High-dispersion manganese-series lithium ion sieve adsorbent and preparation method of precursor of high-dispersion manganese-series lithium ion sieve adsorbent

Abstract

The invention relates to the technical field of preparation of lithium ion sieve adsorbents, in particular to a preparation method of a high-dispersion manganese lithium ion sieve adsorbent and a precursor thereof. The method comprises the following steps: continuously dropwise adding an aqueous solution of alkali into a mixed aqueous solution of a manganese source and a dispersant, adjusting the pH value, adding an oxidant, carrying out solid-liquid separation and drying to obtain Mn3O4 powder, carrying out ball milling, suction filtration and drying on the Mn3O4 powder and a lithium source, roasting to obtain Li1. 33Mn1. 67O4 lithium ion sieve precursor powder, mixing the Li1. 33Mn1. 67O4 lithium ion sieve precursor powder and a binder, molding, and drying to obtain Li1. 33Mn1. 67O4 particles, and carrying out acid washing to obtain the H1. 33Mn1. 67O4 lithium ion sieve. The method has the advantages of low cost, simple process, greenness, energy conservation and the like, and can be well applied to industrial production.

Description

Technical Field

[0001] The invention belongs to the field of materials, and in particular relates to a preparation method of a highly dispersed manganese-based lithium ion sieve adsorbent and a precursor thereof. Background Art

[0002] Due to its excellent performance, lithium metal is widely used in various high-tech fields such as lithium-ion batteries and lithium isotope hydrogen bombs. Therefore, it plays a major role in economic development and the national defense industry, and is an indispensable new energy metal in the 21st century. The total proven reserves of lithium resources worldwide are about 40 million tons, mainly distributed in three forms: seawater, salt lake brine, and accumulation type lithium ore. The traditional solid lithium ore extraction technology is far from meeting the market demand due to the cumbersome steps, high mining costs, and increasingly depleted mineral resources. The exploration of extracting lithium from salt lake brine, low-concentration seawater, and groundwater is becoming an important research topic in the current disciplines of chemistry, chemical engineering, and materials.

[0003] The main methods for extracting lithium ions from brine are: precipitation, evaporation crystallization, solvent extraction, membrane separation, and ion exchange adsorption. Among these methods, manganese-based lithium ion sieve adsorption shows unique advantages. The main reasons are that the adsorbent has good selectivity, relatively low cost, large adsorption capacity, and does not pollute the solution. According to the different lithium-manganese ratios in the ion sieve precursor material, it can be mainly divided into LiMn 2 O 4 Type, Li 1.33 Mn 1.67 O 4 Type and Li 1.6 Mn 1.6 O 4 Among these adsorbent materials, Li 1.33 Mn 1.67 O 4 Type and Li 1.6 Mn 1.6 O 4 The type of lithium ion sieve has a high theoretical adsorption capacity, so it has attracted the attention of more and more researchers. However, the problem of manganese dissolution limits the industrial application of manganese-based lithium ion sieves, so how to inhibit the dissolution of manganese has also become a research hotspot in recent years. Therefore, the research and development of efficient and green ion sieve adsorbents is of great significance for the separation and extraction of lithium from brine by adsorption. This is also the key to the development of salt lake lithium resources in my country. Optimizing its preparation method, improving its structural stability, and improving its lithium ion adsorption performance are the top priorities for the development of my country's lithium industry.

