device is connected to the liquid inlet of the adsorption column.

[0016] The lithium extraction system is reasonably structured and has a good lithium extraction effect.

[0017] Another aspect of the present invention also relates to a lithium extraction method using the lithium extraction system, which includes the following steps:

[0018] Inject the salt lake brine into the adsorption column, and perform the first negative pressure suction on the adsorption column;

[0019] Inject hydrochloric acid into the adsorption column, and perform the second negative pressure suction on the adsorption column.

[0020] The lithium extraction method has high lithium extraction efficiency, can recycle the waste liquid, and realizes sustainable development.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] (1) The preparation method of the lithium ion adsorbent material provided by the present invention is simple. The lithium ion sieve powder and the polymer are dissolved and mixed in a certain proportion, and the lithium ion adsorbent material is prepared by electrospinning technology. It solves the problems that the lithium ion sieve powder is not easy to form and is lost when directly used, can well retain the adsorption sites of the lithium ion sieve, and ensure the lithium ion adsorption capacity; it has a high porosity and a uniform structure, improving the permeability of the material.

[0023] (2) The lithium ion adsorbent material provided by the present invention meets the use conditions of the salt lake lithium extraction process, is not easy to lose, has a high lithium ion adsorption capacity, and a high permeability.

[0024] (3) The lithium extraction system provided by the present invention is reasonably structured and has a good lithium extraction effect.

[0025] (4) The lithium extraction method provided by the present invention has high lithium extraction efficiency, can recycle the waste liquid, and realizes sustainable development. Description of the Drawings

[0026] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0027] Figure 1 Scanning electron microscope image of the lithium ion adsorbent material for Example 1;

[0028] Figure 2 SEM image of the lithium ion adsorbent material of Example 2;

[0029] Figure 3 Schematic structural diagram of the lithium extraction system provided in Example 3.

[0030] Reference numerals:

[0031] 1 - adsorption unit, 2 - salt lake brine storage device, 3 - hydrochloric acid storage device, 4 - adsorption column, 5 - first valve, 6 - second valve. Detailed implementation manners

[0032] The technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and specific implementation manners. However, those skilled in the art will understand that the following described embodiments are some embodiments of the present invention, rather than all embodiments, and are only used to illustrate the present invention and should not be construed as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention. For those conditions not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. For those reagents or instruments without indicating the manufacturer, they are all conventional products that can be obtained through commercial purchase.

[0033] One aspect of the present invention relates to a preparation method of a lithium ion adsorbent material, including the following steps:

[0034] Dissolve and mix the lithium ion sieve and the polymer uniformly to obtain a spinning solution; perform electrospinning on the spinning solution to obtain the lithium ion adsorbent material;

[0035] The mass ratio of the lithium ion sieve to the polymer is (5 - 10):(24 - 40) (such as 5:40, 6:38, 7:27, 8:35, 9:30 or 10:24).

[0036] The preparation method of the lithium ion adsorbent material has a simple preparation method. The lithium ion sieve powder and the polymer are dissolved and mixed in a certain proportion, and the lithium ion adsorbent material is prepared by electrospinning technology, which solves the problems that the lithium ion sieve powder is not easy to form and is lost when directly used, can well retain the adsorption sites of the lithium ion sieve, and ensure the adsorption amount of lithium ions; it has a high porosity and a uniform structure, improving the permeability of the material.

[0037] PVDF has excellent abrasion resistance, flexibility, relatively high tensile strength and impact resistance; PVC is inexpensive and has stable chemical properties, being resistant to acids and alkalis; PES has relatively high mechanical strength and excellent mechanical properties. PVDF, PVC and PES are used for spinning as composite resins, and they have good film-forming properties, good chemical stability and low raw material costs, which are beneficial to industrial production.

[0038] Preferably, the lithium ion sieve includes: H 2 TiO 3 。

[0039] Preferably, the polymer includes: polyvinylidene fluoride, polyethylene and polyethersulfone.

