Method for rapidly and efficiently capturing lithium in dynamic circulation

Abstract

The invention relates to the field of high-selectivity lithium capture, in particular to a method for rapidly and efficiently capturing lithium in dynamic circulation, LTA-NaA, OFF, MAZ and FAU-NaX zeolite molecular sieve adsorbents are flatly laid in an adsorption column, a lithium-containing solution flows through the zeolite molecular sieve adsorbents under the low-temperature condition, and the recovery rate of Li < + > of 80% or above and Li < + > capture with the high adsorption capacity of 3 mmol / g are achieved. Li < + > in the zeolite molecular sieve can be well desorbed, and the original effect is still kept after five times of cyclic utilization. The invention innovatively provides a low-temperature lithium-containing solution which dynamically passes through a zeolite molecular sieve adsorbent, and Li < + > is quickly captured with high selectivity. The method has the advantages of simplicity in operation, no pollution, rapidness, convenience, sustainable cyclic utilization and the like, and has industrial potential of large-scale application.

Description

Technical Field

[0001] The invention relates to the field of high-selectivity lithium capture, and in particular to a method for fast and efficient lithium capture in a dynamic cycle. Background Art

[0002] In the process of global low-carbon transformation, lithium, as a key resource and main raw material for lithium-ion batteries, has a vital strategic position and is often referred to as "white oil". With the widespread use of various fields such as energy storage and new energy industries, the demand for lithium resources has increased year by year, and the external dependence is high. Therefore, finding a sustainable and green lithium resource supply is of great significance to the rapid development of the lithium-ion battery industry.

[0003] At present, lithium resources are mainly extracted from lithium minerals, seawater, brine and retired lithium ions. Due to the complexity of lithium resource extraction from solid lithium minerals and limited reserves, lithium resources as a non-renewable energy source will eventually be scarce. Lithium resources in seawater and brine account for more than 60% of the total, and extracting lithium from liquid resources is a valuable option. In addition, with the increase in the amount of retired lithium-ion batteries, reaching millions of tons, extracting lithium from them is also the key to increasing the supply of lithium resources and realizing resource recycling.

[0004] The traditional solar evaporation method for extracting lithium from seawater and brine resources has strict environmental equipment requirements, long duration, complex steps, and low purity of extracted lithium, which has become a major bottleneck restricting its development. At present, the key problem of extracting lithium from seawater is that the lithium content in seawater is low, and the types and concentrations of other metal ions are high (for example, the concentration of magnesium is dozens or even hundreds of times that of lithium). Therefore, how to efficiently extract lithium from multi-ion competitive solutions in one step is a key problem that needs to be solved. In addition, in the process of treating retired lithium-ion batteries with traditional hydrometallurgical technology, the metal in the positive electrode is converted into a metal ion solution through acid leaching, alkaline leaching and other methods, and then heavy metal ions are preferentially treated through precipitation, extraction and other methods, and finally lithium resources are recovered, resulting in complex steps, low lithium purity, low recovery efficiency and other disadvantages. Therefore, it is also very important to efficiently extract lithium from the leachate of retired lithium-ion batteries in one step.

[0005] Whether it is extracting lithium from seawater or leachate from retired lithium-ion batteries, the key is to solve whether lithium can be captured in a lithium solution with high selectivity in one step in the presence of multiple competing ions. Adsorption separation technology is considered to be a highly selective and environmentally friendly method for separating and recovering metal ions from solutions, and the key is the selection of adsorbents. Among the many adsorbents, zeolite molecular sieve adsorbents are widely used in the fields of solution metal adsorption and wastewater purification because of their cation exchange ability, high adsorption capacity, good stability, easy industrialization, simple synthesis and other advantages. However, most zeolite molecular sieve adsorbents have almost no lithium selectivity, and the adsorption amount of high-valent metal ions is much greater than that of lithium. Therefore, constructing a reverse selective separation system is the key problem we need to solve. The present invention uses zeolite molecular sieve adsorbents to design a method for quickly and efficiently capturing lithium in a dynamic cycle. Summary of the invention

