Method for regenerating aluminum-based lithium adsorbent

Abstract

The present embodiments relate to a method for regenerating an aluminum-based lithium adsorbent. The method for regenerating an aluminum-based lithium adsorbent, according to an embodiment, includes: a step of preparing an aluminum-based lithium adsorbent of which activity is inhibited; and a step of reacting the adsorbent with a solution containing lithium, wherein, in the solution containing lithium, the concentration of lithium ions may be 0.6-5.0 g / L.

Description

Method for regenerating aluminum-based lithium adsorbent

[0001] These examples relate to a method for regenerating an aluminum-based lithium adsorbent.

[0002] Lithium-containing salt lakes contain a variety of dissolved minerals, and much research has been conducted to extract lithium from them. A common method for lithium extraction in the past involved concentrating the brine using natural evaporation, removing any remaining calcium, magnesium, boron, and sulfate ions from the concentrated lithium solution, and then adding sodium carbonate to extract lithium carbonate.

[0003] Recently, research has been conducted on methods for extracting lithium using various adsorbents capable of selectively adsorbing lithium, including lithium manganese oxide (LMO), titanium, zirconium, and aluminum. Among these adsorbents, aluminum-based lithium adsorbents are primarily commercially available.

[0004] The aluminum-based lithium adsorbent may have a Li / Al-LDH (Layered Double Hydroxide) structure, and adsorption is performed by intercalating Li ions into the Li / Al-LDH structure under conditions in which the structure of Li / Al-LDH is appropriately maintained.

[0005] At this time, if the structural stability of Li / Al-LDH is reduced and the structure of the aluminum-based lithium adsorbent is destroyed, Li / Al-LDH undergoes structural transformation and dissociation into gibbsite (Al(OH)3). In this case, lithium ions are not adsorbed to Al(OH)3, so the lithium adsorption efficiency is reduced, and there is a problem that the adsorbent becomes inactivated.

[0006] Accordingly, the present invention was completed by conducting research on a regeneration method that can overcome these problems in aluminum-based lithium adsorbents.

[0007] In this embodiment, a method for regenerating an aluminum-based lithium adsorbent is provided, which can restore the initial lithium adsorption performance by regenerating a damaged structure of the aluminum-based lithium adsorbent using a solution containing lithium.

[0008] A method for regenerating an aluminum-based lithium adsorbent according to one embodiment includes the steps of preparing an aluminum-based lithium adsorbent whose activity is inhibited; and the step of reacting the adsorbent with a solution containing lithium; wherein the concentration of lithium ions in the solution containing lithium is 0.6 to 5.0 g / L.

[0009] In the above lithium-containing solution, the concentration of lithium ions may be 0.9 to 1.5 g / L.

[0010] The temperature of the solution containing the lithium may be 50 to 100°C, and specifically 70 to 90°C.

[0011] The above lithium-containing solution may contain lithium chloride.

[0012] The above aluminum-based lithium adsorbent may be represented by the following chemical formula 1.

[0013] [Chemical Formula 1]

[0014] LiCl·2[Al(OH)3]·nH2O

[0015] The above-mentioned aluminum-based lithium adsorbent with inhibited activity may have a LiCl·2[Al(OH)3]·H2O structure in the entire phase at 60% to 90% when analyzed by XRD.

[0016] The step of reacting the above adsorbent with a solution containing lithium may be a method of introducing a solution containing lithium into a column-shaped adsorbent or a method of immersing the adsorbent in a solution containing lithium.

[0017] After performing the above regeneration method, the aluminum-based lithium adsorbent may have a LiCl·2[Al(OH)3]·H2O structure in the entire phase at 95% to 100% upon XRD analysis.

[0018] According to this embodiment, an aluminum-based lithium adsorbent that has undergone structural deformation and reduced adsorption efficiency due to prolonged use can be reconstituted into its original structure by reacting it with a lithium-containing solution, thereby restoring its initial high adsorption efficiency. Furthermore, this regeneration of the adsorbent allows for its reuse, enabling long-term use.

