阅读说明：本技术 一种锂辉石中锂的提取方法、其提取用吸附材料及制备方法 (extraction method of lithium in spodumene, adsorption material for extraction and preparation method ) 是由 赵�卓 徐亮 张福元 童碧海 田勇攀 姚永林 程衔锟 熊延杭 于 2019-11-22 设计创作，主要内容包括：本发明公开了一种锂辉石中锂的提取方法、其提取用吸附材料及制备方法,属于锂资源提取技术领域。本发明的吸附材料为负载于SiO<Sub>2</Sub>表面上的4-胺基二苯并14冠4冠醚衍生物,本发明的一种锂辉石中锂的提取方法,采用硫酸法进行提取,将锂辉石经焙烧转型-硫酸化焙烧-浸出得到硫酸锂溶液,然后采用上述吸附材料对所得硫酸锂溶液进行吸附处理,最后对吸附材料进行洗涤、解吸后加入纯碳酸钠溶液并加热进行沉锂,经洗涤、干燥后即得到碳酸锂产品。本发明的吸附材料对锂的选择性吸附能力较强,能够有效用于硫酸法锂辉石中锂的提取,其提取效率高,实现了对锂离子的高度富集作用,并克服了现有硫酸法提取工艺存在的不足。(The invention discloses an extraction method of lithium in spodumene, an adsorption material for extraction and a preparation method thereof, belonging to the technical field of lithium resource extraction 2 The invention discloses a 4-amido dibenzo 14 crown 4 crown ether derivative on the surface, and relates to a method for extracting lithium from spodumene, which comprises the steps of extracting by a sulfuric acid method, carrying out roasting transformation, sulfating roasting and leaching on the spodumene to obtain a lithium sulfate solution, then carrying out adsorption treatment on the obtained lithium sulfate solution by using an adsorption material, finally washing and desorbing the adsorption material, adding a pure sodium carbonate solution, heating for precipitating lithium, and washing and drying to obtain a lithium carbonate productThe extraction efficiency is high, the high enrichment effect on lithium ions is realized, and the defects of the existing sulfuric acid method extraction process are overcome.)

1, kinds of absorbing material for extracting lithium from spodumene, characterized in that the absorbing material is loaded on SiO₂A 4-aminodibenzo 14 crown 4 crown ether derivative on a surface having the formula:

a method for preparing the adsorbent material according to claim 1, , comprising the steps of:

(1) adding 1, 3-dibromopropane and catechol into NaOH aqueous solution for heating reaction, and carrying out the following post-treatment on the mixed solution obtained by the reaction: pouring the generated mixed solution into NaOH aqueous solution, adding an extracting agent, sequentially filtering, adjusting the pH value, extracting, drying, removing a solvent, and passing through a silica gel column to obtain a product A;

(2) under the protection of nitrogen, A, LiOH and H are obtained₂O, mixing, then dropwise adding epoxy chloropropane for reaction, cooling to room temperature after reaction, and obtaining a product B by adopting the same post-treatment operation as that in the step (1);

(3) adding the product B and triethylamine into CH₂Cl₂Dropwise adding methylsulfonyl chloride into the solution to react, then adding HCl solution to stir, separate and wash the organic phase, and obtaining a product C by adopting the same post-treatment operation as the step (1);

(4) subjecting the product C, Na₃N、Cs₂CO₃Dissolving in DMF for reaction, extracting the reaction product, drying the organic phase obtained by extraction, spinning, passing through a column, spinning, adding into a solution containing LiAlH₄Adding a NaOH solution into the THF solution mixed solution, stirring and mixing uniformly, and filtering to obtain a product D;

(5) dissolving the product D in a mixed solution of methanol and DMF to obtain a product E;

(6) dissolving the product E and a silane coupling agent in THF, adding ethanol and water, and then adding SiO₂And (4) reacting, and adjusting the pH value to obtain the adsorbing material.