[0004] The quality of lithium ion sieve precursor directly affects the adsorption performance of lithium ion sieve. Its synthesis is the key to the entire lithium ion sieve preparation process. There are two main methods in the existing technology for preparing ion sieve adsorbents. One is high-temperature sintering and the other is the traditional hydrothermal method. However, it is difficult to control the uniformity and dispersibility of particles in the existing methods. CN 106622116 B uses lithium salt and manganese salt as raw materials, adds glycolic acid and tartaric acid as composite acid additives, and uses a sol-gel method to prepare a spinel ion sieve precursor Li 1.6 Mn 1.6 O 4 CN101961634B uses lithium salt and manganese oxide as raw materials, adds acetone or anhydrous ethanol as a dispersant, grinds and mixes; and obtains powdered LiMnO after constant temperature calcination under an inert atmosphere. 2 The intermediate is then calcined with a lithium source to prepare Li 1.6 Mn 1.6 O 4 Adsorbent, which mainly adopts solid phase sintering method, due to the limitation of dispersant's own properties and preparation method, this method is difficult to achieve effective control of particle dispersibility. CN109289756 B adopts microwave hydrothermal reaction method to prepare porous manganese lithium ion sieve adsorbent, and adopts organic polyol as structure regulator and reducing agent for regulating growth, but the hydrothermal reaction needs to be maintained for more than 12 hours, and the energy consumption is too large. CN109289757 A and CN 109289758B respectively adopt organic lipids and organic amines as structure regulator and reducing agent for regulating growth, and adopt microwave hydrothermal reaction method to prepare hexagonal dendrite and hexagonal sheet manganese lithium ion sieve adsorbent, but the dispersant in the preparation method is limited by its own texture properties, which directly limits the specific surface area of ​​the adsorbent and the improvement of manganese dispersion. The above-mentioned lithium ion sieves are all powders, and there are problems such as difficulty in solid-liquid separation and high dissolution rate when directly applied, which leads to its practical application difficulties. In view of this, it is necessary to prepare granules of a certain size for use. Summary of the invention

[0005] The invention provides a method for preparing a manganese-based low-dissolution lithium ion sieve adsorbent and a precursor thereof, aiming to improve the dispersibility and uniformity of manganese-based lithium ion sieve adsorbent particles.

[0006] The present invention provides a method for preparing the manganese-based lithium ion sieve adsorbent, comprising the following steps:

[0007] 1) preparing an aqueous solution of a manganese source and an aqueous solution of an alkali, mixing the aqueous solution of the manganese source and a dispersant, continuously dropping the aqueous solution of the alkali into the mixed aqueous solution of the manganese source and the dispersant, adjusting the pH value, stirring for 0.1 to 1 hour, adding an oxidant, and continuing to stir for 0.1 to 1 hour; after the reaction, vacuum filtration, washing and drying are performed to obtain Mn 3 O4 powder;

[0008] 2) Mn from step 1) 3 O 4 The powder, the lithium source and the solvent are ball-milled in a ball mill, and after ball-milling, a mixture powder is obtained by vacuum filtration and drying;

[0009] 3) calcining the mixture powder of step 2) to obtain a manganese-based lithium ion sieve precursor Li 1.33 Mn 1.67 O 4 powder;

[0010] 4) Li, the precursor of step 3) 1.33 Mn 1.67 O 4 The powder and binder are mixed and formed, and Li is obtained after drying. 1.33 Mn 1.67 O 4 Particles;

[0011] 5) Li from step 4) 1.33 Mn 1.67 O 4 The particles were treated with an acid solution to remove the Li + , obtain manganese-based lithium ion sieve H 1.33 Mn 1.67 O 4 .

[0012] In the above preparation method, in step 1), the manganese source can be at least one of manganese nitrate, manganese chloride, manganese sulfate, manganese acetate, and manganese lactate. The manganese content in the aqueous solution of the manganese source is 2-20%, preferably 4-16%, and more preferably 6-10%.

[0013] The alkali can be at least one of sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate and potassium bicarbonate. The alkali concentration in the aqueous solution of the alkali is 2-6 mol / L, preferably 3-5 mol / L.

[0014] The dispersant may be at least one of silica sol, aluminum sol, zirconium sol, silica aluminum sol, silica zirconium sol, and aluminum zirconium sol. The solid content of the dispersant is 5-40%, preferably 10-30%, for example, 12%, 15%, 20%, 25%, 30%.

[0015] The pH value is 8-11, preferably 8-9.

[0016] The oxidant may be at least one of hydrogen peroxide and peroxy acid. The molar ratio of the oxidant to manganese is 0.5 to 1:1, preferably 0.7 to 1:1.

[0017] The washing includes washing with water such as deionized water.

[0018] The drying temperature is 50 to 150° C., and the drying time is 6 to 24 hours.