[0040] Preferably, the mass ratio of the polyvinylidene fluoride, the polyethylene and the polyethersulfone is (20 - 30):(2 - 5):(2 - 5) (such as 20:2:5, 23:5:2, 28:3:4 or 30:4:3).

[0041] Preferably, the method for preparing the spinning solution includes:

[0042] Taking 20 - 30 parts of PVDF, 2 - 5 parts of PVC and 2 - 5 parts of PES by mass fraction and placing them in a mixed solvent of 30 - 40 parts of dichloromethane (DCM) and 10 - 20 parts of N,N-dimethylformamide, stirring at 70 - 80 °C for 4 - 6 h. After the blend resin is completely dissolved, add 5 - 10 parts of the lithium ion sieve, continue stirring at a constant temperature of 70 - 80 °C for 1 - 2 h, and then perform negative pressure degassing for 1 - 2 h to obtain the spinning solution.

[0043] Preferably, the method for preparing the lithium ion adsorption material includes:

[0044] During the electrospinning process, first fix the receiving substrate aluminum foil on the roller of the electrospinning machine, then place the spinning solution in a syringe, connect it to the high-voltage power supply between the electrospinning machine, and perform electrospinning. The spinning parameters are set as follows: the injection speed is 0.08 - 1.00 mm / min, the rotation speed of the roller is 200 - 300 r / min, the translation speed of the injection is 500 - 600 mm / min, the receiving distance between the spinneret tip and the receiving roller is 15 - 20 cm, the spinning voltage is 8 - 10 kv, the temperature during the whole spinning process is 25 - 28 °C, and the humidity is about 30 - 40% RH. The spinning solution is stretched and refined at the spinneret under the action of a high-voltage electrostatic field, and finally a lithium ion adsorption material with uniform distribution and a thickness of about 0.5 - 1 cm is formed on the aluminum foil substrate.

[0045] Another aspect of the present invention also relates to the lithium ion adsorption material prepared by the method for preparing the lithium ion adsorption material;

[0046] Preferably, the thickness of the lithium ion adsorbent material is 0.5 to 1 cm (such as 0.5 cm, 0.6 cm, 0.7 cm, 0.8 cm, 0.9 cm or 1 cm).

[0047] Another aspect of the present invention also relates to a lithium extraction system, comprising: an adsorption unit 1, a salt lake brine storage device 2 and a hydrochloric acid storage device 3;

[0048] A number of adsorption columns 4 are arranged in the adsorption unit 1; the lithium ion adsorbent material is attached to the inner side wall of the adsorption column 4;

[0049] The liquid outlet of the salt lake brine storage device 2 is connected to the liquid inlet of the adsorption column 4; the liquid outlet of the hydrochloric acid storage device 3 is connected to the liquid inlet of the adsorption column 4.

[0050] Preferably, 50 to 100 (such as 50, 60, 70, 80, 90 or 100) of the adsorption columns 4 are arranged in the adsorption unit 1.

[0051] Preferably, the total volume of the adsorption columns 4 in the adsorption unit 1 is 5 to 10 cm 3 (such as 5 cm 3 , 6 cm 3 , 7 cm 3 , 8 cm 3 , 9 cm 3 or 10 cm 3 ).

[0052] Preferably, the liquid outlet rate of the salt lake brine storage device 2 is 10 to 20 BV / h (such as 10 BV / h, 12 BV / h, 14 BV / h, 16 BV / h, 18 BV / h or 20 BV / h).

[0053] Preferably, the liquid outlet rate of the hydrochloric acid storage device 3 is 10 to 20 BV / h (such as 10 BV / h, 12 BV / h, 14 BV / h, 16 BV / h, 18 BV / h or 20 BV / h).

[0054] Preferably, the concentration of hydrochloric acid in the hydrochloric acid storage device 3 is 0.05 to 0.3 mol / L (such as 0.05 mol / L, 0.1 mol / L, 0.2 mol / L or 0.3 mol / L).

