Lithium adsorption material, method for manufacturing the same, and use

Abstract

This invention relates to the field of adsorption materials and discloses a lithium adsorption material, a method for manufacturing the same, and its use. The lithium adsorption material comprises a core and a shell coated on the surface of the core, wherein pores exist in the shell of the lithium adsorption material, and the average diameter of the pores, as measured by SEM electron microscopy, is 0.01 to 2.5 μm, the core of the lithium adsorption material contains finger-shaped pores, and in the cross-section of the lithium adsorption material, the longest average length of the finger-shaped pores, as measured by SEM electron microscopy, is 1 to 7 μm, and the shortest average length is 0.05 to 2.5 μm, and the thickness of the shell of the lithium adsorption material, as measured by SEM electron microscopy, is 1 to 550 μm. The lithium adsorption material having the above specific structure has a special structure in which the pores of the outer shell are small and the pores of the inner core are large, which can accelerate the mass transfer rate of water and salt. By using it when extracting lithium in a liquid environment, the adsorption capacity for lithium can be greatly improved.

Claims

1. A lithium adsorption material comprising a core and a shell covering the surface of the core, The lithium adsorbent material has a shell with pores, and the average diameter of these pores, as measured by SEM electron microscopy, is 0.01 to 2.5 μm. The core of the lithium adsorbent material contains finger-shaped pores, and the longest average length of the finger-shaped pores measured by SEM electron microscopy in the cross-section of the lithium adsorbent material is 1 to 7 μm, and the shortest average length is 0.05 to 2.5 μm. The shortest average length of finger-shaped pores in the core is greater than the average diameter of pores in the shell. The lithium adsorbent material is characterized in that the thickness of the shell, as measured by an SEM electron microscope, is 1 to 550 μm.

2. The lithium adsorbent material has an average pore diameter of 0.1 to 0.5 μm as measured by an SEM electron microscope. In the cross-section of the lithium adsorbent material, the longest average length of the pores measured by SEM electron microscopy was 2 to 5 μm, and the shortest average length was 0.5 to 1.5 μm. The lithium adsorption material according to claim 1, wherein the thickness of the shell measured by an SEM electron microscope is 30 to 500 μm.

3. The porosity of the lithium adsorbent material is 60 to 80%, preferably 65 to 75%. Preferably, the lithium adsorbent material is spherical and / or substantially spherical. Preferably, the average particle size of the lithium adsorbent material is 2 to 5 mm, preferably 3 to 4 mm. Preferably, the specific surface area of ​​the lithium adsorbent material is 10 to 100 m². ２ / g, preferably 35-65m ２ A lithium adsorption material according to claim 1 or 2, wherein the value is / g.

4. The lithium adsorption material according to any one of claims 1 to 3, wherein the ratio of the sum S1 of the surface areas of the pores in the shell to the sum S2 of the maximum cross-sectional areas of the finger-shaped pores in the core is 0.5 to 0.9:1, preferably 0.6 to 0.8:

1.

5. The lithium adsorbent material comprises a framework and lithium ion sieves dispersed on the framework. The aforementioned skeleton comprises polyvinyl chloride and polyacrylic acid. Preferably, the lithium ion sieve is a hydroxyl-modified lithium ion sieve, and the lithium ion sieve is linked to the skeleton via hydroxyl, the lithium adsorption material according to any one of claims 1 to 4.

6. Based on the total weight of the lithium adsorbent material, the polyvinyl chloride content is 16 to 67 wt%, the polyacrylic acid content is 0.06 to 9 wt%, and the lithium ion sieve content is 45 to 85 wt%. Preferably, the lithium adsorbent material according to claim 5, wherein, based on the total weight of the lithium adsorbent material, the content of polyvinyl chloride is 16 to 54 wt%, the content of polyacrylic acid is 0.9 to 9 wt%, and the content of lithium ion sieve is 45 to 80 wt%.

7. In the hydroxyl-modified lithium ion sieve, the thickness of the coating layer formed with the hydroxyl-providing compound is 1 to 5 nm, preferably 3 to 5 nm. Preferably, the hydroxyl-modified lithium ion sieve is a polyphenol-modified lithium ion sieve. Preferably, the polyphenol is at least one selected from tannic acid, tea polyphenols, apple polyphenols, grape polyphenols, eriodictyol, naringenin, epicatechin, luteolin, naringenin, kaempferol, myricetin, and genistein. Preferably, the lithium ion sieve is selected from a titanium-based lithium ion sieve and / or a manganese-based ion sieve. Preferably, the lithium ion sieve is LiMn ２ O ４ 、Li １．６ Mn １．６ O ４ 、Li １．３３ Mn １．６７ O ４ 、Li ４ Mn ５ O １２ 、LiMnO ２ 、Li ２ TiO ３ 、Li １．３３ Ti １．６６ O ４ 、およびLi ４ Ti ５ O １２ and is at least one selected from Preferably, the water content of the hydroxyl-modified lithium ion sieve is 0.5 wt% or less, preferably 0.1 to 0.3 wt%, the lithium adsorption material according to claim 5 or 6.

