Titanium-based lithium ion sieve with high specific surface area and preparation method of titanium-based lithium ion sieve
By introducing glycerol into the preparation process of titanium-based lithium ion sieves, the pore structure and surface hydrophilicity are optimized, solving the problems of low specific surface area and insufficient pore structure, and achieving high adsorption capacity and rapid adsorption of lithium ions.
Patent Information
- Application Number
- CN202512026240.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-30
- Publication Date
- 2026-02-17
AI Technical Summary
Existing titanium-based lithium-ion sieve adsorption materials suffer from low specific surface area and limited pore structure, resulting in low actual adsorption capacity and short cycle life.
By introducing glycerol into the preparation process, carrying out hydrothermal reaction and calcination, the pore structure and surface hydrophilicity are optimized, and a titanium-based lithium-ion sieve with high specific surface area and porosity is prepared.
It significantly improves the adsorption capacity and adsorption rate of titanium-based lithium ion sieves, enhances the selectivity for lithium ions, and achieves efficient extraction of lithium from salt lake brine and seawater.
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Figure CN121536952A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of lithium-ion sieves, specifically relating to a high-adsorption-capacity titanium-based lithium-ion sieve adsorption material and its preparation method. Background Technology
[0002] Lithium and its compounds have been widely used in pharmaceuticals, ceramics, lubricants, aerospace, and nuclear thermonuclear fusion, with their application being particularly prominent in lithium-ion batteries. With the increasing popularity of lithium-ion batteries, the market demand for lithium resources has grown dramatically in recent years. Lithium resources mainly come from two categories: solid lithium ore and liquid lithium resources (such as seawater, geothermal water, and salt lake brine). Among these, salt lake brine is especially valuable, containing over 60% of the world's lithium resources, and its industrial development value is generally higher than that of solid lithium ore. In China, the richest lithium resources are also found in salt lake brine, accounting for more than 80% of the country's total lithium reserves. Therefore, the efficient extraction of lithium from salt lake brine has become a research hotspot. Currently, the main methods for extracting lithium from salt lake brine include precipitation, electrochemical methods, solvent extraction, membrane separation technology, and adsorption. Among these, precipitation is more suitable for brine with high lithium concentrations; electrochemical methods and membrane separation technology usually rely on costly membrane materials.
[0003] In contrast, adsorption methods, due to their simplicity, high selectivity, high recovery rate, low energy consumption, cost-effectiveness, and environmental friendliness, are considered the most promising method for extracting lithium from lithium-containing liquid resources (such as salt lake brine). Among materials for lithium extraction via adsorption, lithium-ion sieves have gained widespread scientific recognition due to their strong adsorption capacity, cost-effectiveness, and environmental friendliness. In particular, titanium-based lithium-ion sieves have become a research hotspot due to their excellent acid and alkali resistance, low titanium dissolution rate, and high "theoretical" adsorption capacity. However, existing titanium-based lithium-ion sieve adsorption materials still generally suffer from problems such as low specific surface area and insufficient pore structure, resulting in low actual adsorption capacity and short cycle life. Summary of the Invention
[0004] The purpose of this invention is to provide a method for preparing titanium-based lithium ion sieves by aging surfactants, lithium sources, and titanium sources, adding glycerol, and then performing hydrothermal treatment, calcination, and acid washing. The whole process is relatively simple, and its application in lithium extraction has achieved significant results.
[0005] A method for preparing a titanium-based lithium-ion sieve adsorbent material includes the following steps:
[0006] (1) A lithium source, a titanium source and two surfactants are mixed in a solvent and aged to obtain an aging system;
[0007] (2) The aging system is subjected to solid-liquid separation, washing and drying to obtain a solid;
[0008] (3) The solid is dispersed in a mixed solvent of water and alcohol, glycerol is added and hydrothermal reaction is carried out to obtain a titanium-based lithium ion sieve intermediate;
[0009] (4) The intermediate is calcined to obtain a titanium-based lithium ion sieve precursor;
[0010] (5) The precursor is eluted with an eluent to leach lithium ions, and then washed with water to obtain a titanium-based lithium ion sieve adsorbent material.
[0011] The lithium source is at least one of lithium hydroxide, lithium chloride, lithium nitrate, and lithium acetate.
[0012] The Li / Ti molar ratio is 2:(1-1.2).
[0013] The dual surfactant is a mixture of any two of F127, hexadecylamine, and hexadecyltrimethylammonium bromide.
[0014] When the lithium source is lithium hydroxide, the mass ratio of lithium hydroxide to the two surfactants is 0.5-0.8:1.
[0015] The aging time is 12-48 hours.
[0016] In the mixed solvent of water and alcohol, the alcohol is anhydrous ethanol.
[0017] In step (3), the dispersion system is ultrasonically treated before or after the addition of glycerol for 10-60 min.
[0018] In step (3), the amount of glycerol added is 5-30 mL, based on 2 g of dry solid.
[0019] Based on 2g of dry solids, the amount of glycerol added is 10-20mL.
[0020] The hydrothermal reaction is carried out at 100-200℃.
[0021] The hydrothermal reaction time is 12-24 hours.
[0022] The calcination is carried out at 300-600℃.
[0023] The calcination time is 3-5 hours.
[0024] The calcination heating rate is 3-8℃ / min.
[0025] The calcination is carried out in an air atmosphere.
[0026] The eluent is any one of hydrochloric acid, nitric acid, acetic acid, citric acid, and Na2S2O6.
[0027] The concentration of the eluent is 0.1-0.5 mol / L.
[0028] The precursor of the titanium-based lithium ion sieve is Li2TiO3, and the adsorption material of the titanium-based lithium ion sieve is Li2TiO3.
[0029] In step (1), the titanium source is tetrabutyl titanate.
[0030] In step (1), the solvent is an alcohol solvent; in step (3), the alcohol can be selected from any one of anhydrous ethanol, methanol, and isopropanol.
