A lithium adsorbent and its preparation method

Abstract

The present invention discloses a lithium adsorbent and a preparation method thereof. The lithium adsorbent has a porous structure and comprises an aluminum-based lithium adsorbent active material and a hydrophilic binder. The average pore diameter of the lithium adsorbent is 1-10 nm, the pore volume is 0.65-0.8 ml / g, and the specific surface area is 400-600 m 2 / g. The lithium adsorbent of the present invention has a specific average pore diameter of 1-10 nm, and the lithium ion diameter is 0.3 nm. The pore diameter of the lithium adsorbent of the present invention is more than three times larger than the ion diameter, enabling lithium ions to quickly enter and exit the pores. Therefore, this structure can ensure high adsorption efficiency and high desorption efficiency at high flow rates, and make the desorption more concentrated compared with that of general lithium adsorbents, reducing the tailing phenomenon, and can effectively improve the production efficiency of lithium. Moreover, the pore diameter of the product of the present invention is less than 10 nm, resulting in a low dissolution loss rate and a long service life of the lithium adsorbent. The lithium adsorbent of the present invention still has high adsorption efficiency and high desorption efficiency after 1000 adsorption and desorption cycles.

Description

Technical Field

[0001] The present invention belongs to the field of lithium extraction by adsorption method, and specifically relates to a lithium adsorbent and a preparation method thereof. Background Art

[0002] Lithium is the lightest metallic element in the world, and lithium metal can be widely used in fields such as rechargeable batteries, glass, ceramics, alloys, lubricants, and medicine. The lithium resource reserves in salt lake brines account for 70 - 80% of the total lithium resources. Extracting lithium from salt lake brines is the main direction of current lithium salt production. Most of the lithium-containing salt lake brine resources in China are brines with a high magnesium-lithium ratio. The high concentration of divalent magnesium ions makes the technology for separating lithium ions more complex, becoming a technical bottleneck for lithium extraction from brines.

[0003] Currently, the lithium adsorbent commonly used for magnesium-lithium separation in production is an aluminum-based lithium adsorbent. In the existing preparation methods of aluminum-based lithium adsorbents, generally, the precursor LiCl·2Al(OH)3·nH2O is first prepared, then dried and pulverized, and then granulated and formed together with a binder. The preparation steps are numerous and the process is relatively complex. Moreover, the generally disclosed patents generally have larger pore sizes, which will lead to a decrease in adsorption efficiency and strength.

[0004] Therefore, currently, aluminum-based lithium adsorbents generally have disadvantages such as low adsorption efficiency, insufficiently concentrated desorption, and high dissolution loss. These problems have become technical problems that urgently need to be solved in the current field of lithium extraction from salt lakes. Summary of the Invention

[0005] The present invention provides a lithium adsorbent, which has a pore structure with an average pore size of 1 - 10 nm. This structure can ensure high adsorption efficiency and desorption efficiency at high flow rates, and make the desorption more concentrated compared with that of general adsorbents, reducing tailing. The present invention adopts the following technical solutions:

[0006] A lithium adsorbent, the lithium adsorbent has a porous structure and comprises an aluminum-based lithium adsorbent active material and a hydrophilic binder;

[0007] The average pore size of the lithium adsorbent is 1 - 10 nm, the pore volume is 0.65 - 0.8 ml / g, and the specific surface area is 400 - 600 m 2 / g.

[0008] Optionally, the particle size of the lithium adsorbent is 0.8 - 2.0 mm.

[0009] Optionally, the hydrophilic binder is at least one of polyacrylamide, polyacrylate, dextran, agarose, polyvinyl alcohol, and phenolic resin.

[0010] The preparation method of the above lithium adsorbent includes the following steps:

[0011] Mix the raw materials including lithium compounds, aluminum compounds, pore-forming agents, hydrophilic binders, and water, and react at 60 - 100 °C for 2 - 4 h to cause the lithium compounds and aluminum compounds to react to form an aluminum-based lithium adsorbent active material; the weight ratio of the total weight of the lithium compounds, aluminum compounds, and hydrophilic binders to the weight of the pore-forming agent is 100:0.6 - 20;

[0012] After the hydrophilic binder in the raw material mixture is cured, granulate and dry to obtain the lithium adsorbent.

[0013] Preferably, the weight ratio of the total weight of the lithium compounds, aluminum compounds, and hydrophilic binders to the weight of the pore-forming agent is 100:2 - 12.

