Method for one-step lithium extraction from lithium-containing solutions by small-pore zeolites

Abstract

This invention relates to the field of zeolite molecular sieve ion exchange, and more particularly to a one-step method for extracting lithium from a lithium-containing solution using small-pore zeolite. The invention involves cooling the lithium-containing solution to below room temperature, adding small-pore zeolite K-EDI, Na-SOD, or Na-GIS, and continuing stirring under maintained temperature to perform ion exchange, achieving highly selective adsorption of Li. + The ion-exchanged microporous zeolite was filtered and dried, and then subjected to reverse exchange to remove Li in NaCl or KCl solution. + , obtaining only Li + -Na + / K + Solution. This invention is applicable to the one-step separation, recovery, and effective extraction of lithium resources in various ion concentrations or ratios, such as lithium-ion battery leachates, seawater, brine, and brines. Compared to other lithium recovery adsorbents, the zeolite molecular sieve adsorbent used in this invention can be synthesized on a large scale and is simple to synthesize. Furthermore, the zeolite ion exchange process is simple and convenient to operate, produces no secondary pollution, and the zeolite can be recycled.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of ion exchange of zeolite molecular sieve, and particularly relates to a method for one-step lithium extraction from lithium-containing solution by small-pore zeolite. BACKGROUND

[0002] In response to the requirements of low-carbon development, there is an increasing call for the evolution of energy structure. Improving the utilization rate of renewable energy, conversion, and automobile electrification all involve lithium ion batteries (LIBs), which are the most promising energy materials. However, the resource and environmental problems caused by waste LIBs should not be ignored in the face of the momentum of its continuous development. Secondly, the rapid expansion of the lithium battery industry will inevitably lead to a shortage of raw materials, and the continued development of new resources on Earth is also not conducive to its sustainable development.

[0003] Among them, lithium, as an important strategic resource and the main raw material of lithium ion batteries, is often referred to as "white oil". With the rapid development of lithium ion batteries, the consumption of lithium resources has increased dramatically, and there was once a shortage. Without subsequent resource replenishment, it will not be conducive to the sustainable development of the industry. Therefore, the separation and recovery of lithium resources from waste lithium ion batteries not only has the purpose of resource recycling, but also effectively solves the environmental problems it causes. Secondly, the lithium resources on Earth are widely distributed in the ocean, such as seawater, salt lakes, and brine. If they can be effectively utilized, they can serve as an effective supplement to lithium resources. However, it is not easy to extract lithium from waste lithium ion battery leaching solution and the ocean in one step, as it involves the efficient separation of multiple metal ions in solution.

[0004] Currently, extraction, evaporation, and co-precipitation are commonly used in industry to extract and recover lithium resources. However, due to high energy consumption, complex operation, and low selectivity of lithium, there is an urgent need for new recovery methods for the separation and recovery of lithium resources. Adsorption, as a promising green recovery method, has the advantages of simplicity, high recovery rate, and large processing capacity, and is widely used in the separation of different metal ions in liquid. The principle is to use adsorbents to selectively adsorb metal ions, release the ions after elution treatment, and thus achieve the selective separation of specific metal ions in solution.

[0005] The core of adsorption methods lies in the selection of adsorbents. Among them, manganese-based, aluminum-based, and titanium-based ion sieve adsorbents are research hotspots for lithium ion extraction, all based on the difference in the diameter of metal ions to achieve selective separation of lithium. Zeolite molecular sieve adsorbents have been widely used in the water treatment industry due to their simple preparation and ease of scale-up. They achieve metal separation and extraction by utilizing the different adsorption coefficients of the metal ion complexes to be collected by zeolites with cation exchange capabilities, which is an ion exchange method. Therefore, this invention, based on different separation methods and utilizing the ion exchange characteristics of zeolites, designs for the first time a novel one-step method for extracting lithium from lithium-containing solutions using small-pore zeolites. Summary of the Invention

