Titanium lithium adsorbent and preparation method thereof
By preparing a titanium-based lithium adsorbent with a hollow macroporous cross-linked structure, the problems of particle loss, detachment, and poor wettability of existing lithium adsorbents were solved, achieving a highly efficient lithium extraction effect.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-24
- Publication Date
- 2026-04-07
AI Technical Summary
Existing lithium adsorbents suffer from problems such as particle dissolution, shedding, poor wettability, and low extraction rate.
The preparation method of titanium-based lithium adsorbent involves ball milling and dispersing a mixture of lithium source and titanium source with polyethylene glycol, additives and water, followed by spray drying and calcination to form a hollow macroporous cross-linked lithium metatitanate. The polyethylene glycol and additives widen the pores during calcination, increasing wettability, and the cross-linked structure reduces particle dissolution.
It improved the lithium extraction rate, enhanced the wettability of the lithium adsorbent, and reduced particle dissolution and detachment.
Smart Images
Figure CN121797248A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of lithium adsorbent technology, and more specifically, to titanium-based lithium adsorbents and their preparation methods. Background Technology
[0002] Lithium batteries are an important type of new energy battery; therefore, lithium resources play a very important role in the development of new energy batteries, automobiles, and other related fields.
[0003] The main lithium extraction methods provided by related technologies include precipitation, salting out, and solvent extraction. These methods generally have their own limitations and complex processes. Extracting lithium from lithium-containing liquids using lithium adsorbents is gradually being researched and is replacing other lithium extraction methods due to its high lithium selectivity and high recovery rate.
[0004] However, the lithium adsorbents provided by the relevant technologies still have problems such as particle dissolution and shedding, poor wettability, and low extraction rate. Summary of the Invention
[0005] The purpose of this invention is to provide a titanium-based lithium adsorbent and its preparation method. The titanium-based lithium adsorbent prepared by the method of this invention can increase wettability and reduce particle dissolution and shedding, thereby improving the lithium extraction rate.
[0006] This invention is implemented as follows: In a first aspect, the present invention provides a method for preparing a titanium-based lithium adsorbent, comprising: A lithium source and a titanium source are added to a mixture of polyethylene glycol, additives, and water, and the mixture is ball-milled and dispersed to obtain a pre-prepared slurry; the additives include at least one of sucrose, glucose, fructose, starch, and citric acid; The pre-prepared slurry is spray-dried to obtain a dry powder; Lithium metatitanate was prepared by calcining and drying the powder. Lithium titanate was cleaned with an acid solution.
[0007] In an optional embodiment, the mass ratio of polyethylene glycol, additives and water is (0.8~1.2): (0.8~1.2): (7~9).
[0008] In optional embodiments, the molar ratio of lithium source to titanium source is (1.5~2.5):1, preferably 2.1:1; and / or, The titanium source is a primary particle, and the particle size of the titanium source is 100~300nm.
[0009] In an optional embodiment, the particle size of the pre-mixed slurry obtained by ball milling dispersion is ≤0.1μm.
[0010] In an optional embodiment, the calcination temperature is 850~870℃.
[0011] In an optional embodiment, the spray drying temperature is 100~105°C.
[0012] In an optional implementation, air circulation is maintained during the spray drying process.
[0013] In an optional embodiment, the acid solution is hydrochloric acid or nitric acid, and the molar concentration of the acid solution is 0.3~0.7 mol / L; and / or, The solid-liquid ratio of lithium metatitanate to the acid solution is (95~105):1; and / or, The temperature for cleaning lithium titanate with acid solution is 55~65℃.
[0014] In an optional embodiment, the titanium source includes at least one of anatase titanium dioxide, rutile titanium dioxide, and mixed-phase titanium dioxide or metatitanic acid.
[0015] Secondly, the present invention provides a titanium-based lithium adsorbent, which is prepared by any of the aforementioned methods for preparing titanium-based lithium adsorbents.