[0019] In the above preparation method, in step 2), the lithium source can be at least one of lithium hydroxide, lithium chloride, lithium carbonate, lithium sulfate, lithium nitrate, lithium acetate, lithium oxalate, and lithium lactate. The molar ratio of manganese in the manganese source to lithium in the lithium source is 0.5 to 1.5:1, preferably 0.9 to 1.3:1, and more preferably 1.0 to 1.1:1.

[0020] The solvent may be at least one of deionized water and ethanol.

[0021] The ball milling time is 1 to 8 hours.

[0022] The drying temperature is 50 to 150° C., and the drying time is 6 to 24 hours.

[0023] In the above preparation method, in step 3), the atmosphere during calcination can be at least one of air, oxygen and argon. The calcination temperature is 500-850°C, preferably 600-800°C, and the calcination time is 2-12h, preferably 4-8h.

[0024] In the above preparation method, in step 4), the binder can be at least one of acrylic resin emulsion, hydroxy acrylic resin emulsion, epoxy resin emulsion, phenolic resin emulsion, silicone resin emulsion, styrene acrylic resin emulsion, ethylene propylene resin emulsion, polyurethane resin emulsion, and EVA resin emulsion. The amount added is 1 to 30% wt of the mixture powder, preferably 5 to 10% wt, based on the solid phase.

[0025] The drying temperature is 50-100° C., and the drying time is 6-24 hours.

[0026] In the above preparation method, in step 5), the acid solution can be at least one of hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, oxalic acid, and acetic acid. The concentration of the acid solution is 0.01 to 0.2 mol / L, preferably 0.02 to 0.1 mol / L.

[0027] The present invention also provides a method for preparing a manganese-based lithium ion sieve adsorbent precursor, which comprises steps 1) to 3) of the present invention.

[0028] The present invention also provides a manganese-based lithium ion sieve adsorbent precursor and a manganese-based lithium ion sieve adsorbent prepared by the preparation method.

[0029] In one embodiment, the manganese-based lithium ion sieve adsorbent precursor is prepared by the preparation method described in steps 1) to 3).

[0030] In one embodiment, the manganese-based lithium ion sieve adsorbent is prepared by the preparation method described in steps 1) to 5).

[0031] The present invention also provides application of the manganese-based lithium ion sieve adsorbent in lithium extraction.

[0032] In one embodiment, the manganese-based lithium ion sieve adsorbent prepared by the above method can be used to extract lithium from salt lake brine, underground brine, seawater, and lithium-containing solutions.

[0033] The invention provides a method for preparing a lithium ion sieve adsorbent and a precursor thereof, as well as a lithium ion sieve adsorbent and a precursor thereof prepared by the preparation method. The prepared manganese-based lithium ion sieve adsorbent can be used to extract lithium from salt lake water, brine, seawater, and lithium-containing solutions. The dispersant of the invention and the manganese precursor are precipitated with alkaline solution. During the precipitation process, the dispersant can inhibit the aggregation of particles during the precipitation process, improve the dispersion degree of the entire system, and make the adsorbent have a higher specific surface area. The method uses a low-cost manganese source and a lithium source as raw materials, has the advantages of low cost, simple process, green energy saving, etc., and can be well applied in industrial production.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] 1) The method provided by the present invention has mild conditions, simple operation, and few by-products, and is an efficient and clean production process.

[0036] 2) The preparation method provided by the present invention is novel, simple in process, and easy for large-scale production. By adding a dispersant, the surface area of ​​the adsorbent can be greatly increased.

[0037] 3) The present invention uses common sol as a structure regulator to regulate the growth, synthesizes the intermediate, and then uses a high temperature solid phase method to prepare Li 1.33 Mn 1.67 O 4 Lithium ion sieve adsorbent, the synthesized lithium ion sieve has a stable spinel structure. The dynamic adsorption capacity of the prepared lithium ion sieve is up to 25 mg / g, and the adsorption capacity remains above 90% after 6 cycles. The manganese dissolution loss after 6 acid washing and lithium extraction cycles is less than 1%.