[0006] This invention addresses the challenges of lithium extraction and sustainable recycling from lithium-containing solutions by providing a one-step method for lithium extraction from such solutions using microporous zeolites. Due to differences in metal ion charge and size, most zeolites exhibit higher selectivity for high-valence metal ions (M ions) than for low-valence metal ions (M ions). 2+ >M + Therefore, for Ni 2+ / Co 2+ / Mn 2+ / Mg 2+ / Ca 2+ / Li + / Na + / K + Li in a mixed solution of multiple elements + The one-step extraction is quite difficult. Based on Li + With the lightest mass and the highest displacement velocity, it is theoretically possible to achieve the desired zeolite properties for Li by controlling factors such as pore size, temperature, and time. + The kinetic selectivity is high. Therefore, this invention provides a novel method for high-selectivity one-step lithium extraction using small-pore zeolite at low temperature and in a short time by simulating the proportion of metal ions in leachate from spent lithium-ion batteries, seawater, brine, and brines. This method, by adding small-pore zeolite EDI, SOD, and GIS (pore size ≤0.35 nm), achieves one-step extraction of over 95% of lithium ions in the solution within a low temperature ≤25℃ and ≤4h ion exchange time, with minimal adsorption of other metal ions, demonstrating high selectivity for lithium. + / M 2+ (M = Ni) 2+ / Co 2+ / Mn 2+ / Mg 2+ (Up to 100 or more, through zeolite Li) + Desorption and recycling can maintain the original effect for more than 5 cycles.

[0007] The application is realized by the following technical scheme: a method for one-step lithium extraction from a lithium-containing solution by using small-pore zeolite, comprising the following steps:

[0008] (1) cooling the lithium-containing solution to below room temperature;

[0009] (2) adding small-pore zeolite K-EDI, Na-SOD or Na-GIS to the lithium-containing solution in step (1), continuing to stir under heat preservation conditions, performing ion exchange and high-selectivity adsorption of Li + ;

[0010] (3) on the basis of step (2), filtering and drying the small-pore zeolite after ion exchange, and then performing reverse exchange to remove Li + in a NaCl or KCl solution, to obtain a solution containing only Li + -Na + / K + .

[0011] As a further improvement of the technical scheme of the application, after lithium removal in step (3), filtering and drying are continued to obtain reduced zeolite, and the reduced zeolite is repeatedly executed in steps (1), (2) and (3) for reciprocating circulation.

[0012] As a further improvement of the technical scheme of the application, the lithium-containing solution is a lithium-containing multi-metal ion mixed solution.

[0013] As a further improvement of the technical scheme of the application, in addition to Li + , the lithium-containing multi-metal ion mixed solution further comprises any one or more of Ni 2+ , Co 2+ , Mn 2+ , Li + , Mg 2+ , Ca 2+ , Na + , K + metal ions.

[0014] As a further improvement of the technical scheme of the application, the lithium-containing multi-metal ion mixed solution is a Li + -Ni 2+ -Co 2+ -Mn 2+ or Li + -Mg 2+ -Ca 2+ -Na + -K + mixed solution.

[0015] As a further improvement of the technical scheme of the application, the Li + -Ni 2+ -Co2+ -Mn 2+ The molar concentration ratio of each ion in the mixed solution is 3-10: 1-8: 1-2: 1-3; the Li + -Mg 2+ -Ca 2+ -Na + -K + The molar concentration ratio of each ion in the mixed solution is 1: 1-100: 0-0.1: 1-19: 1-6.

[0016] As a further improvement of the technical scheme of the application, in step (2), the stirring time is 1-4h.

[0017] As a further improvement of the technical scheme of the application, in step (3), the anti-exchange Li + is carried out at a temperature of 25-60℃ for 1-4h.

[0018] As a further improvement of the technical scheme of the application, the silicon-aluminum element ratio of the small-pore zeolite K-EDI, Na-SOD and Na-GIS is 2.0, 1.9 and 3.3 respectively.

[0019] The method for one-step extraction of lithium from a lithium-containing solution by small-pore zeolite provided by the application has the following advantages compared with the prior art:

[0020] 1) The application provides a method for one-step extraction and separation of lithium resources from a lithium-containing solution with high selectivity, which realizes the effect of preferential adsorption of lithium under the conditions of ion exchange kinetics and thermodynamics of small-pore zeolite. Secondly, the one-step extraction of lithium resources from solution by zeolite ion exchange is a different mechanism compared with other methods, and it is realized for the first time by small-pore zeolite with high selectivity.