3. The method for producing an adsorbent material according to claim 2, characterized in that: in the step (1), the molar ratio of the 1, 3-dibromopropane to the catechol to the NaOH is as follows: 1, (2-3) adding 1, 3-dibromopropane and catechol into a reaction bottle, stirring and heating to 120-140 ℃, then adding an aqueous solution of NaOH within 1-2 h, and stirring and reacting for 5-10 h; the extractant added in the post-treatment in the step (1) is CH₂Cl₂Adjusting pH value of filtrate to be neutral by adopting HCl solution, and adopting anhydrous Na₂SO₄Drying is carried out.

4. The method for producing an adsorbent material according to claim 2, characterized in that: the molar ratio of the product A, LiOH to the epichlorohydrin in the step (2) is as follows: 1 (2-3) and (1-2) the product A, LiOH and H are first mixed₂Adding O into a reaction bottle, heating to 90-95 ℃, stirring until the O is completely dissolved, then cooling to 40-60 ℃, and then dropwise adding epoxy chloropropane to enable the substances to react for 3-5h at 40-50 ℃; the molar ratio of the product B to the triethylamine to the methylsulfonyl chloride in the step (3) is 2 (1-2) to (9-10), the methylsulfonyl chloride is added dropwise when the temperature of the mixed solution of the product B and the triethylamine is 0-5 ℃, and the mixed solution is heated to room temperature to react for 1-1.5 days after dropwise addition; adding 4-6% of HCl solution by mass, stirring for 20-40 minutes, and separating by using saturated NaHCO after organic phase separation₃Washing to be neutral.

5. The method for producing an adsorbent material according to claim 2, characterized in that: product C, Na from step (4)₃N and Cs₂CO₃The molar ratio of (A) to (B) is: 2 (4-5) and (1-2), the reaction temperature of the solution is 100-110 ℃, the reaction time is 1.5-2.5 days, water and CH are adopted after the reaction₂Cl₂Extracting the reaction product, and adopting anhydrous Na as an organic phase₂SO₄Drying the product C with LiAlH₄The molar ratio is as follows: 1, (5-6); in the step (5), the mass ratio of the product D to the methanol to the DMF is 1 (8-9) to (10-11), and the mixture is stirred at room temperature for 25-35 min; the molar ratio of the product E to the silane coupling agent in the step (6) is 1 (2-3), and the types of the added silane coupling agents are as follows: KH560 SiO with epoxy group on surface₂Micro-spheres of SiO₂The molar ratio of the product E to the product E is 1 (5-6), and after reaction, acetic acid is adopted to adjust the pH value to 4-5.

6, extraction method of lithium in spodumene, which is characterized in that extraction is carried out by sulfuric acid method, the specific operation is that spodumene is roasted, transformed, sulfated and roasted, and leached to obtain lithium sulfate solution, then the obtained lithium sulfate solution is absorbed by the absorbing material in claim 1, finally the absorbing material is washed and desorbed, then pure sodium carbonate solution is added, and heating is carried out to deposit lithium, and lithium carbonate product is obtained after washing and drying.

7. The method for extracting lithium from spodumene according to claim 6, wherein the method comprises roasting spodumene at 950-1100 deg.C, mixing with concentrated sulfuric acid, roasting at 250-300 deg.C, leaching the roasted product with water for 10-20 min to obtain lithium sulfate solution.

8. The method for extracting lithium from spodumene according to claim 6, wherein the adsorption material is placed on an adsorption column during adsorption, the temperature of the lithium sulfate solution during adsorption is 40-60 ℃, the flow rate is 5-10 mL/min, and the adsorption time is 15-60 min.

9. The method for extracting lithium from spodumene according to claim 6, wherein the adsorbed material is washed with dilute sulfuric acid having a concentration of 1-2 mol/L and desorbed with concentrated sulfuric acid having a concentration of 8-12 mol/L at room temperature.

10. The method for extracting lithium from spodumene according to claim 6, wherein the method comprises adding pure sodium carbonate solution after desorption, heating to 80-100 ℃ to precipitate lithium for 30-40 min, washing with pure water at 90-100 ℃ for 2-3 times, and drying at 180-200 ℃.

