Method for adsorbing and desorbing lithium

Abstract

A method for adsorbing and desorbing lithium, according to the present invention, comprises: an adsorption step of passing a lithium-containing solution through an adsorbent packed in a column to obtain an adsorbent on which lithium is adsorbed; a washing step of passing a pretreatment solution containing a salt to the adsorbent on which lithium is adsorbed to remove impurities; and a desorption step of passing a medium to the adsorbent on which lithium is adsorbed to obtain a lithium-containing desorption solution, wherein, in the washing step, equation 1 is satisfied in a phase diagram of the temperature of the column, the flow rate of the pretreatment solution, and the concentration of the pretreatment solution.

Description

Lithium adsorption and desorption method

[0001] This application claims priority to Korean Patent Application No. 10-2024-0191948 filed on December 19, 2024, and all contents of said priority application are incorporated into this specification.

[0002] The present invention relates to a method for the adsorption and desorption of lithium.

[0003] Lithium-ion batteries are an essential component in small devices such as mobile phones and laptops, and recently, the demand for them is also increasing as a power source for hybrid and electric vehicles. Consequently, the demand for lithium, a key raw material for lithium-ion batteries, is also surging.

[0004] Lithium, a key material for such lithium secondary batteries, is generally extracted from minerals, seawater, brine, etc. However, the lithium content in the Earth's crust is only 0.006%, and because of its high reactivity, it is not found in nature in the form of pure metal; generally, it is extracted in the form of lithium compounds such as Li2CO3 and LiOH·H2O rather than in the form of pure metal.

[0005] In addition, although seawater is abundant globally, its lithium content is low at 0.17 mg / L, which results in low efficiency for lithium extraction and high production costs compared to other lithium sources.

[0006] The most common method for extracting lithium is to evaporate water from brine and then add carbonates to extract lithium in the form of lithium carbonate. However, to extract lithium carbonate by adding carbonates, the brine must be concentrated to an economically viable level before proceeding with the extraction process; consequently, there is a problem in that brine sources capable of improving the economic feasibility of lithium extraction are scarce worldwide.

[0007] Therefore, there is an urgent need to develop technologies that can economically and efficiently recover lithium from lithium-containing solutions. As one such method, selective adsorption and desorption technologies for lithium using adsorbents are being researched.

[0008] The present invention aims to provide a method for the adsorption and desorption of lithium that minimizes lithium loss during the washing process and effectively removes impurities.

[0009] The present invention provides a method for the adsorption and desorption of lithium, comprising: an adsorption step of passing a lithium-containing solution through an adsorbent packed in a column to obtain an adsorbent on which lithium is adsorbed; a washing step of passing a pretreatment solution containing a salt solution through the adsorbent on which lithium is adsorbed to remove impurities; and a desorption step of passing a medium through the adsorbent on which lithium is adsorbed to obtain a lithium-containing desorption solution; wherein, in the washing step, the temperature of the column, the flow rate of the pretreatment solution, and the concentration of the pretreatment solution satisfy the following Equation 1.

[0010] [Equation 1]

[0011] 0 ≤ x ≤ 0.52, 0.125 ≤ y ≤ 1.0, 0 ≤ z ≤ 0.875

[0012] In the above Equation 1,

[0013] x is the temperature (°C) of the above column, and

[0014] y is the flow rate (BV / h) of the above pretreatment solution, and

[0015] z is the concentration (g / L) of the above pretreatment solution, and

[0016] The above x, y, and z are values ​​normalized to satisfy x+y+z=1.

[0017] The method for adsorbing and desorbing lithium according to the present invention has the advantage of being able to delay the desorption of lithium from the adsorbent and effectively reduce impurities in the lithium-containing desorption solution.

[0018] Figures 1 to 8 show data representing the lithium concentration according to BV in the washing step and the desorption step according to the experimental example.

[0019] Figure 9 is a diagram showing the conditions of the washing step according to the example and comparative example.

[0020] Hereinafter, embodiments of the present invention will be described in detail. However, these are presented as examples and are not intended to limit the present invention, and the present invention is defined only by the scope of the claims set forth below.

