Application of titanium black in preparation of titanium lithium adsorbent, titanium lithium adsorbent and preparation method and application thereof

Abstract

The application provides application of titanium black in preparation of a titanium lithium adsorbent, the titanium lithium adsorbent and a preparation method and application thereof, and particularly relates to the technical field of lithium adsorbents. The chemical formula of the titanium black is Ti4O7, and the titanium black has a sodium chloride type cubic crystal form and a rutile type square crystal form. The titanium black (Ti4O7) with the sodium chloride type cubic crystal form and the rutile type square crystal form is used as a titanium source in the application, and the valence of titanium in the Ti4O7 includes positive trivalence (Ti 3+ ) and positive tetravalence (Ti 4+ ). The existence of the two valences makes the titanium black have the structural characteristics of the sodium chloride type cubic crystal form and the rutile type square crystal form. The unique crystal structure provides two different occupation sites for lithium ions, and increases the number of lithium ion adsorption sites. In addition, the existence of the positive trivalent titanium ions can promote the rapid migration of lithium ions in the titanium lithium adsorbent crystal lattice, thereby effectively improving the adsorption rate of the titanium lithium adsorbent.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium adsorbents, and in particular to the use of titanium black in the preparation of a titanium-based lithium adsorbent, the titanium-based lithium adsorbent, and a preparation method and application thereof. Background Art

[0002] In engineering applications, the titanium-based lithium adsorbent β-H2TiO3 exhibits a slow adsorption rate. Within three hours, its adsorption capacity is only 14 mg / g, compared to its theoretical saturation capacity of 143 mg / g. This means that the actual adsorption capacity reaches only 10% of the theoretical value. Consequently, 90% of the adsorption sites remain unutilized, severely limiting the widespread application of titanium-based lithium adsorbents.

[0003] The low adsorption rate of titanium-based lithium adsorbents is due to the slow migration rate of lithium ions within their crystal structure. By using different raw materials to synthesize titanium-based lithium adsorbents, products with different microscopic crystal structures can be obtained, and these differences lead to different lithium ion adsorption rates.

[0004] Currently, research on titanium sources mainly focuses on single or combined titanium sources such as metatitanic acid, anatase titanium dioxide, rutile titanium dioxide, and titanium tetrahydroxide. However, the adsorption rate of titanium-based lithium adsorbents synthesized using these titanium sources is still very low, and no substantial improvement has been achieved.

[0005] In view of this, the present invention is proposed. Summary of the Invention

[0006] The purpose of the present invention is to provide the use of titanium black in the preparation of titanium-based lithium adsorbents, titanium-based lithium adsorbents and their preparation methods and applications, aiming to solve at least one of the above-mentioned technical problems in the prior art.

[0007] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are adopted:

[0008] A first aspect of the present invention provides a use of titanium black in the preparation of a titanium-based lithium adsorbent, wherein the titanium black has a chemical formula of Ti4O7 and has a sodium chloride-type cubic crystal form and a rutile-type tetragonal crystal form.

[0009] Furthermore, the chemical formula of the titanium-based lithium adsorbent is β-H2TiO3.

[0010] The second aspect of the present invention provides a method for preparing a titanium-based lithium adsorbent, comprising the following steps: uniformly mixing a lithium source and a titanium source, adding a composite binder and deionized water, and kneading the mixture; then extruding, low-temperature roasting, and high-temperature calcining to obtain a titanium-based lithium adsorbent precursor β-Li2TiO3; acidifying the titanium-based lithium adsorbent precursor β-Li2TiO3 to obtain a titanium-based lithium adsorbent β-H2TiO3; wherein the titanium source is titanium black.

[0011] Furthermore, the lithium source is a soluble lithium source and decomposes to generate gas during the calcination process.

[0012] Preferably, the lithium source includes at least one of lithium nitrate, lithium carbonate and lithium citrate.

[0013] Preferably, the composite adhesive comprises polyethylene glycol and lubricating oil.

[0014] Preferably, the molecular weight of the polyethylene glycol is 200-500.

[0015] Preferably, the lubricating oil is composed of three elements: C, H and O.

[0016] Preferably, the lubricating oil comprises glycerol and / or vegetable oil.

[0017] Preferably, the vegetable oil comprises at least one of soybean oil, rapeseed oil, peanut oil and corn oil.

[0018] Furthermore, the molar ratio of Li in the lithium source to Ti in the titanium source is 1.67-2.13:1.

[0019] Preferably, in the composite binder, the mass ratio of polyethylene glycol to lubricating oil is 2-4:1-3.