Technical Field

The invention belongs to the technical field of extraction of lithium resources, and particularly relates to an extraction method of lithium in spodumene, an adsorption material for extraction and a preparation method of the adsorption material.

Background

In recent years, lithium shows a huge application prospect in the field of new energy due to the superior performance of high energy density and high electrochemical potential (3.045V), particularly with the successful application of lithium ion batteries in electric automobiles and hybrid electric automobiles, the worldwide demand for lithium is rapidly increased, and therefore, the full development and utilization of lithium resources are imminent.

Lithium mineral resources in the nature are mainly existed in salt lake brine and granite pegmatite, the reserve of lithium in the salt lake brine in China accounts for about 85 percent of the total amount of lithium resources in China, wherein the lithium content is high, but the economic utilization is difficult, so the lithium salt products in China still mainly come from ores (78 percent), spodumene is types of granite pegmatite, and the lithium content is high (the theoretical Li content is high)₂O can reach 8.03 percent) and is easy to process, and is the main raw material for extracting lithium from the ore at present.

The method for extracting lithium from spodumene mainly comprises a sulfuric acid method, a sulfate method, a soda ash pressure boiling method, a lime sintering method and the like, wherein the sulfuric acid method has the advantages of strong adaptability to raw materials, flexible process, high recovery rate and the like, and is a main method applied to the current industry, and the sulfuric acid method mainly comprises the steps of (1) roasting spodumene at the temperature of 950 ℃ plus 1100 ℃ to convert a crystal form of the spodumene from a α monoclinic system to a β tetragonal system, (2) roasting sulfuric acid and β spodumene at the temperature of 250 ℃ plus 300 ℃ to generate lithium sulfate and insoluble gangue, (3) leaching sulfated roasted products by using water to obtain a lithium sulfate solution, (4) adding lime to neutralize redundant acid and remove impurity ions such as iron and aluminum, (5) continuously adding lime to adjust the pH value to be more than 11 to remove magnesium and part of calcium, then adding sodium carbonate to remove the residual calcium, and (6) adjusting the pH value of the solution after impurity removal to 7-8 by using acid to evaporate and concentrate lithium carbonate, then adding sodium carbonate to precipitate, and returning to a sodium freezing and leaching mother liquor.

However, the process of extracting lithium from spodumene by adopting the process method has the problems that the demand for acid and alkali is high (acid and alkali are adopted for neutralization), a large amount of acid and alkali waste is easily caused, sodium carbonate is added during calcium removal, part of lithium is lost in calcium slag and is difficult to recover, the lithium sulfate solution after impurity removal can be used for the lithium deposition process after evaporation and concentration, the energy consumption is high, and even if a plurality of impurity removal methods are adopted in the process, the content of impurity ions in the final product is still high.

For example, the chinese patent applications CN 109078601(2018.12.25), CN 109529757(2019.03.29) and CN 108097198(2018.06.01) all disclose improved manganese ion sieves, wherein the manganese ion sieve in the above application can selectively adsorb lithium in a solution (leachate lithium sulfate solution or salt lake brine), so as to ensure that the content of impurity ions in the obtained lithium solution is low and the concentration of lithium is enriched, and the manganese ion sieve in the above application can effectively improve the stability and the service life of the ion sieve by improving the existing manganese ion sieve.

For another example, patent CN109439914A discloses a method for extracting lithium ions from a complex solution containing metal ions such as cobalt, nickel, manganese, and iron by kinds of 14-crown-4 crown ether derivatives, in which a crown ether compound (benzo 15-crown-5 derivative or dibenzo 14-crown-4 derivative) having a selective recognition effect on lithium ions is used as an adsorbent, so as to realize selective separation of lithium ions, and can extract lithium ions from a leachate of a positive electrode material of a waste lithium ion battery.

Disclosure of Invention

1. Problems to be solved

The invention aims at overcoming the defects that when the existing sulfuric acid process is adopted to extract lithium from spodumene, the extraction effect is relatively poor, the acid and alkali consumption is large and the like, and provides absorbing materials for extracting lithium from spodumene and a preparation method thereof.