[0021] In the present invention, when a part is described as "comprising" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0022]

[0023] One aspect of the present invention relates to a method for the adsorption and desorption of lithium, comprising: an adsorption step of passing a lithium-containing solution through an adsorbent packed in a column to obtain an adsorbent on which lithium is adsorbed; a washing step of passing a pretreatment solution containing a salt solution through the adsorbent on which lithium is adsorbed to remove impurities; and a desorption step of passing a medium through the adsorbent on which lithium is adsorbed to obtain a lithium-containing desorption solution, wherein in the washing step, the temperature of the column, the flow rate of the pretreatment solution, and the concentration of the pretreatment solution satisfy the following Equation 1.

[0024] [Equation 1]

[0025] 0 ≤ x ≤ 0.52, 0.125 ≤ y ≤ 1.0, 0 ≤ z ≤ 0.875

[0026] In the above Equation 1,

[0027] x is the temperature (°C) of the above column, and

[0028] y is the flow rate (BV / h) of the above pretreatment solution, and

[0029] z is the concentration (g / L) of the above pretreatment solution, and

[0030] The above x, y, and z are values ​​normalized to satisfy x+y+z=1.

[0031]

[0032] The method for adsorbing and desorbing lithium according to the present invention has the advantage of suppressing the loss of lithium that occurs during the washing process of a process for directly extracting lithium from brine or salt lakes using an adsorbent.

[0033]

[0034] Adsorption stage

[0035] The method for adsorbing and desorbing lithium according to the present invention comprises an adsorption step of passing a lithium-containing solution through an adsorbent packed in a column to obtain an adsorbent on which lithium has been adsorbed.

[0036] The above adsorption step refers to a step of adsorbing lithium from a lithium-containing solution. Specifically, the lithium-containing solution may be passed through an adsorbent packed in a column to adsorb lithium onto the adsorbent.

[0037]

[0038] In another embodiment of the present invention, the lithium concentration of the lithium-containing solution in the adsorption step may be 0.03 to 2.0 g / L. Specifically, the lithium concentration of the lithium-containing solution may be 0.1 to 2.0 g / L, and more specifically 0.5 to 1.5 g / L.

[0039] When the lithium concentration of the above lithium-containing solution satisfies the above range, lithium adsorption on the adsorbent is easy, resulting in excellent adsorption efficiency and the advantage of increasing economic efficiency by reducing the need to operate multiple adsorption columns.

[0040] In addition, since lowering the time to reach the breakthrough point of the adsorbent reduces the need to operate multiple adsorption columns and thereby increases economic efficiency, it is desirable for the lithium concentration of the lithium-containing solution to satisfy the above range.

[0041]

[0042] The above adsorbent is intended to adsorb lithium dissolved in the above lithium-containing solution.

[0043] In another embodiment of the present invention, the adsorbent may be an aluminum-based adsorbent.

[0044] Specifically, the above adsorbent may include aluminum hydroxide.

[0045] When using the aluminum-based adsorbent containing the above aluminum hydroxide, the adsorption amount of lithium dissolved in the lithium-containing solution is high, and since there is almost no loss of aluminum in the desorption step described later, the adsorbent has a long lifespan, thus providing the advantage of excellent economic efficiency in the lithium extraction process.

[0046] The above aluminum-based adsorbent may be a molded body comprising adsorbent powder and a binder.

[0047] The above-mentioned adsorbent powder may be, for example, an adsorbent powder containing aluminum hydroxide. The advantages of using an adsorbent powder containing aluminum hydroxide are the same as those described above.

[0048] The above binder is intended to manufacture the adsorbent powder into a molded body of a suitable shape and serves to bind the adsorbent powders together.

[0049] The binder may include, for example, at least one of polyvinyl chloride (PVC), polysulfone, and polyaniline. Specifically, it is preferable that the binder include polyvinyl chloride (PVC), which can provide excellent bonding strength between adsorbent powders.

[0050]

[0051] Meanwhile, the step of passing a lithium-containing solution through an aluminum-based adsorbent to adsorb lithium onto the aluminum-based adsorbent may include, for example, the reaction of the following reaction scheme 1.

