Preparation process of titanium-based lithium extraction adsorbent

Abstract

The invention relates to a preparation process of a titanium-based lithium extraction adsorbent. The preparation process comprises the following steps: (1) preparing titanium-based lithium extraction adsorbent precursor powder; (2) dissolving an organic binder and an organic pore-foaming agent in an organic solvent, heating, stirring, completely dissolving, and adding a coupling agent to obtain a binder solution; (3) adding titanium lithium extraction adsorbent precursor powder into the binder solution; (4) additionally taking titanium-based lithium extraction adsorbent precursor powder, and adding alumina porous microspheres and an inorganic pore-foaming agent into the titanium-based lithium extraction adsorbent precursor powder; (5) adding the viscous slurry A obtained in the step (3) into the solid mixture obtained in the step (4) at a constant speed; and (6) carrying out vacuum drying, washing, filtering and drying to obtain the titanium-based lithium extraction adsorbent. According to the obtained titanium-based lithium extraction adsorbent, the lithium extraction adsorption capacity in salt lake brine within 24 h is larger than or equal to 14 g / L, the capacity retention rate after 10 times of circulation is larger than or equal to 99%, the desorption rate is larger than or equal to 99%, the titanium dissolution loss rate is smaller than or equal to 0.005%, the granulation step is simple, and controllability is high.

Description

Technical Field

[0001] This invention relates to a process for preparing lithium extraction materials, specifically a process for preparing a titanium-based lithium extraction adsorbent. Background Technology

[0002] Salt lake brines account for approximately 70% of global lithium reserves, making their efficient development of great significance. Adsorption methods have become the mainstream technology due to their high selectivity and environmental friendliness; however, the widely used aluminum-based adsorbents are unsuitable for the numerous weakly alkaline salt lakes in my country. Titanium-based lithium extraction adsorbents, with their unique selectivity for lithium ions, high adsorption capacity, and outstanding cycle stability, have shown great potential in the field of lithium extraction from salt lakes, providing an ideal technical path for the efficient development of such salt lake resources and attracting widespread attention from industry and research.

[0003] However, in the process of transitioning from powder laboratory materials to industrial applications, this type of adsorbent has long faced three major technical bottlenecks:

[0004] 1. The contradiction between molding and strength: Powdered lithium metatitanate precursors must be granulated before they can be used in fixed-bed adsorption columns. Traditional molding processes such as extrusion and spheroidization often require the addition of a large amount of inert binder, which leads to the coating of active sites and a significant decrease in adsorption capacity.

[0005] 2. Limitations of mass transfer kinetics: Dense binders and irregular pore structures severely hinder the diffusion of lithium ions inside adsorbent particles, resulting in slow adsorption rates, long adsorption-desorption cycles, and impacting overall production efficiency.

[0006] 3. Stability and Solubility Issues: In harsh acid-elution-alkaline adsorption systems and during cycling, the interfacial bonding between the binder and the active component is weak, easily leading to the solubility and loss of the active component (titanium). This not only reduces the lifespan of the adsorbent, but the precipitated titanium ions can also contaminate the lithium product solution.

[0007] Therefore, developing a method for preparing titanium-based lithium extraction adsorbents that can simultaneously achieve high adsorption performance, excellent mechanical strength, rapid adsorption kinetics, and good stability, while also making the process simple and easy to scale up industrially, has become a pressing technical challenge in this field. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to overcome the above-mentioned defects of the prior art and provide a preparation process for a titanium-based lithium extraction adsorbent with strong process controllability, stable product quality, and easy industrial production. The resulting titanium-based lithium extraction adsorbent has uniform particle size and high strength, acid and alkali resistance, low titanium solubility, fast adsorption speed, and high adsorption capacity.

[0009] The technical solution adopted by this invention to solve its technical problem is a preparation process of a titanium-based lithium extraction adsorbent, comprising the following steps:

[0010] (1) Preparation of titanium-based lithium extraction adsorbent precursor powder;

[0011] (2) Dissolve an appropriate amount of organic binder and organic porogen in an organic solvent, heat and stir until completely dissolved, add an appropriate amount of coupling agent, and ultrasonically vibrate while mechanically stirring to obtain a uniform binder solution.

[0012] (3) Add an appropriate amount of titanium-based lithium adsorbent precursor powder from step (1) to the binder solution obtained in step (2), and ultrasonically vibrate while mechanically stirring to obtain a uniformly mixed viscous slurry A.

[0013] The simultaneous ultrasonic oscillation and mechanical stirring in steps (2) and (3) can make the solution mix more evenly and less prone to separation.

[0014] (4) Take an appropriate amount of titanium-based lithium extraction adsorbent precursor powder from step (1), add an appropriate amount of alumina porous microspheres and inorganic pore-forming agent to the titanium-based lithium extraction adsorbent precursor powder, mix evenly to obtain solid mixture B.

[0015] (5) Place the solid mixture B obtained in step (4) into the reactor, turn on the high-speed stirring, and then add the viscous slurry A obtained in step (3) into the reactor at a uniform speed to obtain titanium-based lithium extraction adsorbent particles with alumina porous microspheres as carriers.

[0016] (6) The titanium-based lithium extraction adsorbent particles with alumina porous microspheres as carrier obtained in step (5) are vacuum dried to remove organic solvent, and then washed with hot water, filtered and dried to obtain the titanium-based lithium extraction adsorbent.

[0017] Preferably, in step (1), the particle size of the titanium-based lithium extraction adsorbent precursor powder is 1 to 15 μm.

[0018] Preferably, in step (1), titanium dioxide, lithium salt and additives are used as raw materials, and titanium-based lithium adsorbent precursor powder (Li2TiO3 powder) is prepared by ball milling, calcination and pulverization.