The second purpose of the invention is to provide an extraction method of lithium in spodumene, which can selectively adsorb lithium in spodumene, effectively remove other impurity ions, obtain a solution with higher lithium-containing concentration, realize the high enrichment effect on lithium ions, directly precipitate lithium carbonate, further obtain a lithium carbonate product with higher purity, and overcome the defects of the existing sulfuric acid extraction process.

2. Technical scheme

In order to solve the problems, the technical scheme adopted by the invention is as follows:

, an adsorbent for extracting lithium from spodumene of the present invention, wherein the adsorbent is SiO-supported₂A 4-aminodibenzo 14 crown 4 crown ether derivative on a surface having the formula:

secondly, the preparation method of the adsorbing material of the invention comprises the following steps:

(1) adding 1, 3-dibromopropane and catechol into NaOH aqueous solution for heating reaction, and carrying out the following post-treatment on the mixed solution obtained by the reaction: pouring the generated mixed solution into NaOH aqueous solution, adding an extracting agent, sequentially filtering, adjusting the pH value, extracting, drying, removing a solvent, and passing through a silica gel column to obtain a product A;

(2) under the protection of nitrogen, A, LiOH and H are obtained₂O, mixing, then dropwise adding epoxy chloropropane for reaction, cooling to room temperature after reaction, and obtaining a product B by adopting the same post-treatment operation as that in the step (1);

(3) adding the product B and triethylamine into CH₂Cl₂Dropwise adding methylsulfonyl chloride into the solution to react, then adding HCl solution to stir, separate and wash the organic phase, and obtaining a product C by adopting the same post-treatment operation as the step (1);

(4) the product C, Na₃N，CS₂CO₃Dissolving in DMF for reaction, extracting the reaction product, drying the organic phase obtained by extraction, removing part of solvent, passing through a column, spin-drying, and adding into a solution containing LiAlH₄Adding a NaOH solution into the THF solution mixed solution, stirring and mixing uniformly, and filtering to obtain a product D;

(5) dissolving the product D in a mixed solution of methanol and DMF to obtain a product E;

(6) dissolving the product E and a silane coupling agent in THF, adding ethanol and water, and then adding SiO₂And (4) reacting, and adjusting the pH value to obtain the adsorbing material.

, adding the 1, 3-dibromopropane, the catechol and the NaOH in the step (1) according to the molar ratio of 1 (2-3) to (2-3), adding the 1, 3-dibromopropane and the catechol into a reaction bottle, stirring and heating to 120-140 ℃, adding the aqueous solution of the NaOH within 1-2 h, stirring and reacting for 5-10 h, wherein the extractant added during the post-treatment in the step (1) is CH₂Cl₂Adjusting pH value of filtrate to be neutral by adopting HCl solution, and adopting anhydrous Na₂SO₄Drying is carried out.

And , the molar ratio of the product A, LiOH to the epoxy chloropropane in the step (2) is 1 (2-3) to (1-2), and the product A, the LiOH and the H are firstly prepared₂Adding O into a reaction bottle, heating to 90-95 ℃, stirring until the O is completely dissolved, then cooling to 40-60 ℃, and then dropwise adding epoxy chloropropane to enable the substances to react for 3-5h at 40-50 ℃; the molar ratio of the product B to the triethylamine to the methylsulfonyl chloride in the step (3) is (1-2) to (9-10), the methylsulfonyl chloride is added dropwise when the temperature of the mixed solution of the product B and the triethylamine is 0-5 ℃, the mixed solution is heated to room temperature to react for 1-1.5 days after the dropwise addition, the mass fraction of the added HCl solution is 4-6%, the stirring time is 20-40 minutes, and the saturated NaHCO is adopted after organic phase separation₃Washing to be neutral.