[0020] Preferably, the added amount of the composite binder is 10-20% of the total mass of the lithium source and the titanium source.

[0021] Furthermore, the kneading process is performed at a rotation speed of 20-40 rpm and for a time of 10-30 min.

[0022] Preferably, the extruded material has a length of 1 to 3 cm and a diameter of 1 to 3 mm.

[0023] Preferably, the low-temperature calcination temperature is 80-150° C., and the time is 1-3 hours.

[0024] Furthermore, during high-temperature calcination, the charging thickness of the extruded material is 8 to 12 cm.

[0025] Preferably, the high-temperature calcination temperature is 950-1100° C., and the time is 0.3-1 h.

[0026] The third aspect of the present invention provides a titanium-based lithium adsorbent, which is prepared using the above-mentioned preparation method.

[0027] Furthermore, the particle size of the titanium-based lithium adsorbent is 100-500 nm.

[0028] The fourth aspect of the present invention provides the use of the titanium-based lithium adsorbent in lithium extraction or lithium recovery from salt lakes.

[0029] Compared with the prior art, the present invention has at least the following beneficial effects:

[0030] The present invention uses titanium black (Ti4O7) with sodium chloride type cubic crystal and rutile type tetragonal crystal as titanium source, and the valence state of titanium in Ti4O7 includes positive trivalent (Ti 3+ ) and tetravalent (Ti 4+ The presence of these two valence states gives titanium black the structural characteristics of both sodium chloride cubic and rutile tetragonal crystals. This unique crystal structure provides two different occupation sites for lithium ions, increasing the number of lithium ion adsorption sites. Furthermore, the presence of positive trivalent titanium ions promotes the rapid migration of lithium ions within the titanium-based lithium adsorbent's lattice, effectively increasing its adsorption rate.

[0031] The preparation method of the titanium-based lithium adsorbent provided by the present invention kneads the raw materials and then extrudes them into a mold, which is beneficial for making the powders more tightly combined, reducing the distance that the lithium source migrates to the titanium source during the calcination process, and is beneficial for improving the synthesis efficiency, shortening the high-temperature calcination time, improving the synthesis efficiency and reducing energy consumption.

[0032] The titanium-based lithium adsorbent provided by the present invention has a particle size of only 100-500 nm, a high specific surface area, and an adsorption capacity of at least 116 mg / g within 3 hours, reaching 81% of the theoretical saturated adsorption capacity. This greatly improves the adsorption rate of the titanium-based lithium adsorbent and solves the technical problem of low adsorption rate of the titanium-based lithium adsorbent.

[0033] The application of the titanium-based lithium adsorbent provided by the present invention, in view of the advantages of the above-mentioned titanium-based lithium adsorbent, effectively improves the efficiency of lithium adsorption and significantly shortens the duration of the lithium adsorption process, providing strong support for the development of downstream industries and promoting technological progress and industrial upgrading in related fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0035] Figure 1 This is a preparation method roadmap for Example 1;

[0036] Figure 2 This is a scanning electron microscope image of the titanium-based lithium adsorbent precursor β-Li2TiO3 obtained in Example 1;

[0037] Figure 3 This is a scanning electron microscope image of the titanium-based lithium adsorbent precursor β-Li2TiO3 obtained in Example 2;

[0038] Figure 4 This is a scanning electron microscope image of the titanium-based lithium adsorbent precursor β-Li2TiO3 obtained in Example 3;

[0039] Figure 5 The XRD pattern of the titanium-based lithium adsorbent precursor β-Li2TiO3 obtained in Example 1;

[0040] Figure 6 The XRD pattern of the titanium-based lithium adsorbent precursor β-Li2TiO3 obtained in Example 2;

[0041] Figure 7 This is the XRD pattern of the titanium-based lithium adsorbent precursor β-Li2TiO3 obtained in Example 3. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0043] Hereinafter, the terms "including", "having" and their cognates, which may be used in various embodiments of the present invention, are intended only to indicate specific features, numbers, steps, operations, elements, components or combinations of the foregoing items, and should not be understood as first excluding the existence of one or more other features, numbers, steps, operations, elements, components or combinations of the foregoing items or the possibility of adding one or more features, numbers, steps, operations, elements, components or combinations of the foregoing items.

[0044] A first aspect of the present invention provides a use of titanium black in the preparation of a titanium-based lithium adsorbent, wherein the titanium black has a chemical formula of Ti4O7 and has a sodium chloride-type cubic crystal form and a rutile-type tetragonal crystal form.