[0019] Preferably, in step (1), the preparation method of the titanium-based lithium extraction adsorbent precursor powder is the same as that in the patent application number CN202510910569.X entitled "A method for preparing a titanium-based lithium extraction adsorbent precursor".

[0020] Preferably, in step (2), the organic binder is a viscous polymer, such as at least one of acrylonitrile-butadiene-styrene (ABS), polyacrylonitrile (PAN), polyvinyl chloride (PVC), polyvinylidene fluoride (PVDF), phenolic resin (PF), epoxy resin (EP), and polyurethane (PU).

[0021] Preferably, in step (2), the organic porogen is an organic compound soluble in organic solvents and water, such as one or both of polyethylene glycol (PEG) and polyvinylpyrrolidone (PVP). After curing in the organic system, the organic porogen forms sites that can be removed by washing with water, thereby forming a controllable porous structure. The amount of the organic porogen is 0.4–10% (more preferably 0.5–3%) of the total weight of the organic binder.

[0022] Preferably, in step (2), the organic solvent is at least one of acetone, ethanol, dimethylformamide (DMF), dimethylacetamide (DMAc), N-methylpyrrolidone (NMP), and tetrahydrofuran (THF). The amount of the organic solvent used is 2 to 20 times the total weight of the organic binder.

[0023] Preferably, in step (2), the heating is to raise the temperature to 45-80°C.

[0024] Preferably, in step (2), the coupling agent is at least one of titanate coupling agent, aluminate coupling agent, and aluminum-titanium composite coupling agent. The amount of the coupling agent is 0.5% to 5% of the total weight of the organic binder.

[0025] Preferably, in step (3), the mass of the titanium-based lithium extraction adsorbent precursor powder is 1 to 20 times the total weight of the organic binder contained in the binder solution.

[0026] Preferably, in step (4), the mass of the titanium-based lithium extraction adsorbent precursor powder is 1 to 20 times the total weight of the organic binder contained in the binder solution in step (3).

[0027] Preferably, in step (4), the alumina porous microspheres have a particle size of 0.1–1 mm (more preferably 0.2–0.5 mm) and a bulk density of <1 g / mL. The mass of the alumina porous microspheres is 1–20% of the total mass of the titanium-based lithium extraction adsorbent precursor powder in steps (3) and (4). Studies have shown that too little alumina porous microspheres will result in low adsorbent strength, while too much will result in low adsorbent capacity. Selecting alumina porous microspheres with specific particle size and bulk density can ensure that the product capacity meets the standard.

[0028] Preferably, in step (4), the inorganic porogen is at least one of sodium chloride (NaCl), potassium chloride (KCl), sodium carbonate (Na2CO3), potassium carbonate (K2CO3), sodium bicarbonate (NaHCO3), ammonium bicarbonate (NH4HCO3), potassium nitrate (KNO3), and sodium sulfate (Na2SO4) (inorganic salt). The amount of the inorganic porogen is 0.2–10 wt% (more preferably 0.2–5 wt%) of the total mass of the titanium-based lithium extraction adsorbent precursor powder in steps (3) and (4). The porogen should be ground to a particle size d ≤ 30 μm. Studies have shown that too little inorganic porogen will result in a low adsorbent capacity, while too much will result in a low adsorbent particle strength.

[0029] Preferably, in step (5), the stirring speed of the high-speed mixer is 500–2000 rpm. Too high a stirring speed will rapidly form large balls, affecting product quality and yield.

[0030] Preferably, in step (5), the feeding rate of the viscous slurry A is related to the total amount of solid mixture B, and the feeding rate of the viscous slurry A is 30-100 ml / min·kg solid mixture B. Studies have shown that too fast a feeding rate will result in too much adhesive, leading to excessively large spheres; too slow a feeding rate will result in difficulty in forming spheres, resulting in spherical particles that are too small.

[0031] Preferably, in step (5), the particle size of the titanium-based lithium extraction adsorbent particles with alumina porous microspheres as the carrier is controlled to be 0.5–1.5 mm. Studies have shown that if the particle size of the titanium-based lithium extraction adsorbent particles with alumina porous microspheres as the carrier is too small, it is not conducive to industrial packing; if the particle size is too large, the specific surface area is small and the capacity is low.

[0032] Preferably, in step (6), the temperature of the vacuum drying is 50 to 120°C.

[0033] Preferably, in step (6), the organic solvent is recovered during the vacuum drying process and reused.

[0034] Preferably, in step (6), the temperature of the hot water used for washing is 40 to 80°C.

[0035] This invention uses porous alumina microspheres as a pre-formed high-strength carrier, leveraging the inherent high strength, high stability, and porous structure of alumina to provide the core framework for the entire adsorbent particle. By precisely controlling the stirring and feeding speeds, and utilizing shear and adhesion forces, uniform spherical particles are ultimately formed with porous alumina microspheres as the core and a Li₂TiO₃-containing active layer as the shell. This achieves uniform loading of the lithium titanate active component and the binder, ultimately forming core-shell structured composite adsorbent particles. The titanium-based lithium extraction adsorbent obtained by this invention exhibits a lithium extraction adsorption capacity ≥14 g / L in brine within 24 hours, a capacity retention rate ≥99% after 10 cycles, a desorption rate ≥99%, and a titanium dissolution rate ≤0.005%. The granulation process is simple and highly controllable.

[0036] This invention uses porous alumina microspheres as the core framework and titanium-based lithium extraction adsorbent precursor powder as the active shell. Through a pre-set high-strength framework and large-pore transport channels, the active components of the titanium-based lithium extraction adsorbent and the binder are mixed and coated simultaneously under high-speed stirring, so as to achieve uniform loading of the active components of the titanium-based lithium extraction adsorbent and the binder, and finally form core-shell structured composite adsorbent particles.