[0038] 4) The product has high purity, good quality, controllable surface, high dispersibility, uniform distribution, high adsorption capacity, stable lithium adsorption and extraction performance, and low manganese dissolution loss.

[0039] 5) The method of the present invention has good application prospects, has the advantages of low cost, simple process, green energy saving, etc., and can be well applied in industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1The XRD patterns of the adsorbents of the embodiments and comparative examples are shown in FIG. DETAILED DESCRIPTION

[0041] The present invention is further described below through specific examples.

[0042] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0043] Unless otherwise specified, the materials and reagents used in the following examples can be obtained from commercial sources.

[0044] Embodiment 1,

[0045] 1) preparing an aqueous solution of manganese nitrate with a manganese content of 8% and an aqueous solution of 4 mol / L sodium hydroxide, mixing 1600 g of an aqueous solution of 8% manganese nitrate and 23 g of a silica sol with a solid content of 30%, continuously dropping the aqueous solution of 4 mol / L sodium hydroxide into the mixed aqueous solution of manganese nitrate and silica sol, adjusting the pH value to 8.5, stirring for 0.2 h, adding 150 ml of a 30 wt % hydrogen peroxide solution, and continuing to stir for 0.2 h; after the reaction, vacuum filtering, rinsing with deionized water, and drying at 100° C. for 12 h to obtain Mn 3 O 4 powder.

[0046] 2) The molar ratio of lithium to manganese is 1:1. 3 O 4 The powder, lithium hydroxide and ethanol were ball-milled in a ball mill for 2 h. After ball-milling, the mixture was vacuum filtered and dried at 100° C. for 12 h to obtain a mixture powder.

[0047] 3) The mixed powder was calcined in air at 700 °C for 6 h to obtain the manganese-based lithium ion sieve precursor Li 1.33 Mn 1.67 O 4 powder.

[0048] 4) The precursor Li 1.33 Mn 1.67 O 4 The powder and acrylic resin emulsion were mixed and molded, wherein the amount of acrylic resin emulsion added was 5%wt of the mixed powder in terms of solid phase, and Li was obtained after drying at 60°C for 12h. 1.33 Mn 1.67 O 4 Particles.

[0049] 5) Take a certain amount of lithium ion sieve precursor Li prepared by the above method 1.33 Mn 1.67 O 4 Particles, using 0.05mol / L hydrochloric acid solution to remove Li from the precursor + , obtain manganese-based lithium ion sieve H1.33 Mn 1.67 O 4 .

[0050] Embodiment 2,

[0051] 1) preparing an aqueous solution of manganese nitrate with a manganese content of 8% and an aqueous solution of 4 mol / L sodium hydroxide, mixing 1600 g of an aqueous solution of 8% manganese nitrate and 45 g of an aluminum sol with a solid content of 12%, continuously dropping the aqueous solution of 4 mol / L sodium hydroxide into the mixed aqueous solution of manganese nitrate and aluminum sol, adjusting the pH value to 8.5, stirring for 0.2 h, adding 150 ml of a 30 wt % hydrogen peroxide solution, and continuing to stir for 0.2 h; after the reaction, vacuum filtration, washing with deionized water, and drying at 100° C. for 12 h to obtain Mn 3 O 4 powder.

[0052] 2) The molar ratio of lithium to manganese is 1:1. 3 O 4 The powder, lithium chloride and ethanol were ball-milled in a ball mill for 2 h. After ball-milling, the mixture was vacuum filtered and dried at 100° C. for 12 h to obtain a mixture powder.

[0053] 3) The mixed powder was calcined in oxygen at 700 °C for 6 h to obtain the manganese-based lithium ion sieve precursor Li 1.33 Mn 1.67 O 4 powder.

[0054] 4) The precursor Li 1.33 Mn 1.67 O 4 The powder and acrylic resin emulsion were mixed and molded, wherein the amount of acrylic resin emulsion added was 10%wt of the mixed powder in terms of solid phase, and the mixture was dried at 60°C for 12h to obtain Li 1.33 Mn 1.67 O 4 Particles.