[0031] By adjusting the amount of glycerol added, the adsorption capacity of the prepared titanium-based lithium ion sieve reached the expected value. The amount of glycerol added was controlled by calculating the predicted value of the saturated adsorption capacity of the obtained titanium-based lithium ion sieve adsorbent material for lithium. The predicted value was calculated using the following formula:
[0032] ;
[0033] In the formula, , and The parameters to be fitted are... It refers to the amount of glycerin added. It is the equilibrium adsorption capacity.
[0034] A titanium-based lithium-ion sieve adsorbent material is prepared by the aforementioned preparation method.
[0035] Its specific surface area is 72.83-262.27 m². 2 / g, pore volume 0.25-0.34cm³ 3 / g, contact angle is 10.4-26.5°
[0036] The use of titanium-based lithium ion sieve adsorbent material in the recovery of lithium ions from salt lake brine or seawater, wherein the titanium-based lithium ion sieve adsorbent material is the titanium-based lithium ion sieve adsorbent material described above.
[0037] The selective adsorption capacity of the adsorbent material for Li+ exceeds 23 mg / g.
[0038] Under the conditions of an initial Li+ concentration of 200 mg / L and a temperature of 35 °C, the 8-hour equilibrium adsorption capacity of the adsorbent material exceeds 38 mg / g.
[0039] The beneficial effects of this invention are:
[0040] This invention prepares lithium-ion sieves by adding glycerol, which solves the problems of low specific surface area, dense internal structure, and narrow transport channels of titanium-based lithium-ion sieves. It significantly increases the specific surface area and porosity of the adsorption material, exposes more active adsorption sites and enhances adsorption performance, effectively improving the problem of a large gap between theoretical and actual adsorption capacity.
[0041] This invention prepares lithium-ion sieves by adding glycerol, simultaneously achieving surface hydrophilic modification of titanium-based lithium-ion sieves, thus shortening the Li... + The diffusion path accelerates Li + The prepared titanium-based lithium-ion sieve adsorbent material exhibits high adsorption capacity, fast adsorption rate, and good selectivity, and can be applied to lithium-containing solutions such as salt lake brine and seawater to achieve efficient lithium extraction.
[0042] The synthesis method, experimental conditions, and product preparation of this invention are easy to control, and the synthesis process does not pollute the environment. Attached Figure Description
[0043] Figure 1 Example 1: XRD pattern of titanium-based lithium ion sieve precursor Li2TiO3 synthesized under the conditions of Comparative Example 1.
[0044] Figure 2 SEM microscopy image of the titanium-based lithium ion sieve synthesized under the conditions of Example 1.
[0045] Figure 3 Adsorption kinetic curves of titanium-based lithium ion sieves synthesized under the conditions of Examples 1, 2, 3, 4, 5, 6, 7, 8, Comparative Examples 1, 2, and 3.
[0046] Figure 4 Example 1: Pseudo-first-order kinetic (PFO) and pseudo-second-order kinetic (PSO) models of titanium-based lithium-ion sieves synthesized under the conditions of Comparative Example 1.
[0047] Figure 5 : Adsorption selectivity histogram of titanium-based lithium ion sieves synthesized under the conditions of Example 1 and Comparative Example 1.
[0048] Figure 6 Adsorption cycle columnar section of titanium-based lithium ion sieve synthesized under the conditions of Example 1 and Comparative Example 1.
[0049] Figure 7 Pore size distribution curves of titanium-based lithium ion sieves synthesized under the conditions of Example 1 and Comparative Example 1.
[0050] Figure 8 N2 adsorption-desorption isotherms of titanium-based lithium ion sieves synthesized under the conditions of Example 1 and Comparative Example 1.
[0051] Figure 9 XPS distribution of O 1s of titanium-based lithium ion sieve synthesized under the conditions of Example 1 and Comparative Example 1.
[0052] Figure 10 Comparison of calculated and experimental values of training and validation samples for the saturated adsorption capacity prediction model. Detailed Implementation
[0053] This application introduces glycerol into the preparation process of titanium-based lithium-ion sieve adsorption materials to optimize their structure and performance, thereby achieving efficient lithium adsorption. The specific mechanisms and advantages are as follows: 1. Optimized pore structure and specific surface area: Glycerol decomposes during subsequent calcination, producing a large amount of small molecule gases such as CO2. This process effectively enriches the pore structure of the titanium-based lithium-ion sieve, significantly increasing its specific surface area. The increased specific surface area directly increases the number of active sites in the material, thereby improving its lithium-ion adsorption capacity. 2. Enhanced surface hydrophilicity and promotion of lithium-ion migration: Glycerol contains polar groups such as hydroxyl groups. The introduction of these groups significantly improves the hydrophilicity of the titanium-based lithium-ion sieve surface. Enhanced hydrophilicity facilitates the desolvation process of Li⁺ on its surface and accelerates the diffusion and adsorption of Li⁺ into the vacancies inside the ion sieve. Furthermore, this preparation process is simple to operate and highly feasible. Through the above dual optimization, this method significantly improves the performance of titanium-based lithium-ion sieves in efficiently recovering lithium resources from sources such as salt lake brine and seawater.
[0054] In some implementations, the technical solution is as follows:
[0055] A method for preparing and applying a titanium-based lithium-ion sieve adsorbent material using the addition of glycerol is disclosed. The method involves aging a lithium source, a titanium source, and a surfactant, adding glycerol, and then preparing the titanium-based lithium-ion sieve adsorbent material through hydrothermal treatment, calcination, and acid washing. The mass of the titanium source skeleton is used as the reference.
[0056] 1. In the above adsorption materials, the lithium source is at least one of lithium hydroxide, lithium chloride, lithium nitrate, and lithium acetate, the titanium source is tetrabutyl titanate, and the dual surfactants are any two mixtures of F127, hexadecylamine, and hexadecyltrimethylammonium bromide.
[0057] In the above adsorbent materials, the Li / Ti molar ratio is 2:(1~1.2), and the mass ratio of tetrabutyl titanate to the two surfactants is (2.2~2.8):1.