[0037] This invention preserves the inherent adsorption capacity of the active ingredient (Li2TiO3) to the maximum extent. Two porogens work synergistically to create pores: the organic porogen creates mesopores in the binder phase, while the inorganic porogen creates macropores in the active layer, together forming a hierarchical pore structure that ensures a high adsorption rate and mass transfer efficiency during lithium extraction.

[0038] Beneficial effects of this invention:

[0039] (1) By controlling the initial particle size and process parameters of alumina microspheres, spherical products with uniform particle size can be obtained, which is beneficial for filling the adsorption column and reducing pressure drop;

[0040] (2) The adsorbent has the outstanding advantages of high mechanical strength and low titanium dissolution rate, and at the same time has a well-developed multi-level pore structure, which makes the adsorption speed fast and the adsorption capacity large.

[0041] (3) The organic solvents involved in this process can be recycled, which is environmentally friendly and energy-saving;

[0042] (4) The synchronous coating molding process is simple, controllable, and efficient, which is conducive to large-scale industrial production. Attached Figure Description

[0043] Figure 1 This is a physical image of the titanium-based lithium extraction adsorbent obtained in Example 1 of the present invention;

[0044] Figure 2 This is the adsorption stage yield curve of the titanium-based lithium extraction adsorbent obtained in Example 1 of the present invention;

[0045] Figure 3This is the stage adsorption rate curve of the titanium-based lithium extraction adsorbent obtained in Example 1 of the present invention;

[0046] Figure 4 This is the cumulative adsorption capacity curve of the titanium-based lithium extraction adsorbent obtained in Example 1 of the present invention;

[0047] Figure 5 This is the lithium concentration curve of the adsorption liquid of the titanium-based lithium extraction adsorbent obtained in Example 1 of the present invention. Detailed Implementation

[0048] The present invention will be further described below with reference to embodiments, comparative examples and accompanying drawings.

[0049] The raw materials used in the embodiments and comparative examples of this invention were all obtained through conventional commercial means.

[0050] First, referring to patent CN120515395B (a method for preparing a titanium-based lithium extraction adsorbent precursor), 3000g of titanium-based lithium extraction adsorbent precursor Li2TiO3 powder was prepared using titanium oxide (rutile phase), lithium carbonate, ammonium bicarbonate, activated carbon, and hexadecyl dimethylamine as raw materials through ball milling, calcination, and pulverization processes. The particle size of the obtained titanium-based lithium extraction adsorbent precursor powder was 1-15μm. The adsorbent precursors used in subsequent embodiments and comparative examples of this invention were all products from this batch. The raw materials used in the adsorption experiments were all brine prepared according to the composition of Zabuye Salt Lake brine.

[0051] Porous alumina microspheres, bulk density <1g / mL; Manufacturer: Zibo Yinghe Chemical Co., Ltd.

[0052] The brine in each embodiment is weakly alkaline, and the desorption solution is an acidic solution; this verifies the acid and alkali resistance of the adsorbent obtained by the present invention.

[0053] Example 1

[0054] The preparation process of the titanium-based lithium extraction adsorbent in this embodiment includes the following steps:

[0055] (1) Titanium-based lithium extraction adsorbent precursor powder was prepared according to patent CN120515395B;

[0056] (2) Dissolve 14g acrylonitrile-butadiene-styrene (ABS), 20g polyacrylonitrile (PAN) and 0.5g polyvinylpyrrolidone (PVP) in 90g dimethylformamide (DMF), heat in a water bath at 50°C, stir until completely dissolved, add 1.0g aluminum-titanium composite coupling agent, and ultrasonically vibrate while mechanically stirring to obtain a uniform adhesive solution.

[0057] (3) Add 160g of titanium-based lithium adsorbent precursor powder from step (1) to the binder solution in step (2), and ultrasonically vibrate while mechanically stirring to obtain a uniformly mixed viscous slurry A.

[0058] (4) Take another 160g of the titanium-based lithium extraction adsorbent precursor powder from step (1), add 32g of alumina porous microspheres (particle size 0.2-0.5mm) and 3.2g of sodium carbonate (sodium carbonate ground to particle size d≤30μm), mix evenly to obtain solid mixture B;

[0059] (5) Place the solid mixture B obtained in step (4) into the reactor and turn on the high-speed stirring (stirring speed 1000 rpm). Then add the viscous slurry A obtained in step (3) into the reactor at a speed of 10 mL / min to obtain titanium-based lithium extraction adsorbent particles with alumina porous microspheres as carriers. The particle size of the titanium-based lithium extraction adsorbent particles with alumina porous microspheres as carriers is controlled to be 0.5-1.5 mm.

[0060] (6) The titanium-based lithium extraction adsorbent particles with alumina porous microspheres as carrier obtained in step (5) are vacuum dried (60°C) to remove organic solvents, then washed with hot water (50°C), filtered, and dried by blowing air to obtain the titanium-based lithium extraction adsorbent.

[0061] Performance verification test:

[0062] Activation test: 10 mL of the titanium-based lithium extraction adsorbent obtained in this example was packed into the adsorption column and hydrochloric acid solution (0.1 mol / L) was pumped in at a flow rate of 3 BV / h for 48 h at 50 °C.