[0055] 5) Take a certain amount of lithium ion sieve precursor Li prepared by the above method 1.33 Mn 1.67 O 4 Particles, using 0.1mol / L hydrochloric acid solution to remove Li from the precursor + , obtain manganese-based lithium ion sieve H 1.33 Mn 1.67 O 4 .

[0056] Embodiment 3,

[0057] 1) preparing an aqueous solution of manganese chloride with a manganese content of 8% and an aqueous solution of 4 mol / L sodium hydroxide, mixing 1600 g of an aqueous solution of 8% manganese chloride and 65 g of a zirconium sol with a solid content of 22%, continuously dropping the aqueous solution of 4 mol / L sodium hydroxide into the mixed aqueous solution of manganese chloride and zirconium sol, adjusting the pH value to 8, stirring for 0.1 h, adding 150 ml of a 30 wt % hydrogen peroxide solution, and continuing to stir for 0.1 h; after the reaction, vacuum filtering, rinsing with deionized water, and drying at 100° C. for 12 h to obtain Mn 3 O 4 powder.

[0058] 2) The molar ratio of lithium to manganese is 1:1.1. 3 O 4 The powder, lithium carbonate and ethanol were ball-milled in a ball mill for 3 h. After ball-milling, the mixture was vacuum filtered and dried at 100° C. for 12 h to obtain a mixture powder.

[0059] 3) The mixed powder was calcined in air at 600 °C for 6 h to obtain the manganese-based lithium ion sieve precursor Li 1.33 Mn 1.67 O 4 powder.

[0060] 4) The precursor Li 1.33 Mn 1.67 O 4 The powder and epoxy resin emulsion were mixed and molded, wherein the epoxy resin emulsion was added in an amount of 5%wt of the mixed powder based on the solid phase, and dried at 60°C for 12h to obtain Li 1.33 Mn 1.67 O 4 Particles.

[0061] 5) Take a certain amount of lithium ion sieve precursor Li prepared by the above method 1.33 Mn 1.67 O 4 Particles, using 0.05mol / L sulfuric acid solution to remove Li from the precursor + , obtain manganese-based lithium ion sieve H 1.33 Mn 1.67 O 4 .

[0062] Embodiment 4,

[0063] 1) preparing an aqueous solution of manganese chloride with a manganese content of 8% and an aqueous solution of 4 mol / L sodium hydroxide, mixing 1600 g of an aqueous solution of 8% manganese chloride and 40 g of a silica-alumina sol with a solid content of 25%, continuously dropping the 4 mol / L sodium hydroxide aqueous solution into the mixed aqueous solution of manganese chloride and silica-alumina sol, adjusting the pH value to 8, stirring for 0.1 h, adding 150 ml of a 30 wt % hydrogen peroxide aqueous solution, and continuing to stir for 0.1 h; after the reaction, vacuum filtration, washing with deionized water, and drying at 100° C. for 12 h were performed to obtain Mn 3 O 4 powder.

[0064] 2) The molar ratio of lithium to manganese is 1:1.1. 3 O 4 The powder, lithium carbonate and ethanol were ball-milled in a ball mill for 3 h. After ball-milling, the mixture was vacuum filtered and dried at 100° C. for 12 h to obtain a mixture powder.

[0065] 3) The mixed powder was calcined in oxygen at 600 ° C for 6 h to obtain the manganese-based lithium ion sieve precursor Li 1.33 Mn 1.67 O 4 powder.

[0066] 4) The precursor Li 1.33 Mn 1.67 O 4 The powder and epoxy resin emulsion were mixed and molded, wherein the epoxy resin emulsion was added in an amount of 10% wt of the mixed powder based on the solid phase, and dried at 60°C for 12h to obtain Li 1.33 Mn 1.67 O 4 Particles.

[0067] 5) Take a certain amount of lithium ion sieve precursor Li prepared by the above method 1.33 Mn 1.67 O 4 Particles, using 0.05mol / L sulfuric acid solution to remove Li from the precursor + , obtain manganese-based lithium ion sieve H 1.33 Mn 1.67 O 4 .