[0055] Preferably, the preparation method of the adsorption column 4 comprises the following steps:

[0056] First, prepare a large rectangular lithium-ion adsorption material, roll it up to form a cylindrical felt. The diameter of the cylindrical felt is 20 - 40 cm. Then, place the cylindrical felt in a PVC cylinder with a matching diameter, seal both ends of the PVC cylinder with hot melt adhesive, and leave an inlet and a water production outlet at both ports to obtain the adsorption column 4. The water body enters from the inlet end of the PVC cylinder, fully contacts with the lithium-ion adsorption material, and the produced water flows out from the water production outlet end of the PVC cylinder.

[0057] Another aspect of the present invention also relates to a lithium extraction method, using the lithium extraction system described above, including the following steps:

[0058] Inject the salt lake brine into the adsorption column 4, and perform the first negative pressure suction on the adsorption column 4;

[0059] Inject hydrochloric acid into the adsorption column 4, and perform the second negative pressure suction on the adsorption column 4.

[0060] Preferably, the injection rate of the salt lake brine into the adsorption column 4 is 10 - 20 BV / h (for example, 10 BV / h, 12 BV / h, 14 BV / h, 16 BV / h, 18 BV / h or 20 BV / h).

[0061] Preferably, the injection time of the salt lake brine into the adsorption column 4 is 2 - 4 h (for example, 2 h, 3 h or 4 h).

[0062] Preferably, the injection rate of the hydrochloric acid into the adsorption column 4 is 10 - 20 BV / h (for example, 10 BV / h, 12 BV / h, 14 BV / h, 16 BV / h, 18 BV / h or 20 BV / h).

[0063] Preferably, the injection time of the hydrochloric acid into the adsorption column 4 is 0.5 - 1 h (for example, 0.5 h, 0.6 h, 0.7 h, 0.8 h, 0.9 h or 1 h).

[0064] Preferably, the concentration of the hydrochloric acid in the hydrochloric acid storage device 3 is 0.05 - 0.3 mol / L (for example, 0.05 mol / L, 0.1 mol / L, 0.2 mol / L or 0.3 mol / L).

[0065] Next, the implementation schemes of the present invention will be described in detail with specific examples and comparative examples.

[0066] Example 1

[0067] The preparation method of the lithium-ion adsorption material provided in this example includes the following steps:

[0068] (1) By mass fraction, take 25 parts of PVDF, 5 parts of PVC and 5 parts of PES in a mixed solvent of 40 parts of dichloromethane (DCM) and 20 parts of N,N-dimethylformamide, stir at 70 °C for 4 h. After the blend resin is completely dissolved, add 5 parts of lithium ion sieve, continue to stir at a constant temperature of 70 °C for 1 h, and then perform negative pressure degassing for 1 h to obtain a spinning solution;

[0069] (2) During the electrospinning process, first fix the receiving substrate aluminum foil on the roller of the electrospinning machine, then place the spinning solution in a syringe, connect the high-voltage power supply between the syringe and the electrospinning machine, and perform electrospinning. The spinning parameters are set as follows: the injection speed is 0.08 mm / min, the rotation speed of the roller is 200 r / min, the translation speed of the injection is 500 mm / min, the receiving distance between the tip of the spinneret and the receiving roller is 15 cm, the spinning voltage is 8 kv, the temperature during the whole spinning process is about 25 °C, and the humidity is about 30% RH; the spinning solution is stretched and refined at the spinneret under the action of a high-voltage electrostatic field, and finally a lithium ion adsorption material with uniform distribution and a thickness of about 0.5 cm is formed on the aluminum foil substrate; Figure 1 It is a scanning electron microscope image of the lithium ion adsorption material.