[0016] The present invention has the following beneficial effects: In the preparation method of the titanium-based lithium adsorbent provided in this embodiment of the invention, the titanium source forms a cross-linked state after calcination, and the polyethylene glycol and additives (e.g., sucrose) remain inside the material after spray drying, which can play a role in widening the pores during the calcination process. Therefore, this preparation method can obtain lithium metatitanate with a hollow structure of macroporous cross-linked structure as a lithium adsorbent. On the one hand, the larger microporous structure increases the wettability of the material, and on the other hand, the complete cross-linked structure reduces the dissolution and shedding of lithium adsorbent particles, so as to fully improve the extraction rate of lithium by the obtained titanium-based lithium adsorbent.
[0017] The titanium-based lithium adsorbent provided in this embodiment of the invention is prepared by the aforementioned preparation method. This titanium-based adsorbent can increase wettability and reduce particle dissolution and shedding, thereby improving the lithium extraction rate. Attached Figure Description
[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0019] Figure 1 This is a SEM image of the microstructure of the titanium source in Example 1 of the present invention; Figure 2 SEM image of the titanium-based lithium adsorbent prepared in Example 1 of this invention. Figure 1 ; Figure 3 SEM image of the titanium-based lithium adsorbent prepared in Example 1 of this invention. Figure 2 . Detailed Implementation
[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.
[0021] Lithium extraction from lithium-containing liquids using lithium adsorbents is increasingly being studied as a replacement for other lithium extraction methods such as precipitation, salting out, and solvent extraction due to its high lithium selectivity and high recovery rate.
[0022] However, the inventors discovered that the lithium adsorbents provided by the related technologies still suffer from problems such as particle dissolution and shedding, poor wettability, and low extraction rate.
[0023] To address the aforementioned issues, this disclosure provides a titanium-based lithium adsorbent and its preparation method. The titanium-based lithium adsorbent prepared by this method can increase wettability and reduce particle dissolution and detachment, thereby improving the lithium extraction rate.
[0024] The preparation method of the titanium-based lithium adsorbent disclosed herein includes: A lithium source and a titanium source are added to a mixture of polyethylene glycol, additives, and water, and the mixture is ball-milled and dispersed to obtain a pre-prepared slurry; the additives include at least one of sucrose, glucose, fructose, starch, citric acid, etc. The pre-prepared slurry is spray-dried to obtain a dry powder; Lithium metatitanate was prepared by calcining and drying the powder. Lithium titanate was cleaned with an acid solution.
[0025] In this preparation method, the titanium source forms a cross-linked state after calcination, and the polyethylene glycol and additives (e.g., sucrose) remain inside the material after spray drying, which can play a role in widening the pores during calcination. Therefore, this preparation method can produce lithium metatitanate with a hollow macroporous cross-linked structure as a lithium adsorbent. On the one hand, the larger microporous structure increases the wettability of the material, and on the other hand, the complete cross-linked structure reduces the dissolution and shedding of lithium adsorbent particles, so as to fully improve the extraction rate of lithium by the prepared titanium-based lithium adsorbent.
[0026] Optionally, the mass ratio of polyethylene glycol, additives and water is (0.8~1.2): (0.8~1.2): (7~9), for example: 1:1:8, 0.8:1.2:7, 1.2:0.8:9, etc., which are not specifically limited here.
[0027] Optionally, polyethylene glycol may specifically refer to polyethylene glycol 2000, polyethylene glycol 1000, polyethylene glycol 200, etc., without being specifically limited here.
[0028] Optionally, the molar ratio of lithium source to titanium source is (1.5~2.5):1 (e.g., 1.5:1, 2:1, 2.5:1, etc., not specifically limited here), preferably 2.1:1; and the titanium source is a primary particle, and the particle size of the titanium source is 100~300nm (e.g., 100nm, 150nm, 200nm, 250nm, 300nm, etc., not specifically limited here). After sintering, the primary particles exhibit a completely cross-linked structure at the microscopic level, that is, all the primary particles are solid-phase fused together, which can significantly reduce the dissolution and detachment of lithium adsorbent particles.