[0068] Embodiment 5,

[0069] 1) preparing an aqueous solution of manganese sulfate with a manganese content of 8% and an aqueous solution of 4 mol / L sodium hydroxide, mixing 1600 g of an aqueous solution of 8% manganese sulfate and 30 g of aluminum zirconium sol with a solid content of 30%, continuously dropping the aqueous solution of 4 mol / L sodium hydroxide into the mixed aqueous solution of manganese sulfate and aluminum zirconium sol, adjusting the pH value to 9, stirring for 0.3 h, adding 150 ml of a 30 wt % hydrogen peroxide solution, and continuing to stir for 0.3 h; after the reaction, vacuum filtration, rinsing with deionized water, and drying at 100° C. for 12 h to obtain Mn 3 O 4 powder.

[0070] 2) The molar ratio of lithium to manganese is 1:1. 3 O 4 The powder, lithium carbonate and water were ball-milled in a ball mill for 4 h. After ball-milling, the mixture was vacuum filtered and dried at 100° C. for 12 h to obtain a mixture powder.

[0071] 3) The mixed powder was calcined in air at 800 °C for 6 h to obtain the manganese-based lithium ion sieve precursor Li 1.33 Mn 1.67 O 4 powder.

[0072] 4) The precursor Li 1.33 Mn 1.67 O 4 The powder and the polyurethane resin emulsion were mixed and molded, wherein the amount of the polyurethane resin emulsion added was 5%wt of the mixed powder in terms of solid phase, and the Li 1.33 Mn 1.67 O 4 Particles.

[0073] 5) Take a certain amount of lithium ion sieve precursor Li prepared by the above method 1.33 Mn 1.67 O 4 Particles, using 0.02mol / L hydrochloric acid solution to remove Li from the precursor + , obtain manganese-based lithium ion sieve H 1.33 Mn 1.67 O 4 .

[0074] Embodiment 6,

[0075] 1) preparing an aqueous solution of manganese sulfate with a manganese content of 8% and an aqueous solution of 4 mol / L sodium hydroxide, mixing 1600 g of an aqueous solution of 8% manganese sulfate and 35 g of a silica zirconium sol with a solid content of 30%, continuously dropping the aqueous solution of 4 mol / L sodium hydroxide into the mixed aqueous solution of manganese sulfate and silica zirconium sol, adjusting the pH value to 9, stirring for 0.3 h, adding 150 ml of a 30 wt % hydrogen peroxide solution, and continuing to stir for 0.3 h; after the reaction, vacuum filtration, rinsing with deionized water, and drying at 100° C. for 12 h to obtain Mn 3 O 4 powder.

[0076] 2) The molar ratio of lithium to manganese is 1:1. 3 O 4 The powder, lithium sulfate and ethanol were ball-milled in a ball mill for 4 h. After ball-milling, the mixture was filtered by vacuum and dried at 100° C. for 12 h to obtain a mixture powder.

[0077] 3) The mixed powder was calcined in oxygen at 800 °C for 6 h to obtain the manganese-based lithium ion sieve precursor Li 1.33 Mn 1.67 O 4 powder.

[0078] 4) The precursor Li 1.33 Mn 1.67 O 4 The powder and the polyurethane resin emulsion are mixed and molded, wherein the amount of the polyurethane resin emulsion added is 10%wt of the mixed powder in terms of solid phase, and the Li 1.33 Mn 1.67 O 4 Particles.

[0079] 5) Take a certain amount of lithium ion sieve precursor Li prepared by the above method 1.33 Mn 1.67 O 4 Particles, using 0.02mol / L sulfuric acid solution to remove Li from the precursor + , obtain manganese-based lithium ion sieve H 1.33 Mn 1.67 O 4 .

[0080] Comparative Example 1

[0081] 1) preparing an aqueous solution of manganese nitrate with a manganese content of 8% and an aqueous solution of 4 mol / L sodium hydroxide, continuously dropping the aqueous solution of 4 mol / L sodium hydroxide into an aqueous solution of 1600 g of an 8% aqueous solution of manganese nitrate, adjusting the pH value to 8.5, stirring for 0.2 h, adding 150 ml of a 30 wt % hydrogen peroxide solution, and continuing to stir for 0.2 h; after the reaction, vacuum filtering, rinsing with deionized water, and drying at 100° C. for 12 h to obtain Mn3 O 4 powder.