[0045] The present invention uses titanium black (Ti4O7) with sodium chloride type cubic crystal and rutile type tetragonal crystal as titanium source, and the valence state of titanium in Ti4O7 includes positive trivalent (Ti 3+ ) and tetravalent (Ti 4+ The presence of these two valence states gives titanium black the structural characteristics of both sodium chloride cubic and rutile tetragonal crystals. This unique crystal structure provides two different occupation sites for lithium ions, increasing the number of lithium ion adsorption sites. Furthermore, the presence of positive trivalent titanium ions promotes the rapid migration of lithium ions within the titanium-based lithium adsorbent's lattice, effectively increasing its adsorption rate.

[0046] Furthermore, the chemical formula of the titanium-based lithium adsorbent is β-H2TiO3.

[0047] The second aspect of the present invention provides a method for preparing a titanium-based lithium adsorbent, comprising the following steps: uniformly mixing a lithium source and a titanium source, adding a composite binder and deionized water, and kneading the mixture; then extruding, low-temperature roasting, and high-temperature calcining to obtain a titanium-based lithium adsorbent precursor β-Li2TiO3; acidifying the titanium-based lithium adsorbent precursor β-Li2TiO3 to obtain a titanium-based lithium adsorbent β-H2TiO3; wherein the titanium source is titanium black.

[0048] The preparation method of the titanium-based lithium adsorbent provided by the present invention kneads the raw materials and then extrudes them into a mold, which is beneficial for making the powders more tightly combined, reducing the distance that the lithium source migrates to the titanium source during the calcination process, and is beneficial for improving the synthesis efficiency, shortening the high-temperature calcination time, improving the synthesis efficiency and reducing energy consumption.

[0049] Furthermore, the lithium source is a soluble lithium source that decomposes and produces gas during the calcination process. Such a lithium source does not introduce impurities during the preparation process, which helps to ensure the purity of the titanium-based lithium adsorbent.

[0050] Preferably, the lithium source includes at least one of lithium nitrate, lithium carbonate and lithium citrate.

[0051] Preferably, the composite adhesive comprises polyethylene glycol and lubricating oil.

[0052] Preferably, the molecular weight of the polyethylene glycol is 200-600. Polyethylene glycol within this molecular weight range has a moderate viscosity, can effectively wrap and disperse the raw materials, and significantly improve the dispersion efficiency, thereby ensuring that the titanium source and the lithium source fully react.

[0053] Preferably, the lubricating oil is composed of three elements: C, H and O. The lubricant can be completely removed by roasting or calcining without introducing impurities.

[0054] Preferably, the lubricating oil comprises glycerol and / or vegetable oil.

[0055] Preferably, the vegetable oil comprises at least one of soybean oil, rapeseed oil, peanut oil and corn oil.

[0056] Furthermore, the molar ratio of Li in the lithium source to Ti in the titanium source is 1.67-2.13:1.

[0057] Typically but not limitatively, the molar ratio of Li in the lithium source to Ti in the titanium source can be, for example, 1.67:1, 1.9:1, 2.0:1, 2.1:1 or 2.13:1, or any value within the range of 1.67 to 2.13:1.

[0058] Preferably, in the composite binder, the mass ratio of polyethylene glycol to lubricating oil is 2-4:1-3.

[0059] Typically but not limitatively, in the composite binder, the mass ratio of polyethylene glycol to lubricating oil can be, for example, 2:1, 2:2, 2:3, 3:1, 3:2, 3:3, 4:1, 4:2 or 4:3, or any value within the range of 2-4:1-3.

[0060] The present invention does not impose any specific restrictions on the amount of deionized water added; it can be flexibly adjusted based on the actual wetness of the material during the extrusion molding process. By adding deionized water as appropriate, the wetness of the material can be effectively adjusted, ensuring a smooth extrusion molding process while also guaranteeing the quality and performance of the molded material. It should be noted that the amount of deionized water added cannot be zero; another function of deionized water is to dissolve the lithium source and convert it into ionic form.

[0061] Preferably, the amount of the composite binder added is 10-20% of the total mass of the lithium source and the titanium source. If the amount of the composite binder added exceeds 20% of the total mass of the lithium source and the titanium source, the shrinkage rate during low-temperature calcination will be too large, causing cracking of the extruded material particles.

[0062] Typically but not limitatively, the added amount of the composite binder may be, for example, 10%, 12%, 15%, 18% or 20% of the total mass of the lithium source and the titanium source, or any value within the range of 10%-20%.