[0006] In order to solve the problem that most zeolite molecular sieve adsorbents have almost no lithium selectivity and the adsorption capacity of high-valent metal ions is much greater than that of lithium, the present invention provides a method for fast and efficient capture of lithium under dynamic circulation. The present invention extracts lithium from retired lithium-ion battery leachate and seawater, mainly solving the problem of coexisting metal ions, such as: Li + / Ni 2+ / Co 2+ / Mn 2+ and high Mg 2+ / Li + For most zeolite molecular sieve adsorbents, due to their high adsorption capacity and selectivity for divalent metal ions, it is impossible to achieve Li + However, as the lightest metal, lithium has the fastest displacement rate in solution and can preferentially enter the molecular sieve pores and be preferentially exchanged. Based on this, we selected a series of zeolites that have no lithium selectivity under conventional equilibrium conditions but have fast ion exchange kinetics and a pore size of 4Å-7Å. + The fastest kinetic rate is designed to achieve more than 80% Li + The recovery of Li + solution, achieving the Li + The capture with high adsorption capacity (20.8 mg / g) has the advantages of rapidity, high selectivity, greenness and pollution-free, simple operation, etc., and has good potential for industrial application.

[0007] The method is to lay LTA-NaA (4.1Å×4.1Å), OFF (6.7Å×6.8Å, 3.6Å×4.9Å), MAZ (7.4Å×7.4Å×7.4Å, 3.9Å×3.9Å, 3.1Å×3.1Å), FAU-NaX (7.4Å×7.4Å×7.4Å) zeolite molecular sieve adsorbents flat in the adsorption column, and coexist with ion solution (Li + / Ni 2+ / Co 2+ / Mn 2+ , Li + / Mg 2+ / Ca 2+ ) flowed through the zeolite molecular sieve adsorbent at a flow rate of 50 mL / min and low temperature (≤20°C) to achieve more than 80% Li + The recovery rate and high adsorption capacity of 3 mmol / g (20.8 mg / g) Li + Capture. And Li in zeolite molecular sieve + It can be desorbed very well and can be recycled 5 times while still maintaining the original effect.

[0008] The present invention is achieved through the following technical solution: A method for quickly and efficiently capturing lithium in a dynamic cycle, comprising the following steps: (1) loading at least one of LTA-NaA, OFF, MAZ or FAU-NaX zeolite molecular sieves into an adsorption column; (2) Cooling the lithium-containing solution to 0-20°C; (3) When the lithium-containing solution is added to the adsorption column of step (1), the lithium-containing solution is dynamically circulated through the zeolite molecular sieve of the adsorption column, and the number of dynamic cycles is at least 1, so as to achieve high selectivity and high adsorption amount of Li + capture.

[0009] As a further improvement of the technical solution of the method of the present invention, the method further includes step (4), specifically: taking out and washing the zeolite molecular sieve layer in step (3), desorbing Li + Finally, the zeolite molecular sieve is recycled and steps (1), (2), and (3) are repeated.

[0010] As a further improvement of the technical solution of the method of the present invention, the pore size of the zeolite molecular sieve selected in step (1) is 4 Å-7 Å.

[0011] As a further improvement of the technical solution of the method of the present invention, the adsorption column in step (1) contains 1 to 3 zeolite molecular sieve layers.

[0012] As a further improvement of the technical solution of the method of the present invention, the lithium-containing solution is a leaching solution of retired lithium-ion batteries Li + -Ni2+ -Co 2+ -Mn 2+ or seawater brine Li + -Mg 2+ -Ca 2+ Coexisting solution.

[0013] As a further improvement of the technical solution of the method of the present invention, in step (2), the lithium-containing solution Li + The concentration is at least 0.015 mol / L.