[0070] Example 2

[0071] The preparation method of the lithium ion adsorption material provided in this example includes the following steps:

[0072] (1) By mass, take 30 parts of PVDF, 2.5 parts of PVC and 2.5 parts of PES in a mixed solvent of 40 parts of dichloromethane (DCM) and 15 parts of N,N-dimethylformamide, stir at 80 °C for 6 h. After the blend resin is completely dissolved, add 10 parts of lithium ion sieve, continue to stir at a constant temperature of 80 °C for 2 h, and then perform negative pressure degassing for 2 h to obtain a spinning solution;

[0073] (2) During the electrospinning process, first fix the receiving substrate aluminum foil on the roller of the electrospinning machine, then place the spinning solution in a syringe, connect the high-voltage power supply between the syringe and the electrospinning machine, and perform electrospinning. The spinning parameters are set as follows: the injection speed is 1.00 mm / min, the rotation speed of the roller is 300 r / min, the translation speed of the injection is 600 mm / min, the receiving distance between the tip of the spinneret and the receiving roller is 20 cm, the spinning voltage is 10 kv, the temperature during the whole spinning process is about 28 °C, and the humidity is about 30% RH; the spinning solution is stretched and refined at the spinneret under the action of a high-voltage electrostatic field, and finally a lithium ion adsorption material with uniform distribution and a thickness of about 1 cm is formed on the aluminum foil substrate; Figure 2 It is a scanning electron microscope image of the lithium ion adsorption material.

[0074] Example 3

[0075] The lithium extraction system provided in this embodiment, as Figure 3 shown, includes: an adsorption unit 1, a salt lake brine storage device 2, and a hydrochloric acid storage device 3;

[0076] A number of adsorption columns 4 are arranged inside the adsorption unit 1; the lithium ion adsorption material of Example 1 is attached to the inner side wall of the adsorption column 4;

[0077] The liquid outlet of the salt lake brine storage device 2 is connected to the liquid inlet of the adsorption column 4; the liquid outlet of the hydrochloric acid storage device 3 is connected to the liquid inlet of the adsorption column 4;

[0078] A first valve 5 is arranged at the liquid outlet of the salt lake brine storage device 2; a second valve 6 is arranged at the liquid outlet of the hydrochloric acid storage device 3.

[0079] Example 4

[0080] The lithium extraction method provided in this embodiment uses the lithium extraction system of Example 3 and includes the following steps:

[0081] (1) The lithium extraction process system includes adsorption columns 4 with a length of 5 cm 3 , a hydrochloric acid storage tank filled with 0.05 mol / L dilute hydrochloric acid, a storage tank filled with salt lake brine, and 50 adsorption columns 4;

[0082] (2) Adsorption process: Inject the salt lake brine into the adsorption column 4 from the storage tank at a speed of 10 BV / h, and perform adsorption for 2 h until saturated adsorption is reached. Then, use a negative pressure suction device to perform negative pressure suction on the adsorption column 4 to obtain produced water and discharge the produced water to complete the adsorption process;

[0083] (3) Elution process: Inject 0.05 mol / L dilute hydrochloric acid into the tank body from the storage tank at a speed of 10 BV / h, and perform desorption for 0.5 h. After complete desorption, use a negative pressure suction device to perform negative pressure suction on the adsorption column 4 to obtain produced water and discharge the produced water to complete the desorption process; Subsequently, the salt lake brine inlet valve is opened to start a new round of lithium extraction process from the salt lake brine.

[0084] The concentrations of various ions in the influent and produced water during the lithium extraction and elution processes are shown in Table 1. As can be seen from Table 1, the lithium ion concentration in the influent salt lake brine is 260 mg / L, and the lithium ion concentration in the produced water after lithium extraction is 26.9 mg / L, while the concentrations of other ions remain unchanged, indicating that this method can accurately and effectively extract lithium ions from the brine.