[0063] Furthermore, the kneading process is performed at a rotation speed of 20-40 rpm and for a time of 10-30 min.

[0064] Typically but not limitatively, the rotation speed of the kneading process can be, for example, 20 rpm, 25 rpm, 30 rpm, 35 rpm or 40 rpm, or any value within the range of 20 rpm-40 rpm; the time of the kneading process can be, for example, 10 min, 15 min, 20 min, 25 min or 30 min, or any value within the range of 10 min-30 min.

[0065] In the practice of the present invention, the extruded material may be in various forms, including but not limited to granular, cylindrical, tubular, and spiral structures. Regardless of the form, good interparticle connectivity must be ensured during roasting or high-temperature calcination to promote sufficient volatilization of the composite binder and gas diffusion, thereby optimizing heat transfer uniformity, improving synthesis efficiency, and reducing energy consumption.

[0066] In one embodiment of the present invention, the extruded material has a length of 1 to 3 cm and a diameter of 1 to 3 mm.

[0067] Typically but not restrictively, the length of the extruded material can be, for example, 1 cm, 1.5 cm, 2 cm, 2.5 cm or 3 cm, or any value within the range of 1 cm-3 cm; the diameter of the extruded material can be, for example, 1 mm, 1.5 mm, 2 mm, 2.5 mm or 3 mm, or any value within the range of 1 mm-3 mm.

[0068] Materials with a length of 1 to 3 cm are used as materials for high-temperature calcination instead of powdered materials mixed with lithium and titanium sources. Since the materials are stacked and arranged in a criss-cross pattern and there are certain gaps between the materials, heat radiation can penetrate from top to bottom and from all sides to the center, achieving uniform heating reaction of all materials in the 8-12 cm thick sagger, making the product performance uniform and stable.

[0069] Preferably, the low-temperature calcination temperature is 80-150° C., and the time is 1-3 hours.

[0070] Typically but not limitatively, the low-temperature calcination temperature may be, for example, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C or 150°C, or any value within the range of 80°C-150°C; the low-temperature calcination time may be, for example, 1h, 1.5h, 2h, 2.5h or 3h, or any value within the range of 1h-3h.

[0071] Furthermore, during high-temperature calcination, the charging thickness of the extruded material is 8 to 12 cm.

[0072] When powder materials are placed in a sagger to a depth of 8-12 cm, it is difficult to achieve uniform heat radiation during high-temperature calcination, resulting in uneven performance of the calcined product. However, using extruded materials as the material for high-temperature calcination can achieve uniform heating.

[0073] Typically, but not limiting, when calcined at high temperature, the charge thickness of the extruded material can be, for example, 8 cm, 9 cm, 10 cm, 11 cm or 12 cm, or any value within the range of 8 cm to 12 cm.

[0074] Preferably, the high-temperature calcination temperature is 950-1100° C., and the time is 0.3-1 h.

[0075] Typically but not limitatively, the temperature of the high-temperature calcination can be, for example, 950°C, 975°C, 1000°C, 1025°C, 1050°C, 1075°C or 1100°C, or any value within the range of 950°C-1100°C; the time of the high-temperature calcination can be, for example, 0.3h, 0.4h, 0.5h, 0.6h, 0.7h, 0.8h, 0.9h or 1h, or any value within the range of 0.3h-1h.

[0076] The third aspect of the present invention provides a titanium-based lithium adsorbent, which is prepared using the above-mentioned preparation method.

[0077] The titanium-based lithium adsorbent provided by the present invention has a particle size of only 100-500 nm, a high specific surface area, and an adsorption capacity of at least 116 mg / g within 3 hours, reaching 81% of the theoretical saturated adsorption capacity. This greatly improves the adsorption rate of the titanium-based lithium adsorbent and solves the technical problem of low adsorption rate of the titanium-based lithium adsorbent.

[0078] Furthermore, the particle size of the titanium-based lithium adsorbent is 100-500 nm.

[0079] The fourth aspect of the present invention provides the use of the titanium-based lithium adsorbent in lithium extraction or lithium recovery from salt lakes.

[0080] The application of the titanium-based lithium adsorbent provided by the present invention, in view of the advantages of the above-mentioned titanium-based lithium adsorbent, effectively improves the efficiency of lithium adsorption and significantly shortens the duration of the lithium adsorption process, providing strong support for the development of downstream industries and promoting technological progress and industrial upgrading in related fields.