[0052] [Reaction Equation 1]

[0053] (1-x)LiCl·2Al(OH)3·nH2O + xLiCl → LiCl·2Al(OH)3·nH2O

[0054]

[0055] Washing step

[0056] The method for adsorbing and desorbing lithium according to the present invention comprises a washing step of removing impurities by passing distilled water through the aforementioned lithium-adsorbed adsorbent; wherein, in the washing step, the temperature of the column, the flow rate of the pretreatment solution, and the concentration of the pretreatment solution satisfy the following Equation 1.

[0057] [Equation 1]

[0058] 0 ≤ x ≤ 0.52, 0.125 ≤ y ≤ 1.0, 0 ≤ z ≤ 0.875

[0059] In the above Equation 1,

[0060] In the above Equation 1,

[0061] x is the temperature (°C) of the above column, and

[0062] y is the flow rate (BV / h) of the above pretreatment solution, and

[0063] z is the concentration (g / L) of the above pretreatment solution, and

[0064] The above x, y, and z are values ​​normalized to satisfy x+y+z=1.

[0065]

[0066] Specifically, in the washing step using a pretreatment solution, the present invention provides conditions for effective washing when various variables, such as the temperature of the column, more specifically the temperature inside the column, the flow rate of the pretreatment solution, the concentration of the pretreatment solution, specifically the concentration of NaCl in the pretreatment solution, interact in combination, thereby suppressing the phenomenon of initial lithium desorption and having the advantage of easily removing impurities.

[0067]

[0068] The above x is a value normalized from the column temperature (°C). For example, the above x may be a value normalized by dividing the column temperature (°C) by 10 and satisfying x+y+z=1.

[0069] The above y is a value normalized from the flow rate (BV / h) of the pretreatment solution. For example, the above y may be a value normalized by dividing the flow rate (BV / h) of the pretreatment solution by 10 and satisfying x+y+z=1.

[0070] The above z is a value normalized from the concentration (g / L) of the pretreatment solution. Specifically, the above z may be a value normalized from the concentration (g / L) of the pretreatment solution such that x+y+z=1.

[0071]

[0072] In one embodiment of the present invention, in the washing step; the following Equation 2 can be satisfied in the state diagram of the temperature of the column, the flow rate of the pretreatment solution, and the concentration of the pretreatment solution.

[0073] [Equation 2]

[0074] 0.125 ≤ x ≤ 0.52, 0.125 ≤ y ≤ 1.0, 0 < z ≤ 0.875

[0075] In the above Equation 2,

[0076] x to z are as defined in Equation 1 above.

[0077]

[0078] In another embodiment of the present invention, in the washing step, the following Equation 3 can be satisfied in the state diagram of the temperature of the column, the flow rate of the pretreatment solution, and the concentration of the pretreatment solution.

[0079]

[0080] [Equation 3]

[0081] 0.125 ≤ x ≤ 0.52, 0.125 ≤ y ≤ 0.6, 0 < z ≤ 0.875

[0082] In the above Equation 3,

[0083] x to z are as defined in Equation 1 above.

[0084]

[0085] In the above washing step, if the range of the above formula is satisfied in the state diagram of the temperature of the column, the flow rate of the pretreatment solution, and the concentration of the pretreatment solution, the desired effect, namely the lithium desorption delay effect, becomes more excellent.

[0086]

[0087] In another embodiment of the present invention, in the washing step; the flow rate of the pretreatment solution may be 10 to 100 BV / h, preferably 10 to 85 BV / h, more preferably 30 to 85 BV / h.

[0088] It is desirable that the flow rate of the above pretreatment solution satisfies the above range, as this can exhibit a lithium desorption delay effect. Specifically, it is desirable that the flow rate satisfies the above range at room temperature, as the flow rate is appropriate, resulting in excellent lithium desorption delay and the ability to suppress the problem of excessive differential pressure.

[0089]

[0090] In another embodiment of the present invention, in the washing step; the temperature of the column may be 10 to 80 ℃, preferably 25 to 80 ℃, more preferably 25 to 60 ℃.

[0091] When the temperature of the above column satisfies the above range, it is desirable because it minimizes the energy required for the washing step while achieving the desired effects, namely, the lithium desorption delay effect and the impurity removal effect.