[0021] 2) By selecting small-pore zeolite, the rate of metal ions entering the zeolite pore is reduced, thereby effectively amplifying the + fastest displacement rate to achieve the purpose of kinetic preferential selection.

[0022] 3) By reducing the exchange temperature, the diffusion rate of metal ions is further reduced, the + kinetic difference with other metals is improved, and at the same time, the exchange of zeolite for divalent metal ions is effectively inhibited, and the selectivity for lithium ions is improved.

[0023] 4) The effect achieved by small-pore zeolite ion exchange is obvious, such as: EDI zeolite can adsorb more than 95% of Li + in the solution, and other metal ions are adsorbed <14%, and the selectivity for Li +selectivity of up to 100 or more, and can be recycled for 5 times or more with basically unchanged adsorption efficiency; GIS zeolite can also effectively realize preferential lithium extraction under low temperature conditions by controlling ion exchange kinetics and thermodynamics, and other ions are hardly adsorbed; the SOD zeolite can realize one-step lithium extraction from a high Mg / Li ratio (1, 10, 100) solution at room temperature, and still realizes one-step lithium extraction in the presence of multiple ions Li + -Mg 2+ -Ca 2+ -Na + -K + .

[0024] 5) The present application can be applied to lithium ion battery leaching solution, seawater, brine and brine, etc. Various ions or different concentrations, one-step separation and recovery of lithium resources and effective extraction. Compared with the method of recovering lithium or other adsorbents in industry, the SOD zeolite used in the present application is the most common zeolite, which can be synthesized on a large scale, and the synthesis is simple. Secondly, the ion exchange process of zeolite is simple and convenient to operate, and there is no secondary pollution, and the zeolite can be recycled. BRIEF DESCRIPTION OF DRAWINGS

[0025] The drawings incorporated into the specification and forming a part thereof, demonstrate embodiments consistent with the present application, and together with the specification, serve to explain the principles of the present application.

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced below, and obviously, other drawings can also be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0027] Figure 1 For the case of Li + : Ni 2+ : Co 2+ : Mn 2+ concentration ratio of 3:1:1:1, the schematic diagram of K-EDI zeolite adsorption efficiency for four kinds of metal ions. It is shown that at 5℃, K-EDI zeolite can effectively adsorb 95% of Li + , Ni 2+ , Co 2+ , Mn 2+ ion adsorption <14%, realizing high selective extraction of Li + .

[0028] Figure 2 For the case of Li + : Ni 2+ : Co 2+ : Mn 2+A schematic diagram illustrating the selectivity of K-EDI zeolite for four ions at a concentration ratio of 3:1:1:1 and low temperature. This indicates that K-EDI zeolite exhibits high Li ion selectivity. + Li adsorption, and still exhibiting lithium selectivity even at low concentrations, therefore, Li + Selectivity coefficient K d Very high. Secondly, K-EDI zeolite exhibits high selectivity for lithium. Li exhibits excellent performance + Selectivity.

[0029] Figure 3 For step (3) in Example 1, which is a repeated loop of steps (1) and (2), after each loop, for Li + A schematic diagram of adsorption efficiency. It shows that after five ion exchange cycles, K-EDI zeolite still retains over 90% Li. + The adsorption efficiency and performance remain essentially unchanged.

[0030] Figure 4 The image shows the XRD diffraction pattern of K-EDI zeolite after repeated cycles in Example 1. It indicates that the K-EDI zeolite structure remained intact and undamaged before and after the cycles.

[0031] Figure 5 In Example 2, in Li + Ni 2+ Co 2+ Mn 2+ A schematic diagram showing the adsorption capacity of Na-GIS zeolite for four ions at a concentration ratio of 3:1:1:1. This indicates that Na-GIS can adsorb 0.6 mmol / L of Li at 0℃. + And for Ni 2+ Co 2+ Mn 2+ It hardly adsorbs and exhibits high Li content. + Selectivity, enabling the selective processing of Li in mixed solutions + One-step extraction.