[0014] As a further improvement of the technical solution of the method of the present invention, in step (3), the lithium-containing solution is dynamically circulated through the zeolite molecular sieve of the adsorption column by suction filtration, filtration or free flow.

[0015] As a further improvement of the technical solution of the method of the present invention, the salt solution in step (4) is a NaCl solution.

[0016] As a further improvement of the technical solution of the method of the present invention, in step (4), the salt solution desorbs Li + The desorption conditions are as follows: desorption temperature is 25℃~60℃, and the desorption time is 0.5~2h. + The exchanged Li + Substitution and desorption of Li + And reduce the zeolite molecular sieve.

[0017] The method for quickly and efficiently capturing lithium in a dynamic cycle provided by the present invention has the following advantages compared with the prior art: 1) The present invention innovatively proposes a method for dynamically passing a low-temperature lithium-containing solution through a zeolite molecular sieve adsorbent to rapidly and highly selectively achieve the adsorption of Li + This method has the advantages of simple operation, no pollution, fast and convenient, sustainable recycling, etc., and has industrial potential for large-scale application.

[0018] 2) The 4Å-7Å zeolite molecular sieve adsorbent selected in the present invention is Li-free under equilibrium conditions. + Selective, mostly used for the removal of heavy metal ions in aqueous solutions. We use Li + Taking advantage of fast kinetic diffusion, a dynamic circulation strategy is proposed to capture Li with high selectivity + .

[0019] 3) The selected LTA-NaX zeolite molecular sieve adsorbent for Li + / M 2+ (M 2+ = Ni 2+ 、Co 2+ , Mn 2+ Mg 2+ , Ca2+ ) adsorption capacity ratio is as high as 70, and at low concentrations of Li + In solution, Li + The adsorption capacity is as high as 3 mmol / g (20.8 mg / g), which has the advantages of ultra-low Li + Secondly, more than 80% of Li + of recycling. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 This is the specific operation process in Example 1, and the molecular sieve ion exchange operation is achieved through dynamic reciprocating circulation and limited cycle times.

[0023] Figure 2 is Li in Example 1 + :Ni 2+ :Co 2+ :Mn 2+ The adsorption capacity of LTA-NaA molecular sieve for four metal ions and Li before and after 6 dynamic cycles in a coexistence solution with a concentration ratio of 3:1:1:1 + Recovery rate. It shows that with the increase of the number of cycles, LTA-NaA has a + The adsorption capacity of Li+ gradually weakened, and the metal adsorption capacity of divalent metals increased. + Selectivity and adsorption capacity (0.94 mmol / L) for Li + Highly selective capture.

[0024] Figure 3 The specific operation process in Example 2 is to keep 50 mL of the coexisting metal ion solution unchanged, and only change the amount of LTA-NaA molecular sieve added, so as to achieve high recovery rate of lithium capture through one cycle.

[0025] Figure 4 The adsorption capacity of the four metal ions and Li +The recovery rate was affected. It was shown that by changing the amount of LTA-NaA molecular sieve added, the recovery rate of Li + Highly selective capture, with the increase of LTA-NaA addition, Li + The adsorption capacity is reduced, but the Li + The recovery rate reaches over 80%.

[0026] Figure 5 The specific operation process in Example 2 is to keep the amount of LTA-NaA molecular sieve added unchanged, change the amount of coexisting metal ion solution added, and realize lithium capture through a one-step dynamic cycle.

[0027] Figure 6 The adsorption capacity of the four metal ions and Li + The recovery rate was affected. It showed that LTA-NaA still achieved high selectivity for Li + Capture, as the solution processing volume increases, the adsorption capacity increases and the recovery rate decreases. When the solution processing volume is small, more than 80% Li + Recovery rate.

[0028] Figure 7 According to the specific operation process in Example 2, the number of molecular sieve layers in the adsorption column is increased, other conditions are kept unchanged, and lithium is captured at a high recovery rate through a one-step dynamic cycle filtration.