[0063] Adsorption experiment: Using prepared brine as raw material, dynamic adsorption was carried out at a flow rate of 3 BV / h at room temperature. The brine contained 0.0572% lithium (brine composition is shown in Table 1, and the same applies to the following examples and comparative examples). Adsorption was stopped after 24 h, and the lithium adsorption capacity was obtained by detecting and analyzing the lithium concentration of the brine after adsorption. Subsequently, desorption was carried out using sufficient hydrochloric acid solution (0.1 mol / L) at 50℃ for 10 h. The lithium and titanium concentrations in the desorbate were detected and analyzed to obtain the lithium desorption capacity and titanium dissolution rate. This cycle was repeated 10 times to examine the adsorption capacity and stability of the adsorbent. The experimental data of the adsorption curve are shown in Table 2 and [Table data would be inserted here]. Figure 2 , 3 4, 5, and the remaining experimental results are shown in Table 3. Figure 1 This is a physical image of the titanium-based lithium extraction adsorbent obtained in Example 1 of the present invention; Figure 2 This is the adsorption stage yield curve of the titanium-based lithium extraction adsorbent obtained in Example 1 of the present invention; Figure 3 This is the stage adsorption rate curve of the titanium-based lithium extraction adsorbent obtained in Example 1 of the present invention; Figure 4This is the cumulative adsorption capacity curve of the titanium-based lithium extraction adsorbent obtained in Example 1 of the present invention; Figure 5 This is the lithium concentration curve of the adsorption liquid of the titanium-based lithium extraction adsorbent obtained in Example 1 of the present invention.

[0064] Example 2

[0065] The preparation process of the titanium-based lithium extraction adsorbent in this embodiment includes the following steps:

[0066] (1) Titanium-based lithium extraction adsorbent precursor powder was prepared according to patent CN120515395B;

[0067] (2) Dissolve 14g acrylonitrile-butadiene-styrene (ABS), 20g polyacrylonitrile (PAN) and 0.5g polyethylene glycol (PEG) in 90g dimethylformamide (DMF), heat in a water bath at 50°C, stir until completely dissolved, add 1.0g titanate coupling agent, and ultrasonically vibrate while mechanically stirring to obtain a uniform adhesive solution.

[0068] (3) Add 160g of titanium-based lithium adsorbent precursor powder from step (1) to the binder solution obtained in step (2), and ultrasonically vibrate while mechanically stirring to obtain a uniformly mixed viscous slurry A.

[0069] (4) Take another 160g of titanium-based lithium extraction adsorbent precursor powder from step (1), add 32g of alumina porous microspheres (particle size 0.2-0.5mm) and 3.2g of ground potassium carbonate (potassium carbonate ground to particle size d≤30μm) to the titanium-based lithium extraction adsorbent precursor powder, mix evenly to obtain solid mixture B;

[0070] (5) Place the solid mixture B obtained in step (4) into the reactor and turn on the high-speed stirring (stirring speed 1200 rpm). Then add the viscous slurry A obtained in step (3) into the reactor at a speed of 10 mL / min to obtain titanium-based lithium extraction adsorbent particles with alumina porous microspheres as carriers. The particle size of the titanium-based lithium extraction adsorbent particles with alumina porous microspheres as carriers is controlled to be 0.5-1.5 mm.

[0071] (5) The particles obtained in step (5) are vacuum dried (60°C) to remove the organic solvent, then washed with hot water (50°C), filtered, and dried by blowing air to obtain the titanium-based lithium extraction adsorbent.

[0072] Performance verification test:

[0073] Activation test: 10 mL of the titanium-based lithium extraction adsorbent obtained in this example was packed into the adsorption column and hydrochloric acid solution (0.1 mol / L) was pumped in at a flow rate of 3 BV / h for 48 h at 50 °C.

[0074] Adsorption experiment: Using the prepared brine as raw material, dynamic adsorption was carried out at a flow rate of 3 BV / h at room temperature. After 24 hours of adsorption, the adsorption was stopped. The lithium adsorption capacity was obtained by detecting and analyzing the lithium concentration in the brine after adsorption. Subsequently, desorption was carried out using a sufficient amount of hydrochloric acid solution (0.1 mol / L) at 50℃ for 8 hours. The lithium and titanium concentrations in the desorbate were detected and analyzed to obtain the lithium desorption capacity and titanium dissolution rate. This cycle was repeated 10 times to examine the adsorption capacity and stability of the adsorbent. The specific experimental results are shown in Table 3.

[0075] Example 3

[0076] The preparation process of the titanium-based lithium extraction adsorbent in this embodiment includes the following steps:

[0077] (1) Titanium-based lithium extraction adsorbent precursor powder was prepared according to patent CN120515395B;

[0078] (2) Dissolve 14g acrylonitrile-butadiene-styrene (ABS), 20g polyacrylonitrile (PAN) and 0.5g polyvinylpyrrolidone (PVP) in 90g dimethylformamide (DMF), heat in a water bath at 50°C, stir until completely dissolved, add 1.0g aluminate coupling agent, and ultrasonically vibrate while mechanically stirring to obtain a uniform adhesive solution.

[0079] (3) Add 160g of titanium-based lithium adsorbent precursor powder to the binder solution obtained in step (2), and ultrasonically vibrate while mechanically stirring to obtain a uniformly mixed viscous slurry A.

[0080] (4) Take another 160g of titanium-based lithium extraction adsorbent precursor powder, add 32g of alumina porous microspheres (particle size 0.2-0.5mm) and 3.2g of ground potassium carbonate (potassium carbonate ground to particle size d≤30μm), mix evenly to obtain solid mixture B;

[0081] (5) Place the solid mixture B obtained in step (4) into the reactor and turn on the high-speed stirring (stirring speed 1000 rpm). Then add the viscous slurry A obtained in step (3) into the reactor at a speed of 10 mL / min to obtain titanium-based lithium extraction adsorbent particles with alumina porous microspheres as carriers. The particle size of the titanium-based lithium extraction adsorbent particles with alumina porous microspheres as carriers is controlled to be 0.5-1.5 mm.

[0082] (6) The titanium-based lithium extraction adsorbent particles with alumina porous microspheres as carrier obtained in step (5) are vacuum dried (60°C) to remove organic solvents, then washed with hot water (50°C), filtered, and dried by blowing air to obtain the titanium-based lithium extraction adsorbent.