[0092]

[0093] The above pretreatment solution may contain salt.

[0094] In another embodiment of the present invention, the salt may comprise one or more selected from the group consisting of NaCl, KCl, MgCl2, CaCl2, and LiCl.

[0095] Specifically, the salt may be NaCl. The NaCl has the advantage of being inexpensive and easy to obtain. In addition, the NaCl is desirable because its high solubility can suppress scale formation caused by precipitates in columns or subsequent processes.

[0096]

[0097] In another embodiment of the present invention, the concentration of the salt, specifically NaCl, in the pretreatment solution may be 0.1 to 20 g / L, preferably 0.3 to 20 g / L, and more preferably 0.3 to 10 g / L.

[0098] If the NaCl concentration of the above pretreatment solution satisfies the above range, it is desirable to be able to satisfy both the lithium desorption delay effect and the impurity removal effect while reducing process costs.

[0099]

[0100] Specifically, the flow rate of the pretreatment solution, the temperature of the column, and the salt concentration of the pretreatment solution can be selected to satisfy the equation in the phase diagram within the aforementioned range.

[0101]

[0102] Although it is not desired to be limited by theory, in the washing step described above, as the temperature of the distilled water increases, lithium ions have a high diffusivity, and as the temperature decreases, the diffusivity of lithium ions decreases. Therefore, when the temperature is high, the desorption of lithium ions adsorbed on the adsorbent to the outside of the adsorbent is promoted. At the same temperature, if the flow rate of the distilled water increases, the contact time between the adsorbent and the pretreatment solution is shortened; thus, the diffusivity of lithium in the adsorbent on which lithium ions are adsorbed decreases, allowing for effective washing of impurities outside the adsorbent while delaying the diffusion of lithium adsorbed inside, thereby obtaining a sufficient desorption delay effect.

[0103] In addition, when the total dissolved solids (TDS) concentration of the pretreatment solution is high, desorption is inhibited due to hydration competition between the adsorbed lithium and the salt in the pretreatment solution; therefore, in the washing step of the present invention, the temperature of the column, the flow rate of the pretreatment solution, and the concentration of the pretreatment solution, specifically the salt concentration of the pretreatment solution, are controlled together.

[0104]

[0105] With respect to the total 100% by weight of lithium present in the adsorbent after the above adsorption step, the amount of lithium contained in the pretreatment solution after passing the adsorbent through and washing with the pretreatment solution may be in the range of 0.1 to 30.0% by weight, and specifically, may be in the range of 1.0 to 8.0% by weight, 1.0 to 6.0% by weight, 1.0 to 4.0% by weight, or 1.0 to 2.5% by weight.

[0106] This means that the desorption of lithium adsorbed on the adsorbent in the above washing step is suppressed.

[0107]

[0108] In the above washing step; the value of the integrated area in the volume range of the pretreatment solution in the graph of the concentration of desorbed lithium according to the volume of the pretreatment solution may be 700 BV·mg / L or less.

[0109] Specifically, the integrated area value refers to the area of ​​the graph at the level of the amount of lithium (mg / L) desorbed into the pretreatment solution according to the amount of the pretreatment solution flowed (BV), in other words, the integrated area value.

[0110] For example, when the above pretreatment solution is flowed up to 2 BV, the area of ​​the graph when the volume of the above pretreatment solution is from 0 to 2 BV, in other words, the integrated area value may be 700 BV·mg / L or less. When the above pretreatment solution is flowed up to 1 BV, it is the area of ​​the graph when the volume of the above pretreatment solution is from 0 to 1 BV, and when the above pretreatment solution is flowed up to 3 BV, it is the area of ​​the graph when the volume of the above distilled water is from 0 to 3 BV.

[0111] Specifically, the graph above can utilize the concentration graph of lithium that is desorbed into the pretreatment solution or desorption solution according to the washing and desorption steps as shown in FIGS. 1 to 7.

[0112] Satisfying the above integral area value means that the amount of lithium desorption in the washing section is small, and may mean that lithium desorption is delayed during the washing step.