[0014] Optionally, the aluminum compound is at least one of aluminum chloride, aluminum nitrate, aluminum sulfate, aluminum carbonate, aluminum hydroxide, alumina, and aluminum sol.

[0015] Optionally, the lithium compound is at least one of lithium chloride, lithium carbonate, and lithium hydroxide.

[0016] Optionally, the pore-forming agent is an organic pore-forming agent, and the organic pore-forming agent is at least one of polyvinylpyrrolidone, polyethylene glycol, Span emulsifiers, and Tween emulsifiers.

[0017] Optionally, the polyvinylpyrrolidone is PVP K30, and the polyethylene glycol is PEG2000.

[0018] The raw materials contain chloride ions.

[0019] The aluminum-based lithium adsorbent active material refers to the LiCl·2Al(OH)3·nH2O material.

[0020] Optionally, the raw materials further contain a filler;

[0021] The weight ratio of the total weight of the lithium compounds, aluminum compounds, and hydrophilic binders to the weight of the filler is 100:0 - 20;

[0022] The weight ratio of the total weight of the lithium compounds, aluminum compounds, hydrophilic binders, and filler to the weight of the pore-forming agent is 100:0.6 - 20.

[0023] Preferably, the weight ratio of the total weight of the lithium compounds, aluminum compounds, hydrophilic binders, and filler to the weight of the pore-forming agent is 100:2 - 12.

[0024] Optionally, the filler is at least one of lithium ore, aluminum ore, and secondary recycled materials of lithium adsorbents;

[0025] Optionally, the particle size of the filler is less than 0.15 mm.

[0026] Optionally, the secondary recycled material of the lithium adsorbent is particles smaller than 0.8 mm obtained during the granulation of the lithium adsorbent.

[0027] Optionally, the hydrophilic binder is at least one of polyacrylamide, polyacrylate, dextran, agarose, polyvinyl alcohol, and phenolic resin.

[0028] Optionally, the raw material further contains a curing agent;

[0029] The curing agent is selected from at least one of azobisisobutyronitrile, potassium persulfate, ammonium persulfate, sulfuric acid, hydrochloric acid, sodium hydroxide, dialdehyde compounds, and epichlorohydrin.

[0030] Optionally, the dialdehyde compounds include at least one of glyoxal, malonaldehyde, succinaldehyde, glutaraldehyde, and adipaldehyde.

[0031] Optionally, the weight ratio of the curing agent to the binder is 1:1 to 10.

[0032] Optionally, the molar ratio of the lithium compound to the aluminum compound is 1:2 to 6.

[0033] Optionally, the weight ratio of the total weight of the lithium compound and the aluminum compound to the hydrophilic binder is 100:5 - 25.

[0034] Optionally, the weight ratio of the total weight of the lithium compound and the aluminum compound to water in the raw material is 1:1 to 2.5.

[0035] Optionally, the drying is carried out by drying at 80 - 150 °C.

[0036] Optionally, the equipment used for curing is a double - cone dryer or a kneader.

[0037] Optionally, the equipment used for granulation is a pair - roll granulator or a screw extrusion granulator.

[0038] Optionally, the equipment used for drying is a tunnel - type hot - air circulation drying tunnel electric heating equipment or a rotary kiln.

[0039] The above-mentioned curing equipment can precisely control the reaction temperature and time, enabling the cured product to have high toughness and improving the yield of qualified granular products. The drying equipment can achieve zone temperature control, making the intermediate polymerization and forming process controllable and gradually forming the target pore size. During the polymer curing process, the pore-forming agent can support the pore structure, and after washing with water, the water replaces the pore-forming agent, and the pore structure remains. Due to the high cost of lithium raw materials at present, after multiple experiments, ground lithium ore fillers, ground aluminum ore fillers, and small-sized finished product fillers are added, which can not only reduce costs but also recycle waste. In short, the selected curing equipment, granulation equipment, and drying equipment can effectively improve the production efficiency of the curing, granulation, and drying links, reduce labor, increase lithium production and yield, and effectively reduce costs.