[0019] Figure 1 illustrates the XRD results of the adsorbent of Example 1 regenerated through the regeneration method of the present invention.

[0020] Figure 2 shows the XRD results of the adsorbent of Manufacturing Example 1.

[0021] Figure 3 shows the XRD results of the adsorbent of Manufacturing Example 2.

[0022] Figure 4 shows a comparison of the XRD results of the adsorbents of Example 1, Comparative Example 2, and Comparative Example 5.

[0023] The terms first, second, and third, etc., are used to describe, but are not limited to, various parts, components, regions, layers, and / or sections. These terms are used only to distinguish one part, component, region, layer, or section from another part, component, region, layer, or section. Accordingly, a first part, component, region, layer, or section described below may be referred to as a second part, component, region, layer, or section without departing from the scope of the present invention.

[0024] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the present invention. As used herein, the singular forms "singular" and "comprising" include plural forms as well, unless the context clearly dictates otherwise. The word "comprising" as used herein specifies a particular feature, region, integer, step, operation, element, and / or component, but does not exclude the presence or addition of other features, regions, integers, steps, operations, elements, and / or components.

[0025] When a part is referred to as being "on" or "over" another part, it can be directly on or over the other part, or there may be other parts intervening. Conversely, when a part is referred to as being "directly on" another part, there are no other parts intervening.

[0026] Although not defined otherwise, all terms, including technical and scientific terms, used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention pertains. Terms defined in commonly used dictionaries are further interpreted to have meanings consistent with the relevant technical literature and the present disclosure, and are not to be construed as ideal or overly formal unless otherwise defined.

[0027] Also, unless otherwise stated, % means weight%, and 1 ppm is 0.0001 weight%.

[0028] In this specification, the term "combination(s) thereof" described in the expression in the Makushi format means one or more mixtures or combinations selected from the group consisting of the components described in the expression in the Makushi format, and means including any one or more selected from the group consisting of said components.

[0029] Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement them. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein.

[0030]

[0031] Method for regenerating aluminum-based lithium adsorbent

[0032] As mentioned above, aluminum-based lithium adsorbents have a problem in that their structure changes over time and Al(OH)3) is formed, which inhibits the activity of the adsorbent.

[0033] However, in this embodiment, this problem was solved by reacting a solution containing the adsorbent and lithium in an aluminum-based lithium adsorbent with inhibited activity.

[0034] Specifically, a method for regenerating an aluminum-based lithium adsorbent according to one embodiment may include the steps of preparing an aluminum-based lithium adsorbent with reduced activity; and the step of reacting the adsorbent with a solution containing lithium.

[0035]

[0036] First, an aluminum-based lithium adsorbent with inhibited activity is prepared.

[0037] An aluminum-based lithium adsorbent is intended to adsorb lithium dissolved in a lithium-containing solution, and may include, for example, aluminum hydroxide. When an aluminum-based lithium adsorbent containing aluminum hydroxide is used as in this embodiment, the amount of lithium dissolved in the lithium-containing solution is high, and aluminum loss during the desorption process is small, resulting in a long lifespan of the adsorbent, thereby providing excellent economic efficiency for the lithium extraction process. Using the regeneration method according to the present invention can further extend the lifespan of the adsorbent, and further improve economic efficiency.

[0038] The above aluminum-based lithium adsorbent can be represented by the following chemical formula 1.

[0039] [Chemical Formula 1]

[0040] LiCl·2[Al(OH)3]·nH2O

[0041] The above chemical formula 1 can be obtained by the reaction of the following reaction formula 1.

[0042] [Reaction Formula 1]

[0043] 2AlCl3·6H2O + LiCl + 6NaOH + nH2O → LiCl·2Al(OH)3·nH2O + 6NaCl

[0044] Li ions are adsorbed into the interstitial spaces within the plate-like aluminum hydroxide double layers, and Cl ions exist together with water to balance the charge between the layers. Specifically, the crystal structure of Li / Al-LDH is composed of two repeating layers, one layer consisting of aluminum hydroxide and intercalated lithium ions, and the other layer consisting of water molecules and charge-balancing anions. LDH materials have the advantages of unique exchange capacity, low cost, and low toxicity due to this structure.