[0081] The present invention is further illustrated below by specific examples and comparative examples. However, it should be understood that these examples are merely for the purpose of further explanation and should not be construed as limiting the present invention in any form. The raw materials used in the examples and comparative examples of the present invention, unless otherwise specified, were prepared under conventional conditions or conditions recommended by the manufacturer. Reagents or instruments used without manufacturer's indication are all commercially available conventional products.

[0082] Example 1

[0083] This embodiment provides a titanium-based lithium adsorbent, the preparation method of which is as follows: Figure 1 As shown, specifically:

[0084] 1. In a 40L kneader, add 5kg of LiNO3 powder, 3kg of Li2CO3 powder, and 7kg of Ti4O7 powder. Mix at a stirring speed of 20 rpm for 30 minutes. Mix the materials evenly and set aside for use.

[0085] 2. Add 1 kg of PEG-400, 0.5 kg of glycerol, and 2 kg of deionized water to the uniformly mixed lithium source and titanium source, and knead for 10 minutes at a stirring speed of 20 rpm.

[0086] 3. Transfer the kneaded material to a horizontal extruder and extrude the material into strips with a diameter of 1 mm and a length of 1-3 cm.

[0087] 4. Place the above strips in an oven at 80°C and bake for 1 hour. Take them out and cool them to room temperature.

[0088] 5. The low-temperature baked material was placed in a sagger made of mullite with a volume of 15 L and a loading thickness of 8 cm. The sagger was transferred to a muffle furnace. The calcination temperature in the high-temperature section was 950 ° C and the calcination time was 0.3 h. The material was cooled to room temperature to obtain a titanium-based lithium adsorbent precursor β-Li2TiO3. After acidification with a 1M hydrochloric acid solution, a titanium-based lithium adsorbent β-H2TiO3 was obtained.

[0089] Example 2

[0090] This embodiment provides a titanium-based lithium adsorbent, and the specific preparation method is as follows:

[0091] 1. In a 40L kneader, add 8kg of LiNO3 powder, 4kg of Li2CO3 powder, and 8kg of Ti4O7 powder. Mix at a stirring speed of 40 rpm for 90 minutes. Mix the materials evenly and set aside for use.

[0092] 2. Add 2 kg of PEG-400, 1.5 kg of glycerol, and 4 kg of deionized water to the uniformly mixed lithium source and titanium source, and knead for 30 minutes at a stirring speed of 40 rpm.

[0093] 3. Transfer the kneaded material to a horizontal extruder and extrude the material into strips with a diameter of 3 mm and a length of 1-3 cm.

[0094] 4. Place the above strips in an oven at 150°C for 3 hours, then take them out and cool them to room temperature.

[0095] 5. The low-temperature baked material was placed in a sagger made of mullite with a volume of 15 L and a loading thickness of 12 cm. The sagger was transferred to a muffle furnace. The calcination temperature in the high-temperature section was 1100 ° C and the calcination time was 1 h. The temperature was cooled to room temperature to obtain a titanium-based lithium adsorbent precursor β-Li2TiO3. After acidification with 1M hydrochloric acid solution, a titanium-based lithium adsorbent β-H2TiO3 was obtained.

[0096] Example 3

[0097] This embodiment provides a titanium-based lithium adsorbent, and the specific preparation method is as follows:

[0098] 1. In a 40L kneader, add 6.5kg of LiNO3 powder, 3.5kg of Li2CO3 powder, and 7.5kg of Ti4O7 powder. Mix at a stirring speed of 30 rpm for 60 minutes. Mix the materials evenly and set aside for use.

[0099] 2. Add 1.5 kg of PEG-400, 1 kg of glycerol, and 3 kg of deionized water to the uniformly mixed lithium source and titanium source, and knead for 20 minutes at a stirring speed of 30 rpm.

[0100] 3. Transfer the kneaded material to a horizontal extruder and extrude the material into strips with a diameter of 2 mm and a length of 1-3 cm.

[0101] 4. Place the above strips in an oven at 115°C and bake for 2 hours. Take them out and cool them to room temperature.

[0102] 5. The low-temperature baked material was placed in a sagger made of mullite with a volume of 15 L and a loading thickness of 10 cm. The sagger was transferred to a muffle furnace. The calcination temperature in the high-temperature section was 1025 ° C and the calcination time was 0.65 h. The material was cooled to room temperature to obtain a titanium-based lithium adsorbent precursor β-Li2TiO3. After acidification with 1M hydrochloric acid solution, a titanium-based lithium adsorbent β-H2TiO3 was obtained.