[0032] Figure 6 In Example 3, in Li + Mg 2+ Ca 2+ Na + :K + A schematic diagram showing the adsorption capacity of Na-SOD zeolite for metal ions in a mixed solution at a concentration ratio of 1:1:0.1:1:1. This indicates that Na-SOD zeolite adsorbs Li... + The highest adsorption capacity was observed at 1.0 mmol / L, which is more than 5 times higher than the adsorption capacity of other metal ions (<0.2 mmol / L), demonstrating high Li adsorption capacity.+ Selectivity.

[0033] Figure 7 In Example 3, in Li + Mg 2+ Ca 2+ Na + :K + A schematic diagram showing the adsorption capacity of Na-SOD zeolite for metal ions in a mixed solution at a concentration ratio of 1:10:0.1:1:1. This indicates that when Mg in the mixed solution... 2+ Even with a 10-fold increase in concentration, it still exhibits high Li content. + Its adsorption capacity and selectivity make it suitable for high concentrations of Mg. 2+ / Li + Li in salt water + One-step extraction.

[0034] Figure 8 In Example 3, in Li + Mg 2+ Ca 2+ Na + :K + A schematic diagram showing the adsorption capacity of Na-SOD zeolite for metal ions in a mixed solution at a concentration ratio of 1:100:0.1:1:1. This indicates that when Mg in the mixed solution... 2+ Even with a 100-fold increase in concentration, it still exhibits the highest Li content. + The adsorption capacity can achieve higher concentrations of Mg. 2+ / Li + Li in salt water + One-step extraction.

[0035] Figure 9 In Example 4, in Li + Mg 2+ Na + :K + A schematic diagram illustrating the adsorption efficiency of K-EDI zeolite for metal ions in a mixed solution at a concentration ratio of 1:30:19:6 and at low temperature. This indicates that K-EDI zeolite exhibits excellent Li... + It has strong adsorption capacity, with an adsorption efficiency exceeding 90%, and it adsorbs almost no Mg. 2+ It has the ability to react with high concentrations of Mg 2+ / Li + The ability to extract lithium resources from seawater in one step.

[0036] Figure 10 In Example 5, in Li + Ni 2+ Co 2+ Mn 2+A schematic diagram showing the adsorption efficiency of K-EDI zeolite for four metal ions after the solution temperature is increased to 30℃ at a concentration ratio of 3:1:1:1. It indicates that with increasing temperature, the zeolite's adsorption efficiency for Ni... 2+ Co 2+ Mn 2 The adsorption efficiency of metal ions increases rapidly, and for Li + The efficiency reduction is significant for Li + The selectivity also decreases. Therefore, low temperature conditions are used as a high-selectivity adsorption condition for zeolites to absorb Li. + The importance of.

[0037] Figure 11 In Example 5, in Li + Ni 2+ Co 2+ Mn 2+ A schematic diagram illustrating the adsorption efficiency of Na-GIS zeolite for four metal ions at a concentration ratio of 3:1:1:1 and a solution temperature increased to 30℃. This shows that with increasing temperature, Na-GIS zeolite exhibits increased adsorption efficiency for divalent metal Co. 2+ Mn 2+ The adsorption efficiency of Li increases rapidly, while Li + When replaced by it, the adsorption efficiency decreases, exhibiting the characteristics of Mn. 2+ Selectivity. Therefore, under high-temperature conditions, zeolites do not possess selective Li adsorption. 2+ This highlights the importance of low temperatures. Detailed Implementation

[0038] To better understand the above-mentioned objectives, features, and advantages of the present invention, the solutions of the present invention will be further described below. It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other.

[0039] Many specific details are set forth in the following description in order to provide a full understanding of the invention, but the invention may also be practiced in other ways different from those described herein; obviously, the embodiments in the specification are only some embodiments of the invention, and not all embodiments.