[0045] Meanwhile, the aluminum-based lithium adsorbent may be a molded body including adsorbent powder and a binder.

[0046] The above 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.

[0047] The binder is used to form a molded body of the adsorbent powder into an appropriate shape and serves to bind the adsorbent powder together. The binder may include, for example, at least one of polyvinyl chloride (PVC), polysulfone, and polyaniline. In particular, in the present embodiment, the binder preferably includes polyvinyl chloride (PVC), which can provide excellent binding strength between the adsorbent powders.

[0048] The above aluminum-based lithium adsorbent may have its activity inhibited through long-term adsorption and desorption stages.

[0049] The above adsorption step refers to a step of adsorbing lithium from a lithium-containing solution. Specifically, it may be a step of adsorbing lithium onto the adsorbent by passing the lithium-containing solution through the adsorbent.

[0050] The step of passing a lithium-containing solution through an aluminum-based adsorbent to adsorb lithium onto the aluminum-based adsorbent includes, for example, the reaction of the following reaction formula 2.

[0051] [Reaction Formula 2]

[0052] (1-x)LiCl·Al(OH)3·nH2O + Li + → LiCl·Al(OH)3·nH2O + (1-x)Li +

[0053] The above desorption step refers to a step of desorbing lithium from the lithium-adsorbed aluminum-based lithium adsorbent. Specifically, it may be a step of obtaining a lithium-containing desorbent by passing a medium (e.g., distilled water or an aqueous solution containing a lithium salt) through the medium.

[0054] The step of passing a medium through an aluminum adsorbent on which lithium is adsorbed to obtain a lithium-containing desorbent includes, for example, the reaction of the following reaction formula 3.

[0055] [Reaction Formula 3]

[0056] LiCl·Al(OH)3·nH2O + H2O → (1-x)LiCl·Al(OH)3·nH2O + xLiCl

[0057] When the adsorption and desorption steps described above are defined as one cycle, an aluminum-based lithium adsorbent that has undergone three or more cycles for 0.5 to 20 hours in a temperature range of 20 to 100°C has its activity inhibited.

[0058] In the case of the aluminum-based lithium adsorbent before its activity is inhibited, the LiCl·2[Al(OH)3]·H2O structural phase can be detected at 90% to 100%, specifically 95% to 100%, in the entire phase during XRD analysis. On the other hand, in the case of the aluminum-based lithium adsorbent whose activity is inhibited, the LiCl·2[Al(OH)3]·H2O structural phase can be detected at 60% to 90%, specifically 60% to 88%, in the entire phase during XRD analysis.

[0059] At this time, the LiCl·2[Al(OH)3]·H2O structure in the XRD results can be confirmed and distinguished by calculating the ratio of the characteristic peaks of the Al(OH)3 structure in the adsorbent before the activity is inhibited by washing with deionized water after manufacturing to remove impurities (such as NaCl) and performing adsorption and desorption, and after the LiCl structure between layers is lost and the activity is inhibited by performing adsorption and desorption. This is possible because the positions of the X-ray diffraction peaks are different because the layer spacing of the two structures is different, and the main peak stands out clearly due to the characteristics of the layered structure with crystalline properties. In order to specifically quantify this, the most common method is to calculate the quantitative ratio by utilizing the Rietveld refinement method based on the peak of the standard material previously entered in the database.

[0060] As described above, when the LiCl·2[Al(OH)3]·H2O structural phase is in the range of 60% to 90% in the entire phase during XRD analysis, the activity of the aluminum-based lithium adsorbent is inhibited, and the lithium adsorption amount may be reduced by 5 to 25 wt% compared to when the LiCl·2[Al(OH)3]·H2O structural phase is 96.8% in the entire phase during XRD analysis. Specifically, this is a range derived as the change in the LiCl·2[Al(OH)3]·H2O structural phase corresponds to 60% / 96.8% to 90% / 96.8%, since the lithium adsorption performance is reduced as it is not the LiCl·2[Al(OH)3]·H2O structural phase.