[0083] Performance verification test:

[0084] Activation test: 10 mL of the titanium-based lithium extraction adsorbent obtained in this example was packed into the adsorption column and hydrochloric acid solution (0.1 mol / L) was pumped in at a flow rate of 3 BV / h for 48 h at 50 °C.

[0085] Adsorption experiment: Using the prepared brine as raw material, dynamic adsorption was carried out at a flow rate of 3 BV / h at room temperature. After 24 hours of adsorption, the adsorption was stopped. The lithium adsorption capacity was obtained by detecting and analyzing the lithium concentration in the brine after adsorption. Subsequently, desorption was carried out using a sufficient amount of hydrochloric acid solution (0.1 mol / L) at 50℃ for 8 hours. The lithium and titanium concentrations in the desorbate were detected and analyzed to obtain the lithium desorption capacity and titanium dissolution rate. This cycle was repeated 10 times to examine the adsorption capacity and stability of the adsorbent. The specific experimental results are shown in Table 3.

[0086] Example 4

[0087] The preparation process of the titanium-based lithium extraction adsorbent in this embodiment includes the following steps:

[0088] (1) Titanium-based lithium extraction adsorbent precursor powder was prepared according to patent CN120515395B;

[0089] (2) Dissolve 14g of polyvinyl chloride (PVC), 20g of polyvinylidene fluoride (PVDF) and 0.5g of polyvinylpyrrolidone (PVP) in 90g of N-methylpyrrolidone, heat in a water bath at 50°C, stir until completely dissolved, add 1.0g of aluminate coupling agent, and ultrasonically vibrate while mechanically stirring to obtain a uniform adhesive solution.

[0090] (3) Add 160g of titanium-based lithium adsorbent precursor powder to the binder solution obtained in step (2), and ultrasonically vibrate while mechanically stirring to obtain a uniformly mixed viscous slurry A.

[0091] (4) Take another 160g of titanium-based lithium extraction adsorbent precursor powder, add 32g of alumina porous microspheres (particle size 0.2-0.5mm) and 3.2g of ground potassium carbonate (potassium carbonate ground to particle size d≤30μm), mix evenly to obtain solid mixture B;

[0092] (5) Place the solid mixture B obtained in step (4) into the reactor and turn on the high-speed stirring (stirring speed 1000 rpm). Then add the viscous slurry A obtained in step (3) into the reactor at a speed of 10 mL / min to obtain titanium-based lithium extraction adsorbent particles with alumina porous microspheres as carriers. The particle size of the titanium-based lithium extraction adsorbent particles with alumina porous microspheres as carriers is controlled to be 0.5-1.5 mm.

[0093] (6) The titanium-based lithium extraction adsorbent particles with alumina porous microspheres as carrier obtained in step (5) are vacuum dried (60°C) to remove organic solvents, then washed with hot water (50°C), filtered, and dried by blowing air to obtain the titanium-based lithium extraction adsorbent.

[0094] Performance verification test:

[0095] Activation test: 10 mL of the titanium-based lithium extraction adsorbent obtained in this example was packed into the adsorption column and hydrochloric acid solution (0.1 mol / L) was pumped in at a flow rate of 3 BV / h for 48 h at 50 °C.

[0096] Adsorption experiment: Using the prepared brine as raw material, dynamic adsorption was carried out at a flow rate of 3 BV / h at room temperature. After 24 hours of adsorption, the adsorption was stopped. The lithium adsorption capacity was obtained by detecting and analyzing the lithium concentration in the brine after adsorption. Subsequently, desorption was carried out using a sufficient amount of hydrochloric acid solution (0.1 mol / L) at 50℃ for 8 hours. The lithium and titanium concentrations in the desorbate were detected and analyzed to obtain the lithium desorption capacity and titanium dissolution rate. This cycle was repeated 10 times to examine the adsorption capacity and stability of the adsorbent. The specific experimental results are shown in Table 3.

[0097] Comparative Example 1 (no inorganic porogen added)

[0098] The preparation process of this comparative titanium-based lithium extraction adsorbent includes the following steps:

[0099] (1) Dissolve 14g acrylonitrile-butadiene-styrene (ABS), 20g polyacrylonitrile (PAN) and 0.5g polyvinylpyrrolidone (PVP) in 90g dimethylformamide (DMF), heat in a water bath at 50°C, stir until completely dissolved, add 1.0g aluminum-titanium composite coupling agent, and ultrasonically vibrate while mechanically stirring to obtain a uniform adhesive solution.

[0100] (2) Add 160g of titanium-based lithium adsorbent precursor powder to the binder solution in step (1), and ultrasonically vibrate while mechanically stirring to obtain a uniformly mixed viscous slurry A.

[0101] (3) In addition, 32g of porous alumina microspheres (particle size 0.2-0.5mm) were added to 160g of titanium-based lithium extraction adsorbent precursor powder and mixed evenly to obtain solid mixture B;

[0102] (4) Place solid mixture B in a reactor and turn on high-speed stirring (stirring speed 1000 rpm). Then add slurry A into the reactor at a speed of 10 mL / min to obtain titanium-based lithium extraction adsorbent particles with alumina porous microspheres as carriers. The particle size of the obtained titanium-based lithium extraction adsorbent particles with alumina porous microspheres as carriers is controlled to be 0.5-1.5 mm.

[0103] (5) The particles obtained in step (4) are vacuum dried (60°C) to remove the organic solvent, then washed and filtered with hot water (50°C), and dried by blowing air to obtain the titanium-based lithium extraction adsorbent.

[0104] Performance verification test:

[0105] Activation test: 10 mL of the titanium-based lithium extraction adsorbent obtained in this example was packed into the adsorption column and hydrochloric acid solution (0.1 mol / L) was pumped in at a flow rate of 3 BV / h for 48 h at 50 °C.