[0029] Optionally, the particle size of the pre-mixed slurry obtained by ball milling dispersion is ≤0.1μm, for example: 0.1μm, 0.8μm, 0.7μm, etc., which is not specifically limited here. Sufficient ball milling dispersion is beneficial to promoting the formation of cross-linked bodies after sintering.
[0030] Optionally, the calcination temperature is 850~870℃, for example: 850℃, 855℃, 860℃, 865℃, 870℃, etc., without specific limitation. The calcination temperature has a crucial and systematic impact on the performance of the prepared titanium-based lithium adsorbent. Specifically, the calcination temperature determines the core process parameters of the material's final crystal structure, pore structure, surface chemistry, and mechanical stability, which are directly related to the adsorbent's lithium-ion exchange capacity, selectivity, kinetics, and cycle stability. Therefore, calcination within the above-mentioned temperature range can ensure the good microstructure and adsorption performance of the titanium-based lithium adsorbent.
[0031] Optionally, the calcination time can be 2 to 3 hours, such as 2 hours, 2.5 hours, 3 hours, etc., without specific limitation.
[0032] Optionally, the spray drying temperature is 100~105℃, for example: 100℃, 102℃, 105℃, etc., without specific limitation.
[0033] Optionally, air circulation can be maintained during the spray drying process.
[0034] Optionally, the acid solution is hydrochloric acid or nitric acid, and the molar concentration of the acid solution is 0.3~0.7 mol / L, for example: 0.3 mol / L, 0.5 mol / L, 0.7 mol / L, etc., without specific limitation.
[0035] Acid washing removes lithium ions from the precursor (e.g., Li) + Replace with H + This forms a lithium adsorbent with an ion sieve effect. This structure has a high specificity for lithium ions and can efficiently separate lithium from salt lake brines with a high magnesium-to-lithium ratio, reducing interference from coexisting ions such as magnesium and sodium.
[0036] Optionally, the solid-liquid ratio of lithium metatitanate to acid solution is (95~105):1 (e.g., 95:1, 98:1, 100:1, 102:1, 105:1, etc., which are not specifically limited here); the temperature for cleaning lithium metatitanate with acid solution is 55~65℃, e.g., 55℃, 57℃, 60℃, 62℃, 65℃, etc., which are not specifically limited here.
[0037] The above-mentioned temperature can promote lithium ion elution, that is, the acid washing temperature is a key factor in the lithium extraction rate.
[0038] Meanwhile, increasing the temperature requires balancing lithium removal and structural protection; that is, acid washing at the above temperatures must maintain the titanium dissolution rate. Generally speaking, the titanium dissolution rate (the rate of loss of titanium ions in the adsorbent) increases with increasing temperature, while the lithium removal rate is positively correlated with the adsorption capacity. After lithium ions are removed from the adsorbent, more vacancies are formed, providing active sites for subsequent lithium ion adsorption. The acid washing temperature needs to be optimized in conjunction with other conditions (such as acid concentration and time) to balance lithium removal and structural stability.
[0039] Optionally, the cleaning time can be 20 to 30 hours, such as 20 hours, 22 hours, 24 hours, 27 hours, 30 hours, etc., without specific limitations.
[0040] Optionally, the titanium source includes at least one of anatase titanium dioxide, rutile titanium dioxide, and mixed-phase titanium dioxide or metatitanic acid.
[0041] Optionally, the lithium source includes lithium carbonate (Li2CO3), lithium hydroxide (LiOH), lithium oxide (Li2O), etc.
[0042] The present invention will be further described in detail below with reference to the embodiments.
[0043] Example 1 (1) A lithium source and a titanium source with a molar ratio of 2:1 were used (see SEM images of the microstructure). Figure 1(The lithium source is Li2CO3, the titanium source is anatase titanium dioxide, and the primary particle size of the titanium source is 100 nm.) Lithium and titanium sources were added to a mixed solution of polyethylene glycol 2000, sucrose, and deionized water, wherein the mass ratio of polyethylene glycol to sucrose and deionized water was 1:1:8. The prepared solution was then dispersed by ball milling to a particle size of 0.1 μm.