[0061]

[0062] After preparing an aluminum-based lithium adsorbent with inhibited activity as described above, a solution containing the adsorbent and lithium is reacted.

[0063] The step of reacting the above adsorbent and the solution containing lithium can be performed using the adsorbent in a wet state as is.

[0064] In addition, the step of reacting the above adsorbent and the solution containing lithium can be performed using a method of introducing the solution containing lithium into a column-shaped adsorbent or a method of immersing the adsorbent in a solution containing lithium.

[0065] Damage to the adsorbent pellets can be minimized through the above method. By not including a separate step of introducing an organic solvent, the organic solvent can be prevented from dissolving in the organic and inorganic mixture. In addition, by not including a drying step, the impact on the bonding surface of the binder and the adsorbent can be prevented due to changes in the gap between the LDH structures of the adsorbent caused by dehydration during drying.

[0066] Furthermore, because the adsorbent powder maintains its shape within the column, it minimizes mechanical shock during removal or refilling, minimizing the amount of adsorbent lost through crushing during the process. Furthermore, because the adsorbent does not move, the adsorption-desorption-regeneration cycle can be controlled simply by changing the flowing solution, which can be advantageous for process configuration.

[0067] At this time, in the solution containing lithium, the concentration of lithium ions may be 0.6 to 5.0 g / L, specifically 0.65 to 3.5 g / L, or 0.7 to 2.0 g / L.

[0068] If it falls below the above range, the structure of the aluminum-based lithium adsorbent is not reconstructed, making it difficult to regenerate the activity of the adsorbent as it was initially. If it falls above the above range, lithium is adsorbed on the adsorbent while the high-concentration lithium-containing brine injected in the regeneration process remains in the adsorbent. However, there is a problem in that the concentration of the solution in which lithium adsorption must occur is relatively low, making it difficult to sufficiently adsorb.

[0069] The temperature of the solution containing the lithium may be 50 to 100°C, specifically 70 to 90°C, or 80 to 90°C.

[0070] If it is below the above range, the reaction between the lithium-containing solution and the aluminum-based lithium adsorbent with reduced activity does not occur smoothly, so the structure of the adsorbent is not reconstructed, making it difficult to restore the activity of the adsorbent to its initial state. If it is exceeded, the structure of the adsorbent may be deformed due to the high temperature.

[0071] In the above lithium-containing solution, lithium can be provided through a lithium salt. Specifically, the lithium salt may be LiCl, LiPF6, LiClO4, LiAsF6, LiBF4, LiSbF6, LiAl04, LiAlCl4, LiCF3SO3, LiC4F9SO3, LiN(C2F5SO3)2, LiN(C2F5SO2)2, LiN(CF3SO2)2. LiI, or LiB(C2O4)2.

[0072] Preferably, the solution containing lithium may contain lithium chloride, and at this time, the concentration and temperature conditions of lithium chloride may be in the ranges described above, and the effect when the ranges are not satisfied may also be as described above.

[0073]

[0074]

[0075] After performing the above regeneration method, the aluminum-based lithium adsorbent may have a LiCl·2[Al(OH)3]·H2O structure phase of 95% to 100% in the entire phase when analyzed by XRD, and specifically, may have a structure of 97% to 100%, or 99% to 100%.

[0076] When the above range is satisfied, the structure of the aluminum-based lithium adsorbent is reconstructed, so that the lithium adsorption efficiency can be exhibited at the same level as that of the aluminum-based lithium adsorbent when the adsorption and desorption steps described above are performed three or fewer cycles for 0.5 to 20 hours at a temperature range of 20 to 100°C after manufacture.

[0077]

[0078] Hereinafter, embodiments of the present invention will be described in more detail through examples. However, the following examples are merely preferred embodiments of the present invention, and the present invention is not limited to the following examples.