[0040] This invention provides a specific embodiment of a method for one-step lithium extraction from a lithium-containing solution using small-pore zeolite, comprising the following steps:

[0041] (1) Cool the lithium-containing solution to below room temperature;

[0042] (2) In the lithium-containing solution of step (1), add small-pore zeolite K-EDI, Na-SOD or Na-GIS, and continue stirring under heat preservation to carry out ion exchange and highly selectively adsorb Li. + ;

[0043] (3) On the basis of step (2), the ion-exchanged small-pore zeolite is filtered and dried, and then subjected to reverse exchange in a NaCl or KCl solution to remove Li + + + + solution.

[0044] In step (1), the lithium-containing solution is a lithium-containing multi-metal ion mixed solution. Specifically, the lithium-containing multi-metal ion mixed solution contains any one or more of Ni + , Co 2+ , Mn 2+ , Li 2+ , Mg + , Ca 2+ , Na 2+ , K + in addition to Li + . The concentration of Li + in the lithium-containing multi-metal ion mixed solution is 0.01-0.1 mol / L.

[0045] In one embodiment of the present application, the lithium-containing multi-metal ion mixed solution is a Li + -Ni 2+ -Co 2+ -Mn 2+ or Li + -Mg 2+ -Ca 2+ -Na + -K + mixed solution. The molar concentration ratio of the ions in the Li + -Ni 2+ -Co 2+ -Mn 2+ mixed solution is 3-10: 1-8: 1-2: 1-3; and the molar concentration ratio of the ions in the Li + -Mg 2+ -Ca 2+ -Na + -K + mixed solution is 1: 1-100: 0-0.1: 1-19: 1-6. In the aforementioned molar concentration ratios, 0 in 0-0.1 means that the concentration of the ion in the mixed solution is 0.

[0046] Specifically, the Li + -Ni 2+ -Co 2+ -Mn 2+ mixed solution contains Li​​The molar concentration ratio of each ion in the mixed solution is 3:1:1:1 or 10:5:2:3 or 10:6:2:2 or 10:8:1:1. The aforementioned mixed solution is used to simulate the leaching solution rich in lithium cobalt manganese nickel metal ions obtained by hydrometallurgy in different types of ternary battery industries.

[0047] Li + -Mg 2+ -Ca 2+ -Na + -K + The molar concentration ratio of each ion in the mixed solution is 1:1:0.1:1:1 or 1:10:0.1:1:1 or 1:100:0.1:1:1. The aforementioned mixed solution is used to simulate the proportion of metal ions in salt lake water.

[0048] Li + -Mg 2+ -Ca 2+ -Na + -K + The molar concentration ratio of each ion in the mixed solution is 1:30:0:19:6. The aforementioned mixed solution is used to simulate the proportion of metal ions in real seawater.

[0049] The various mixed solutions provided by the present application are only used to simulate the proportion of metal ions in various environments, and the method described in the present application is not limited to the above-mentioned mixed solutions.

[0050] Wherein the room temperature below is specifically 0-25℃. In different embodiments, the lithium-containing solution can be cooled by placing it in an ice water bath. In different embodiments, the lithium-containing solution can be cooled to 0℃, 5℃, 10℃, 15℃, 20℃, 25℃, or at a temperature within any two defined ranges.

[0051] In step (2), the stirring speed after adding the small-pore zeolite is 300-700 r / min, and the stirring time is 1-4 h. In different embodiments, the stirring speed can be 300 r / min, 400 r / min, 500 r / min, 600 r / min, 700 r / min, or at a stirring speed within any two defined ranges. In different embodiments, the stirring time can be 0 h, 0.5 h, 1 h, 1.5 h, 2 h, 2.5 h, 3 h, 3.5 h, 4 h, or at a stirring time within any two defined ranges.

[0052] The silicon-aluminum element ratio of the small-pore zeolite K-EDI, Na-SOD and Na-GIS is 2.0, 1.9 and 3.3 respectively.

[0053] In step (3), the ion-exchanged microporous zeolite is filtered and dried at a temperature of 60-100℃. Subsequently, reverse exchange to remove Li is carried out in NaCl or KCl solution. + At that time, the concentration of NaCl or KCl solution used was 1-2 mol / L. The purpose of reverse exchange is to remove Li from the lithium-containing zeolite. + Released into the solution, while Na + or K + Supplementing Li in zeolite + The position it occupies, thereby reducing the zeolite.