[0040] The technical solution of the present invention has the following advantages:

[0041] 1. The lithium adsorbent of the present invention has a specific average pore size of 1-10 nm, and the diameter of lithium ions is 0.3 nm. The pore size of the lithium adsorbent of the present invention is more than three times larger than the ion diameter, enabling lithium ions to quickly enter and exit the pores. Therefore, this structure can ensure high adsorption efficiency and high desorption efficiency at high flow rates, and makes the desorption more concentrated and reduces the tailing phenomenon compared with general lithium adsorbents, which can effectively improve the production efficiency of lithium. Moreover, the pore size of the product of the present invention is less than 10 nm, resulting in a low dissolution loss rate and a long service life of the lithium adsorbent. The lithium adsorbent of the present invention still has high adsorption efficiency and high desorption efficiency after 1000 adsorption and desorption cycles.

[0042] 2. The preparation method in the present invention adopts a one-step method. Instead of first synthesizing a precursor from aluminum and lithium raw materials, the aluminum and lithium raw materials, water, and binder are directly cured and formed together. The one-step forming greatly simplifies the preparation process, improves production efficiency, and reduces production costs. Specific Embodiments

[0043] The following embodiments are provided to better understand the present invention further. They are not limited to the best implementation mode, and do not constitute a limitation to the content and protection scope of the present invention. Any product that is the same as or similar to the present invention obtained by anyone under the inspiration of the present invention or by combining the features of the present invention with other prior art features falls within the protection scope of the present invention.

[0044] For those in the embodiments who do not specify the specific experimental steps or conditions, the operations or conditions of the conventional experimental steps described in the literature in this field can be followed. For the reagents or instruments whose manufacturers are not specified, they are all conventional reagent products that can be obtained through commercial purchase.

[0045] Example 1

[0046] In a 1000L reactor, add 500 kg of water, 260 kg of aluminum chloride hexahydrate, 17.5 kg of lithium carbonate, 40.5 kg of PVPK30, 100 kg of sodium hydroxide, 62 kg of acrylamide, 7 kg of N,N-methylenebisacrylamide, and stir and react at normal pressure at 60 °C for 2 h. Transfer the above slurry to a 2000L double-cone dryer, add 0.2 kg of potassium persulfate, start stirring and mixing evenly, then raise the temperature to 60 °C and react for 2 h, then discharge the material, transfer it to a pair-roll granulator and cut it to 0.8 - 2.0 mm. Transfer the cut intermediate to a tunnel-type hot air circulation drying tunnel electric heating device, and dry it at 90 °C until the water content is less than 5% (w / w) to obtain the finished product.

[0047] Example 2

[0048] In a 1000L reactor, add 500 kg of water, 400 kg of aluminum nitrate nonahydrate, 8.75 kg of lithium carbonate, neutralize with hydrochloric acid to pH = 6, 15 kg of span65, 40 kg of polyvinyl alcohol 0599, and stir at 80 °C for 2 h. Transfer the above slurry to a 2000L kneader, add 5 kg of borax, start stirring and mixing evenly, then raise the temperature to 70 °C and react at normal pressure for 2 h, discharge the material, transfer it to a pair-roll granulator and cut it to 0.8 - 2.0 mm. Transfer the cut intermediate to a double-cone drying device, and dry it at 80 °C until the water content is less than 5% (w / w) to obtain the finished product.

[0049] Example 3

[0050] In a 1000L reactor, add 500 kg of water, 200 kg of aluminum hydroxide, 25 kg of lithium chloride, 5 kg of span60, 0.625 kg of tween80, 17 kg of sodium hydroxide, 40 kg of acrylamide 1799, 7 kg of N,N-methylenebisacrylamide, and stir at normal pressure at 60 °C for 2 h. Transfer the above slurry to a 2000L kneader, add 0.2 kg of ammonium persulfate, start stirring and mixing evenly, then raise the temperature to 70 °C and react for 2 h, discharge the material, transfer it to a pair-roll granulator and cut it to 0.8 - 2.0 mm. Transfer the cut intermediate to a double-cone drying device, and dry it at 130 °C until the water content is less than 5% (w / w) to obtain the finished product.

[0051] Example 4

[0052] In a 1000L reactor, add 500 kg of water, 400 kg of industrial-grade acidic aluminum sol (aluminum content 11.1%), 25 kg of lithium chloride, 20 kg of PEG 20000, 40 kg of methyl acrylate, 5 kg of TAIC, and stir at 70°C under normal pressure for 2 h. Transfer the above slurry to a 2000L kneader, add 0.1 kg of azobisisobutyronitrile, start stirring and mixing evenly, then heat up to 70°C and keep warm for 2 h, cool down, discharge, transfer to a pair-roll granulator and cut to 0.8 - 2.0 mm. Transfer the cut intermediate to a tunnel-type hot air circulation drying oven with electric heating, dry at 90°C until the water content is less than 5% (w / w), and the finished product can be obtained.