[0079]

[0080] Manufacturing Example 1 - Manufacturing of aluminum-based adsorbent

[0081] Aluminum chloride and lithium chloride were charged in a molar ratio of 2:1 into a reactor filled with distilled water and then dissolved. A 6 mol / L sodium hydroxide aqueous solution was added to the dissolved aluminum chloride and lithium chloride mixture at a rate of 45.6 mL / min for 1 hour, and the reaction was carried out as shown in the following reaction scheme 1.

[0082] [Reaction Formula 1]

[0083] 2AlCl3+ LiCl + 6NaOH → LiCl.2Al(OH)3.nH2O + 6NaCl The above reaction was performed at 80°C and 500 rpm for about 2 hours to obtain a lithium adsorbent slurry. The obtained lithium adsorbent slurry was separated into solid and liquid through general reduced pressure filtration to obtain a cake.

[0084] Thereafter, to remove sodium chloride remaining in the obtained cake, the sodium chloride (NaCl) in the cake was washed using washing water at least four times the weight of the lithium adsorbent slurry. The washed cake was dried using a dryer at 40°C to 50°C for more than 24 hours to produce lithium adsorbent powder.

[0085] The manufactured lithium adsorbent powder was placed in a mixer with a binder to form a dough. The binder was prepared by dissolving 30 wt% polyvinyl chloride (PVC) in an organic solvent called methyl ethyl ketone (MEK).

[0086] Next, the above mixing was performed at a speed of 60 rpm until it was suitable for extrusion. The state of the dough thus manufactured showed a torque value of 5 Nm on a rotational viscometer.

[0087] After this, 1 kg of the dough was placed into an extruder with a diameter of 50 mm and extruded through a mold at a speed of 50 mm per minute into a cylindrical shape with a diameter of 0.5 to 1.0 mm. The extruded lithium adsorbent was dried in a 45 degree oven for 24 hours to remove the organic solvent.

[0088] The lithium adsorbent formed as described above was filled into a glass tube measuring 2.5 cm in diameter × 50 cm in length to form a column.

[0089]

[0090] Manufacturing Example 2 - Aluminum-based adsorbent used for a long time

[0091] Adsorbent powder is prepared and a column is constructed using the same method as in Manufacturing Example 1.

[0092] After that, an adsorption step is performed for 4 hours by passing 2 L of a lithium-containing solution having a lithium concentration of 0.3 g / L at 60°C through an adsorbent at a rate of 0.4 L / hr, and a desorption step is performed for 4 hours by passing 1.6 L of deionized water not containing lithium through an adsorbent on which lithium is adsorbed at a rate of 0.4 L / hr to desorb lithium.

[0093] When the adsorption and desorption steps are performed for a total of 8 hours as described above, one cycle is performed, and 20 cycles of the adsorption and desorption steps are performed.

[0094] Accordingly, the total adsorption and desorption time, i.e., the usage time, of the adsorbent of Manufacturing Example 2 is 160 hours. In other words, the adsorbent of Manufacturing Example 2 is used for a long period of time, and its activity is inhibited.

[0095]

[0096] Example 1

[0097] For the manufacturing example 2 adsorbent used for a long time, a beaker containing 500 mL of a LiCl solution containing lithium ions at a concentration of 1 g / L at a temperature of 85°C was connected to 5 g of the column-shaped adsorbent in a wet state, and the solution was injected into the adsorbent at a rate of about 0.1 / hr, and the discharged liquid was collected again in the beaker, and a regeneration process was performed for 72 hours.

[0098]

[0099] Example 2

[0100] The regeneration process was performed on an adsorbent that had been used for a long time in the same manner as in Example 1, except that the lithium ion concentration condition of the LiCl solution injected into the adsorbent in the regeneration process was changed to 0.7 g / L.

[0101]

[0102] Example 3

[0103] In the regeneration process, the regeneration process was performed on an adsorbent that had been used for a long time in the same manner as in Example 1, except that the temperature condition of the LiCl solution injected into the adsorbent was changed to 60°C.