[0058] A method for preparing the above-mentioned adsorbent material, wherein the method for preparing the adsorbent material is as follows:
[0059] (1) Preparation of titanium-based lithium ion sieve intermediates by hydrothermal method
[0060] The lithium source and tetrabutyl titanate were dissolved in a solution containing two surfactants and aged at room temperature for 12-48 h. After centrifugation, washing and drying, appropriate amounts of distilled water and anhydrous ethanol were added and sonicated for 10-60 min. Glycerol was added and a hydrothermal reaction was carried out to obtain a titanium-based lithium ion sieve intermediate.
[0061] (2) Preparation of titanium-based lithium-ion sieve precursor by calcination method
[0062] The obtained titanium-based lithium ion sieve intermediate was washed, dried, and calcined to obtain the titanium-based lithium ion sieve precursor.
[0063] (3) Preparation of titanium-based lithium ion sieves by acid washing
[0064] The titanium-based lithium ion sieve precursor was leached with an eluent to extract lithium ions, and then washed with water to obtain a high-adsorption-capacity titanium-based lithium ion sieve adsorbent material.
[0065] In the above method, the lithium source is at least one of lithium hydroxide, lithium chloride, lithium nitrate, and lithium acetate, and the Li / Ti molar ratio is 2: (1~1.2).
[0066] In the above method, the dual surfactant is any two of the following: F127, hexadecylamine, and hexadecyltrimethylammonium bromide, and the mass ratio of tetrabutyl titanate to the dual surfactant is (2.2~2.8):1.
[0067] In the above method, the hydrothermal reaction conditions are: reaction in a high-pressure reactor at 100~200℃ for 12~24 h.
[0068] In the above method, the calcination conditions are: calcination at 300~600℃ for 3~5 h in an air atmosphere, with a heating rate of 3~8℃ / min.
[0069] In the above method, the eluent is any one of hydrochloric acid, nitric acid, acetic acid, citric acid and Na2S2O6, with a concentration of 0.1~0.5 mol / L.
[0070] The adsorption reaction conditions and adsorption capacity of this invention: The lithium ion or other metal ion content was tested using ICP. 0.5 g of a titanium-based lithium ion sieve was added to 500 mL of lithium hydroxide solution for adsorption for 12 h. At different time points, the supernatant was collected, centrifuged, filtered, and the lithium concentration in the solution was measured using ICP. The adsorption conditions were: initial lithium hydroxide concentration of 200 mg / L, temperature of 35℃, pH of 12, and rotation speed of 150 rpm.
[0071] The adsorption selectivity reaction conditions and adsorption capacity of this invention: ICP was used to test the lithium ion or other metal ion content. 0.5 g of a titanium-based lithium ion sieve was added to 500 mL of a solution containing Li... +N + K + Mg 2+ The metal ions in the simulated brine were adsorbed for 12 h. The supernatant was then centrifuged, filtered, and subjected to ICP-measured concentrations. The adsorption conditions were: Li + N + K + Mg 2+ The initial concentration was 200 mg / L, the temperature was 35℃, the pH was 10, and the rotation speed was 150 rmp.
[0072] Example 1
[0073] (1) Preparation of titanium-based lithium ion sieve intermediates by hydrothermal method
[0074] 1.5 g of F127 and 0.9 g of hexadecylamine were added sequentially to 100 mL of anhydrous ethanol and stirred at room temperature for 1 h. Then, 15 mL of lithium hydroxide solution (2.4 mol / L) and 6 mL of tetrabutyl titanate were added and stirred for 1 h, followed by aging for 12 h. The aged mixture was centrifuged, washed, and dried. 2 g of the dried product was taken and added to 30 mL of distilled water and 30 mL of anhydrous ethanol, mixed, and sonicated for 30 min. 15 mL of glycerol was added dropwise and stirred for 10 min. The mixture was then reacted in a high-pressure reactor at 160 °C for 24 h to obtain a titanium-based lithium ion sieve intermediate.
[0075] (2) Preparation of titanium-based lithium-ion sieve precursor by calcination method
[0076] The obtained titanium-based lithium ion sieve intermediate was washed, dried, and then calcined at 500°C for 4 h in air at a heating rate of 5°C / min.
[0077] (3) Preparation of titanium-based lithium ion sieves by acid washing
[0078] The titanium-based lithium ion sieve precursor was leached with 0.2 mol / L hydrochloric acid to extract lithium ions. After leaching, the precursor was washed with water to obtain a titanium-based lithium ion sieve adsorbent material with high adsorption capacity.
[0079] (4) Adsorption reaction conditions and adsorption amount
[0080] like Figure 3 As shown in Table 2, lithium ion and other metal ion content were tested using ICP. 0.5 g of titanium-based lithium ion sieve was added to 500 mL of lithium hydroxide solution for adsorption for 12 h. At different time points, the supernatant was collected, centrifuged, filtered, and subjected to ICP to measure the lithium concentration in the solution. The adsorption conditions were: initial lithium hydroxide concentration of 200 mg / L, temperature of 35℃, pH of 12, rotation speed of 150 rpm, and the equilibrium adsorption capacity of the adsorbent material exceeded 43 mg / g after 6 h.
[0081] (5) Adsorption selectivity reaction conditions and adsorption capacity
[0082] As shown in Table 3, lithium ion or other metal ion content was tested using ICP. 0.5 g of titanium-based lithium ion sieve was added to 500 mL of solution containing Li... + N + K + Mg 2+ The metal ions in the simulated brine were adsorbed for 12 h. The supernatant was then centrifuged, filtered, and subjected to ICP-measured concentrations. The adsorption conditions were: Li + N + K + Mg 2+ The initial concentrations were all 200 mg / L, the temperature was 35℃, the pH was 10, and the rotation speed was 150 rpm. The adsorbent material exhibited good performance on Li... + Its selective adsorption capacity exceeds 33 mg / g.
