Titanium-based lithium ion sieve taking waste scr denitration catalyst as titanium source and preparation method and application thereof

Abstract

The application discloses a titanium-based lithium ion sieve taking waste SCR denitration catalyst as a titanium source and a preparation method and application thereof. The preparation method is as follows: waste SCR denitration catalyst powder is mixed with lye and then heated and stirred to obtain coarse titanium slag; the obtained coarse titanium slag is reacted with acid liquor to obtain metatitanic acid containing tungsten; the metatitanic acid is mixed with a lithium source and then subjected to hydrothermal reaction, the residue is calcined to obtain a lithium ion sieve precursor; and the lithium ion sieve precursor is washed with acid liquor to elute lithium ions to obtain the titanium-based lithium ion sieve. The titanium-based lithium ion sieve precursor and the adsorbent have regular octahedral structures under microscopes, and the specific surface area is 65-75 m 2 / g. + Under the condition that the initial concentration is 200 mg / L, the titanium-based lithium ion sieve has an adsorption capacity of 33.68 mg / g for Li + The lithium / magnesium separation factor is about 7.7, and the titanium-based lithium ion sieve has a great application prospect in the fields of lithium extraction from salt lake brine and lithium extraction from other water bodies with low lithium concentration.

Description

Technical Field

[0001] The present invention belongs to the field of solid adsorbent preparation, and specifically relates to a titanium-based lithium ion sieve using a waste SCR denitration catalyst as a titanium source, and a preparation method and application thereof. Background Art

[0002] Lithium, due to its high redox potential, high specific heat capacity, and low density, is widely used in industries such as energy storage, ceramics, and glass. Lithium exists primarily in nature as lithium-rich brines and high-grade lithium ore. Salt lake brines contain over 69% of the world's total lithium reserves. Therefore, research is urgently needed on lithium extraction technologies from salt lake brines to address the imbalance between lithium supply and demand.

[0003] Adsorption-based lithium extraction technology is widely used due to its simple and efficient operation, high adsorption selectivity, high product purity, and compatibility with most salt lakes. Its core is the adsorbent. Metal-based adsorbents offer advantages such as high lithium adsorption capacity, high adsorption selectivity, and strong cycling performance. Currently, the most researched metal-based adsorbents include manganese-based lithium ion sieves, aluminum-based lithium ion sieves, and titanium-based lithium ion sieves. Aluminum-based lithium ion sieves offer excellent stability and are widely used in industry, but their greatest drawback is their low lithium ion adsorption capacity. Manganese-based lithium ion sieves suffer from severe manganese dissolution losses during adsorption and desorption, making them extremely unstable. Compared to manganese-based lithium ion sieves, titanium-based lithium ion sieves have a more stable structure and a lower titanium dissolution rate. Compared to aluminum-based lithium ion sieves, they offer advantages such as high adsorption capacity and high adsorption selectivity, thus holding broad application prospects.

[0004] Synthesis method and micromorphology of titanium-based lithium ion sieves for their effects on Li + The adsorption performance has a great influence. Chinese patent CN113041988B discloses a method for preparing titanium-based lithium ion sieve, which uses fresh anatase-type TiO2 as a titanium source and synthesizes an Al-doped titanium-based lithium ion sieve by a hydrothermal method. The adsorbent has a low adsorption capacity at low lithium ion concentrations and a relatively high cost; Chinese patent 116637586A discloses a method for preparing Fe-doped titanium-based lithium ion sieve, which uses tetraethyl titanate, tetrabutyl titanate or tetraisopropyl titanate as a titanium source and synthesizes an irregularly shaped iron-doped titanium-based lithium ion sieve by a roasting method. The titanium source used in this method is relatively expensive, and the synthesized adsorbent has a small specific surface area due to its uneven morphology, which affects its Li + Adsorption performance. Summary of the Invention

[0005] In order to overcome the shortcomings and deficiencies of the prior art, the primary purpose of the present invention is to provide a method for preparing a W-doped regular octahedral titanium-based lithium ion sieve with a waste SCR denitration catalyst as a titanium source and regular particle morphology.

[0006] The present invention uses titanium dioxide in waste SCR denitration catalyst as titanium source to reduce the preparation cost of titanium-based lithium ion sieve from the raw material level, and prepares a titanium-based lithium ion sieve with high Li by optimizing the synthesis process. + Adsorption capacity and selectivity of octahedral titanium-based lithium ion sieves.