[0103] Example 4

[0104] This embodiment provides a titanium-based lithium adsorbent. Unlike Example 1, Li2CO3 is not added, the mass of LiNO3 powder is adjusted to 10.59 kg, and the remaining preparation steps are the same as those in Example 1 and will not be repeated here.

[0105] Example 5

[0106] This embodiment provides a titanium-based lithium adsorbent. Unlike Example 1, LiNO3 is not added, the mass of Li2CO3 powder is adjusted to 5.68 kg, and the remaining preparation steps are the same as those in Example 1 and will not be repeated here.

[0107] Example 6

[0108] This embodiment provides a titanium-based lithium adsorbent. The difference from Example 1 is that 10.76 kg of lithium citrate (C6H5Li3O7) is used instead of lithium nitrate and lithium carbonate. The remaining raw materials and preparation methods are the same as those in Example 1 and are not repeated here.

[0109] Example 7

[0110] This embodiment provides a titanium-based lithium adsorbent. The difference from Example 1 is that in step 3, the material is extruded into granules with a particle size of 5 mm. The remaining raw materials and preparation methods are the same as those in Example 1 and are not repeated here.

[0111] Comparative Example 1

[0112] This comparative example provides a titanium-based lithium adsorbent, and the specific preparation method is as follows:

[0113] 1. In a 40L kneader, add 5kg of LiNO3 powder, 3kg of Li2CO3 powder, and 10kg of amorphous metatitanate H2TiO3 powder. Mix at a stirring speed of 20 rpm for 60 minutes. Mix the materials evenly and set aside for use.

[0114] Steps 2 to 5 are prepared in the same manner as the corresponding steps in Example 1.

[0115] Comparative Example 2

[0116] This comparative example provides a titanium-based lithium adsorbent, and the specific preparation method is as follows:

[0117] 1. In a 40L kneader, add 5kg of LiNO3 powder, 3kg of Li2CO3 powder, and 8kg of anatase TiO2 powder. Mix at a stirring speed of 20 rpm for 30 minutes. Mix the materials evenly and set aside.

[0118] Steps 2 to 5 are prepared in the same manner as the corresponding steps in Example 1.

[0119] Comparative Example 3

[0120] This comparative example provides a titanium-based lithium adsorbent, and the specific preparation method is as follows:

[0121] 1. In a 40L kneader, add 5kg of LiNO3 powder, 3kg of Li2CO3 powder, and 8kg of rutile TiO2 powder. Mix at a stirring speed of 20 rpm for 30 minutes. Mix the materials evenly and set aside for use.

[0122] Steps 2 to 5 are prepared in the same manner as the corresponding steps in Example 1.

[0123] Comparative Example 4

[0124] This comparative example provides a titanium-based lithium adsorbent, and the specific preparation method is as follows:

[0125] 1. In a 40L kneader, add 5kg of LiNO3 powder, 3kg of Li2CO3 powder, and 12kg of amorphous Ti(OH)4 powder. Mix at a stirring speed of 20 rpm for 30 minutes. Mix the materials evenly and set aside for use.

[0126] Steps 2 to 5 are prepared in the same manner as the corresponding steps in Example 1.

[0127] Comparative Example 5

[0128] This comparative example provides a titanium-based lithium adsorbent. Unlike Example 1, steps 2, 3, and 4 are omitted, and the materials are directly calcined at high temperature after mixing.

[0129] Comparative Example 6

[0130] This comparative example provides a titanium-based lithium adsorbent. The difference from Example 1 is that glycerol is omitted in step 2, and the mass of PEG-400 is adjusted to 1.5 kg. The remaining principles and preparation methods are the same as those in Example 1 and will not be repeated here.

[0131] Comparative Example 7

[0132] This comparative example provides a titanium-based lithium adsorbent. The difference from Example 1 is that PEG-400 is omitted in step 2, and the mass of glycerol is adjusted to 1.5 kg. The remaining principles and preparation methods are the same as those in Example 1 and will not be repeated here.

[0133] Comparative Example 8

[0134] This comparative example provides a titanium-based lithium adsorbent. The difference from Example 1 is that deionized water is omitted in step 2. The remaining principles and preparation methods are the same as those in Example 1 and will not be repeated here.

[0135] Characterization Example 1

[0136] The titanium-based lithium adsorbent precursor β-Li2TiO3 obtained in Example 1-3 was subjected to a scanning electron microscope, and the obtained scanning electron microscope image corresponds to the following: Figure 2 、 Figure 3 and Figure 4 shown.