[0029] Figure 8 In Example 2, the adsorption capacity of the four metal ions and Li + The recovery rate is affected. It shows that any number of molecular sieve layers can achieve high selectivity for Li + Capture, increase the number of layers, Li + The recovery rate is increased, and more than 80% Li can be achieved + Recovery rate.

[0030] Fig. 9 For the specific operation process in Example 3, the ion selectivity and maximum ion adsorption capacity of the LTA-NaA molecular sieve were explored through continuous dynamic liquid inflow.

[0031] Fig.10 The effect of different amounts of coexisting metal ion solutions on the adsorption capacity of the four metal ions in Example 3 shows that despite processing more solution, LTA-NaA molecular sieve can still achieve high selectivity for Li + Capture, as the solution processing volume increases, molecular sieve Li + The adsorption capacity increased to 3 mmol / g (20.8 mg / g). +In solution, the adsorption capacity is at a relatively high level.

[0032] Fig.11 In Example 4, Li + :Mg 2+ :Ca 2+ When the concentration ratio is 1:1:1, the adsorption capacity of LTA-NaA molecular sieve for three metal ions and Li + Recovery rate. This shows that LTA-NaA molecular sieve can capture Li + The recovery rate is over 80%, and Mg is basically not adsorbed. 2+ , Ca 2+ , with Li + / Mg 2+ Separation ability.

[0033] Fig.12 In Example 4, Li + :Mg 2+ :Ca 2+ When the concentration ratio is 1:100:1, the adsorption capacity of LTA-NaA molecular sieve for three metal ions and Li + Recovery rate. It shows that when the solution contains Mg 2+ The concentration is increased by 100 times, and it still has high Li + Adsorption capacity, to achieve higher concentration of Mg 2+ / Li + Li in seawater + One-step capture has practical application value.

[0034] Fig.13 is the adsorption capacity of the OFF molecular sieve for four metal ions under dynamic cycle in Example 5. It shows that after one cycle, the OFF molecular sieve has the highest Li + Adsorption capacity and selectivity can achieve Li + of capture.

[0035] Fig.14 is the adsorption capacity of four metal ions under dynamic cycle of MAZ molecular sieve in Example 5. It shows that after one cycle, MAZ molecular sieve has the highest Li + The adsorption capacity and selectivity are similar to those of LTA-NaA zeolite.

[0036] Fig.15 is the adsorption capacity of the four metal ions under the dynamic cycle of FAU-NaX molecular sieve in Example 5. Since the pore size of FAU-NaX molecular sieve is larger than that of LTA-NaA, OFF and MAZ molecular sieves, as the pore size of the molecular sieve increases, the adsorption capacity of Ni 2+ 、Co 2+ , Mn 2+ The adsorption capacity increases, and through one dynamic cycle, Li + The adsorption capacity remains the highest, but the selectivity decreases.

[0037] Fig.16 The reusability of the molecular sieve adsorbent in Example 6 shows that after 5 desorption and regeneration experiments, the molecular sieve adsorbent still maintains a high Li + Adsorption capacity and selectivity, with reusability.

[0038] Fig.17 The adsorption capacity and selectivity of the four metal ions by the LTA-NaA molecular sieve ion exchange under stirring in Comparative Example 1 show that as the exchange continues, the adsorption of LTA-NaA on Li + Compared with the dynamic cycle operation, the adsorption capacity and selectivity of the molecular sieve to Li under stirring are reduced. + The selectivity is low and lithium extraction cannot be achieved. After the LTA-NaA ion exchange reaches equilibrium, the Li + The adsorption capacity is the lowest and it cannot be used as an efficient lithium extraction adsorbent.

[0039] Fig.18 The adsorption capacity and selectivity of the OFF molecular sieve ion exchange for four metal ions under stirring in Comparative Example 1 show that in the initial exchange stage, the adsorption of Li + The adsorption capacity of Ni 2 + 、Co 2+ , Mn 2+ The adsorption capacity continued to increase for Li + The adsorption capacity is reduced and effective lithium extraction cannot be achieved.