[0083] Figure 1 The XRD pattern of the titanium-based lithium-ion sieve precursor Li₂TiO₃ prepared in Example 1 is shown below. Figure 1 It can be seen that the titanium-based lithium ion sieve precursor prepared in Example 1 has a relatively pure composition.
[0084] Figure 2 Here is a SEM image of the titanium-based lithium-ion sieve prepared in Example 1. Figure 2 It is known that in the titanium-based lithium-ion sieve synthesized in this invention, individual aggregates are composed of nanoscale particles with relatively uniform particle morphology; gaps exist between the small particles, and the remaining pores can serve as Li + Diffusion channel.
[0085] Example 2
[0086] (1) Preparation of titanium-based lithium ion sieve intermediates by hydrothermal method
[0087] 1.5 g of F127 and 0.9 g of hexadecylamine were added sequentially to 100 mL of anhydrous ethanol and stirred at room temperature for 1 h. Then, 15 mL of lithium hydroxide solution (2.4 mol / L) and 6 mL of tetrabutyl titanate were added and stirred for 1 h, followed by aging for 12 h. The aged mixture was centrifuged, washed, and dried. 2 g of the dried product was taken and added to 30 mL of distilled water and 30 mL of anhydrous ethanol, mixed, and sonicated for 30 min. 5 mL of glycerol was added dropwise and stirred for 10 min. The mixture was then reacted in a high-pressure reactor at 160 °C for 24 h to obtain a titanium-based lithium ion sieve intermediate.
[0088] (2) Preparation of titanium-based lithium-ion sieve precursor by calcination method
[0089] The obtained titanium-based lithium ion sieve intermediate was washed, dried, and then calcined at 500°C for 4 hours in air at a heating rate of 5°C / min.
[0090] (3) Preparation of titanium-based lithium ion sieves by acid washing
[0091] The titanium-based lithium ion sieve precursor was leached with 0.2 mol / L hydrochloric acid to extract lithium ions. After leaching, the precursor was washed with water to obtain a titanium-based lithium ion sieve adsorbent material with high adsorption capacity.
[0092] (4) Adsorption reaction conditions and adsorption amount
[0093] like Figure 3 As shown, lithium ion or other metal ion content was measured using ICP. 0.5 g of a titanium-based lithium ion sieve was added to 500 mL of lithium hydroxide solution for adsorption for 12 h. At different time points, the supernatant was collected, centrifuged, filtered, and subjected to ICP measurement to determine the lithium concentration in the solution. The adsorption conditions were: initial lithium hydroxide concentration of 200 mg / L, temperature of 35℃, pH of 12, rotation speed of 150 rpm, and the equilibrium adsorption capacity of the adsorbent material exceeded 32 mg / g after 9 h.
[0094] (5) Adsorption selectivity reaction conditions and adsorption capacity
[0095] As shown in Tables 3 and 2, lithium ion or other metal ion content was tested using ICP. 0.5 g of a titanium-based lithium ion sieve was added to 500 mL of a solution containing Li... + N + K + Mg 2+ The metal ions in the simulated brine were adsorbed for 9 hours. The supernatant was then centrifuged, filtered, and subjected to ICP-measured concentrations. The adsorption conditions were: Li + N + K + Mg 2+ The initial concentrations were all 200 mg / L, the temperature was 35℃, the pH was 10, and the rotation speed was 150 rpm. The adsorbent material exhibited good performance on Li... + Its selective adsorption capacity exceeds 19 mg / g.
[0096] Example 3
[0097] (1) Preparation of titanium-based lithium ion sieve intermediates by hydrothermal method
[0098] 1.5 g of F127 and 0.9 g of hexadecylamine were added sequentially to 100 mL of anhydrous ethanol and stirred at room temperature for 1 h. Then, 15 mL of lithium hydroxide solution (2.4 mol / L) and 6 mL of tetrabutyl titanate were added and stirred for 1 h, followed by aging for 12 h. The aged mixture was centrifuged, washed, and dried. 2 g of the dried product was taken and added to 30 mL of distilled water and 30 mL of anhydrous ethanol, mixed, and sonicated for 30 min. 10 mL of glycerol was added dropwise and stirred for 10 min. The mixture was then reacted in a high-pressure reactor at 160 °C for 24 h to obtain a titanium-based lithium ion sieve intermediate.
[0099] (2) Preparation of titanium-based lithium-ion sieve precursor by calcination method
[0100] The obtained titanium-based lithium ion sieve intermediate was washed, dried, and then calcined at 500°C for 4 hours in air at a heating rate of 5°C / min.
[0101] (3) Preparation of titanium-based lithium ion sieves by acid washing
[0102] The titanium-based lithium ion sieve precursor was leached with 0.2 mol / L hydrochloric acid to extract lithium ions. After leaching, the precursor was washed with water to obtain a titanium-based lithium ion sieve adsorbent material with high adsorption capacity.
[0103] (4) Adsorption reaction conditions and adsorption amount
[0104] like Figure 3 As shown, lithium ion or other metal ion content was measured using ICP. 0.5 g of a titanium-based lithium ion sieve was added to 500 mL of lithium hydroxide solution for adsorption for 12 h. At different time points, the supernatant was collected, centrifuged, filtered, and subjected to ICP measurement to determine the lithium concentration in the solution. The adsorption conditions were: initial lithium hydroxide concentration of 200 mg / L, temperature of 35℃, pH of 12, rotation speed of 150 rpm, and the equilibrium adsorption capacity of the adsorbent material exceeded 34 mg / g after 8 h.
[0105] (5) Adsorption selectivity reaction conditions and adsorption capacity
[0106] As shown in Tables 3 and 2, lithium ion or other metal ion content was tested using ICP. 0.5 g of a titanium-based lithium ion sieve was added to 500 mL of a solution containing Li... + N + K + Mg 2+ The metal ions in the simulated brine were adsorbed for 9 hours. The supernatant was then centrifuged, filtered, and subjected to ICP-measured concentrations. The adsorption conditions were: Li + N + K + Mg 2+The initial concentrations were all 200 mg / L, the temperature was 35℃, the pH was 10, and the rotation speed was 150 rpm. The adsorbent material exhibited good performance on Li... + Its selective adsorption capacity exceeds 21 mg / g.