[0007] Another object of the present invention is to provide a titanium-based lithium ion sieve prepared by the above method.

[0008] Another object of the present invention is to provide applications of the titanium-based lithium ion sieve.

[0009] The purpose of the present invention is achieved through the following technical solutions:

[0010] A method for preparing a regular octahedral titanium-based lithium ion sieve using a waste SCR denitration catalyst as a titanium source comprises the following steps:

[0011] (1) washing the spent SCR denitration catalyst and grinding it into powder;

[0012] (2) mixing the spent SCR denitration catalyst powder with alkaline solution and performing a heating and stirring reaction in a reactor. After the reaction is completed, filtering, washing and drying are performed to obtain crude titanium slag;

[0013] (3) reacting the crude titanium slag obtained in step (2) with an acid solution, filtering, washing, and drying after the reaction to obtain tungsten-containing metatitanic acid;

[0014] (4) mixing the metatitanic acid obtained in step (3) with a lithium source and placing the mixture in a reactor for hydrothermal reaction, filtering, washing and drying the mixture after the reaction, and calcining the filter residue to obtain a lithium ion sieve precursor;

[0015] (5) The lithium ion sieve precursor is subjected to acid solution to remove lithium ions to obtain a titanium-based lithium ion sieve.

[0016] The titanium source used in the present invention can be a deactivated waste SCR denitration catalyst, or a fresh commercial SCR denitration catalyst.

[0017] Preferably, in step (1), the main components of the waste SCR denitration catalyst are 80 wt% to 90 wt% of titanium dioxide and 3 wt% to 10 wt% of tungsten trioxide.

[0018] Preferably, in step (1), water is used as the cleaning liquid in the washing process.

[0019] Preferably, in step (1), the grinding process is to grind the spent SCR denitration catalyst to below 200 mesh.

[0020] Preferably, in step (2), the alkali solution is a sodium hydroxide solution with a mass concentration of 20% to 40%, and the liquid-to-solid ratio of the sodium hydroxide solution to the waste SCR denitration catalyst powder is 3:1 to 5:1 (ml / g).

[0021] Preferably, in step (2), the reaction is carried out under a pressure of 0.2 MPa-1.55 MPa, the reaction time is 2.5 h to 4.5 h, and the reaction temperature is 120° C. to 180° C.

[0022] Preferably, in step (3), the acid solution is a hydrochloric acid solution with a mass concentration of 5% to 15%, and the liquid-to-solid ratio of the hydrochloric acid solution to the metatitanic acid is 4:1 to 6:1 (ml / g). The liquid-to-solid ratio of the hydrochloric acid solution to the metatitanic acid is more preferably 5:1 (ml / g).

[0023] Preferably, in step (4), the lithium source is a lithium hydroxide solution with a concentration of 0.5 to 1 mol / L, the liquid-to-solid ratio of the lithium hydroxide solution to metatitanic acid is 50:1 to 150:1 (ml / g), the temperature of the hydrothermal reaction is 120° C. to 180° C., and the hydrothermal reaction time is 12 to 30 hours. More preferably, the lithium source is a lithium hydroxide solution with a concentration of 0.5 mol / L.

[0024] Preferably, in step (4), the temperature is raised to the calcination temperature at a heating rate of 5 to 10° C. / min, the calcination temperature is 250 to 650° C., and the calcination time is 4 to 6 hours.

[0025] Preferably, in step (5), the acid solution is a hydrochloric acid solution with a concentration of 0.3 to 0.6 mol / L, and the liquid-solid ratio of the hydrochloric acid solution to the lithium ion sieve precursor is 75:1 to 125:1 (ml / g). The liquid-solid ratio of the hydrochloric acid solution to the lithium ion sieve precursor is more preferably 100:1 (ml / g).

[0026] The titanium-based lithium ion sieve synthesized by the present invention has a uniformly dispersed regular octahedral structure, a particle size of 300-400nm, a pore size mainly of mesopores, and a specific surface area of ​​up to 65-75m 2 / g.

[0027] The titanium-based lithium ion sieve provided by the present invention has high Li + Adsorption performance and high Li + Selectivity can be used to efficiently extract lithium resources from salt lake brine, or to extract lithium resources from water bodies with low lithium concentration.