Further step (4) is adding C, Na₃N and Cs₂CO₃The molar ratio of (A) to (B) is: 2 (4-5) and (1-2), the reaction temperature of the solution is 100-110 ℃, the reaction time is 1.5-2.5 days, water and CH are adopted after the reaction₂Cl₂Extracting the reaction product, and adopting anhydrous Na as an organic phase₂SO₄Drying the product C with LiAlH₄The molar ratio of (A) to (B) is: 1, (5-6); in the step (5), the mass ratio of the product D to the methanol to the DMF is 1 (8-9) to (10-11), and the mixture is stirred at room temperature for 25-35 min; the molar ratio of the product E to the silane coupling agent in the step (6) is 1 (2-3), and the types of the added silane coupling agents are as follows: KH 560; added SiO₂Is SiO with epoxy group on the surface₂The microspheres react and SiO₂The molar ratio of the product E to the product E is 1 (5-6), and after reaction, acetic acid is adopted to adjust the pH value to 4-5.

Thirdly, the extraction method of the lithium in spodumene adopts a sulfuric acid method for extraction, and the specific operation is that the spodumene is roasted, transformed, sulfated and roasted and leached to obtain a lithium sulfate solution, then the obtained lithium sulfate solution is adsorbed by adopting the adsorbing material, finally the adsorbing material is washed and desorbed, then a pure sodium carbonate solution is added and heated for precipitating the lithium, and a lithium carbonate product is obtained after washing and drying.

And , roasting spodumene at 950-1100 ℃, mixing with concentrated sulfuric acid, roasting at 250-300 ℃, leaching the roasted product with water for 10-20 min to obtain a lithium sulfate solution, placing the adsorption material on an adsorption column, and adsorbing lithium in the lithium sulfate solution.

And , the temperature of the lithium sulfate solution during adsorption is 40-60 ℃, the flow rate is 5-10 mL/min, and the contact time of the lithium sulfate solution and the adsorption material is 15-60 min.

And , at room temperature, washing the adsorbed adsorbing material with dilute sulfuric acid with the concentration of 1-2 mol/L, and desorbing with concentrated sulfuric acid with the concentration of 8-12 mol/L.

And , adding a pure sodium carbonate solution after desorption, heating to 80-100 ℃, precipitating lithium for 30-40 min, washing for 2-3 times by adopting pure water at 90-100 ℃, and drying at 180-200 ℃.

3. Advantageous effects

Compared with the prior art, the invention has the beneficial effects that:

(1) kinds of adsorbents for extracting lithium from spodumene of the present invention, wherein the adsorbents are SiO-supported adsorbents₂The 4-amido dibenzo 14 crown 4 crown ether derivative on the surface is novel crown ether derivatives, the structure of the crown ether derivative is adjusted and optimally designed, the size of an inner cavity of the crown ether derivative is matched with the diameter of lithium ions, and therefore, the selective complexation of the lithium ions is realized, compared with the existing crown ether, the crown ether derivative has stronger selective complexation capability on the lithium ions, is particularly more suitable for extracting lithium in spodumene, has higher adsorption rate on the lithium and can reach more than 95.55 percent₂The surface of the adsorption material is insoluble in water, so that the problem of dissolution loss can not occur during use, the use effect can be ensured, the service life is long, and the production cost can be effectively reduced.

(2) The preparation method of the adsorbing material can synthesize new crown ethers by optimizing and designing the preparation process of the adsorbing materialThe crown ether derivative (hydroxyl is introduced into a ring of dibenzo 14-crown-4, and step of conversion from hydroxyl to amino is realized), can effectively enhance the extraction effect of lithium ions in spodumene due to the unique structure, and is loaded on SiO₂The surface of the lithium ion extraction solution can effectively solve the problem that the traditional crown ether is dissolved in water, can effectively avoid more loss caused in the lithium ion extraction process, and further ensures the extraction efficiency of lithium ions. The method is particularly suitable for extracting lithium from spodumene, and the extraction effect is good. Meanwhile, the synthetic route of the adsorbing material has the advantages of short flow and high yield, and the single step yield can reach more than 70%.