8. The lithium adsorbent material is the lithium adsorbent material according to any one of claims 5 to 7, wherein the average particle diameter of the lithium ion sieve in the cross-section of the lithium adsorbent material measured by SEM electron microscope is 2.5 μm or less, preferably 1.5 μm or less.

9. The lithium adsorbent material according to any one of claims 1 to 8, wherein the total surface area of ​​the pores present in the shell is 30 to 90%, preferably 50 to 90%, based on the total surface area of ​​the shell of the lithium adsorbent material.

10. A method for producing a lithium adsorbent material according to any one of claims 1 to 9, wherein the method is: Step (1) involves mixing polyvinyl chloride, polyacrylic acid, and lithium ion sieve with an oil phase solvent to obtain a mixed solution, A method characterized by comprising the step (2) of obtaining a lithium adsorbent material by dropping a mixed solution into an aqueous solvent under conditions of a temperature of 20 to 60°C and a humidity of 40 to 80%.

11. In step (1), the lithium ion sieve is selected from a titanium-based lithium ion sieve and / or a manganese-based ion sieve. Preferably, the lithium ion sieve is made of LiMn ２ O ４ Li １．６ Mn １．６ O ４ Li １．３３ Mn １．６７ O ４ Li ４ Mn ５ O １２ LiMnO ２ Li ２ TiO ３ Li １．３３ Ti １．６６ O ４ , and Li ４ Ti ５ O １２ At least one selected from, Preferably, the weight-average molecular weight of the polyvinyl chloride is 5 to 110,000 g / mol. Preferably, the weight-average molecular weight of the polyacrylic acid is 10 to 1,300,000 g / mol. Preferably, the oil phase solvent is at least one selected from N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, and dimethyl sulfoxide. Preferably, the amounts of polyvinyl chloride, polyacrylic acid, and hydroxyl-modified lithium ion sieve used are such that, based on the total weight of the lithium adsorbent material, the polyvinyl chloride content is 16 to 67 wt%, the polyacrylic acid content is 0.06 to 9 wt%, and the lithium ion sieve content is 45 to 85 wt%. Preferably, the method according to claim 10, wherein, based on the total weight of the lithium adsorbent material, the content of polyvinyl chloride is 16 to 54 wt%, the content of polyacrylic acid is 0.9 to 9 wt%, and the content of lithium ion sieve is 45 to 80 wt%.

12. In step (2), the mixture is added dropwise to the aqueous solvent under conditions of a temperature of 35 to 60°C and a humidity of 60 to 80%. Preferably, the aqueous solvent is at least one selected from water, ethanol, and acetic acid, preferably water, according to claim 10 or 11.

13. The lithium ion sieve is a hydroxyl-modified lithium ion sieve. Preferably, the lithium ion sieve is modified with an aqueous solution of a hydroxyl-containing compound, solid-liquid separation is performed and it is dried to obtain a hydroxyl-modified lithium ion sieve. Preferably, the hydroxyl-containing compound is a polyphenol, and preferably at least one selected from tannic acid, tea polyphenol, apple polyphenol, grape polyphenol, eriodictyol, naringenin, epicatechin, luteolin, naringenin, kaempferol, myricetin, and genistein. Preferably, the concentration of the aqueous solution of the hydroxyl-containing compound is 0.05 mg / L to 0.1 mg / L. Preferably, the mass ratio of the lithium ion sieve to the hydroxyl-containing compound is 1:0.01 to 0.

3. Preferably, the modification conditions include a reaction time of 30 min to 4 h and a reaction temperature of 25 to 40°C, according to any one of claims 10 to 12.

14. The method further includes the step of washing the lithium adsorbent material with an acidic solution, Preferably, the lithium adsorbent material is circulated and washed with an acidic solution under the action of a peristaltic pump. Preferably, the acidic solution is at least one selected from hydrochloric acid, phosphoric acid, and sulfuric acid. Preferably, H ＋ The concentration of the acidic solution is 0.1 to 1 mol / L, Preferably, the flow rate of the peristaltic pump is 1 to 25 BV / h, and the circulation time is 1 to 48 h, according to any one of claims 10 to 13.

15. A lithium adsorbent material manufactured by the method described in any one of claims 10 to 14.

16. Use of a lithium adsorbent material according to any one of claims 1 to 9 and 15 in lithium extraction, preferably lithium extraction in a liquid environment.

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