[0028] Compared with the prior art, the present invention has the following advantages and technical effects:

[0029] (1) The titanium-based lithium ion sieve prepared by the method of the present invention has W elements embedded in the lattice of the titanium-based lithium ion sieve, which exposes more H exchange sites, thereby reducing the mass transfer resistance of Li-H in the exchange process and improving Li + Adsorption performance; in Li + Under the condition of initial concentration of 200 mg / L, the titanium-based lithium ion sieve has a great + The adsorption capacity is as high as 33.68 mg / g, and the Li / Mg separation factor is about 7.7.

[0030] (2) The titanium-based lithium ion sieve prepared by the method of the present invention has a regular microscopic morphology, a large specific surface area, and a regular octahedral structure.

[0031] (3) The titanium-based lithium ion sieve prepared by the method of the present invention is Li in a low lithium concentration solution. + The adsorption capacity is high, the adsorption selectivity is good, and the adsorbent cycle stability is excellent.

[0032] (4) The titanium-based lithium ion sieve prepared by the method of the present invention can use waste SCR denitrification catalyst as raw material, which not only turns hazardous waste into treasure, but also reduces the production cost of the titanium-based lithium ion sieve from the raw material level. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is the X-ray diffraction pattern of the titanium-based lithium ion sieve precursor prepared in Example 1;

[0034] Figure 2 The Li + Adsorption isotherms;

[0035] Figure 3 is the X-ray diffraction pattern of the titanium-based lithium ion sieve precursor prepared in Example 2;

[0036] Figure 4 is the Li + Adsorption isotherms;

[0037] Figure 5 X-ray diffraction patterns of the titanium-based lithium ion sieve precursor and titanium-based lithium ion sieve prepared in Example 3;

[0038] Figure 6 is the N2 adsorption-desorption isotherm of the titanium-based lithium ion sieve prepared in Example 3;

[0039] Figure 7 This is a scanning electron microscope image of the titanium-based lithium ion sieve precursor prepared in Example 3;

[0040] Figure 8 This is a scanning electron microscope image of the titanium-based lithium ion sieve prepared in Example 3;

[0041] Figure 9 FTIR spectra of the titanium-based lithium ion sieve precursor and titanium-based lithium ion sieve prepared in Example 3;

[0042] Figure 10 The titanium-based lithium ion sieve prepared in Example 3 is Li + Mg 2+ 、Na + , K + adsorption capacity;

[0043] Figure 11 The titanium-based lithium ion sieve prepared in Example 3 is Li + 5 adsorption-desorption cycle performance;

[0044] Figure 12 This is the XRD comparison of the titanium-based lithium ion sieve prepared in Example 3 before adsorption and after 5 adsorption cycles. In the figure, HTO represents the titanium-based lithium ion sieve before adsorption, and cycle5-HTO represents the titanium-based lithium ion sieve after 5 adsorption cycles. DETAILED DESCRIPTION

[0045] The technical solution of the present invention is further described in detail below with reference to specific embodiments and drawings, but the protection scope and implementation methods of the present invention are not limited thereto.

[0046] In the following specific embodiments, the waste SCR denitration catalyst involved is derived from discarded commercial titanium-based denitration catalyst, and its composition is shown in Table 1; sodium hydroxide, hydrochloric acid, lithium hydroxide monohydrate, lithium chloride, sodium chloride, magnesium chloride, potassium chloride, ammonium chloride, and ammonia water are all commercially available chemically pure reagents; the lithium standard solution, magnesium standard solution, sodium standard solution, and potassium standard solution used for flame atomic absorption spectrometer testing all comply with the GSB04-1738-2004 standard.

[0047]

[0048] In the present invention, the prepared titanium-based lithium ion sieve precursor is characterized by an X-ray diffractometer, a scanning electron microscope and an infrared spectrometer, and the prepared titanium-based lithium ion sieve is characterized by an X-ray diffractometer, a scanning electron microscope, an infrared spectrometer and a chemical adsorption meter.