[0137] from Figure 2 、 Figure 3 and Figure 4 It can be seen that the particle size of the synthesized β-Li2TiO3 is 100-500 nm, which is very small, which is conducive to improving the adsorption capacity of the titanium-based lithium adsorbent.

[0138] Characterization Example 2

[0139] The titanium-based lithium adsorbent precursor β-Li2TiO3 obtained in Example 1-3 was subjected to XRD, and the obtained XRD pattern corresponded to the following: Figure 5 、 Figure 6 and Figure 7 shown.

[0140] from Figure 5 、 Figure 6 and Figure 7 It can be seen that the crystal form of the synthesized titanium-based lithium adsorbent precursor is β-Li2TiO3 crystal form, which proves that the crystal form of the titanium-based lithium ion sieve synthesized in Examples 1-3 is single and has no other impurities.

[0141] Test Case

[0142] One gram of the titanium-based lithium adsorbent β-H2TiO3 obtained in the Examples and Comparative Examples was placed in 2 L of real brine (lithium ion concentration of 250 mg / L) for 3 hours of adsorption. The lithium ion concentration in the adsorbed solution was then sampled and tested, and the lithium adsorption capacity was calculated. The measured lithium adsorption capacity after 3 hours of adsorption is shown in Table 1.

[0143] Table 1

[0144]

[0145] As can be seen from Table 1, the titanium sources of Comparative Examples 1-4 are amorphous metatitanic acid, anatase TiO2, rutile TiO2, and amorphous Ti(OH)4, respectively. The 3h lithium adsorption capacity of the synthesized titanium-based lithium adsorbent is only 15-25 mg / g, which is only 10.5-17.5% of the theoretical saturated adsorption capacity (143 mg / g). It can be seen that the adsorption rate of the titanium-based lithium adsorbent synthesized by using amorphous metatitanic acid, anatase TiO2, rutile TiO2, and amorphous Ti(OH)4 as titanium sources is very slow and the adsorption capacity is very low.

[0146] As can be seen from Example 1 relative to Comparative Example 5, the method of calcining the raw material powder after forming is adopted, rather than directly calcining after the raw material powder is mixed, which is conducive to making the raw material powder combine more tightly, reducing the distance that the lithium source migrates to the titanium source during the calcining process, and is conducive to improving synthesis efficiency. The calcination time of this synthetic high temperature section only needs 0.3-1h, which greatly shortens the time required for high temperature calcination, improves synthesis efficiency and reduces energy consumption. Moreover, when the powder raw material is contained in a sagger and has a depth of 8-12cm, the thermal radiation during the high temperature calcination process can achieve uniform radiation of all powder materials. Utilizing 1-3cm strips as the material for high temperature calcination, due to the formation of a crisscross stacking arrangement between the strips and the strips, there is a certain gap between the strips, and thermal radiation can be carried out from top to bottom and from all around to the center for penetrating radiation, which can achieve the uniform thermal reaction of all materials in the sagger with a thickness of 8-12cm, making the product performance uniform and stable.

[0147] As can be seen from Example 1 compared to Comparative Example 6, when PEG-400 is used as the sole binder for kneading and extrusion, the synthesized titanium-based lithium adsorbent has a 3-hour lithium adsorption capacity of 37 mg / g, which is 26% of the theoretical saturated adsorption capacity (143 mg / g). This indicates that the adsorption rate and adsorption capacity of the titanium-based lithium adsorbent synthesized using PEG-400 as the sole binder for kneading and extrusion are very slow. This is because the viscosity of PEG-400 liquid is lower than that of glycerin. When the viscosity of the binder is too high, it is not conducive to uniform dispersion of the powder and binder. Therefore, the introduction of PEG-400 can solve the problem of uneven dispersion of the powder and binder caused by the high viscosity of glycerin, and promote uniform dispersion of the powder and binder system. However, glycerin has higher lubricity than PEG-400. Due to the smaller pores and greater resistance during extrusion, the strong lubricity of glycerin can make extrusion smoother.

[0148] Compared to Comparative Example 7, Example 1 shows that when glycerol is used as the sole binder for kneading and extrusion, the synthesized titanium-based lithium adsorbent has a 3-hour lithium adsorption capacity of 35 mg / g, which is 24.5% of the theoretical saturated adsorption capacity (143 mg / g). This indicates that the adsorption rate and adsorption capacity of the titanium-based lithium adsorbent synthesized using glycerol as the sole binder for kneading and extrusion are very slow. This is because the viscosity of PEG-400 liquid is lower than that of glycerol. When the viscosity of the binder is too high, it is not conducive to uniform dispersion of the powder and binder. Therefore, the introduction of PEG-400 can solve the problem of uneven dispersion of the powder and binder caused by the high viscosity of glycerol, and promote uniform dispersion of the powder and binder system.