(3) The method for extracting lithium from spodumene of the invention has selective recognition capability to lithium ions by synthesizing an adsorbing material with selective complexing capability to Li (I), and using the adsorbing material to adsorb lithium sulfate solution after roasting transformation-sulfating roasting-leaching of spodumene, thereby being capable of removing lithium ions from Al-containing solution³⁺、Ca²⁺、Fe²⁺、Mg²⁺The lithium ions are extracted from the complex solution of the metal ions, the traditional method can extract the lithium after separating other metal ions except the lithium, the operation steps are complex, and a large amount of acid and alkali is added for neutralization, so that resource waste is easily caused.

(4) The extraction methods of lithium in spodumene of the invention, adopt this adsorption material to extract the lithium ion in the lithium sulfate solution after roasting of spodumene, the operation process is simple and convenient, need not to carry on the impurity removal treatment to the lithium sulfate solution, therefore can avoid effectively appearing because the impurity removal operation causes the lithium to lose in the impurity and follow-up difficult problem to lithium recovery, meanwhile, because the adsorption material is to the selective adsorption mechanism of lithium, can get the lithium-containing solution with higher concentration through washing, desorption after absorbing, thus realize the effective enrichment to lithium.

Detailed Description

kinds of lithium compounds of the inventionAn adsorbing material for extracting lithium from pyroxene, wherein the surface of the adsorbing material is loaded with SiO₂A crown ether derivative of a microsphere having the chemical name: 4-amino dibenzo 14 crown 4, the structural formula of which is shown in the following figure:

the crown ethers are types containing [ -O-CH₂-CH₂-O-]For example, in patent application (application number: 201910015505.8) of the applicant in 2019, 01, 08, the application discloses methods for selectively separating lithium from leachate of positive electrode materials of waste lithium-ion batteries, and the application adopts 14-crown-4 crown ether derivatives as an adsorbent, and the 14-crown-4 crown ether derivatives are dissolved in organic solvents to extract Li⁺Thereby realizing the Li in the leaching solution of the anode material of the waste lithium ion battery⁺The recovery rate is relatively high.

However, since the adsorption mechanism of crown ether to metal ions is very complex, the types of crown ether are more than hundreds, the types of lithium-containing aqueous solution are very rich, and the selective extraction of lithium can be realized only when the types of crown ether and the components of lithium-containing aqueous phase are completely matched. Meanwhile, the 14-crown-4 crown ether has a plurality of functionalizable sites, a plurality of derivatives, and the functionalization type and position are opposite to Li⁺The coordination ability of (A) is greatly influenced, and not all the 14-crown-4 crown ether derivatives are on Li⁺Has good coordination capacity only for Li⁺The proper structure is designed according to the characteristics of the Li-Li⁺The 14-crown-4 type crown ether derivative in the above application has a specific structure that hydrogen on the benzene ring at the side of dibenzo 14-crown-4 is substituted by of hydroxyl, amino, methyl substituted by hydroxyl and methyl substituted by amino, since the substituent in the application is located on the benzene ring at the side of dibenzo 14-crown-4 and is farther from the crown ether ring, and a shield of the benzene ring is addedThe function does not play a role in the synergistic coordination of functional groups, so that the extraction requirement of lithium in spodumene is difficult to meet. In addition, the crown ether in the application has strong water solubility, so that the extraction efficiency of lithium is greatly influenced, and the crown ether cannot be effectively used for extracting lithium in a spodumene roasting leachate system.

According to the 14-crown-4 crown ether derivative, the structure is adjusted and optimally designed, so that the selective adsorption effect on lithium can be effectively ensured only when the type of crown ether is completely matched with the lithium-containing water phase component in aspect, the crown ether derivative is used for adsorbing lithium ions, particularly lithium in a spodumene roasting leachate system, due to the specific structure, the adsorption effect is better, in addition, in aspect, the adsorption material is used for extracting lithium in spodumene, the selectivity on the lithium ions can be further enhanced by steps, so that the extraction effect of the lithium in the spodumene roasting leachate can be effectively met, and particularly, amine groups are grafted on methylene in a dibenzo 14 crown 4 ring in the 14-crown-4 crown ether derivative, so that the oxygen atoms and the Li can be cooperated with each other⁺Complex occurs, and can effectively strengthen the Li pair⁺Of Li, thus to Li⁺The selectivity is stronger, and the adsorption rate is higher and can reach more than 95.55 percent when the catalyst is used for extracting lithium ions.