[0049] Example 1

[0050] In this embodiment, a regular octahedral titanium-based lithium ion sieve is prepared using waste SCR denitration catalyst as a titanium source. The preparation steps are as follows:

[0051] (1) After washing the spent SCR denitration catalyst with deionized water, grind it into powder and pass it through a 200-mesh sieve;

[0052] (2) Weigh 20.0056 g of spent SCR denitration catalyst powder, take 30.0062 g of sodium hydroxide to prepare 100 ml of 30 wt% sodium hydroxide solution, mix the spent SCR denitration catalyst powder with 70 ml of sodium hydroxide solution, and then add the mixture into a high-pressure reactor for reaction at 160° C. for 3.5 hours. After the reaction is completed, filter, wash and dry to obtain 22.3384 g of crude titanium slag;

[0053] (3) 23.85 ml of concentrated hydrochloric acid was used to prepare 100 ml of a 10% hydrochloric acid solution. 20.0013 g of crude titanium slag was mixed with the hydrochloric acid solution and stirred at room temperature for 12 h. After filtering, washing and drying, 14.5900 g of metatitanic acid was obtained.

[0054] (4) 0.8037 g of metatitanic acid, 0.8421 g of lithium hydroxide monohydrate and 40 ml of deionized water were mixed and stirred for 30 min, ultrasonicated for 30 min, and then added to the reactor. The reactor was placed in a 120 ° C oven for 24 h; after the reaction, the product was filtered, washed and dried, and the product was placed in a muffle furnace and the temperature was increased to 250 ° C at a heating rate of 5 ° C / min and maintained for 4 h to finally obtain a titanium-based lithium ion sieve precursor;

[0055] (5) 4.3 ml of concentrated hydrochloric acid was prepared into 100 ml of 0.5 mol / L hydrochloric acid solution. 0.3025 g of the titanium-based lithium ion sieve precursor obtained above was mixed with 30 ml of 0.5 mol / L hydrochloric acid solution and stirred at room temperature for 24 h. The titanium-based lithium ion sieve was obtained after filtration, washing and drying.

[0056] 0.1016 g of the above titanium-based lithium ion sieve was added to 100 mL of Li + To a 200 mg / L LiCl solution, 0.15 g of ammonium chloride and 0.5 ml of aqueous ammonia were added as buffers and shaken at room temperature for 24 hours. A flame atomic absorption spectrometer was used to measure the lithium ion concentration in the solution before and after adsorption, and the adsorption capacity of the titanium-based lithium ion sieve was calculated.

[0057] In this example, the X-ray diffraction pattern of the prepared titanium-based lithium ion sieve precursor was characterized and its adsorption isotherm was tested. Figure 1 This is the X-ray diffraction pattern of the titanium-based lithium ion sieve precursor prepared in Example 1. Figure 2 This is the isothermal adsorption curve of the titanium-based lithium ion sieve prepared in Example 1. It is measured that the adsorption capacity of the titanium-based lithium ion sieve prepared in Example 1 at room temperature is 9.45 mg / g.

[0058] Example 2

[0059] The difference between this embodiment and embodiment 1 is that in step (4), 0.8026g of the obtained metatitanic acid, 2.5216g of lithium hydroxide monohydrate and 120ml of deionized water are mixed and stirred for 30min, ultrasonicated for 30min, and then added to the reactor, and the reactor is placed in a 120°C oven for reaction for 24h; after the reaction is completed, it is filtered, washed and dried, and the product is placed in a muffle furnace and the temperature is raised to 350°C at a heating rate of 5°C / min and maintained for 4h to finally obtain a titanium-based lithium ion sieve precursor; in step (5), 4.3ml of concentrated hydrochloric acid is prepared into 100ml of 0.5mol / L hydrochloric acid solution, 0.3036g of the above-mentioned titanium-based lithium ion sieve precursor is mixed with 30ml of 0.5mol / L hydrochloric acid solution, and then stirred at room temperature for reaction for 24h, filtered, washed and dried to obtain a titanium-based lithium ion sieve.

[0060] In this example, the X-ray diffraction pattern of the prepared titanium-based lithium ion sieve precursor was characterized and its adsorption isotherm was tested. Figure 3 This is the X-ray diffraction pattern of the titanium-based lithium ion sieve precursor prepared in Example 2. Figure 4 This is the isothermal adsorption curve of the titanium-based lithium ion sieve prepared in Example 2. It is measured that the adsorption capacity of the titanium-based lithium ion sieve at room temperature is 27.78 mg / g.