[0040] Fig.19 The adsorption capacity and selectivity of the MAZ molecular sieve for four metal ions under stirring in comparative example 1 are shown in Table 1. 2+ 、Co 2+ , Mn 2+ The adsorption capacity continued to increase and was higher than that of Li + , no power + Selective.

[0041] Fig. 20 The adsorption capacity and selectivity of the FAU-NaX molecular sieve ion exchange for four metal ions under stirring in Comparative Example 1 show that under stirring operation, the FAU-NaX molecular sieve has no Li + Selectivity, after ion exchange reaches equilibrium, only Ni is adsorbed2+ 、Co 2+ , Mn 2+ , basically no adsorption of Li + . DETAILED DESCRIPTION

[0042] In order to more clearly understand the above-mentioned objectives, features and advantages of the present invention, the scheme of the present invention will be further described below. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0043] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present invention, rather than all of the embodiments.

[0044] The present invention provides a specific embodiment of a method for quickly and efficiently capturing lithium in a dynamic cycle, comprising the following steps: (1) loading at least one of LTA-NaA, OFF, MAZ or FAU-NaX zeolite molecular sieves into an adsorption column; (2) Cooling the lithium-containing solution to 0-20°C; (3) When the lithium-containing solution is added to the adsorption column of step (1), the lithium-containing solution is dynamically circulated through the zeolite molecular sieve of the adsorption column, and the number of dynamic cycles is at least 1, so as to achieve high selectivity and high adsorption amount of Li + capture.

[0045] In this embodiment, when the number of dynamic cycles is 1, the lithium-containing solution continuously flows through the zeolite molecular sieve of the adsorption column.

[0046] In one embodiment provided by the present invention, step (4) is further included, specifically: taking out and cleaning the zeolite molecular sieve layer in step (3), desorbing Li + Finally, the zeolite molecular sieve is recycled and steps (1), (2), and (3) are repeated.

[0047] Preferably, the pore size of the zeolite molecular sieve selected in step (1) is 4 Å-7 Å. The silicon-aluminum element ratios of the LTA-NaA, OFF, MAZ or FAU-NaX zeolite molecular sieves used are 2.0, 7.0, 4.0, and 2.0, respectively.

[0048] The zeolite molecular sieve selected in the present invention has no Li under ion exchange equilibrium. + Zeolite molecular sieve adsorbent with selective but fast ion exchange kinetics can achieve one-step Li enhancement through low temperature and dynamic circulation + .

[0049] Furthermore, under laboratory conditions, the thickness of the zeolite molecular sieve layer filled in the adsorption column in step (1) is 1 to 4 mm, and may include 1 to 3 zeolite molecular sieve layers. The flow rate of the lithium-containing solution is 20 to 100 mL / min, and it can be dynamically circulated 2 to 6 times, or it can continuously feed 10 to 1000 mL of liquid (i.e., 1 dynamic cycle).

[0050] In one embodiment provided by the present invention, the lithium-containing solution is a leaching solution of retired lithium-ion batteries Li + -Ni 2+ -Co 2+ -Mn 2+ or seawater brine Li + -Mg 2+ -Ca 2+ Coexisting solution. In the leachate of retired lithium-ion batteries, Li + / Ni 2+ / Co 2+ / Mn 2+ The molar concentration ratio of each ion in the coexisting solution is 1-10:1-8:1-3:1-3. In seawater brine, Li + -Mg 2+ -Ca 2+ The molar concentration ratio of each ion in the mixed solution is 1:1 to 100:1.

[0051] Preferably, in the retired lithium-ion battery leachate, Li + / Ni 2+ / Co 2+ / Mn 2+ The molar concentration ratio of each ion in the coexisting solution is 3:1:1:1 or 10:5:2:3 or 10:6:2:2 or 10:8:1:1. The aforementioned retired lithium-ion battery leachate is used to simulate the positive electrode of the power ternary battery (LiNi x Co y Mn 1–x–y O 2 ) A lithium, nickel, cobalt and manganese metal ion solution obtained from the leaching solution.