[0082] 2) The molar ratio of lithium to manganese is 1:1. 3 O 4 The powder, lithium hydroxide and ethanol were ball-milled in a ball mill for 2 h. After ball-milling, the mixture was vacuum filtered and dried at 100° C. for 12 h to obtain a mixture powder.

[0083] 3) The mixed powder is calcined at 700°C in air to obtain a manganese-based lithium ion sieve precursor Li 1.33 Mn 1.67 O 4 powder.

[0084] 4) The precursor Li 1.33 Mn 1.67 O 4 The powder and acrylic resin emulsion were mixed and molded, wherein the amount of acrylic resin emulsion added was 5%wt of the mixed powder in terms of solid phase, and Li was obtained after drying at 60°C for 12h. 1.33 Mn 1.67 O 4 Particles.

[0085] 5) Take a certain amount of lithium ion sieve precursor Li prepared by the above method 1.33 Mn 1.67 O 4 Particles, using 0.05mol / L hydrochloric acid solution to remove Li from the precursor + , obtain manganese-based lithium ion sieve H 1.33 Mn 1.67 O 4 .

[0086] Single adsorption experiment process:

[0087] 1) 3L of salt lake brine with a lithium content of 110mg / L passed through a 10g manganese lithium ion sieve H at a rate of 10ml / min. 1.33 Mn 1.67 O 4 , the lithium ions in the salt lake brine are adsorbed on the manganese-based lithium ion sieve.

[0088] 2) Passing an acid solution through the manganese-based lithium ion sieve at a rate of 10 ml / min, eluting and desorbing the lithium ions adsorbed on the manganese-based lithium ion sieve until the pH is less than 2.5, and obtaining a desorption solution.

[0089] Multiple experimental processes repeat the above single experimental process.

[0090] The properties of the lithium ion sieve adsorbents of the embodiments and comparative examples are as follows: Figure 1 And as shown in Table 1.

[0091] Table 1 Specific surface area, adsorption capacity and manganese dissolution loss of adsorbents

[0092]

[0093]

[0094] *Total manganese loss is calculated based on the manganese content in the lithium-rich solution and the adsorbent.

[0095] Depend on Figure 1 It can be seen from Table 1 that: 1) compared with the pure lithium ion sieve in Comparative Example 1, the highly dispersed lithium ion sieve prepared in the present invention has a smaller grain size and an increased specific surface area.

[0096] 2) Compared with the simple lithium ion sieve in Comparative Example 1, the highly dispersed lithium ion sieve prepared in the present invention has a greatly increased adsorption capacity for lithium ions; this indicates that the highly dispersed lithium ion sieve prepared in the present application has a high adsorption capacity and high selectivity for lithium ions.

[0097] 3) Compared with the simple lithium ion sieve in Comparative Example 1, the manganese dissolution loss of the highly dispersed lithium ion sieve prepared by the present invention is significantly lower than the manganese dissolution loss of the simple lithium ion sieve in Comparative Example 1.

[0098] The lithium ion sieve with high specific surface area prepared by the method of the present invention is pickled after use, and the lithium ion sieve with high specific surface area after pickling can continue to adsorb lithium ions; combined with the above Table 1, it can be seen that the adsorption capacity of the lithium ion sieve with high specific surface area in Examples 1 to 6 is maintained at more than 90% after 6 cycles; while the adsorption capacity of the lithium ion sieve in the comparative example is maintained at about 60% after 6 cycles, and its adsorption performance retention rate is obviously not as good as that of the lithium ion sieve with high specific surface area prepared by the method of the present invention. The highly dispersed lithium ion sieve in the present invention has high adsorption capacity, high selectivity for lithium ions, low manganese dissolution rate, strong stability, and can be used for repeated recycling. The method of the present invention is conducive to large-scale manufacturing and application.