[0054] Reverse exchange deLi + The temperature was 25-60℃, and the time was 1-4 hours. In different embodiments, reverse exchange desorption of Li... + The temperature is 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, or 60°C, or any two of the defined temperature ranges. In different embodiments, the time can be 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, 3.5 hours, or 4 hours, or any two of the defined time ranges.

[0055] After delithiation in step (3), filtration and drying are continued to obtain reduced zeolite. The reduced zeolite is then subjected to steps (1), (2), and (3) in a cyclical manner. Preferably, the drying temperature is 60-100℃.

[0056] The specific embodiments of the present invention will be described in detail below.

[0057] Example 1:

[0058] ① By adding lithium chloride, cobalt chloride, manganese chloride, and nickel chloride samples, Li was prepared with an initial molar concentration ratio of 3:1:1:1 (or 10:5:2:3, 10:6:2:2, or 10:8:1:1). + -Ni 2+ -Co 2+ -Mn 2+ Mixed solution, in which Li + The concentration was 0.015 mol / L. When the solution temperature cooled to 5℃, K-EDI zeolite was added to 50 mL of the mixed solution, resulting in a K-EDI zeolite concentration of 14 g / L. The mixture was stirred for 4 h at a stirring rate of 500 r / min for lithium extraction via ion exchange. The remaining metal ion content in the solution was then determined by ICP testing. The adsorption capacity of K-EDI zeolite for each metal ion in the mixed solution is shown in the table below.

[0059] ② The solution from step ① was filtered to obtain lithium-containing zeolite (LiK-EDI), which was then dried at 80℃ for 24 h. Subsequently, the dried lithium-containing zeolite was added to 50 ml of a 1.5 mol / L KCl solution, resulting in a zeolite concentration of 20 g / L. The solution was stirred at 40℃ for 2 h to obtain Li + -K + The solution was then used to reduce the zeolite.

[0060] ③ Wash and filter the product from step ② to obtain the reduced K-EDI zeolite, and repeat steps ① and ② for 5 cycles.

[0061] Table 1

[0062]

[0063] As can be seen from the table above, under simulated leaching solution concentrations for different types of lithium-ion batteries, when the solution temperature is cooled to 5℃, the K-EDI remains high for all Li... + It exhibits an adsorption capacity that is more than 30 times that of other metal ions, enabling highly selective one-step separation and recovery of Li from four metal ions. + The ability.

[0064] Example 2:

[0065] Lithium chloride, cobalt chloride, manganese chloride, and nickel chloride were added to a sample to prepare Lithium chloride solution with an initial molar concentration ratio of 3:1:1:1. + -Ni 2+ -Co 2+ -Mn 2+ Mixed solution, in which Li + The concentration was 0.015 mol / L. When the solution temperature was cooled to 0℃, Na-GIS zeolite was added to 50 mL of the mixed solution, and the concentration of Na-GIS zeolite in the solution was 10 g / L. The mixture was stirred for 4 h at a stirring rate of 400 r / min to carry out lithium extraction by ion exchange. Finally, the content of residual metal ions in the solution was tested by ICP.

[0066] ② The solution from step ① was filtered to obtain lithium-containing zeolite (LiNa-GIS), which was then dried at 80℃ for 24 h. Subsequently, the dried lithium-containing zeolite was added to 50 ml of a 2 mol / L NaCl solution, resulting in a zeolite concentration of 20 g / L. The solution was stirred at 60℃ for 2 h to obtain Li + -Na + The solution was then used to reduce the zeolite.

[0067] Example 3:

[0068] Li + -Mg 2+ -Ca 2+ -Na + -K + mixed solution, wherein Li + concentration is 0.015 mol / L. At 25℃, Na-SOD zeolite is added into 50 mL mixed solution, and the concentration of Na-SOD zeolite in the solution is 4 g / L, and stirring is carried out for 4 h at a stirring rate of 600 r / min, ion exchange is carried out to extract lithium, and finally the content of residual metal ions in the solution is tested by ICP.