[0106] Adsorption experiment: Using the prepared brine as raw material, dynamic adsorption was carried out at a flow rate of 3 BV / h at room temperature. After 24 hours of adsorption, the adsorption was stopped. The lithium adsorption capacity was obtained by detecting and analyzing the lithium concentration in the brine after adsorption. Subsequently, desorption was carried out using a sufficient amount of hydrochloric acid solution (0.1 mol / L) at 50℃ for 8 hours. The lithium and titanium concentrations in the desorbate were detected and analyzed to obtain the lithium desorption capacity and titanium dissolution rate. This cycle was repeated 10 times to examine the adsorption capacity and stability of the adsorbent. The specific experimental results are shown in Table 3.

[0107] Comparative Example 2 (no organic or inorganic porogens added)

[0108] The preparation process of this comparative titanium-based lithium extraction adsorbent includes the following steps:

[0109] (1) Dissolve 14g acrylonitrile-butadiene-styrene (ABS) and 20g polyacrylonitrile (PAN) in 90g dimethylformamide (DMF), heat in a water bath at 50°C, stir until completely dissolved, add 1.0g aluminum-titanium composite coupling agent, and ultrasonically vibrate while mechanically stirring to obtain a uniform binder solution.

[0110] (2) Add 160g of titanium-based lithium adsorbent precursor powder to the binder solution in step (1), and ultrasonically vibrate while mechanically stirring to obtain a uniformly mixed viscous slurry A.

[0111] (3) In addition, 32g of porous alumina microspheres (particle size 0.2-0.5mm) were added to 160g of titanium-based lithium extraction adsorbent precursor powder and mixed evenly to obtain solid mixture B;

[0112] (4) Place solid mixture B in a reactor and turn on high-speed stirring (stirring speed 1000 rpm). Then add slurry A into the reactor at a speed of 10 mL / min to obtain titanium-based lithium extraction adsorbent particles with alumina porous microspheres as carriers. The particle size of the obtained titanium-based lithium extraction adsorbent particles with alumina porous microspheres as carriers is controlled to be 0.5-1.5 mm.

[0113] (5) The particles obtained in step (4) are vacuum dried (60°C) to remove the organic solvent, then washed and filtered with hot water (50°C), and dried by blowing air to obtain the titanium-based lithium extraction adsorbent.

[0114] Performance verification test:

[0115] Activation test: 10 mL of the titanium-based lithium extraction adsorbent obtained in this example was packed into the adsorption column and hydrochloric acid solution (0.1 mol / L) was pumped in at a flow rate of 3 BV / h for 48 h at 50 °C.

[0116] Adsorption experiment: Using the prepared brine as raw material, dynamic adsorption was carried out at a flow rate of 3 BV / h at room temperature. After 24 hours of adsorption, the adsorption was stopped. The lithium adsorption capacity was obtained by detecting and analyzing the lithium concentration in the brine after adsorption. Subsequently, desorption was carried out using a sufficient amount of hydrochloric acid solution (0.1 mol / L) at 50℃ for 8 hours. The lithium and titanium concentrations in the desorbate were detected and analyzed to obtain the lithium desorption capacity and titanium dissolution rate. This cycle was repeated 10 times to examine the adsorption capacity and stability of the adsorbent. The specific experimental results are shown in Table 3.

[0117] Comparative Example 3 (without coupling agent)

[0118] The preparation process of this comparative titanium-based lithium extraction adsorbent includes the following steps:

[0119] (1) Dissolve 14g acrylonitrile-butadiene-styrene (ABS), 20g polyacrylonitrile (PAN) and 0.5g polyvinylpyrrolidone (PVP) in 90g dimethylformamide (DMF), heat in a water bath at 50°C, stir until completely dissolved, and then sonicate to obtain a uniform adhesive solution.

[0120] (2) Add 160g of titanium-based lithium adsorbent precursor powder to the binder solution in step (1), and ultrasonically vibrate while mechanically stirring to obtain a uniformly mixed viscous slurry A.

[0121] (3) In addition, 32g of porous alumina microspheres (particle size 0.2-0.5mm) and 3.2g of ground sodium carbonate (sodium carbonate ground to particle size d≤30μm) were added to 160g of titanium-based lithium extraction adsorbent precursor powder, and the mixture was mixed evenly to obtain solid mixture B;

[0122] (4) Place solid mixture B in a reactor and turn on high-speed stirring (stirring speed 1000 rpm). Then add slurry A into the reactor at a speed of 10 mL / min to obtain titanium-based lithium extraction adsorbent particles with alumina porous microspheres as carriers. The particle size of the obtained titanium-based lithium extraction adsorbent particles with alumina porous microspheres as carriers is controlled to be 0.5-1.5 mm.

[0123] (5) The particles obtained in step (4) are vacuum dried (60°C) to remove the organic solvent, then washed and filtered with hot water (50°C), and dried by blowing air to obtain the titanium-based lithium extraction adsorbent.

[0124] Performance verification test:

[0125] Activation test: 10 mL of the titanium-based lithium extraction adsorbent obtained in this example was packed into the adsorption column and hydrochloric acid solution (0.1 mol / L) was pumped in at a flow rate of 3 BV / h for 48 h at 50 °C.

[0126] Adsorption experiment: Using prepared brine as raw material, dynamic adsorption was carried out at room temperature and a flow rate of 3 BV / h. The brine contained 0.0582% lithium. After 24 h of adsorption, the adsorption was stopped, and the lithium concentration in the brine after adsorption was detected and analyzed to obtain its lithium adsorption capacity. Subsequently, desorption was carried out with sufficient hydrochloric acid solution (0.1 mol / L) at 50℃ for 8 h. The lithium and titanium concentrations in the desorbate were detected and analyzed to obtain its lithium desorption capacity and titanium dissolution rate. This cycle was repeated 10 times to examine the adsorption capacity and stability of the adsorbent. The specific experimental results are shown in Table 3.