[0107] Example 4
[0108] (1) Preparation of titanium-based lithium ion sieve intermediates by hydrothermal method
[0109] 1.5 g of F127 and 0.9 g of hexadecylamine were added sequentially to 100 mL of anhydrous ethanol and stirred at room temperature for 1 h. Then, 15 mL of lithium hydroxide solution (2.4 mol / L) and 6 mL of tetrabutyl titanate were added and stirred for 1 h, followed by aging for 12 h. The aged mixture was centrifuged, washed, and dried. 2 g of the dried product was taken and added to 30 mL of distilled water and 30 mL of anhydrous ethanol, mixed, and sonicated for 30 min. 20 mL of glycerol was added dropwise and stirred for 10 min. The mixture was then reacted in a high-pressure reactor at 160 °C for 24 h to obtain a titanium-based lithium ion sieve intermediate.
[0110] (2) Preparation of titanium-based lithium-ion sieve precursor by calcination method
[0111] The obtained titanium-based lithium ion sieve intermediate was washed, dried, and then calcined at 500°C for 4 hours in air at a heating rate of 5°C / min.
[0112] (3) Preparation of titanium-based lithium ion sieves by acid washing
[0113] The titanium-based lithium ion sieve precursor was leached with 0.2 mol / L hydrochloric acid to extract lithium ions. After leaching, the precursor was washed with water to obtain a titanium-based lithium ion sieve adsorbent material with high adsorption capacity.
[0114] (4) Adsorption reaction conditions and adsorption amount
[0115] like Figure 3 As shown, lithium ion or other metal ion content was measured using ICP. 0.5 g of a titanium-based lithium ion sieve was added to 500 mL of lithium hydroxide solution for adsorption for 12 h. At different time points, the supernatant was collected, centrifuged, filtered, and subjected to ICP measurement to determine the lithium concentration in the solution. The adsorption conditions were: initial lithium hydroxide concentration of 200 mg / L, temperature of 35℃, pH of 12, rotation speed of 150 rpm, and the equilibrium adsorption capacity of the adsorbent material exceeded 38 mg / g after 8 h.
[0116] (5) Adsorption selectivity reaction conditions and adsorption capacity
[0117] As shown in Tables 3 and 2, lithium ion or other metal ion content was tested using ICP. 0.5 g of a titanium-based lithium ion sieve was added to 500 mL of a solution containing Li... +N + K + Mg 2+ The metal ions in the simulated brine were adsorbed for 9 hours. The supernatant was then centrifuged, filtered, and subjected to ICP-measured concentrations. The adsorption conditions were: Li + N + K + Mg 2+ The initial concentrations were all 200 mg / L, the temperature was 35℃, the pH was 10, and the rotation speed was 150 rpm. The adsorbent material exhibited good performance on Li... + Its selective adsorption capacity exceeds 26 mg / g.
[0118] Example 5
[0119] (1) Preparation of titanium-based lithium ion sieve intermediates by hydrothermal method
[0120] 1.5 g of F127 and 0.9 g of hexadecylamine were added sequentially to 100 mL of anhydrous ethanol and stirred at room temperature for 1 h. Then, 15 mL of lithium hydroxide solution (2.4 mol / L) and 6 mL of tetrabutyl titanate were added and stirred for 1 h, followed by aging for 12 h. The aged mixture was centrifuged, washed, and dried. 2 g of the dried product was taken and added to 30 mL of distilled water and 30 mL of anhydrous ethanol, mixed, and sonicated for 30 min. 25 mL of glycerol was added dropwise and stirred for 10 min. The mixture was then reacted in a high-pressure reactor at 160 °C for 24 h to obtain a titanium-based lithium ion sieve intermediate.
[0121] (2) Preparation of titanium-based lithium-ion sieve precursor by calcination method
[0122] The obtained titanium-based lithium ion sieve intermediate was washed, dried, and then calcined at 500°C for 4 hours in air at a heating rate of 5°C / min.
[0123] (3) Preparation of titanium-based lithium ion sieves by acid washing
[0124] The titanium-based lithium ion sieve precursor was leached with 0.2 mol / L hydrochloric acid to extract lithium ions. After leaching, the precursor was washed with water to obtain a titanium-based lithium ion sieve adsorbent material with high adsorption capacity.
[0125] (4) Adsorption reaction conditions and adsorption amount
[0126] like Figure 3As shown in Table 2, lithium ion and other metal ion content were tested using ICP. 0.5 g of titanium-based lithium ion sieve was added to 500 mL of lithium hydroxide solution for adsorption for 12 h. At different time points, the supernatant was collected, centrifuged, filtered, and subjected to ICP to measure the lithium concentration in the solution. The adsorption conditions were: initial lithium hydroxide concentration of 200 mg / L, temperature of 35℃, pH of 12, rotation speed of 150 rpm, and the equilibrium adsorption capacity of the adsorbent material exceeded 36 mg / g after 8 h.
[0127] (5) Adsorption selectivity reaction conditions and adsorption capacity
[0128] As shown in Table 3, lithium ion or other metal ion content was tested using ICP. 0.5 g of titanium-based lithium ion sieve was added to 500 mL of solution containing Li... + N + K + Mg 2+ The metal ions in the simulated brine were adsorbed for 12 h. The supernatant was then centrifuged, filtered, and subjected to ICP-measured concentrations. The adsorption conditions were: Li + N + K + Mg 2+ The initial concentrations were all 200 mg / L, the temperature was 35℃, the pH was 10, and the rotation speed was 150 rpm. The adsorbent material exhibited good performance on Li... + Its selective adsorption capacity exceeds 23 mg / g.