[0113]

[0114] Detachment step

[0115] The method for adsorbing and desorbing lithium according to the present invention comprises a desorption step of passing a medium through the aforementioned adsorbent on which lithium is adsorbed to obtain a lithium-containing desorbent.

[0116] Specifically, a lithium-containing desorbent can be obtained by passing a medium, such as distilled water or an aqueous solution containing a lithium salt, through the aluminum adsorbent on which the lithium is adsorbed.

[0117] At this time, the amount of medium passed through the aluminum adsorbent on which the lithium is adsorbed can be 10 to 50 BV, specifically 15 to 40 BV, and more specifically 15 to 30 BV, based on the bed volume (BV) of the adsorbent column.

[0118]

[0119] In the total lithium-containing desorbent obtained by passing a medium through an adsorbent, most of the lithium adsorbed on the adsorbent must be desorbed so that the lithium concentration in the desorbent after 80 volume% of the medium has passed is 0.2 g / L or less, specifically 0.1 g / L or 0.05 g / L, so that it is possible to adsorb lithium again using the said adsorbent. Therefore, a step of passing an amount of medium within the above range through the aluminum adsorbent in which lithium is adsorbed may be necessary.

[0120] Lithium chloride can be recovered through a desorption solution with a high lithium concentration obtained through the above desorption step, but is not limited thereto. Specifically, the lithium-containing desorption solution can be used in the process up to the step of passing through a medium of 10 BV after the washing step in which impurities are removed, and preferably, the lithium-containing desorption solution can be used up to the step of passing through a medium of 7 BV or 5 BV, but may vary depending on the shape of the desorption curve.

[0121] With respect to the total 100 weight% of lithium present in the adsorbent after the adsorption step, the amount of lithium obtained in the desorption step may be in the range of 50.0 to 99.9 weight%, and specifically, in the range of 70.0 to 99.9 weight%.

[0122]

[0123] In the case where the washing step according to the present invention is not included, the amount of lithium lost with respect to 100% by weight of the total lithium present in the adsorbent after the adsorption step may be in the range of 10.0 to 70.0% by weight, and specifically, may be in the range of 25.0 to 60.0% by weight or 30.0 to 50.0% by weight. The reason for such lithium loss is that a lithium-containing desorption solution containing a high concentration of impurities may be difficult to use in the lithium recovery process. It is preferable that the concentration of impurities (salts excluding lithium) be lower, and specifically, in the case of a lithium-containing desorption solution containing impurities (salts excluding lithium) of 20 g / L, 15 g / L, or 10 g / L or less, the recovery rate of lithium hydroxide obtained after proceeding with the subsequent process described below may be excellent.

[0124]

[0125] The step of obtaining a lithium-containing desorbent by passing a medium through the above-mentioned aluminum adsorbent on which lithium is adsorbed may include, for example, the reaction of Reaction Scheme 2 below.

[0126] [Reaction Equation 2]

[0127] LiCl·2Al(OH)3·nH2O → (1-x)LiCl·2Al(OH)3·nH2O + xLiCl

[0128]

[0129] The medium used in the above desorption step may be an aqueous solution containing a lithium salt, specifically, the medium may be an aqueous solution containing lithium chloride. In this case, the concentration of lithium in the obtained desorption solution may be increased. This improvement in the lithium concentration in the desorption solution can reduce the load on the downstream concentration process.

[0130] Specifically, the lithium concentration in the medium may be in the range of 0.05 to 1.50 g / L, and more specifically, 0.10 to 1.00 g / L, 0.10 to 0.80 g / L, or 0.10 to 0.40 g / L.

[0131] When the lithium concentration in the medium satisfies the above range, it is desirable to suppress the phenomenon in which lithium (Li) contained in the aluminum adsorbent is lost and causes damage to the LDH (Layered Double Hydroxide) structure, and to suppress the phenomenon in which adsorption rather than desorption occurs.

[0132] The concentration of lithium contained in the lithium-containing desorption solution obtained by the above method may be 0.1 g / L to 3.0 g / L, or 0.2 g / L to 3.0 g / L, and more specifically, 0.8 g / L to 2.5 g / L.