[0104]

[0105] Example 4

[0106] In the regeneration process, the lithium ion concentration and temperature conditions of the LiCl solution injected into the adsorbent were changed to 0.7 g / L and 60°C, respectively, and the regeneration process was performed on the adsorbent that had been used for a long time in the same manner as in Example 1.

[0107]

[0108] Comparative Example 1

[0109] In the regeneration process, the lithium ion concentration conditions and temperature conditions of the LiCl solution injected into the adsorbent were changed to 0.5 g / L and , respectively, and the regeneration process was performed on the adsorbent that had been used for a long time in the same manner as in Example 1.

[0110]

[0111] Comparative Example 2

[0112] The regeneration process was performed on an adsorbent that had been used for a long time in the same manner as in Example 1, except that deionized water, which is pure water that does not contain lithium, was added to the adsorbent instead of the LiCl solution in the regeneration process.

[0113]

[0114] Comparative Example 3

[0115] In the regeneration process, the lithium ion concentration and temperature conditions of the LiCl solution injected into the adsorbent were changed to 0.5 g / L and 60°C, respectively, and the regeneration process was performed on the adsorbent that had been used for a long time in the same manner as in Example 1.

[0116]

[0117] Comparative Example 4

[0118] In the regeneration process, the lithium ion concentration and temperature conditions of the LiCl solution injected into the adsorbent were changed to 0.3 g / L and 60°C, respectively, and the regeneration process was performed on the adsorbent that had been used for a long time in the same manner as in Example 1.

[0119]

[0120] Comparative Example 5

[0121] In the regeneration process, the regeneration process was performed on an adsorbent that had been used for a long time in the same manner as in Example 1, except that deionized water containing no lithium was added to the adsorbent instead of the LiCl solution and the temperature of the solution was set to 60°C.

[0122]

[0123] Experimental Example 1 - Analysis of lithium re-adsorption amount of adsorbent

[0124] For the above examples and comparative examples, the amount of lithium reabsorbed by the adsorbent through the regeneration process from a solution containing lithium, i.e., the amount of lithium re-adsorption, was measured.

[0125] In the step of reacting an adsorbent with a solution containing lithium, i.e., the regeneration process, the amount of lithium re-adsorbed was derived by subtracting the amount of lithium contained in the discharged liquid after the regeneration process from the amount of lithium contained in the solution containing used lithium. If the lithium concentration in the solution containing lithium increased after the regeneration process, i.e., if lithium was released from the adsorbent, this was indicated as a negative (-) value.

[0126] Table 1 below summarizes the lithium re-adsorption amounts of examples and comparative examples.

[0127] Temperature of the solution containing lithium (℃) Lithium concentration in the solution containing lithium before performing the regeneration process (g / L) Lithium concentration in the discharged solution containing lithium after performing the regeneration process (g / L) Lithium re-adsorption amount (mg) Example 1 850.99 70.95 720.1 Example 2 850.70 50.69 26.5 Example 3 600.99 70.98 65.8 Example 4 600.70 50.69 55.0 Comparative Example 1 850.50 50.50 6-0.7 Comparative Example 2 850.00 0.167-83.4 Comparative Example 3 600.50 50.517-5.8 Comparative Example 4 600.30 90.33 4-12.4 Comparative Example 5 600.00 116-57.8

[0128] As confirmed in the above table, when the lithium concentration (g / L) in the solution containing lithium before the regeneration process is less than 0.7 g / L, it can be confirmed that lithium is not re-adsorbed into the adsorbent but rather desorbed, and thus the lithium concentration in the discharged solution containing lithium after the regeneration process actually increases.

[0129] In addition, through a comparison of Examples 1 and 3, it can be confirmed that the lithium re-adsorption amount is 3.5 times greater at 85°C than at 60°C.