[0053] Example 5

[0054] In a 1000L reactor, add 500 kg of water, 260 kg of aluminum chloride hexahydrate, 7.52 kg of lithium hydroxide, 30 kg of PVPK30, 20 kg of aluminum ore (purchased from Yunnan Wenshan Aluminum Industry, with an AL2O3 content of 58.27%) ground to 100 mesh (less than 0.15 mm), 100 kg of sodium hydroxide, 40 kg of phenol, and stir at 80°C under normal pressure for 2 h. Transfer the above slurry to a 2000L double-cone dryer, add 20 kg of formaldehyde, start stirring and mixing evenly, then heat up to 80°C and react for 2 h, discharge, transfer to a pair-roll granulator and cut to 0.8 - 2.0 mm. Transfer the cut intermediate to a tunnel-type hot air circulation drying oven with electric heating, dry at 150°C until the water content is less than 5% (w / w), and the finished product can be obtained.

[0055] Example 6

[0056] In a 1000L reactor, add 500 kg of water, 260 kg of aluminum chloride hexahydrate, 20 kg of lithium hydroxide, 35 kg of PVPK30, 25 kg of lithium ore (purchased from Nanning Biaohong Trading Co., Ltd., with a Li2O content of 0.26%) ground to 100 mesh (less than 0.15 mm), 31 kg of the finished product from Example 1 ground to less than 100 mesh (less than 0.15 mm), 100 kg of sodium hydroxide, 40 kg of dextran 2w, stir at 90°C under normal pressure for 1 h, cool down, add 7 kg of epichlorohydrin, then transfer to a kneader, mix and heat up to 70°C and react for 0.5 h to form a gel, transfer to a screw extrusion granulator to produce appropriate particle size, transfer the cut intermediate to a tunnel-type hot air circulation drying oven with electric heating, and the finished product can be obtained at 90°C for 6 h.

[0057] Example 7

[0058] In a 1000L reactor, add 500 kg of water, 400 kg of industrial-grade acidic aluminum sol (aluminum content 11.1%), 25 kg of lithium chloride, 20 kg of PEG20000, and 40 kg of agarose. Stir and react at 90°C under normal pressure for 2 h. Transfer the above slurry to a 2000L kneader. After starting stirring and mixing evenly, cool down, discharge the material, and transfer it to a pair-roll granulator to cut it into appropriate particle size to obtain the finished product.

[0059] Comparative Example 1

[0060] In a 1000L reactor, add 500 kg of water, 200 kg of aluminum hydroxide, 25 kg of lithium chloride, 17 kg of sodium hydroxide, and 40 kg of polyvinyl alcohol 2399. Stir at 90°C under normal pressure for 2 h. Transfer the above slurry to a 2000L kneader, and add 20 kg of adipic dialdehyde. After starting stirring and mixing evenly, heat up to 70°C and react for 2 h, discharge the material, transfer it to a pair-roll granulator to cut it to 0.8 - 2.0 mm, and transfer the cut intermediate to a double-cone drying equipment. Dry it at 130°C until the water content is less than 5% (w / w) to obtain the finished product.

[0061] Comparative Example 2

[0062] In a 1000L reactor, add 500 kg of water, 260 kg of aluminum chloride hexahydrate, 17.5 kg of lithium carbonate, 1 kg of PVPK30, 100 kg of sodium hydroxide, 62 kg of acrylamide, and 7 kg of N,N'-methylenebisacrylamide. Stir at 60°C under normal pressure for 2 h. Transfer the above slurry to a 2000L double-cone dryer, and add 0.2 kg of potassium persulfate. After starting stirring and mixing evenly, heat up to 60°C and react for 2 h, then discharge the material, transfer it to a pair-roll granulator to cut it to 0.8 - 2.0 mm, and transfer the cut intermediate to a tunnel-type hot air circulation drying oven with electric heating equipment. Dry it at 90°C until the water content is less than 5% (w / w) to obtain the finished product.