[0069] ②The filtering operation is carried out on step ① to obtain lithium-containing zeolite (LiNa-SOD), and the lithium-containing zeolite after drying is added into 50 mL NaCl solution with a concentration of 1 mol / L, and the concentration of zeolite is 10 g / L, stirring is carried out at 25℃ for 4 h to obtain Li + -Na + solution, and the zeolite is reduced.

[0070] Example 4:

[0071] Li + -Mg 2+ -Na + -K + mixed solution, wherein Li + concentration is 0.015 mol / L. When the temperature of the solution is cooled to 0℃, K-EDI zeolite is added into 50 mL mixed solution, and the concentration of K-EDI zeolite in the solution is 14 g / L, and stirring is carried out for 4 h at a stirring rate of 500 r / min, ion exchange is carried out to extract lithium, and finally the content of residual metal ions in the solution is tested by ICP.

[0072] Example 5:

[0073] Li + -Ni 2+ -Co 2+ -Mn 2+Mixing solution. Increase the solution temperature to 30℃, K-EDI or Na-GIS zeolite is added to 50mL mixed solution respectively, the concentration of K-EDI zeolite in the solution is 14g / L, the concentration of Na-GIS zeolite in the solution is 10g / L, respectively stirring for 4h, the stirring rate is 400r / min, finally test the content of residual metal ions in the solution by ICP.

[0074] The above description is only a specific implementation of the present application, which enables those skilled in the art to understand or implement the present application. Although the foregoing embodiments are described in detail, those skilled in the art should understand that the technical solutions described in the foregoing embodiments can be modified, or some or all of the technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments, and they should be covered in the protection scope of the claims.

Claims

1. A method for one-step extraction of lithium from a lithium-containing solution using small-pore zeolite, characterized in that, Includes the following steps: (1) Cool the lithium-containing solution to 0℃-15℃, wherein the lithium-containing solution is a mixed solution of lithium polymetallic ions; (2) In the lithium-containing solution of step (1), add small-pore zeolite K-EDI, Na-SOD or Na-GIS, and continue stirring under heat preservation for 1-4 hours to carry out ion exchange and highly selectively adsorb Li. + ; (3) Based on step (2), the ion-exchanged microporous zeolite is filtered and dried, and then reverse-exchange Li removal is carried out in NaCl or KCl solution. + , obtaining only Li + -Na + / K + Solution.

2. The method for one-step lithium extraction from a lithium-containing solution using small-pore zeolite according to claim 1, characterized in that, After delithiation in step (3), filtration and drying are continued to obtain reduced zeolite. The reduced zeolite is then subjected to repeated steps (1), (2), and (3) in a cycle.

3. The method for one-step lithium extraction from a lithium-containing solution using small-pore zeolite according to claim 1, characterized in that, In the lithium-containing multimetal ion mixed solution, except for Li + In addition, Ni 2+ Co 2+ Mn 2+ Li + Mg 2+ Ca 2+ Na + K + Any one or more metal ions.

4. The method for one-step lithium extraction from a lithium-containing solution using small-pore zeolite according to claim 3, characterized in that, The lithium-containing multimetal ion mixed solution is Li + -Ni 2+ -Co 2+ -Mn 2+ Or Li + -Mg 2+ -Ca 2+ -Na + -K + Mixed solution.

5. The method for one-step lithium extraction from a lithium-containing solution using small-pore zeolite according to claim 4, characterized in that, The Li + -Ni 2+ -Co 2+ -Mn 2+ The molar concentration ratio of each ion in the mixed solution is 3–10:1–8:1–2:1–3; the Li + -Mg 2+ -Ca 2+ -Na + -K + The molar concentration ratio of each ion in the mixed solution is 1:1~100:0~0.1:1~19:1~6.

6. The method for one-step lithium extraction from a lithium-containing solution using small-pore zeolite according to claim 1, characterized in that, In step (3), the temperature for reverse exchange to remove Li+ is 25-60℃ and the time is 1-4h.

7. The method for one-step lithium extraction from a lithium-containing solution using small-pore zeolite according to claim 1, characterized in that, The silicon-to-aluminum ratios of the microporous zeolites K-EDI, Na-SOD, and Na-GIS are 2.0, 1.9, and 3.3, respectively.

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