[0130]

[0131] Experimental Example 2 - XRD (X-ray Diffraction) Analysis of Adsorbent

[0132] XRD was analyzed to measure the structural phase of the adsorbent of Manufacturing Example 1 before performing the adsorption and desorption steps after manufacturing the adsorbent, the adsorbent of Manufacturing Example 2 after performing the long-term adsorption and desorption steps, Example 1, and Comparative Examples 2 and 5.

[0133] In the entire phase of the adsorbent, the LiCl·2[Al(OH)3]·H2O structural phase can be quantitatively analyzed using X-ray diffraction analysis (XRD) using Cu Kα X-rays. Specifically, quantitative analysis can be made possible by placing the particles of the adsorbent to be measured in a holder, irradiating the particles with X-rays, and analyzing the resulting diffraction grating.

[0134] Sampling was prepared by placing the powder sample of the target particle into the groove in the center of a general powder holder, smoothing the surface using a slide glass, and ensuring that the sample height was the same as the edge of the holder. Then, X-ray diffraction analysis was performed using a Bruker D8 Endeavor (light source: Cu Kα, λ=1.54Å) equipped with a LynxEye XE-T position sensitive detector, under the conditions of FDS 0.5°, 2θ=0°~90° range, step size 0.02°, and total scan time of approximately 20 minutes.

[0135] For the measured data, Rieveld refinement was performed considering the charge (+3 for metal ions at transition metal sites, +2 for Ni ions at Li sites) and cation mixing at each site. During the structural analysis, instrumental brodadening was considered using the Fundamental Parameter Approach (FPA) implemented in the Bruker TOPAS program, and the entire peaks of the measurement range were used for fitting. The peak shape was fitted using only the Lorenzian contribution as the First Principle (FP) among the peak types available in TOPAS, and strain was not considered at this time.

[0136]

[0137] Figure 2 shows the XRD results of the adsorbent of Manufacturing Example 1 before performing the adsorption and desorption steps after manufacturing the adsorbent.

[0138] As a result of quantitative XRD analysis, it was confirmed that the LiCl·2[Al(OH)3]·H2O phase was present at 96.8% and the NaCl phase was present at 3.2% in the entire phase.

[0139] When manufacturing an adsorbent, Al(OH)3 is manufactured using the reaction AlCl3+ 3 NaOH, so a small amount of NaCl, NaOH, etc. may be present. If NaCl, which tends to cause large crystal growth, remains, it may damage the adsorbent. However, since it has a high solubility in water, it is expected to be removed as an impurity in the adsorption and desorption stages, so it can be determined that there is no problem in using the adsorbent of Manufacturing Example 1.

[0140]

[0141] Figure 3 shows the XRD results of the adsorbent of Manufacturing Example 2 used for 160 hours.

[0142] As a result of quantitative XRD analysis, it was confirmed that the LiCl·2[Al(OH)3]·H2O phase was present at 87.2% and the Al(OH)3 phase was present at 12.8% in the entire phase.

[0143] That is, it was confirmed through repeated adsorption and desorption experiments that part of the adsorbent structure changed to gibbsite (Al(OH)3). Specifically, in the LiCl·2[Al(OH)3]·H2O structure, an appropriate amount of LiCl was included, so that the gaps between the layer structures were wide, but due to repeated adsorption and desorption, LiCl was lost from the adsorbent, and the structure changed to Al(OH)3 with narrow gaps, which can be judged to be a breakdown of the adsorbent structure.

[0144]

[0145] Figure 1 shows the XRD results of the adsorbent of Example 1 regenerated through the regeneration method described above.

[0146] Quantitative XRD analysis results confirmed that the LiCl·2[Al(OH)3]·H2O phase was present 100% throughout the entire phase, and no other phases were detected.

[0147] That is, it can be confirmed that the adsorbent structure has been restored through the above-described adsorbent regeneration method. Specifically, it can be confirmed that not only has it been completely restored, but the structure has been reconfigured to exhibit even better lithium adsorption performance through lithium re-adsorption.