[0133] When the lithium concentration of the desorption solution is high, it implies that the amount of water that needs to be removed in the subsequent concentration step is reduced, which can significantly improve the process burden of the downstream process. In this case, the downstream process may refer to the concentration step.

[0134] A method for the adsorption and desorption of lithium according to one embodiment may further include a step of concentrating the total desorbed solution obtained through the desorption step.

[0135] Specifically, the concentration step may include a concentration process of the desorbent using reverse osmosis and electrodialysis, through which the target lithium concentration can be determined according to the characteristics of the intermediate to be extracted. If additional concentration is required beyond the above methods, the lithium concentration can be raised to the desired level through a concentration step using reduced pressure / evaporation.

[0136]

[0137] Preferred embodiments and comparative examples of the present invention are described below. However, the following examples are merely preferred embodiments of the present invention, and the present invention is not limited to the following examples.

[0138]

[0139]

[0140] Experimental Example

[0141] A brine solution with the composition shown in Table 1 below was prepared. Subsequently, Al-LDH [LiCl] 0-1 The adsorbent was passed through a [Al(OH)3]2 adsorbent. Afterward, the adsorbent was washed with a pretreatment solution containing NaCl for 2 BV volumes according to column temperature, pretreatment solution flow rate, and concentration conditions (see Table 2), and desorption was completed by flowing a LiCl solution at a flow rate of 100 BV / h.

[0142]

[0143] Saline composition LiNaKCaB mg / L 360 44,000 16,500 30,400 390

[0144] (1) Checking washing and desorption results according to the concentration and flow rate of the NaCl pretreatment solution

[0145] According to the NaCl concentration and flow rate conditions in Table 2 below, lithium concentration data according to the BV of the washing and desorption steps is shown in Figures 1 to 5, and the area values ​​(unit: BV*mg / L) derived from the graph of the concentration of desorbed lithium according to the volume of the pretreatment solution obtained finally are also shown.

[0146] Specifically, the above area value represents the area of ​​the graph at the level of the amount of pretreatment solution used, in other words, the integrated area value, in the graph of the concentration (mg / L) of lithium desorbed into the pretreatment solution according to the amount (BV) of the pretreatment solution.

[0147] At this time, the area value represents the lithium loss rate during the washing step, and if the area value is 700 or more, it means that there is no delay and the lithium detachment delay effect is not achieved.

[0148]

[0149] Pretreatment solution flow rate (BV / h) Column temperature (°C) Pretreatment solution NaCl concentration (g / L) Area Related drawing Sample 1 50 60 - (Distilled water) 870°C Sample 1 2 50 60 0.3368°C Sample 2 3 50 60 1480°C Sample 3 4 50 60 550 4°C Sample 4 5 30 60 5666°C 5

[0150] (2) Check washing and desorption results according to the concentration, temperature, and flow rate of the pretreatment solution

[0151] According to the concentration of the pretreatment solution, flow rate, and column temperature in Table 3 below, lithium concentration data according to the BV of the washing and desorption steps is shown in Figures 6 to 8, and the area value (unit: BV*mg / L) derived from the graph of the concentration of desorbed lithium according to the volume of the washing solution is also shown.

[0152]

[0153] Pretreatment solution flow rate (BV / h) Column temperature (°C) Pretreatment solution NaCl concentration (g / L) Area Related drawing Sample 6 10 25 17 57°C Sample 6 7 10 40 10 8 28°C Sample 7 8 30 40 14 63°C 8

[0154] Referring to Figures 3 to 8, it can be seen that as the temperature of the column decreases, delay can be achieved even with a lower flow rate, but the amount of detachment in the detachment section outside the washing section is also reduced.

[0155]

[0156] Examples and Comparative Examples

[0157] The procedure was carried out in the same manner as the above experimental example, but a volume of 2 BV was washed using the pretreatment solution according to the example and comparative example, and desorption was completed by flowing a LiCl solution with a lithium concentration of 0.3 g / L at a flow rate of 100 BV / h. At this time, the conditions of the pretreatment solution according to the example and comparative example were divided by 10 for the column temperature and pretreatment solution flow rate conditions, respectively, and are shown in Table 4 below. These were then normalized to satisfy x+y+z=1 to create a phase diagram, which is shown in Figure 9. The presence of lithium desorption delay was determined based on an area value of 700.