[0129] Example 6
[0130] (1) Preparation of titanium-based lithium ion sieve intermediates by hydrothermal method
[0131] 1.5 g of F127 and 0.9 g of hexadecylamine were added sequentially to 100 mL of anhydrous ethanol and stirred at room temperature for 1 h. Then, 15 mL of lithium hydroxide solution (2.4 mol / L) and 6 mL of tetrabutyl titanate were added and stirred for 1 h, followed by aging for 12 h. The aged mixture was centrifuged, washed, and dried. 2 g of the dried product was taken and added to 30 mL of distilled water and 30 mL of anhydrous ethanol, mixed, and sonicated for 30 min. 30 mL of glycerol was added dropwise and stirred for 10 min. The mixture was then reacted in a high-pressure reactor at 160 °C for 24 h to obtain a titanium-based lithium ion sieve intermediate.
[0132] (2) Preparation of titanium-based lithium-ion sieve precursor by calcination method
[0133] The obtained titanium-based lithium ion sieve intermediate was washed, dried, and then calcined at 500°C for 4 hours in air at a heating rate of 5°C / min.
[0134] (3) Preparation of titanium-based lithium ion sieves by acid washing
[0135] The titanium-based lithium ion sieve precursor was leached with 0.2 mol / L hydrochloric acid to extract lithium ions. After leaching, the precursor was washed with water to obtain a titanium-based lithium ion sieve adsorbent material with high adsorption capacity.
[0136] (4) Adsorption reaction conditions and adsorption amount
[0137] like Figure 3 As shown, lithium ion or other metal ion content was measured using ICP. 0.5 g of a titanium-based lithium ion sieve was added to 500 mL of lithium hydroxide solution for adsorption for 12 h. At different time points, the supernatant was collected, centrifuged, filtered, and subjected to ICP measurement to determine the lithium concentration in the solution. The adsorption conditions were: initial lithium hydroxide concentration of 200 mg / L, temperature of 35℃, pH of 12, rotation speed of 150 rpm, and the equilibrium adsorption capacity of the adsorbent material exceeded 30 mg / g after 13 h.
[0138] (5) Adsorption selectivity reaction conditions and adsorption capacity
[0139] As shown in Tables 3 and 2, lithium ion or other metal ion content was tested using ICP. 0.5 g of a titanium-based lithium ion sieve was added to 500 mL of a solution containing Li... + N + K + Mg 2+ The metal ions in the simulated brine were adsorbed for 9 hours. The supernatant was then centrifuged, filtered, and subjected to ICP-measured concentrations. The adsorption conditions were: Li + N + K + Mg 2+ The initial concentrations were all 200 mg / L, the temperature was 35℃, the pH was 10, and the rotation speed was 150 rpm. The adsorbent material exhibited good performance on Li... + Its selective adsorption capacity exceeds 16 mg / g.
[0140] Example 7
[0141] (1) Preparation of titanium-based lithium ion sieve intermediates by hydrothermal method
[0142] 1.5 g of F127 and 0.9 g of hexadecylamine were added sequentially to 100 mL of anhydrous ethanol and stirred at room temperature for 1 h. Then, 15 mL of lithium nitrate solution (2.4 mol / L) and 6 mL of tetrabutyl titanate were added and stirred for 1 h, followed by aging for 12 h. The aged mixture was centrifuged, washed, and dried. 2 g of the dried product was taken and added to 30 mL of distilled water and 30 mL of anhydrous ethanol, mixed, and sonicated for 30 min. 15 mL of glycerol was added dropwise and stirred for 10 min. The mixture was then reacted in a high-pressure reactor at 160 °C for 24 h to obtain a titanium-based lithium ion sieve intermediate.
[0143] (2) Preparation of titanium-based lithium-ion sieve precursor by calcination method
[0144] The obtained titanium-based lithium ion sieve intermediate was washed, dried, and then calcined at 500°C for 4 hours in air at a heating rate of 5°C / min.
[0145] (3) Preparation of titanium-based lithium ion sieves by acid washing
[0146] The titanium-based lithium ion sieve precursor was leached with 0.2 mol / L hydrochloric acid to extract lithium ions. After leaching, the precursor was washed with water to obtain a titanium-based lithium ion sieve adsorbent material with high adsorption capacity.
[0147] (4) Adsorption reaction conditions and adsorption amount
[0148] like Figure 3 As shown in Table 2, lithium ion and other metal ion content were tested using ICP. 0.5 g of titanium-based lithium ion sieve was added to 500 mL of lithium hydroxide solution for adsorption for 12 h. At different time points, the supernatant was collected, centrifuged, filtered, and subjected to ICP to measure the lithium concentration in the solution. The adsorption conditions were: initial lithium hydroxide concentration of 200 mg / L, temperature of 35℃, pH of 12, rotation speed of 150 rpm, and the equilibrium adsorption capacity of the adsorbent material exceeded 37 mg / g after 10 h.
[0149] (5) Adsorption selectivity reaction conditions and adsorption capacity
[0150] As shown in Table 3, lithium ion or other metal ion content was tested using ICP. 0.5 g of titanium-based lithium ion sieve was added to 500 mL of solution containing Li... + N + K + Mg 2+ The metal ions in the simulated brine were adsorbed for 12 h. The supernatant was then centrifuged, filtered, and subjected to ICP-measured concentrations. The adsorption conditions were: Li + N + K + Mg 2+ The initial concentrations were all 200 mg / L, the temperature was 35℃, the pH was 10, and the rotation speed was 150 rpm. The adsorbent material exhibited good performance on Li... + Its selective adsorption capacity exceeds 25 mg / g.