[0085] Table 1 Results of the lithium extraction process in Example 4

[0086] Ion Lithium extraction influent water (mg / L) Lithium extraction effluent water (mg / L) <![CDATA[Li + > 260 26.9 <![CDATA[Na + > 44060 44060 <![CDATA[K + > 7820 7820 <![CDATA[Mg 2+ > 80 80 <![CDATA[Ca 2+ > 10 10 <![CDATA[Cl - > 52360 52360 <![CDATA[SO 4 2- > 5060 5060 <![CDATA[CO 3 2- > 18830 18830

[0087] Example 5

[0088] The lithium extraction method provided in this embodiment uses the lithium extraction system of Embodiment 3 and includes the following steps:

[0089] (1) The lithium extraction process system includes an adsorption column 4 with a length of 10 cm, a hydrochloric acid storage tank filled with 0.3 mol / L dilute hydrochloric acid, a storage tank filled with salt lake brine, and 100 adsorption columns 4; 3

[0090] (2) Adsorption process: Inject the salt lake brine into the adsorption column 4 from the storage tank at a speed of 20 BV / h, and perform adsorption for 4 h until saturated adsorption is reached. Then, use a negative pressure suction device to perform negative pressure suction on the adsorption column 4 to obtain produced water and discharge the produced water to complete the adsorption process;

[0091] (3) Elution process: Inject 0.3 mol / L dilute hydrochloric acid into the pool from the storage tank at a speed of 20 BV / h, and perform desorption for 1 h. After complete desorption, use a negative pressure suction device to perform negative pressure suction on the adsorption column 4 to obtain produced water and discharge the produced water to complete the desorption process; Subsequently, open the salt lake brine inlet valve to start a new round of lithium extraction process from the salt lake brine.

[0092] The concentrations of various ions in the influent and produced water during the lithium extraction and elution processes are shown in Table 2. As can be seen from Table 2, the lithium ion concentration in the influent salt lake brine is 260 mg / L, and the lithium ion concentration in the produced water after lithium extraction is 18.7 mg / L, while the concentrations of other ions remain unchanged, indicating that this method can accurately and effectively extract lithium ions from the brine.

[0093] Table 2 Results of the lithium extraction process of Embodiment 5

[0094] Ion Lithium extraction influent water (mg / L) Lithium extraction effluent water (mg / L) <![CDATA[Li + > 260 18.7 <![CDATA[Na + > 44060 44060 <![CDATA[K + > 7820 7820 <![CDATA[Mg 2+ > 80 80 <![CDATA[Ca 2+ > 10 10 <![CDATA[Cl - > 52360 52360 <![CDATA[SO 4 2- > 5060 5060 <![CDATA[CO 3 2- > 18830 18830

[0095] Comparative Example 1

[0096] Compared with Embodiment 4, the only difference in this comparative example is that the dosage of lithium ion sieve is 15 parts. The lithium extraction results are shown in Table 3.

[0097] Table 3 Results of the lithium extraction process of Comparative Example 1

[0098] Ion Lithium extraction influent water (mg / L) Lithium extraction effluent water (mg / L) <![CDATA[Li + > 260 89.6 <![CDATA[Na + > 44060 44060 <![CDATA[K + > 7820 7820 <![CDATA[Mg 2+ > 80 80 <![CDATA[Ca 2+ > 10 10 <![CDATA[Cl - > 52360 52360 <![CDATA[SO 4 2- > 5060 5060 <![CDATA[CO 3 2- > 18830 18830

[0099] Comparative Example 2

[0100] Compared with Embodiment 4, the only difference in this comparative example is that the dosage of PVDF is 33 parts, the dosage of PVC is 1 part, and the dosage of PES is 1 part. The lithium extraction results are shown in Table 4.

[0101] Table 4 Results of the lithium extraction process of Comparative Example 2

[0102] Ion Lithium extraction influent water (mg / L) Lithium extraction effluent water (mg / L) <![CDATA[Li + > 260 105.9 <![CDATA[Na + > 44060 44060 <![CDATA[K + > 7820 7820 <![CDATA[Mg 2+ > 80 80 <![CDATA[Ca 2+ > 10 10 <![CDATA[Cl - > 52360 52360 <![CDATA[SO 4 2- > 5060 5060 <![CDATA[CO 3 2- > 18830 18830 ​

[0103] Comparative Example 3

[0104] The difference between this comparative example and Example 4 is only that the speed of injecting the salt lake brine into the adsorption column 4 is 30 BV / h. The lithium extraction results are shown in Table 5.