[0061] Example 3

[0062] The difference between this embodiment and embodiment 2 is that in step (4), 0.4022g of the obtained metatitanic acid, 1.0508g of lithium hydroxide monohydrate and 50ml of deionized water are mixed and stirred for 30min, ultrasonicated for 30min, and then added to the reactor, which is placed in a 120°C oven for reaction for 24h. After the reaction is completed, it is filtered, washed and dried, and the product is placed in a muffle furnace and the temperature is raised to 450°C at a heating rate of 5°C / min and maintained for 4h to finally obtain a titanium-based lithium ion sieve precursor (denoted as 2-LTO-450); in step (5), 4.3ml of concentrated hydrochloric acid is prepared into 100ml of 0.5mol / L hydrochloric acid solution, 0.3021g of the above-obtained precursor 2-LTO-450 is mixed with 30ml of 0.5mol / L hydrochloric acid solution, and then stirred at room temperature for reaction for 24h, filtered, washed and dried to obtain a titanium-based lithium ion sieve (denoted as 2-HTO-450). The lithium ion adsorption capacity of the obtained titanium-based lithium ion sieve is 33.68 mg / g.

[0063] (1) The X-ray diffraction patterns and N2 adsorption-desorption isotherms of the titanium-based lithium ion sieve precursor and titanium-based lithium ion sieve prepared in this example were used to characterize their morphologies.

[0064] Figure 5The X-ray diffraction patterns of the titanium-based lithium ion sieve precursor and the titanium-based lithium ion sieve prepared in Example 3 are shown. From the X-ray diffraction pattern, it can be seen that the diffraction peaks of the titanium-based lithium ion sieve precursor correspond to the standard card PDF#75-1602, indicating that the titanium-based lithium ion sieve precursor has been successfully synthesized; after the titanium-based lithium ion sieve precursor is eluted with hydrochloric acid to remove lithium ions, the peaks corresponding to lithium ions disappear, but since the structure has not changed, some diffraction peaks remain.

[0065] Figure 6 This is the nitrogen adsorption and desorption isotherm of the titanium-based lithium ion sieve prepared in Example 3. Its specific surface area is 72m 2 / g, the pore size is mainly mesopores.

[0066] Figure 7 、 8 This is a scanning electron microscope image of the titanium-based lithium ion sieve precursor and the titanium-based lithium ion sieve prepared in Example 3. As can be seen from the image, the titanium-based lithium ion sieve precursor and the titanium-based lithium ion sieve both have regular octahedral structures.

[0067] Figure 9 The Fourier transform infrared spectra of the titanium-based lithium ion sieve precursor and the titanium-based lithium ion sieve prepared in Example 3 are shown in FIG. As can be seen from the figure, after the lithium ions of the titanium-based lithium ion sieve precursor are eluted with hydrochloric acid, the stretching vibration peak representing the O-Li bond (1496 cm -1 、1438cm -1 ) disappeared, indicating that lithium ions were successfully eluted to obtain titanium-based lithium ion sieve.

[0068] (2) Add 0.1008 g of the titanium-based lithium ion sieve prepared in Example 3 to 100 mL of Li + Mg 2+ 、Na + , K + 0.15g of ammonium chloride and 0.5ml of ammonia water were added as buffer to a mixed solution of lithium chloride, magnesium chloride, sodium chloride and potassium chloride with a concentration of 200mg / L, and the mixture was shaken on a shaker at room temperature for 24h. The Li content in the solution before and after adsorption was determined using a flame atomic absorption spectrometer. + Mg 2+ 、Na + , K + The concentration was determined and the adsorption capacity of titanium-based lithium ion sieve for different ions was calculated respectively.

[0069] Figure 10 The saturated adsorption capacity of the titanium-based lithium ion sieve prepared in Example 3 for various metal ions was measured. The Li / Mg separation factor of the titanium-based lithium ion sieve at room temperature was 7.7, the Li / Na separation factor was 16.3, and the Li / K separation factor was 32.

[0070] (3) Add 0.1012 g of the titanium-based lithium ion sieve prepared in Example 3 to 100 mL of Li + In a lithium chloride solution with a concentration of 200 mg / L, 0.15 g of ammonium chloride and 0.5 ml of ammonia water were added as buffers and shaken at room temperature for 24 hours. After the adsorption was completed, the (L)TO lithium ion sieve after adsorbing lithium ions was placed in 100 ml of 0.5 mol / L hydrochloric acid solution for desorption at room temperature for 24 hours. After the desorption was completed, the HTO adsorbent was obtained by filtering, washing and drying. The adsorption and desorption were repeated 5 times according to the above steps. The Li in the solution before and after each cycle of adsorption was determined by flame atomic absorption spectrometry. + The concentration was determined and the change in adsorption capacity of the titanium-based lithium ion sieve adsorbent after 5 adsorption and desorption cycles was calculated.