[0158]

[0159] Column Temperature (°C / 10) Pretreatment Solution Flow Rate (BV / h / 10) Concentration (g / L) Retardation Comparison Example 1 2.5 11 × Example 1 43 1 ○ Example 2 63 5 ○ Example 3 65 1 ○ Example 4 65 5 ○ Example 5 66 0 ○ Comparative Example 2 65 0 × Example 6 66 20 ○ Example 7 68.5 20 ○ Example 8 41 0 5 ○ Comparative Example 3 41 10 ×

[0160] Referring to FIG. 9, it can be seen that when using the cleaning conditions according to the embodiment, the lithium detachment delay effect is excellent.

[0161]

[0162] The present invention is not limited to the above embodiments and can be manufactured in various different forms, and those skilled in the art will understand that the invention can be implemented in other specific forms without changing the technical concept or essential features of the invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive.

Claims

1. An adsorption step of passing a lithium-containing solution through an adsorbent packed in a column to obtain an adsorbent on which lithium is adsorbed; A washing step of removing impurities by passing a pretreatment solution containing salt through the above lithium-adsorbed adsorbent; and A desorption step of obtaining a lithium-containing desorbent by passing a medium through the adsorbent on which the lithium is adsorbed; Includes, In the above washing step; A method for the adsorption and desorption of lithium satisfying the following Equation 1 in the phase diagram of the temperature of the column, the flow rate of the pretreatment solution, and the concentration of the pretreatment solution: [Equation 1] 0 ≤ x ≤ 0.52, 0.125 ≤ y ≤ 1.0, 0 ≤ z ≤ 0.875 In the above Equation 1, x is the temperature (°C) of the above column, and y is the flow rate (BV / h) of the above pretreatment solution, and z is the concentration (g / L) of the above pretreatment solution, and The above x, y, and z are values ​​normalized to satisfy x+y+z=1.

2. In Paragraph 1, In the above washing step; A method for the adsorption and desorption of lithium satisfying the following Equation 2 in the phase diagram of the temperature of the column, the flow rate of the pretreatment solution, and the concentration of the pretreatment solution: [Equation 2] 0.125 ≤ x ≤ 0.52, 0.125 ≤ y ≤ 1.0, 0 < z ≤ 0.875 In the above Equation 2, x to z are as defined in Equation 1 above.

3. In Paragraph 2, In the above washing step; A method for the adsorption and desorption of lithium satisfying the following Equation 3 in the phase diagram of the temperature of the column, the flow rate of the pretreatment solution, and the concentration of the pretreatment solution: [Equation 3] 0.125 ≤ x ≤ 0.52, 0.125 ≤ y ≤ 0.6, 0 < z ≤ 0.875 In the above Equation 3, x to z are as defined in Equation 1 above.

4. In Paragraph 1, A method for the adsorption and desorption of lithium, wherein, in the washing step above, the flow rate of the pretreatment solution is 10 to 100 BV / h.

5. In Paragraph 1, A method for the adsorption and desorption of lithium, wherein, in the washing step above, the temperature of the column is 10 to 80 ℃.

6. In Paragraph 1, A method for the adsorption and desorption of lithium, wherein the above pretreatment solution has a salt concentration of 0.1 to 20 g / L.

7. In Paragraph 1, A method for the adsorption and desorption of lithium, wherein the lithium concentration of the lithium-containing solution in the above adsorption step is 0.03 to 2.0 g / L.

8. In Paragraph 1, A method for the adsorption and desorption of lithium, wherein the lithium concentration of the medium used in the above desorption step is 0.05 to 1.50 g / L.

9. In Paragraph 1, A method for the adsorption and desorption of lithium, wherein the above salt comprises one or more selected from the group consisting of NaCl, KCl, MgCl2, CaCl2, and LiCl.

10. In Paragraph 1, A method for the adsorption and desorption of lithium in which the above-mentioned adsorbent is an aluminum-based adsorbent.

11. In Paragraph 1, A method for the adsorption and desorption of lithium, further comprising the step of concentrating the total desorbed solution obtained through the above desorption step.

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