[0151] Example 8
[0152] (1) Preparation of titanium-based lithium ion sieve intermediates by hydrothermal method
[0153] 1.5 g of F127 and 0.9 g of hexadecylamine were added sequentially to 100 mL of anhydrous ethanol and stirred at room temperature for 1 h. Then, 15 mL of lithium hydroxide solution (2.4 mol / L) and 7 mL of tetrabutyl titanate were added and stirred for 1 h, followed by aging for 12 h. The aged mixture was centrifuged, washed, and dried. 2 g of the dried product was taken and added to 30 mL of distilled water and 30 mL of anhydrous ethanol, mixed, and sonicated for 30 min. 15 mL of glycerol was added dropwise and stirred for 10 min. The mixture was then reacted in a high-pressure reactor at 200 °C for 24 h to obtain a titanium-based lithium ion sieve intermediate.
[0154] (2) Preparation of titanium-based lithium-ion sieve precursor by calcination method
[0155] The obtained titanium-based lithium ion sieve intermediate was washed, dried, and then calcined at 500°C for 4 hours in air at a heating rate of 5°C / min.
[0156] (3) Preparation of titanium-based lithium ion sieves by acid washing
[0157] The titanium-based lithium ion sieve precursor was leached with 0.2 mol / L hydrochloric acid to extract lithium ions. After leaching, the precursor was washed with water to obtain a titanium-based lithium ion sieve adsorbent material with high adsorption capacity.
[0158] (4) Adsorption reaction conditions and adsorption amount
[0159] like Figure 3 As shown, lithium ion or other metal ion content was measured using ICP. 0.5 g of a titanium-based lithium ion sieve was added to 500 mL of lithium hydroxide solution for adsorption for 12 h. At different time points, the supernatant was collected, centrifuged, filtered, and subjected to ICP measurement to determine the lithium concentration in the solution. The adsorption conditions were: initial lithium hydroxide concentration of 200 mg / L, temperature of 35℃, pH of 12, rotation speed of 150 rpm, and the equilibrium adsorption capacity of the adsorbent material exceeding 35 mg / g after 10 h.
[0160] (5) Adsorption selectivity reaction conditions and adsorption capacity
[0161] As shown in Table 3, lithium ion or other metal ion content was tested using ICP. 0.5 g of titanium-based lithium ion sieve was added to 500 mL of solution containing Li... + N + K + Mg 2+ The metal ions in the simulated brine were adsorbed for 12 h. The supernatant was then centrifuged, filtered, and subjected to ICP-measured concentrations. The adsorption conditions were: Li + N + K + Mg 2+The initial concentrations were all 200 mg / L, the temperature was 35℃, the pH was 10, and the rotation speed was 150 rpm. The adsorbent material exhibited good performance on Li... + Its selective adsorption capacity exceeds 21 mg / g.
[0162] Comparative Example 1
[0163] (1) Preparation of titanium-based lithium ion sieve intermediates by hydrothermal method
[0164] 1.5 g of F127 and 0.9 g of hexadecylamine were added sequentially to 100 mL of anhydrous ethanol and stirred at room temperature for 1 h. Then, 15 mL of lithium hydroxide solution (2.4 mol / L) and 6 mL of tetrabutyl titanate were added and stirred for 1 h, followed by aging for 12 h. The aged mixture was centrifuged, washed, and dried. 2 g of the dried product was taken and mixed with 30 mL of distilled water and 30 mL of anhydrous ethanol, and sonicated for 30 min. The mixture was then reacted in a high-pressure reactor at 160 °C for 24 h to obtain a titanium-based lithium ion sieve intermediate.
[0165] (2) Preparation of titanium-based lithium-ion sieve precursor by calcination method
[0166] The obtained titanium-based lithium ion sieve intermediate was washed, dried, and then calcined at 500°C for 4 hours in air at a heating rate of 5°C / min.
[0167] (3) Preparation of titanium-based lithium ion sieves by acid washing
[0168] The titanium-based lithium ion sieve precursor was leached with 0.2 mol / L hydrochloric acid to extract lithium ions. After leaching, the precursor was washed with water to obtain a titanium-based lithium ion sieve adsorbent material with high adsorption capacity.
[0169] (4) Adsorption reaction conditions and adsorption amount
[0170] like Figure 3 As shown, lithium ion or other metal ion content was measured using ICP. 0.5 g of a titanium-based lithium ion sieve was added to 500 mL of lithium hydroxide solution for adsorption for 12 h. At different time points, the supernatant was collected, centrifuged, filtered, and subjected to ICP measurement to determine the lithium concentration in the solution. The adsorption conditions were: initial lithium hydroxide concentration of 200 mg / L, temperature of 35℃, pH of 12, and rotation speed of 150 rpm. The equilibrium adsorption capacity of the adsorbent material exceeded 31 mg / g after 12 h.
[0171] (5) Adsorption selectivity reaction conditions and adsorption capacity
[0172] As shown in Table 3, lithium ion or other metal ion content was tested using ICP. 0.5 g of titanium-based lithium ion sieve was added to 500 mL of solution containing Li... + N + K+ Mg 2+ The metal ions in the simulated brine were adsorbed for 12 h. The supernatant was then centrifuged, filtered, and subjected to ICP-measured concentrations. The adsorption conditions were: Li + N + K + Mg 2+ The initial concentrations were all 200 mg / L, the temperature was 35℃, the pH was 10, and the rotation speed was 150 rpm. The adsorbent material exhibited good performance on Li... + Its selective adsorption capacity exceeds 18 mg / g.
[0173] (6) Comparison effect
[0174] Compared with Example 1, it can be seen that without the addition of glycerol, the adsorption capacity and the adsorption of Li + The adsorption selectivity decreased significantly, the adsorption equilibrium time increased significantly, and the cycle stability weakened.
[0175] Table 1. Comparison of specific surface area, pore structure, and contact angle between the embodiments and comparative examples.
[0176]
[0177] Table 2 Comparison of adsorption equilibrium time and adsorption capacity between the examples and comparative examples
[0178]
[0179] Table 3. Comparison of adsorption selectivity between the examples and comparative examples.