[0044] (2) The above-dispersed slurry is spray-dried, and the outlet air temperature of the spray dryer is controlled at 100℃ to obtain dried powder.
[0045] (3) The above powder was calcined under air circulation at a temperature of 850°C for 2.5 hours to obtain lithium metatitanate.
[0046] (4) At 60℃, with a liquid-to-solid ratio of 100:1, the adsorbent was soaked and acid-washed with 0.5 mol / L HCl solution for 24 h, then washed with deionized water and dried to obtain the porous titanium-doped lithium adsorbent (microscopic morphology SEM image is shown in...). Figure 2 and Figure 3 ).
[0047] according to Figure 2 and Figure 3 It can be seen that the prepared titanium-based lithium adsorbent forms a completely cross-linked structure (i.e., all primary particles are solid-phase fused together) and has large micropores, which can increase wettability, reduce particle dissolution and detachment, and improve the adsorption rate of lithium.
[0048] Example 2 (1) Take a lithium source and a titanium source with a molar ratio of 2.5:1; wherein the lithium source is LiOH, the titanium source is anatase titanium dioxide, and the primary particle size of the titanium source is 300 nm. Lithium and titanium sources were added to a mixed solution of polyethylene glycol 2000, glucose, and deionized water, wherein the mass ratio of polyethylene glycol to glucose and deionized water was 0.8:0.8:7. The prepared solution was then dispersed by ball milling, and the particle size after dispersion was 0.09 μm.
[0049] (2) The above-dispersed slurry is spray-dried, and the outlet air temperature of the spray dryer is controlled at 105℃ to obtain dried powder.
[0050] (3) The above powder was calcined under air circulation at a temperature of 870°C for 3 hours to obtain lithium metatitanate.
[0051] (4) At 55℃, with a liquid-to-solid ratio of 95:1, the porous doped titanium-based lithium adsorbent was soaked and acid-washed with 0.7mol / L nitric acid solution for 24h, washed with deionized water and dried.
[0052] Example 3 (1) Take a lithium source and a titanium source with a molar ratio of 1.5:1; wherein the lithium source is Li2O, the titanium source is anatase titanium dioxide, and the primary particle size of the titanium source is 200 nm. Lithium and titanium sources were added to a mixed solution of polyethylene glycol 2000, fructose, and deionized water, wherein the mass ratio of polyethylene glycol to fructose and deionized water was 1.2:1.2:9. The prepared solution was then dispersed by ball milling to a particle size of 0.1 μm.
[0053] (2) The above-dispersed slurry is spray-dried, and the outlet air temperature of the spray dryer is controlled at 102℃ to obtain dried powder.
[0054] (3) The above powder was calcined under air circulation at a temperature of 860°C for 2 hours to obtain lithium metatitanate.
[0055] (4) At 65℃, with a liquid-to-solid ratio of 105:1, the porous doped titanium-based lithium adsorbent was obtained by soaking and acid washing with 0.3 mol / L HCl solution for 24 h, followed by washing with deionized water and drying.
[0056] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that no sucrose was added in step (1); other processes are the same as in Example 1.
[0057] Step (1) involves adding lithium and titanium sources to a mixed solution of polyethylene glycol 2000 and deionized water without adding sucrose. Other processes are described in Example 1.
[0058] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that less sucrose is added in step (1), wherein the mass ratio of polyethylene glycol to sucrose and deionized water is 1:0.5:8; other processes are the same as in Example 1.
[0059] Step (1) involves a mass ratio of polyethylene glycol to sucrose and deionized water of 1:0.5:8. Other processes are described in Example 1.
[0060] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that the spray drying in step (2) was not performed, the slurry dispersed in step (1) was dried, and then calcined in step (3); other processes are the same as in Example 1.
[0061] Comparative Example 4 The difference between Comparative Example 4 and Example 1 is that the calcination temperature in step (3) is 800°C, and the other processes are the same as in Example 1.