[0127] Comparative Example 4 (without added organic porogen)

[0128] The preparation process of this comparative titanium-based lithium extraction adsorbent includes the following steps:

[0129] (1) Dissolve 14g acrylonitrile-butadiene-styrene (ABS) and 20g polyacrylonitrile (PAN) in 90g dimethylformamide (DMF), heat in a water bath at 50°C, stir until completely dissolved, add 1.0g aluminum-titanium composite coupling agent, and ultrasonically vibrate while mechanically stirring to obtain a uniform binder solution.

[0130] (2) Add 160g of titanium-based lithium adsorbent precursor powder to the binder solution in step (1), and ultrasonically vibrate while mechanically stirring to obtain a uniformly mixed viscous slurry A.

[0131] (3) In addition, 32g of porous alumina microspheres (particle size 0.2-0.5mm) and 3.2g of ground potassium carbonate (ground to particle size d≤30μm) were added to 160g of titanium-based lithium extraction adsorbent precursor powder, and the mixture was mixed evenly to obtain solid mixture B;

[0132] (4) Place solid mixture B in a reactor and turn on high-speed stirring (stirring speed 1000 rpm). Then add slurry A into the reactor at a speed of 10 mL / min to obtain titanium-based lithium extraction adsorbent particles with alumina porous microspheres as carriers. The particle size of the obtained titanium-based lithium extraction adsorbent particles with alumina porous microspheres as carriers is controlled to be 0.5-1.5 mm.

[0133] (5) The particles obtained in step (4) are vacuum dried (60°C) to remove the organic solvent, then washed with hot water (50°C), filtered, and dried by blowing air to obtain the titanium-based lithium extraction adsorbent.

[0134] Performance verification test:

[0135] Activation test: 10 mL of the titanium-based lithium extraction adsorbent obtained in this example was packed into the adsorption column and hydrochloric acid solution (0.1 mol / L) was pumped in at a flow rate of 3 BV / h for 48 h at 50 °C.

[0136] Adsorption experiment: Using the prepared brine as raw material, dynamic adsorption was carried out at a flow rate of 3 BV / h at room temperature. After 24 hours of adsorption, the adsorption was stopped. The lithium adsorption capacity was obtained by detecting and analyzing the lithium concentration in the brine after adsorption. Subsequently, desorption was carried out using a sufficient amount of hydrochloric acid solution (0.1 mol / L) at 50℃ for 8 hours. The lithium and titanium concentrations in the desorbate were detected and analyzed to obtain the lithium desorption capacity and titanium dissolution rate. This cycle was repeated 10 times to examine the adsorption capacity and stability of the adsorbent. The specific experimental results are shown in Table 3.

[0137] Table 1. Composition of simulated Zabuye brine

[0138] Ionic composition <![CDATA[K + ]]> <![CDATA[Cl - ]]> <![CDATA[SO4 2- ]]> <![CDATA[Na + ]]> <![CDATA[Li + ]]> <![CDATA[B2O3]]> <![CDATA[CO3 2- ]]> <![CDATA[H2O]]> wt% 1.922 14.011 0.751 9.206 0.0572 0.495 1.468 72.090

[0139] Table 2 Adsorption curve data of adsorbent in Example 1

[0140] Volume (BV) Cumulative time (min) Stage quality (g) <![CDATA[Liquid-phase Li + (mg / kg)]]> Stage yield (%) Stage adsorption capacity (mg) Stage adsorption rate (mg / mL*min) Cumulative adsorption amount (mg) Cumulative adsorption capacity (g / L) 0 0 　0 0.00 　0 0 0.00 0.50 10 6.05 1 99.83 3.45 0.035 3.45 0.35 1.00 20 6.07 3 99.48 3.45 0.035 6.91 0.69 1.51 30 6.20 4 99.30 3.52 0.035 10.43 1.04 2.02 40 6.12 6 98.95 3.46 0.035 13.89 1.39 2.52 50 6.09 8 98.60 3.43 0.034 17.33 1.73 3.02 60 6.03 11 98.08 3.38 0.034 20.71 2.07 4.02 80 12.12 29 94.93 6.58 0.033 27.29 2.73 5.02 100 12.08 46 91.96 6.35 0.032 33.65 3.36 6.01 120 12.01 63 88.99 6.11 0.031 39.76 3.98 7.51 150 18.13 82 85.66 8.88 0.030 48.64 4.86 9.01 180 18.09 110 80.77 8.36 0.028 57.00 5.70 10.51 210 18.21 145 74.65 7.78 0.026 64.78 6.48 12.00 240 18.04 180 68.53 7.07 0.024 71.85 7.18 15.00 300 36.22 223 61.01 12.64 0.021 84.49 8.45 17.99 360 36.20 271 52.62 10.90 0.018 95.39 9.54 23.99 480 72.58 320 44.06 18.29 0.015 113.68 11.37 30.00 600 72.78 388 32.17 13.39 0.011 127.07 12.71 36.02 720 72.81 440 23.08 9.61 0.008 136.68 13.67 42.04 840 72.84 508 11.19 4.66 0.004 141.34 14.13 48.05 960 72.79 530 7.34 3.06 0.003 144.40 14.44 54.08 1080 72.95 551 3.67 1.53 0.001 145.93 14.59 60.10 1200 72.79 562 1.75 0.73 0.001 146.66 14.67 66.11 1320 72.74 570 0.35 0.15 0.000 146.80 14.68 72.13 1440 72.86 572 0.00 0.00 0.000 146.80 14.68

[0141] Table 3 Performance parameter test results for each embodiment and comparative example