[0052] The aforementioned seawater brine is used to simulate low-grade seawater and the solution of metal ions in the brine.

[0053] The various lithium-containing solutions provided by the present invention are only for simulating the proportions of metal ions under various environments, and the method of the present invention is not limited to the above lithium-containing solutions.

[0054] In another embodiment provided by the present invention, the lithium-containing solution in step (2) contains Li + The concentration is at least 0.015mol / L.

[0055] In one embodiment provided by the present invention, in step (3), the lithium-containing solution is dynamically circulated through the zeolite molecular sieve of the adsorption column by suction filtration, filtration or free flow.

[0056] In another embodiment provided by the present invention, the salt solution in step (4) is a NaCl solution.

[0057] In one embodiment provided by the present invention, in step (4), the salt solution desorbs Li + The desorption conditions are as follows: desorption temperature is 25℃~60℃, and the desorption time is 0.5~2h. + The exchanged Li + Substitution and desorption of Li + And reduce the zeolite molecular sieve.

[0058] The specific embodiments of the present invention are described in detail below. Example 1

[0059] Prepare Li with an initial molar concentration ratio of 3:1:1:1 (or 10:5:2:3 or 10:6:2:2 or 10:8:1:1) + / Ni 2+ / Co 2+ / Mn 2+ Lithium-containing solution, wherein Li + The concentration is 0.015mol / L, and the solution temperature is reduced to 10℃. Four groups of 0.5g LTA-NaA molecular sieves are laid flat in the adsorption column, and 50 mL of lithium-containing solution is poured in respectively. The dynamic circulation experiment is carried out at a rate of 50 mL / min, and the cycle is repeated once. After one cycle, samples are taken and the metal content in the zeolite molecular sieve is tested by ICP, so as to calculate the adsorption capacity and recovery rate of the zeolite molecular sieve for each metal ion. Table 1

[0060]

[0061] It can be seen from the above table that under the simulated concentration of different types of power ternary battery leachate, through a dynamic cycle experiment, LTA-NaA molecular sieves all maintain high Li + Adsorption capacity: basically no adsorption of divalent metal ions, with high selectivity among the four metal ions to capture Li in one step + ability. Example 2

[0062] Prepare Li with an initial molar concentration ratio of 3:1:1:1 + / Ni 2+ / Co 2+ / Mn 2+ Coexisting solution, in which Li +The concentration is 0.015 mol / L, and the solution temperature is lowered to 0°C. 0.6g, 0.7g, 0.8g, 0.9g, 1g, and 1.5g of LTA-NaA are spread flat in the corresponding adsorption columns (such as Figure 3 As shown in the figure), 50 mL of solution was poured in respectively and the dynamic cycle was performed once at a rate of 20 mL / min. The metal ion content in the zeolite molecular sieve was tested by ICP, and the adsorption capacity and recovery rate of the zeolite molecular sieve for each metal ion were calculated. The results are shown in Figure 4 .

[0063] Prepare Li with an initial molar concentration ratio of 3:1:1:1 + / Ni 2+ / Co 2+ / Mn 2+ Coexisting solution, in which Li + The concentration was 0.015 mol / L, and the solution temperature was lowered to 0°C. Four groups of 0.5 g LTA-NaA adsorbent were spread flat in the corresponding adsorption columns, and 10 mL, 20 mL, 30 mL, and 40 mL of solution were poured in respectively, and dynamically circulated once at a rate of 20 mL / min (e.g. Figure 5 The metal ion content in the zeolite molecular sieve is tested by ICP, so as to calculate the adsorption capacity and recovery rate of the zeolite molecular sieve for each metal ion. The results are shown in Figure 6 .