[0071] Figure 11 The change in adsorption capacity of the titanium-based lithium ion sieve prepared in Example 3 after 5 adsorption and desorption cycles. From the experimental results, it can be seen that after 5 cyclic adsorption experiments, the adsorption capacity only decreased from 33.68 mg / g to 32.45 mg / g. Figure 12 The XRD comparison of the titanium-based lithium ion sieve prepared in Example 3 before adsorption and after 5 adsorption cycles shows that the characteristic peaks of the titanium-based lithium ion sieve still exist after 5 adsorption cycles, indicating that the titanium-based lithium ion sieve has good structural stability.

[0072] The above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit them. Those skilled in the art should understand that any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a titanium-based lithium ion sieve using waste SCR denitration catalyst as a titanium source, characterized in that: The following steps are involved: (1) washing a waste SCR denitration catalyst and grinding it into powder; the waste SCR denitration catalyst comprises: 80 wt% to 90 wt% titanium dioxide and 3 wt% to 10 wt% tungsten trioxide; (2) mixing the spent SCR denitration catalyst powder with alkali solution and heating and stirring the mixture in a reactor, filtering, washing and drying the mixture after the reaction is completed to obtain crude titanium slag; (3) reacting the crude titanium slag obtained in step (2) with an acid solution, filtering, washing and drying after the reaction to obtain tungsten-containing metatitanic acid; (4) The metatitanic acid obtained in step (3) is mixed with a lithium source and placed in a reactor for hydrothermal reaction. After the reaction is completed, the mixture is filtered, washed and dried, and the filter residue is calcined to obtain a lithium ion sieve precursor; the temperature of the hydrothermal reaction is 120°C to 180°C, the time of the hydrothermal reaction is 12 to 30 hours, and the calcination temperature is 350°C to 650°C, and the calcination time is 4 to 6 hours; (5) The lithium ion sieve precursor is subjected to acid solution to remove lithium ions to obtain a titanium-based lithium ion sieve.

2. The preparation method according to claim 1, characterized in that The washing process in step (1) uses water as the cleaning liquid; The grinding process in step (1) is to grind the waste SCR denitration catalyst to below 200 mesh.

3. The preparation method according to claim 1, characterized in that The alkali solution in step (2) is a sodium hydroxide solution with a mass concentration of 20% to 40%, and the liquid-to-solid ratio of the sodium hydroxide solution to the waste SCR denitration catalyst powder is 3:1 to 5:1, ml / g.

4. The preparation method according to claim 1, characterized in that In step (2), the reaction is carried out under a pressure of 0.2 MPa-1.55 MPa, the reaction time is 2.5 h to 4.5 h, and the reaction temperature is 120° C. to 180° C.

5. The preparation method according to claim 1, characterized in that In step (3), the acid solution is a hydrochloric acid solution with a mass concentration of 5% to 15%, and the liquid-to-solid ratio of the hydrochloric acid solution to titanic acid is 4:1 to 6:1, ml / g.

6. The preparation method according to claim 1, characterized in that In step (4), the lithium source is a lithium hydroxide solution with a concentration of 0.5 to 1 mol / L, and the liquid-to-solid ratio of the lithium hydroxide solution to titanic acid is 50:1 to 150:1, ml / g; 。 7. The preparation method according to claim 1, characterized in that In step (4), the temperature is raised to the calcination temperature at a heating rate of 5-10°C / min.

8. The preparation method according to claim 1, characterized in that In step (5), the acid solution is a hydrochloric acid solution with a concentration of 0.3 to 0.6 mol / L; the liquid-solid ratio of the hydrochloric acid solution to the lithium ion sieve precursor is 75:1 to 125:1, ml / g.

9. A titanium-based lithium ion sieve prepared by the method according to any one of claims 1 to 8.

10. Use of the titanium-based lithium ion sieve according to claim 9 in extracting lithium from salt lake brine and other water bodies with low lithium concentration.

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