[0142] Serial Number Mechanical strength N Particle size d (0.5~1.5mm) percentage % Initial lithium adsorption capacity (g / L) Adsorption capacity retention rate (%) after 10 cycles 10-time average resolution % Average titanium dissolution rate (%) after 10 cycles Example 1 12.8 98.2 14.68 99.45 99.68 0.0025 Example 2 13.4 98.1 14.49 99.57 99.52 0.0019 Example 3 12.3 98.5 14.62 99.60 99.55 0.0029 Example 4 12.5 98.3 14.59 99.54 99.51 0.0024 Comparative Example 1 11.8 98.3 13.32 99.55 98.51 0.0026 Comparative Example 2 13.4 98.4 11.17 99.61 96.85 0.0020 Comparative Example 3 10.1 98.1 14.52 97.11 99.50 0.0256 Comparative Example 4 12.1 98.2 13.18 99.48 98.33 0.0102

Claims

1. A preparation process for a titanium-based lithium extraction adsorbent, characterized in that, Includes the following steps: (1) Preparation of titanium-based lithium extraction adsorbent precursor powder; (2) Dissolve an appropriate amount of organic binder and organic porogen in an organic solvent, heat and stir until completely dissolved, add an appropriate amount of coupling agent, and ultrasonically vibrate while mechanically stirring to obtain a uniform binder solution. (3) Add an appropriate amount of titanium-based lithium adsorbent precursor powder from step (1) to the binder solution obtained in step (2), and ultrasonically vibrate while mechanically stirring to obtain a uniformly mixed viscous slurry A. (4) Take an appropriate amount of titanium-based lithium extraction adsorbent precursor powder from step (1), add an appropriate amount of alumina porous microspheres and inorganic pore-forming agent to the titanium-based lithium extraction adsorbent precursor powder, mix evenly to obtain solid mixture B. (5) Place the solid mixture B obtained in step (4) into the reactor, turn on the high-speed stirring, and then add the viscous slurry A obtained in step (3) into the reactor at a uniform speed to obtain titanium-based lithium extraction adsorbent particles with alumina porous microspheres as carriers. (6) The titanium-based lithium extraction adsorbent particles with alumina porous microspheres as carrier obtained in step (5) are vacuum dried to remove organic solvent, and then washed with hot water, filtered and dried to obtain the titanium-based lithium extraction adsorbent.

2. The preparation process of the titanium-based lithium extraction adsorbent according to claim 1, characterized in that, In step (1), the particle size of the titanium-based lithium extraction adsorbent precursor powder is 1 to 15 μm.

3. The preparation process of the titanium-based lithium extraction adsorbent according to claim 1 or 2, characterized in that, In step (2), the organic binder is at least one of acrylonitrile-butadiene-styrene, polyacrylonitrile, polyvinyl chloride, polyvinylidene fluoride, phenolic resin, epoxy resin, and polyurethane; and / or, in step (2), the organic porogen is one or two of polyethylene glycol and polyvinylpyrrolidone; and / or, the amount of the organic porogen is 0.4 to 10% of the total weight of the organic binder; and / or, in step (2), the organic solvent is at least one of acetone, ethanol, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, and tetrahydrofuran; and / or, the amount of the organic solvent is 2 to 20 times the total weight of the organic binder.

4. The preparation process of the titanium-based lithium extraction adsorbent according to claim 1 or 2, characterized in that, In step (2), the heating is to raise the temperature to 45-80°C; and / or, in step (2), the coupling agent is at least one of titanate coupling agent, aluminate coupling agent, and aluminum-titanium composite coupling agent; and / or, the amount of the coupling agent is 0.5-5% of the total weight of the organic binder.

5. The preparation process of the titanium-based lithium extraction adsorbent according to claim 1 or 2, characterized in that... In step (3), the mass of the titanium-based lithium-extraction adsorbent precursor powder is 1 to 20 times the total weight of the organic binder contained in the binder solution.

6. The preparation process of the titanium-based lithium extraction adsorbent according to claim 1 or 2, characterized in that, In step (4), the mass of the titanium-based lithium extraction adsorbent precursor powder is 1 to 20 times the total weight of the organic binder contained in the binder solution in step (3).

7. The preparation process of the titanium-based lithium extraction adsorbent according to claim 1 or 2, characterized in that, In step (4), the alumina porous microspheres have a particle size of 0.1-1 mm and a bulk density of <1 g / mL; and / or, the mass of the alumina porous microspheres is 1-20% of the total mass of the titanium-based lithium extraction adsorbent precursor powder in steps (3) and (4); and / or, in step (4), the inorganic porogen is at least one of sodium chloride, potassium chloride, sodium carbonate, potassium carbonate, sodium bicarbonate, ammonium bicarbonate, potassium nitrate, and sodium sulfate; and / or, the amount of the inorganic porogen is 0.2-10 wt% of the total mass of the titanium-based lithium extraction adsorbent precursor powder in steps (3) and (4); and / or, the porogen is ground to a particle size d ≤ 30 μm.

8. The preparation process of the titanium-based lithium extraction adsorbent according to claim 1 or 2, characterized in that, In step (5), the stirring speed of the high-speed mixer is 500 to 2000 rpm; and / or, in step (5), the feeding speed of the viscous slurry A is 30 to 100 ml / min·kg solid mixture B.

9. The preparation process of the titanium-based lithium extraction adsorbent according to claim 1 or 2, characterized in that, In step (5), the particle size of the titanium-based lithium extraction adsorbent particles with alumina porous microspheres as carrier is controlled to be 0.5-1.5 mm.

10. The preparation process of the titanium-based lithium extraction adsorbent according to claim 1 or 2, characterized in that, In step (6), the temperature of the vacuum drying is 50-120°C; and / or, in step (6), the temperature of the hot water for washing is 40-80°C.

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