[0064] Prepare Li with an initial molar concentration ratio of 3:1:1:1 + / Ni 2+ / Co 2+ / Mn 2+ Coexisting solution, in which Li + The concentration was 0.015 mol / L, and the solution temperature was lowered to 0°C. 0.5 g of LTA-NaA was spread on one layer and two layers of adsorption column plates, 50 mL of solution was added, and dynamic circulation was performed once at a rate of 20 mL / min (e.g. Figure 7 The metal ion content in the zeolite molecular sieve is tested by ICP, so as to calculate the adsorption capacity and recovery rate of the zeolite molecular sieve for each metal ion. The results of the single-layer adsorption column plate and the double-layer adsorption column plate are compared in Figure 8 . Example 3

[0065] Prepare Li with an initial molar concentration ratio of 3:1:1:1 + / Ni 2+ / Co 2+ / Mn 2+ Coexisting solution, in which Li +The concentration was 0.015 mol / L, and the solution temperature was lowered to 0°C. Four groups of 0.5 g LTA-NaA adsorbent were spread flat in the corresponding adsorption columns, and 100, 200, 300, and 350 mL of solution were poured in respectively, and dynamic circulation was performed once at a rate of 80 mL / min (e.g. Fig. 9 After the completion of the test, samples were taken and the metal content in the zeolite molecular sieve was tested by ICP, so as to calculate the adsorption capacity of the zeolite molecular sieve for each metal ion. The results are shown in Fig.10 . Example 4

[0066] Prepare Li with an initial molar concentration ratio of 1:1:1 (1:100:1) + / Mg 2+ / Ca 2+ Coexisting solution, in which Li + The concentration is 0.015mol / L, and the solution temperature is lowered to 10℃. Two groups of 0.5g LTA-NaA adsorbents are spread in the corresponding adsorption columns, and 50 mL of the corresponding solution is added respectively and the dynamic cycle is performed once at a rate of 50 mL / min. The metal ion content in the zeolite molecular sieve is tested by ICP, so as to calculate the adsorption capacity and recovery rate of the zeolite molecular sieve for each metal ion, see Fig.11 as well as Fig.12 . Example 5

[0067] Prepare Li with an initial molar concentration ratio of 3:1:1:1 + / Ni 2+ / Co 2+ / Mn 2+ Coexisting solution, in which Li + The concentration is 0.015mol / L, and the solution temperature is reduced to 0℃. 0.5g of OFF, MAZ, and FAU-NaX adsorbents are placed flat in the adsorption column, 50 mL of solution is added, and dynamic circulation is performed at a rate of 50mL / min. The cycle is repeated once. The metal ion content in the zeolite molecular sieve is tested by ICP, and the adsorption capacity and recovery rate of the zeolite molecular sieve for each metal ion are calculated. See Figure 13-Figure 15 . Example 6

[0068] In order to prove the reusability of the molecular sieve adsorbent, based on Example 1, the molecular sieve layer after exchange was taken and thoroughly washed. + 1g LTA-NaA is added to 0.1~0.5mol / L Na + The solution was stirred at 60 °C for 1 h and then washed with a large amount of water to reduce the molecular sieve. The reduced molecular sieve was then used to capture Li +Repeat the regeneration 5 times, and calculate the adsorption capacity and recovery rate of zeolite molecular sieve for each metal ion after each dynamic cycle. Fig.16 .

[0069] Comparative Example 1 Prepare Li with an initial molar concentration ratio of 3:1:1:1 + / Ni 2+ / Co 2+ / Mn 2+ Coexisting solution, in which Li + The concentration is 0.015 mol / L, and the solution temperature is reduced to 0°C. 0.5 g of LTA-NaA, OFF, MAZ, and FAU-NaX adsorbents are added to the corresponding 50 mL of the coexisting solution, stirred for ion exchange, and the residual metal ion concentration in the solution is tested by ICP, and the adsorption capacity of the zeolite molecular sieve for each metal ion is calculated, see Figure 17-Figure 20 .