[0062] Comparative Example 5 The difference between Comparative Example 5 and Example 1 is that the calcination temperature in step (3) is 900°C, and the other processes are the same as in Example 1.
[0063] The lithium adsorbents prepared in Example 1 and Comparative Examples 1-5 were subjected to lithium adsorption tests and solubility loss tests, and the test methods are as follows.
[0064] Lithium adsorption test: First, prepare a lithium salt solution ([Li... + =1 g / L); 20 mL of the prepared lithium adsorbent was packed into the chromatography column, and 100 mL of the prepared lithium salt solution was passed through the column at a flow rate of 5 BV / h for 1 hour. The lithium ion concentration after passing through the column was tested to obtain the lithium adsorption capacity.
[0065] Dissolution rate test: Measure 20 ml of lithium adsorbent, dry it to constant weight, and adsorption and desorption constitute one cycle. After 100 cycles, take out the lithium adsorbent, dry it, weigh it, and calculate the dissolution rate according to the ratio.
[0066] The results are shown in the table below:
[0067] As shown in the table above, the adsorption effect of the adsorbent decreases when no sucrose is added or only a small amount of sucrose is added. Furthermore, without spray drying before calcination, polyethylene glycol and sucrose cannot remain inside the material, thus failing to widen the pore structure within the adsorbent material during calcination, significantly reducing lithium adsorption performance.
[0068] As can be seen from the table above, when the calcination temperature is lower than the calcination temperature required by this invention, the dissolution rate increases; when the calcination temperature is higher than the temperature required by this invention, the amount of lithium adsorbed decreases.
[0069] In summary, the titanium-based lithium adsorbent prepared by the method of the present invention can increase wettability and reduce particle dissolution and shedding, thereby improving the lithium extraction rate.
[0070] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A method for preparing a titanium-based lithium adsorbent, characterized in that, include: A lithium source and a titanium source are added to a mixture of polyethylene glycol, additives, and water, and the mixture is ball-milled and dispersed to obtain a pre-prepared slurry; the additives include at least one of sucrose, glucose, fructose, starch, and citric acid. The pre-prepared slurry is spray-dried to obtain a dry powder. Lithium metatitanate was obtained by calcining the dried powder. The lithium metatitanate was cleaned with an acid solution.
2. The method for preparing the titanium-based lithium adsorbent according to claim 1, characterized in that, The mass ratio of the polyethylene glycol, the additive, and the water is (0.8~1.2): (0.8~1.2): (7~9).
3. The method for preparing the titanium-based lithium adsorbent according to claim 1, characterized in that, The molar ratio of the lithium source to the titanium source is (1.5~2.5):1; The titanium source is a primary particle, and the particle size of the titanium source is 100~300nm.
4. The method for preparing the titanium-based lithium adsorbent according to claim 1, characterized in that, The pre-prepared slurry obtained by ball milling dispersion has a particle size ≤0.1μm.
5. The method for preparing the titanium-based lithium adsorbent according to claim 1, characterized in that, The calcination temperature is 850~870℃.
6. The method for preparing the titanium-based lithium adsorbent according to claim 1, characterized in that, The spray drying temperature is 100~105℃.
7. The method for preparing the titanium-based lithium adsorbent according to claim 1, characterized in that, The spray drying process maintains an air supply.
8. The method for preparing the titanium-based lithium adsorbent according to claim 1, characterized in that, The acid solution is hydrochloric acid or nitric acid, and the molar concentration of the acid solution is 0.3~0.7 mol / L; and / or, The solid-liquid ratio of the lithium metatitanate to the acid solution is (95~105):1; and / or, The lithium metatitanate is cleaned with the acid solution at a temperature of 55~65℃.
9. The method for preparing the titanium-based lithium adsorbent according to any one of claims 1-8, characterized in that, The titanium source includes at least one of anatase titanium dioxide, rutile titanium dioxide, and mixed-phase titanium dioxide or metatitanic acid.
10. A titanium-based lithium adsorbent, characterized in that, It is prepared by the method of preparing titanium-based lithium adsorbent according to any one of claims 1-9.