[0180]
[0181] This patent further describes the effect of glycerol addition on the equilibrium adsorption capacity of lithium-ion sieves, and establishes a function. Characterizing the lithium-ion sieve for Li under given adsorption test conditions + The equilibrium adsorption capacity (mg / g) and the amount of glycerol added The relationship between the two is as follows. The model derivation process of this invention is as follows: First, the equilibrium adsorption capacity is decomposed into a background adsorption term and a glycerol-induced structure gain term:
[0182]
[0183] In the formula, This refers to the amount of glycerol added, defined as the amount of glycerol used per unit of dry solid (mL / g). It is the equilibrium adsorption capacity (mg / g). This is the background adsorption term, representing the intrinsic adsorption contribution determined by the material's intrinsic crystalline framework and chemical composition, and not modifiable by glycerol. It reflects the background adsorption level of the material system under given evaluation conditions, and is distinct from the pore structure and wettability modulation effects caused by glycerol. Within a certain dosage range, glycerol, as a pore structure modulator, can be approximated by a first-order approximation to the potential newly accessible sites. Proportional; on the other hand, when When excessive, pore connectivity may decrease, the probability of local blockage may increase, wettability may decline, and diffusion resistance may rise, leading to a decrease in the site reachability score; the reachability score is denoted as... And it is described using an exponential decay form: Then, multiply the potential new terms by the reachability score to obtain the shape function of the effective gain: .
[0184] Further normalize the above unimodal function to make it in When the time is 1, then let Directly corresponds to the peak gain amplitude. Because when From time to time Therefore, a normalized shape function is constructed: .
[0185] The final model is then written as:
[0186] in , and These are the parameters to be fitted.
[0187] Based on the adsorption coefficients of lithium-ion sieves obtained under different glycerol addition amounts in Examples 1-6, 5 sets of data were randomly selected as the fitting dataset, and the remaining set was used as the validation dataset. In the fitting dataset, 4 data points were selected for fitting each time using the leave-one-out method, and the remaining data was used to calculate the prediction result. The average value of the fitting parameters was then calculated based on the prediction result. Finally, the error on the validation data was calculated, and the results are as follows:
[0188] Table 4 Model Parameters
[0189]
[0190] Table 5. Fitting Results of Training Data
[0191]
[0192] Table 6. Validation data fit results
[0193]
[0194] The model obtained relatively stable parameter estimates through 4-fold cross-validation. The correlation coefficient of the training set was 0.893, indicating a good fit. The relative error of the validation set was 15.77%, indicating that the model also has a certain predictive ability on unseen data. However, the predicted values were low and the residuals were large at low glycerol addition (5.0 mL), which may be a limitation of the model under boundary conditions.
Claims
1. A method of preparing a titanium-based lithium ion-sieve adsorbent material, characterized by, The preparation method comprises the following steps: (1) mixing and aging a lithium source, a titanium source and a double surfactant in a solvent to obtain an aging system; (2) performing solid-liquid separation, washing and drying on the aging system to obtain a solid; (3) dispersing the solid in a mixed solvent of water and alcohol, adding glycerol and performing hydrothermal reaction to obtain a titanium-based lithium ion sieve intermediate; (4) calcining the intermediate to obtain a titanium-based lithium ion sieve precursor; (5) eluting the precursor with an eluent to leach out lithium ions, and then washing with water to obtain a titanium-based lithium ion sieve adsorbent.
2. The method of claim 1, wherein: The lithium source is at least one of lithium hydroxide, lithium chloride, lithium nitrate and lithium acetate; The molar ratio of Li / Ti is 2:(1-1.2); The double surfactant is a mixture of any two of F127, hexadecylamine and cetyltrimethylammonium bromide.
3. The method of claim 1, wherein: When the lithium source is lithium hydroxide, the mass ratio of lithium hydroxide to double surfactant is 0.5-0.8:1; The aging time is 12-48 h.
4. The method of any one of claims 1-3, wherein: The mixed solvent of water and alcohol contains anhydrous ethanol; In step (3), the dispersion system is subjected to ultrasonic treatment before or after the addition of glycerol, and the ultrasonic treatment time is 10-60 min; In step (3), the amount of glycerol added is 5-30 mL based on 2 g of dry solid.
5. The method of claim 1, wherein: The hydrothermal reaction is performed at 100-200 ℃, and the hydrothermal reaction time is 12-24 h; The calcination is performed at 300-600 ℃, the calcination time is 3-5 h, the calcination heating rate is 3-8 ℃ / min, the calcination is performed in an air atmosphere, the eluent is any one of hydrochloric acid, nitric acid, acetic acid, citric acid and Na2S2O6, and the eluent concentration is 0.1-0.5 mol / L.
6. The method of claim 1, wherein: The titanium-based lithium ion sieve precursor is H2TiO3, and the titanium-based lithium ion sieve adsorbent is H2TiO3; in step (1), the titanium source is tetrabutyl titanate, and the solvent is an alcohol solvent; in step (3), the alcohol can be selected from any one of anhydrous ethanol, methanol and isopropanol.
7. The method of claim 1, wherein: The addition amount of glycerol is controlled by calculating the predicted value of the saturated adsorption capacity of the titanium-based lithium ion sieve adsorbent for lithium, and the predicted value is calculated by the following formula: ； wherein , and are parameters to be fitted, is the glycerol addition, is the equilibrium adsorption capacity.
8. A titanium-based lithium ion-sieve adsorbent material, characterized by: The preparation method is prepared by any one of claims 1-7.
9. The titanium-based lithium ion-sieve adsorbent material of claim 8, wherein: having a specific surface area of 72.83-262.27 m 2 / g, and a pore volume of 0.25-0.34 cm 3 / g, and a contact angle of 10.4-26.5°.
10. Use of a titanium-based lithium ion-sieve adsorbent material for the recovery of lithium ions from a salt lake brine or seawater, characterized in that: The titanium-based lithium ion sieve adsorbent is the titanium-based lithium ion sieve adsorbent of claim 9, and the selective adsorption capacity of the adsorbent for Li+ exceeds 23 mg / g.