[0063] Comparative Example 3

[0064] In a 1000L reactor, add 500 kg of water, 260 kg of aluminum chloride hexahydrate, 17.5 kg of lithium carbonate, 100 kg of PVPK30, 100 kg of sodium hydroxide, 62 kg of acrylamide, and 7 kg of N,N'-methylenebisacrylamide. Stir at 60°C under normal pressure for 2 h. Transfer the above slurry to a 2000L double-cone dryer, and add 0.2 kg of potassium persulfate. After starting stirring and mixing evenly, heat up to 60°C and react for 2 h, then discharge the material, transfer it to a pair-roll granulator to cut it to 0.8 - 2.0 mm, and transfer the cut intermediate to a tunnel-type hot air circulation drying oven with electric heating equipment. Dry it at 90°C until the water content is less than 5% (w / w) to obtain the finished product.

[0065] Comparative Example 4

[0066] The JW-LAHS adsorbent purchased from Jiangsu Jiuwu High-Tech Co., Ltd. was used as Comparative Example 4.

[0067] The pore size data was detected using a JW-BK300 specific surface area and pore size analyzer as follows:

[0068]

[0069] Leaching loss rate evaluation:

[0070] 1000 ml of the finished product in each example was measured with a graduated cylinder and filled into an ion exchange column with an inner diameter of 70 mm and a length of 500 mm. The brine of Qarhan Salt Lake (K + 972 mg / L, Na + 2021 mg / L, Ca 2+ 68 mg / L, Mg 2+ 116285 mg / L, B 309 mg / L, Li + 56 mg / L, Cl - 296732 mg / L, SO4 2- 13911 mg / L, Si 10 mg / L, pH 4.95) was passed through at 10 bv (1 bv is 1000 ml), and then deionized water was passed through at 10 bv. This was considered one cycle. After 1000 cycles, the volume of the finished product in each example was then measured with a graduated cylinder.

[0071] Leaching loss rate (%) = (1 - volume of the finished product after 1000 cycles (ml) / 1000) * 100

[0072]

[0073]

[0074] Application evaluation:

[0075] 1000 ml of the finished product in each example and comparative example, and the samples of Example 1, Example 2, and Comparative Example 3 after 1000 cycles obtained in the leaching loss rate evaluation were filled into an ion exchange column. The brine of Qarhan Salt Lake with a lithium content of 56 ppm (K + 972 mg / L, Na + 2021 mg / L, Ca 2+ 68 mg / L, Mg 2+ 116285 mg / L, B 309 mg / L, Li + 56 mg / L, Cl - 296732 mg / L, SO4 2-(13911 mg / L, Si 10 mg / L, pH 4.95) was passed through the column at a rate of 20 bv / h (1 bv is 1000 ml), adsorbed for 40 bv, and the tail liquid mixture of every 10 bv of adsorption was collected for detecting the lithium content. After the adsorption was completed, it was desorbed with deionized water at a flow rate of 20 bv / h for 5 bv, and the desorption mixture of every 1 bv was collected for detection. The detection results and the adsorption weight and desorption total amount calculated according to formula (1) and formula (2) are as follows:

[0076] (1) Total adsorption amount = 56 * 40 - 10 * (Li + content 0-10bv +Li + content 10-20bv +Li + content 20-30bv +Li + content 30-40bv )

[0077] (2) Total desorption amount = 1 * (Li + content 1bv +Li + content 2bv +Li + content 3bv +Li + content 4bv +Li + content 5bv )

[0078] The detection results are as follows:

[0079]

[0080]

[0081] It can be found through application experiments that the lithium adsorbent of the present invention has a larger adsorption amount and a larger desorption amount compared with the comparative example at high flow rates. The desorption peak is twice that of the sample without pore-forming agent, and the desorption is more concentrated and the tailing phenomenon is reduced. Compared with the commercially available comparative example 4 sample, the desorption peak is higher and the desorption amount is also larger, showing obvious advantages. From the adsorption and desorption data after 1000 cycles of Example 1, Example 2 and Comparative Example 3, it can be seen that the sample prepared according to the scheme of the present invention has a long service life, and the attenuation after 1000 cycles of adsorption and desorption is < 5%.