[0099] Obviously, the description of the above embodiments is only used to help understand the method of the present invention and its core idea. It should be pointed out that for ordinary technicians in the technical field, several improvements and modifications can be made to the present invention without departing from the principle of the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing a manganese-based lithium ion sieve adsorbent, characterized in that: The steps include: 1) preparing an aqueous solution of a manganese source and an aqueous solution of an alkali, mixing the aqueous solution of the manganese source and a dispersant, continuously dropping the aqueous solution of the alkali into the mixed aqueous solution of the manganese source and the dispersant, adjusting the pH value, stirring for 0.1 to 1 hour, adding an oxidant, and continuing to stir for 0.1 to 1 hour; after the reaction, vacuum filtering, washing and drying to obtain Mn3O4 powder; 2) ball milling the Mn3O4 powder, lithium source and solvent in step 1) in a ball mill, and obtaining a mixture powder by vacuum filtration and drying after ball milling; 3) calcining the mixture powder of step 2) to obtain a manganese-based lithium ion sieve precursor Li 1.33 Mn 1.67 O4 powder; 4) Li, the precursor of step 3) 1.33 Mn 1.67 O4 powder and binder are mixed and formed, and Li is obtained after drying. 1.33 Mn 1.67 O4 particles; 5) Li from step 4) 1.33 Mn 1.67 The Li in O4 particles is removed by acid solution. + , obtain manganese-based lithium ion sieve H 1.33 Mn 1.67 O4.

2. The preparation method according to claim 1, in step 1), the manganese source is at least one of manganese nitrate, manganese chloride, manganese sulfate, manganese acetate, and manganese lactate; the manganese content in the aqueous solution of the manganese source is 2-20%; The alkali is at least one of sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate and potassium bicarbonate, and the alkali concentration in the aqueous solution of the alkali is 2-6 mol / L; The dispersant is at least one of silica sol, aluminum sol, zirconium sol, silica aluminum sol, silica zirconium sol, and aluminum zirconium sol, and the solid content of the dispersant is 5-40%; The pH value is 8 to 11; The oxidant is at least one of hydrogen peroxide and peracid, and the molar ratio of the oxidant to manganese is 0.5 to 1:

1.

3. The preparation method according to claim 1, in step 2), the lithium source is at least one of lithium hydroxide, lithium chloride, lithium carbonate, lithium sulfate, lithium nitrate, lithium acetate, lithium oxalate, and lithium lactate, and the molar ratio of manganese in the manganese source to lithium in the lithium source is 0.5 to 1.5:1; The solvent is at least one of deionized water and ethanol.

4. The preparation method according to claim 1, in step 3), the atmosphere during calcination is at least one of air, oxygen and argon; The calcination temperature is 500-800° C., and the calcination time is 2-12 hours.

5. The preparation method according to claim 1, in step 4), the binder is at least one of acrylic resin emulsion, hydroxy acrylic resin emulsion, epoxy resin emulsion, phenolic resin emulsion, silicone resin emulsion, styrene acrylic resin emulsion, ethylene propylene resin emulsion, polyurethane resin emulsion, and EVA resin emulsion, and its addition amount based on solid phase is 1 to 30%wt of the mixture powder.

6. The preparation method according to claim 1, in step 5), the acid solution is at least one of hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, oxalic acid, and acetic acid; The acid solution concentration is 0.01-0.2 mol / L.

7. A method for preparing a manganese-based lithium ion sieve adsorbent precursor, characterized in that: The method comprises steps 1) to 3) according to any one of claims 1 to 4.

8. A manganese-based lithium ion sieve adsorbent prepared by the preparation method according to any one of claims 1 to 6 or a manganese-based lithium ion sieve adsorbent precursor prepared by the preparation method according to claim 7.

9. Use of the manganese-based lithium ion sieve adsorbent described in claim 8 in lithium extraction.

10. The use according to claim 9, characterized in that: The manganese-based lithium ion sieve adsorbent is used to extract lithium from salt lake brine, underground brine, seawater, and lithium-containing solutions.

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