[0105] Table 5 Results of the lithium extraction process in Comparative Example 3

[0106] Ion Lithium extraction influent water (mg / L) Lithium extraction effluent water (mg / L) <![CDATA[Li + > 260 76.8 <![CDATA[Na + > 44060 44060 <![CDATA[K + > 7820 7820 <![CDATA[Mg 2+ > 80 80 <![CDATA[Ca 2+ > 10 10 <![CDATA[Cl - > 52360 52360 <![CDATA[SO 4 2- > 5060 5060 <![CDATA[CO 3 2- > 18830 18830

[0107] Although the present invention has been illustrated and described with reference to specific embodiments, it should be understood that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; those of ordinary skill in the art should understand that: without departing from the spirit and scope of the present invention, the technical solutions described in the foregoing embodiments may be modified, or some or all of the technical features may be equivalently replaced; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention; therefore, this means that all such replacements and modifications that fall within the scope of the present invention are included in the appended claims.

Claims

1. A preparation method of a lithium ion adsorption material, characterized in that, it includes the following steps: Dissolve and mix the lithium ion sieve and the polymer uniformly to obtain a spinning solution; perform electrospinning on the spinning solution to obtain the lithium ion adsorption material; The mass ratio of the lithium ion sieve to the polymer is (5~10):(24~40); The polymer includes: polyvinylidene fluoride, polyvinyl chloride and polyethersulfone; The mass ratio of the polyvinylidene fluoride, the polyvinyl chloride and the polyethersulfone is (20~30):(2~5):(2~5).

2. A lithium ion adsorption material prepared by the preparation method of the lithium ion adsorption material according to claim 1; The thickness of the lithium ion adsorption material is 0.5~1 cm.

3. A lithium extraction system, characterized in that, it includes: An adsorption unit, a salt lake brine storage device and a hydrochloric acid storage device; A number of adsorption columns are arranged inside the adsorption unit; the lithium ion adsorption material according to claim 1 or 2 is attached to the inner side wall of the adsorption column; The liquid outlet of the salt lake brine storage device is connected to the liquid inlet of the adsorption column; the liquid outlet of the hydrochloric acid storage device is connected to the liquid inlet of the adsorption column.

4. According to the lithium extraction system described in claim 3, characterized in that, 50~100 of the adsorption columns are arranged inside the adsorption unit; The total volume of the adsorption columns in the adsorption unit is 5 to 10 cm 3 .

5. According to the lithium extraction system described in claim 3, characterized in that, The liquid outlet speed of the salt lake brine storage device is 10~20 BV / h; The liquid outlet speed of the hydrochloric acid storage device is 10~20 BV / h.

6. According to the lithium extraction system described in claim 3, characterized in that, The concentration of hydrochloric acid in the hydrochloric acid storage device is 0.05~0.3 mol / L.

7. A lithium extraction method, using the lithium extraction system according to any one of claims 3~6, characterized in that, it includes the following steps: Inject the salt lake brine into the adsorption column, and the adsorption column performs the first negative pressure suction; Inject hydrochloric acid into the adsorption column, and the adsorption column performs the second negative pressure suction.

8. According to the lithium extraction method described in claim 7, characterized in that, The injection speed of the salt lake brine into the adsorption column is 10~20 BV / h; The injection time of the salt lake brine into the adsorption column is 2~4 h.

9. According to the lithium extraction method described in claim 7, characterized in that, The injection speed of the hydrochloric acid into the adsorption column is 10~20 BV / h; The injection time of the hydrochloric acid into the adsorption column is 0.5~1 h; The concentration of hydrochloric acid in the hydrochloric acid storage device is 0.05~0.3 mol / L.

Images