[0082] Obviously, the above embodiments are only examples for clear illustration and are not limitations on the implementation manners. For those of ordinary skill in the art, 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 manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. A lithium adsorbent, characterized in that, The lithium adsorbent has a porous structure and comprises an aluminum-based lithium adsorbent active material and a hydrophilic binder; The average pore diameter of the lithium adsorbent is 1-10 nm, the pore volume is 0.65-0.8 ml / g, and the specific surface area is 400-600 m 2 / g; The preparation method of the lithium adsorbent comprises the following steps: Mix raw materials including a lithium compound, an aluminum compound, a pore-forming agent, a hydrophilic binder, and water, and react at 60-100 °C for 2-4 h to cause the lithium compound and the aluminum compound to react to form an aluminum-based lithium adsorbent active material; the weight ratio of the total weight of the lithium compound, the aluminum compound, and the hydrophilic binder to the weight of the pore-forming agent is 100:(0.6-20); After the hydrophilic binder in the raw material mixture is cured, the lithium adsorbent is obtained through granulation and drying; The pore-forming agent is an organic pore-forming agent selected from at least one of polyvinylpyrrolidone, polyethylene glycol, Span emulsifiers, and Tween emulsifiers; The hydrophilic binder is at least one of polyacrylamide, dextran, agarose, and polyvinyl alcohol; The molar ratio of the lithium compound to the aluminum compound is 1:(2-6); The weight ratio of the total weight of the lithium compound and the aluminum compound to the weight of the hydrophilic binder is 100:(5-25).

2. The lithium adsorbent according to claim 1, wherein The particle size of the lithium adsorbent is 0.8-2.0 mm.

3. A method for preparing a lithium adsorbent according to claim 1 or 2, characterized in that, Comprises the following steps: Mix raw materials including a lithium compound, an aluminum compound, a pore-forming agent, a hydrophilic binder, and water, and react at 60-100 °C for 2-4 h to cause the lithium compound and the aluminum compound to react to form an aluminum-based lithium adsorbent active material; the weight ratio of the total weight of the lithium compound, the aluminum compound, and the hydrophilic binder to the weight of the pore-forming agent is 100:(0.6-20); After the hydrophilic binder in the raw material mixture is cured, the lithium adsorbent is obtained through granulation and drying; The pore-forming agent is an organic pore-forming agent selected from at least one of polyvinylpyrrolidone, polyethylene glycol, Span emulsifiers, and Tween emulsifiers; The hydrophilic binder is at least one of polyacrylamide, dextran, agarose, and polyvinyl alcohol; The molar ratio of the lithium compound to the aluminum compound is 1:(2-6); The weight ratio of the total weight of the lithium compound and the aluminum compound to the weight of the hydrophilic binder is 100:(5-25).

4. The preparation method according to claim 3, characterized in that, The aluminum compound is at least one of aluminum chloride, aluminum nitrate, aluminum sulfate, aluminum carbonate, aluminum hydroxide, aluminum oxide, and aluminum sol.

5. The preparation method according to claim 3, characterized in that, The lithium compound is at least one of lithium chloride, lithium carbonate, and lithium hydroxide.

6. The preparation method according to claim 3, characterized in that, The raw materials further contain a filler; The weight ratio of the total weight of the lithium compound, the aluminum compound, and the hydrophilic binder to the weight of the filler is 100:(0-20), and the weight of the filler is not 0; The weight ratio of the total weight of the lithium compound, the aluminum compound, the hydrophilic binder, and the filler to the weight of the pore-forming agent is 100:(0.6-20).

7. The preparation method according to claim 6, characterized in that, The filler is at least one of lithium ore, aluminum ore, and secondary recycled material of the lithium adsorbent; The particle size of the filler is less than 0.15 mm.

8. The preparation method according to claim 3, characterized in that, The raw materials further contain a curing agent; The curing agent is selected from at least one of azobisisobutyronitrile, potassium persulfate, ammonium persulfate, sulfuric acid, hydrochloric acid, sodium hydroxide, dialdehyde compounds, and epichlorohydrin.

9. The preparation method according to claim 8, wherein, The dialdehyde compounds include at least one of glyoxal, malondialdehyde, succinaldehyde, glutaraldehyde, and adipic dialdehyde.

10. The preparation method according to claim 3, characterized in that, The weight ratio of the total weight of the lithium compound and the aluminum compound to water in the raw materials is 1:(1 - 2.5).

11. The preparation method according to claim 3, wherein, The drying is carried out by drying at 80 - 150 °C.

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