Meanwhile, the invention also optimizes the preparation process of the adsorbing material, so that SiO is loaded on the surface of the synthesized crown ether derivative₂The microsphere enables the adsorption material to have the characteristic of insolubility in water, when the microsphere is used for selectively extracting lithium from a lithium sulfate solution obtained by roasting and transforming spodumene, roasting sulfuric acid and water leaching, compared with the existing crown ether, the microsphere has the advantages of low dissolution loss rate, higher extraction efficiency of lithium, capability of effectively ensuring the use effect in the aspect of , capability of being recycled for multiple times in the aspect of and long service life, so that the production cost can be effectively reduced.

The preparation method of the adsorbing material specifically comprises the following steps:

(1) 1, 3-dibromopropane, catechol and NaOH are mixed according to the molar ratio: 1, (2-3) and (2-3) carrying out reaction, wherein the preferable molar ratio is as follows: 1:2:2. Specifically, 1, 3-dibromopropane and catechol are added into a reaction bottle, stirred and heated to 120-140 ℃, aqueous solution of NaOH is added within 1-2 h, and stirred and reacted for 5-10 h; pouring the mixed solution obtained by the reaction into a 5N NaOH aqueous solution, and adding a proper amount of CH₂Cl₂Filtering to remove solid impurities, adjusting the filtrate to neutral with HCl solution, and adding CH₂Cl₂Extracted, anhydrous Na₂SO₄Drying, removing the solvent by using a rotary evaporator, and passing silica gel powder through a column to obtain a product A, wherein the structural formula of the product A is as follows:

(2) the product A, LiOH and epichlorohydrin are mixed according to the molar ratio: 1, (2) to (3) to (1 to 2), wherein the preferable molar ratio is as follows: 1:2:1. Specifically, under the protection of nitrogen, product A, LiOH and H are firstly mixed₂Adding O into a reaction bottle, heating to 90-95 ℃, and stirring until the O is completely dissolved; when the temperature is reduced to 40-60 ℃, dropwise adding epoxy chloropropane, completing the dropwise adding of the epoxy chloropropane within 3h, reacting for 3-5h at 40-50 ℃, and cooling to room temperature; adopting the same post-treatment operation as the step (1) to obtain a product B, wherein the structural formula of the product B is as follows:

(3) reacting the product B, triethylamine and methylsulfonyl chloride in a molar ratio of 2 (1-2) to 9-10, wherein the preferred molar ratio is as follows: 2:1:10. Concretely, the product B and triethylamine are added into CH₂Cl₂In the solution, dropwise adding methylsulfonyl chloride when the temperature of the mixed solution of the product B and triethylamine is reduced to 0-5 ℃, and after dropwise adding, raising the temperature to room temperature for reaction for 1-1.5 d; adding 4-6% of HCl solution by mass percent, stirring for 20-40 minutes, and adopting saturated NaHCO₃Washing to be neutral; then adopting the same post-treatment operation as that in the step (1) to obtainTo product C, and the structural formula of product C is as follows:

(4) mixing the product C, Na3N, C_S2CO₃And LiAlH₄The mol ratio is as follows: 2, (4) to 5), (1) to 2), (10 to 12) in the following molar ratio: 2:4:1:5. Specifically, the products C and Na are firstly prepared₃N，C_S2CO₃Dissolving in dry DMF, and reacting at 100-110 ℃ for 1.5-2.5 d; then using water and CH₂Cl₂Extracting, and using anhydrous Na for organic phase₂SO₄Drying, spin-drying, and adding CH₂Cl₂Passing through a column, spin-drying the obtained liquid to 4-6 ml again, and adding the liquid to a liquid containing LiAlH at 0 DEG C₄Stirring the mixture solution at the temperature of 0-5 ℃ for 0.5-1.5 h, and quenching redundant LiAlH by using ethanol and water (the volume ratio of the added ethanol to the added water is 1:1)₄Adding a NaOH solution with the mass fraction of 5%, stirring for 0.5-2 h at normal temperature, and filtering to obtain a product D, wherein the structural formula of the product D is as follows:

(5) and (3) reacting the product D, methanol and DMF according to a mass ratio of 1 (8-9) to 10-11, wherein the preferable molar ratio is as follows: 1:8:10. Specifically, dissolving the product D in a mixed solution of methanol and DMF, and stirring at room temperature for 25-35 min to obtain a product E, wherein the structural formula of the product E is as follows:

(6) the product E, a silane coupling agent KH560 and SiO₂The mol ratio is as follows: 1, (2) to (3) to (5) to (6), wherein the preferable molar ratio is as follows: 1:2:5. Specifically, the product E and a silane coupling agent KH560 are dissolved in THF, ethanol and water are added (the volume ratio of the added ethanol to the added water is 1:1), and SiO with a large amount of epoxy groups on the surface is added₂Microsphere reaction, regulating solution p with acetic acid after reactionH value is 4-5, so that silanol bonds and SiO on the product are bonded₂The epoxy groups on the surface are dehydrated, so that the epoxy groups are grafted to the SiO₂And (5) surface, wherein the obtained product is the adsorbing material.

The methods for extracting lithium from spodumene of the invention adopt the adsorbing material to extract lithium, and the specific process is as follows:

step , roasting spodumene for 20-40 min at 950-1100 ℃ to convert the crystal form of the spodumene from a α monoclinic crystal form to a β tetragonal crystal form, mixing the roasted and converted spodumene with concentrated sulfuric acid, roasting for 20-30 min at 250-300 ℃, replacing Li + with H + to generate lithium sulfate and insoluble gangue, and leaching the lithium sulfate and insoluble gangue with water for 10-20 min to generate a lithium sulfate solution.

And step two, placing the prepared adsorbing material in an adsorption column, placing the lithium sulfate solution in the step in a water bath at the temperature of 40-60 ℃, enabling the lithium sulfate solution to flow through the adsorption column at the flow rate of 5-10 mL/min, enabling the feed liquid to contact with the adsorbing material for 15-60 min, selectively adsorbing lithium in the solution, and enabling the effluent solution to return to the leaching process for recycling.

Step three: at room temperature, washing the adsorption column after adsorption by using dilute sulfuric acid with the concentration of 1-2 mol/L, and desorbing by using concentrated sulfuric acid with the concentration of 8-12 mol/L to obtain a pure lithium sulfate solution.

Step four: and (3) adding a pure sodium carbonate solution into the pure lithium sulfate solution obtained in the third step, heating to 80-100 ℃ and precipitating lithium, wherein the lithium precipitation time is 30-40 min. And then washing the lithium carbonate by pure water at the temperature of 90-100 ℃ for 2-3 times, and drying the lithium carbonate at the temperature of 180-200 ℃ to obtain a high-purity lithium carbonate product.

The method can be effectively used for extracting lithium from spodumene , and the selective recognition capability of the adsorption material on lithium enables the adsorption material to be extracted from the lithium-containing Al³⁺、Ca²⁺、Fe²⁺、Mg²⁺Extracting lithium ions from the complex solution of the metal ions. However, the conventional method requires separation of other metal ions except lithium to extract lithium, and the operation steps are complicated, and the conventional method requiresIn addition, , the adsorbing material is used for extracting lithium ions in a lithium sulfate solution after spodumene roasting, the operation process is simple and convenient, and the lithium sulfate solution does not need to be subjected to impurity removal treatment, so that the problems that lithium is lost in impurities due to the impurity removal operation and the subsequent lithium recovery is difficult can be effectively avoided, the process operation for extracting lithium from spodumene can be optimized, and the production cost is favorably reduced.

The invention is described in step with reference to specific embodiments.