[0148]

[0149] Figure 4 shows the XRD results of the adsorbent of Example 1 regenerated through the regeneration method described above, compared with Comparative Examples 2 and 5, which have different concentration and temperature conditions.

[0150] As a result of quantitative XRD analysis, it was confirmed that Comparative Example 2 had 19.3% of the LiCl·2[Al(OH)3]·H2O phase and 80.7% of the Al(OH)3 phase in the entire phase.

[0151] As a result of quantitative XRD analysis, it was confirmed that Comparative Example 5 had 71.0% of the LiCl·2[Al(OH)3]·H2O phase and 29.0% of the Al(OH)3 phase in the entire phase.

[0152] In the case of Comparative Examples 2 and 5, where the solution reacting with the adsorbent does not contain lithium, the structure of the adsorbent is severely collapsed, and in particular, in the case of Comparative Example 2, where the temperature of the solution reacting with the adsorbent is 85°C, it can be confirmed that the structure of the adsorbent is collapsed by more than 50% more than in the case of Comparative Example 5, where the temperature of the solution reacting with the adsorbent is 60°C.

[0153] Through this, it can be seen that the appropriate temperature range of the solution containing lithium according to one embodiment of the present invention is 70 to 90°C, which is specific to the concentration of lithium ions in the solution containing lithium according to one embodiment of the present invention.

[0154]

[0155] Referring to FIGS. 1 to 4, in the case of Examples 1 to 4, it was confirmed that the LiCl·2[Al(OH)3]·H2O structure was recovered and implemented within the range according to the present invention as a result of appropriately controlling the conditions of the regeneration process of the adsorbent, such as the concentration of lithium ions in the solution containing lithium, the temperature of the solution, the injection speed and amount of the solution. In addition, it was confirmed that the lithium adsorption efficiency would be the same as or greater than that of the initial adsorbent.

[0156]

[0157] The present invention is not limited to the above-described embodiments, but can be manufactured in a variety of different forms. Those skilled in the art will appreciate that the present invention can be implemented in other specific forms without altering the technical spirit or essential characteristics of the present invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive.

Claims

1. A step for preparing an aluminum-based lithium adsorbent with inhibited activity; and A step of reacting a solution containing the above adsorbent and lithium; In the solution containing the lithium, the concentration of lithium ions is 0.6 to 5.0 g / L. Method for regenerating aluminum-based lithium adsorbent.

2. In paragraph 1, In the solution containing the lithium, the concentration of lithium ions is 0.9 to 1.5 g / L. Method for regenerating aluminum-based lithium adsorbent.

3. In paragraph 1, The temperature of the solution containing the lithium is 50 to 100°C. Method for regenerating aluminum-based lithium adsorbent.

4. In paragraph 1, The temperature of the solution containing the lithium is 70 to 90°C. Method for regenerating aluminum-based lithium adsorbent.

5. In paragraph 1, The above lithium-containing solution contains lithium chloride. Method for regenerating aluminum-based lithium adsorbent.

6. In paragraph 1, The above aluminum-based lithium adsorbent is represented by the following chemical formula 1: Method for regenerating aluminum-based lithium adsorbent: [Chemical Formula 1] LiCl·2[Al(OH)3]·nH2O 7. In paragraph 1, The above-mentioned activity-inhibited aluminum-based lithium adsorbent is, In the XRD analysis, the LiCl·2[Al(OH)3]·H2O structure is 60% to 90% in the entire phase. Method for regenerating aluminum-based lithium adsorbent.

8. In paragraph 1, The step of reacting the above adsorbent and the solution containing lithium is: A method of introducing a solution containing lithium into a column-shaped adsorbent or a method of immersing the adsorbent in a solution containing lithium is used. Method for regenerating aluminum-based lithium adsorbent.

9. In paragraph 1, The aluminum-based lithium adsorbent after performing the above regeneration method is, In the XRD analysis, the LiCl·2[Al(OH)3]·H2O structure is 95% to 100% in the entire phase. Method for regenerating aluminum-based lithium adsorbent.

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