[0070] Comparative Example 2 Prepare Li with an initial molar concentration ratio of 3:1:1:1 + / Ni 2+ / Co 2+ / Mn 2+ Coexisting solution, in which Li + The concentration is 0.015mol / L, and the solution temperature is room temperature 25℃. 0.5g LTA-NaA, OFF, MAZ, and FAU-NaX adsorbents are placed flat in the adsorption column, 50 mL of solution is added, and dynamic circulation is performed at a rate of 50mL / min, and the cycle is repeated once. The metal ion content in the zeolite molecular sieve is tested by ICP, and the adsorption capacity of the zeolite molecular sieve for each metal ion is calculated. Table 2

[0071]

[0072] As can be seen from the table above, the dynamic cycle of the four molecular sieves at room temperature 25°C is better than that at low temperature ≤ 20°C. + The adsorption capacity of Co 2+ , Mn 2+ 、Ni 2+ Adsorption capacity is improved, Li + The selectivity is reduced, but it can still be maintained. Therefore, dynamic cycle operation at a lower temperature can capture Li more selectively. + .

[0073] The above is only a specific implementation of the present invention, which enables those skilled in the art to understand or implement the present invention. Although detailed descriptions are given with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein 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 all be covered by the protection scope of the claims.

Claims

1. A method for rapidly and efficiently capturing lithium in a dynamic cycle, characterized in that: The steps include: (1) loading at least one of LTA-NaA, OFF, MAZ or FAU-NaX zeolite molecular sieves into an adsorption column; (2) Cooling the lithium-containing solution to 0-20°C; (3) When the lithium-containing solution is added to the adsorption column of step (1), the lithium-containing solution is dynamically circulated through the zeolite molecular sieve of the adsorption column, and the number of dynamic cycles is at least 1, so as to achieve high selectivity and high adsorption amount of Li + capture.

2. The method for quickly and efficiently capturing lithium in a dynamic cycle according to claim 1, characterized in that: The method further comprises the following steps: removing and cleaning the zeolite molecular sieve layer in step (3), and desorbing Li + Finally, the zeolite molecular sieve is recycled and steps (1), (2), and (3) are repeated.

3. The method for quickly and efficiently capturing lithium in a dynamic cycle according to claim 1, characterized in that: The pore size of the zeolite molecular sieve selected in step (1) is 4 Å -7 Å.

4. The method for rapidly and efficiently capturing lithium in a dynamic cycle according to claim 1, characterized in that: In step (1), the adsorption column contains 1 to 3 zeolite molecular sieve layers.

5. The method for rapidly and efficiently capturing lithium in a dynamic cycle according to claim 1, characterized in that: The lithium-containing solution is a leaching solution of retired lithium-ion batteries Li + -Ni 2+ -Co 2+ -Mn 2+ or seawater brine Li + -Mg 2+ -Ca 2+ Coexisting solution.

6. The method for rapidly and efficiently capturing lithium in a dynamic cycle according to claim 1, characterized in that: In step (2), the lithium-containing solution Li + The concentration is 0.015 mol / L.

7. The method for rapidly and efficiently capturing lithium in a dynamic cycle according to claim 1, characterized in that: In step (3), the lithium-containing solution is dynamically circulated through the zeolite molecular sieve of the adsorption column by suction filtration, filtration or free flow.

8. The method for rapidly and efficiently capturing lithium in a dynamic cycle according to claim 2, characterized in that: The salt solution in step (4) is NaCl solution.

9. The method for rapidly and efficiently capturing lithium in a dynamic cycle according to claim 2, characterized in that: Step (4) Li is desorbed from the salt solution + The desorption conditions are as follows: desorption temperature is 25℃~60℃, and the desorption time is 0.5~2h. + The exchanged Li + Substitution and desorption of Li + And reduce the zeolite molecular sieve.

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