[0149] As can be seen from Example 1 compared to Comparative Example 8, when deionized water is not added during the raw material kneading process, the synthesized titanium-based lithium adsorbent has a 3-hour lithium adsorption capacity of 5.2 mg / g, which is 3.6% of the theoretical saturated adsorption capacity (143 mg / g). This indicates that the adsorption rate of the synthesized titanium-based lithium adsorbent without deionized water during the raw material kneading process is very slow and the adsorption capacity is very low. This is because the addition of deionized water dissolves the soluble lithium source. After the lithium nitrate powder is dissolved, this portion of the lithium source infiltrates the titanium black Ti4O7 in the form of lithium ions, uniformly covering the surface of the titanium black Ti4O7. During the high-temperature calcination process, this portion of lithium ions can be rapidly intercalated into the titanium compound's crystal lattice, significantly shortening the calcination time and increasing the synthesis rate.

[0150] The titanium-based lithium adsorbent β-H2TiO3 prepared by the present invention has a lithium adsorption capacity of 116-123 mg / g after adsorption for 3 hours, reaching 81-86% of the theoretical saturated adsorption capacity (143 mg / g). It can be seen that the titanium-based lithium adsorbent synthesized by the present invention has the advantages of high adsorption capacity and high adsorption rate.

[0151] Finally, it should be noted that the above-described embodiments are only specific implementations of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the above-described embodiments, those skilled in the art should understand that any person skilled in the art can modify or easily conceive of changes to the technical solutions described in the above-described embodiments within the technical scope disclosed by the present invention, or replace some of the technical features therein with equivalents. Such modifications, changes, or replacements do not deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A method for preparing a titanium-based lithium adsorbent, characterized in that: The following steps are involved: After the lithium source and the titanium source are uniformly mixed, a composite binder and deionized water are added and kneaded; then, the mixture is subjected to extrusion molding, low-temperature roasting and high-temperature calcination to obtain a titanium-based lithium adsorbent precursor β-Li2TiO3; the titanium-based lithium adsorbent precursor β-Li2TiO3 is acidified to obtain a titanium-based lithium adsorbent β-H2TiO3; Wherein, the titanium source is titanium black; The chemical formula of the titanium black is Ti4O7, and it has a sodium chloride type cubic crystal form and a rutile type tetragonal crystal form; the composite binder includes polyethylene glycol and glycerol.

2. The preparation method according to claim 1, characterized in that The lithium source is a soluble lithium source and decomposes to generate gas during the calcination process.

3. The preparation method according to claim 1, characterized in that The lithium source includes at least one of lithium nitrate, lithium carbonate and lithium citrate.

4. The preparation method according to claim 1, characterized in that The molecular weight of the polyethylene glycol is 200-600.

5. The preparation method according to claim 1, characterized in that The molar ratio of Li in the lithium source to Ti in the titanium source is 1.67-2.13:

1.

6. The preparation method according to claim 1, characterized in that In the composite binder, the mass ratio of polyethylene glycol to glycerol is 2-4:1-3.

7. The preparation method according to claim 1, characterized in that The added amount of the composite binder is 10-20% of the total mass of the lithium source and the titanium source.

8. The preparation method according to any one of claims 1 to 7, characterized in that The kneading process is performed at a rotation speed of 20 to 40 rpm and a time of 10 to 30 minutes.

9. The preparation method according to any one of claims 1 to 7, characterized in that The extruded material has a length of 1 to 3 cm and a diameter of 1 to 3 mm.

10. The preparation method according to any one of claims 1 to 7, characterized in that The temperature of the low-temperature calcination is 80-150° C., and the time is 1-3 hours.

11. The preparation method according to any one of claims 1 to 7, characterized in that When calcined at high temperature, the charging thickness of the extruded material is 8~12cm.

12. The preparation method according to any one of claims 1 to 7, characterized in that The high-temperature calcination temperature is 950-1100° C., and the time is 0.3-1 h.

13. A titanium-based lithium adsorbent, characterized in that: The method is described in any one of claims 1 to 12.

14. The titanium-based lithium adsorbent according to claim 13, characterized in that The particle size of the titanium-based lithium adsorbent is 100-500 nm.

15. Use of the titanium-based lithium adsorbent according to claim 14 in lithium extraction or lithium recovery from salt lakes.

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