Method for recovering metal from lithium secondary battery and recovery system

Abstract

The invention provides a method for recovering metal of a lithium secondary battery and a recovery system. In a method for recovering a metal of a lithium secondary battery, a lithium-containing positive electrode active material mixture is prepared. The positive electrode active material mixture is reduced to produce a lithium precursor. A lithium precursor is dissolved in water to form an aqueous lithium precursor solution. The lithium precursor aqueous solution is introduced into the aluminum adsorption resin column, so that aluminum is adsorbed into the aluminum adsorption resin column. A first treatment liquid containing distilled water is injected into the aluminum adsorbent resin column at a flow rate of 100 L / h to 1200 L / h to obtain a regenerated aluminum adsorbent resin column in which aluminum is desorbed.

Description

Technical Field

[0001] The present invention relates to a method and a recovery system for recovering metals from lithium secondary batteries. More specifically, the present invention relates to a method and a recovery system for recovering metals from lithium secondary batteries using an aluminum adsorption resin. Background Art

[0002] In recent years, secondary batteries have been widely used and developed as power sources for portable electronic communication devices such as portable video cameras, mobile phones, and laptop computers (PCs), and vehicles such as hybrid electric vehicles and electric vehicles. As secondary batteries, lithium secondary batteries have a high operating voltage and an energy density per unit weight, and are advantageous for charging speed and weight reduction, and thus are actively developed and applied.

[0003] As the demand for secondary batteries increases, the number of waste batteries also increases. Considering environmental protection issues, price competitiveness, etc., research on methods for recycling waste batteries is also increasing. For example, due to cost issues caused by the use of high-cost valuable metals (e.g., nickel, cobalt, manganese, etc.) and environmental protection issues caused by wastewater generated during the treatment or process of waste batteries, recycling of waste batteries is required.

[0004] In the process of recovering lithium from waste batteries, it is necessary to remove impurities (e.g., aluminum, sulfate, etc.). To remove the impurities, ion exchange resins can be used. For example, metal impurities in the form of metal ions can be removed by a metal adsorption resin.

[0005] However, ion exchange resins need to be regenerated for reuse. Depending on the substances used in the regeneration process of the ion exchange resin (e.g., acids, alkalis, regeneration chemicals, etc.), the treatment cost may increase and the treatment process may be complicated. In addition, substances generated during the regeneration process of the ion exchange resin may cause environmental problems. Therefore, a method is needed that can effectively regenerate the ion exchange resin while effectively recovering metals from lithium secondary batteries. Summary of the Invention

[0006] (I) Technical Problems to be Solved

[0007] One technical problem of the present invention is to provide a method for effectively recovering metals from lithium secondary batteries.

[0008] One technical problem of the present invention is to provide a system for effectively recovering metals from lithium secondary batteries.

[0009] (II) Technical Solutions

[0010] A method for recovering metals from a lithium secondary battery according to the present invention prepares a lithium-containing cathode active material mixture. The cathode active material mixture is reduced to generate a lithium precursor. The lithium precursor is dissolved in water to form an aqueous solution of the lithium precursor. The aqueous solution of the lithium precursor is passed through an aluminum adsorption resin column, so that aluminum is adsorbed onto the aluminum adsorption resin column. A first treatment liquid containing distilled water is injected into the aluminum adsorption resin column at a flow rate of 100 L / hour to 1200 L / hour to obtain a regenerated aluminum adsorption resin column from which aluminum has been desorbed.

[0011] According to an exemplary embodiment, the regenerated aluminum adsorption resin column can be reused in the step of adsorbing the aluminum.

[0012] According to an exemplary embodiment, a second treatment liquid containing desorbed aluminum in the first treatment liquid can be generated in the step of obtaining the regenerated aluminum adsorption resin column.

[0013] According to an exemplary embodiment, the content of aluminum contained in the second treatment liquid can be 200 ppm or more.

[0014] According to an exemplary embodiment, the method for recovering metals from a lithium secondary battery may further include: a step of generating a third treatment liquid formed by evaporating the second treatment liquid; and a step of recovering the third treatment liquid into the first treatment liquid.

[0015] According to an exemplary embodiment, a specified fraction of distilled water and desorbed aluminum in the second treatment liquid can be removed simultaneously in the step of generating the third treatment liquid.

[0016] According to an exemplary embodiment, the amount of the distilled water fraction can be 0.01 wt% to 5 wt% relative to the total weight of the distilled water contained in the second treatment liquid.

[0017] According to an exemplary embodiment, the first treatment liquid can be injected at a flow rate of 1000 L / hour to 1200 L / hour.

[0018] According to an exemplary embodiment, the first treatment liquid can be injected at a linear velocity of 8 m / hour to 13 m / hour.

[0019] According to an exemplary embodiment, the aluminum adsorption resin column can include a resin containing an amino group and a hydroxyl group.

[0020] According to an exemplary embodiment, the resin containing an amino group and a hydroxyl group can include methylglucosylamine.

[0021] The system for recovering metals from lithium secondary batteries of the present invention includes: an aluminum adsorption resin column; a flow rate control unit for supplying distilled water to the aluminum adsorption resin column; an evaporation treatment unit for evaporating the distilled water passing through the aluminum adsorption resin column to generate water vapor; a distilled water regeneration unit for collecting distilled water from the water vapor generated by the evaporation treatment unit; and a distilled water supply unit for supplying the regenerated distilled water from the distilled water regeneration unit to the flow rate control unit.

[0022] According to an exemplary embodiment, the evaporation treatment unit may include a discharge unit for discharging a portion of the distilled water and aluminum that have not been treated into water vapor.

[0023] (III) Beneficial effects

[0024] According to the method for recovering metals from lithium secondary batteries according to an embodiment of the present invention, since distilled water is used, a wastewater treatment process generated by using acids or alkalis is not required. Therefore, the energy and cost used in recovering metals from lithium secondary batteries can be reduced, and metals can be recovered in an environmentally friendly manner.

[0025] According to an exemplary embodiment, the ion exchange capacity of the aluminum adsorption resin column can be maintained by injecting distilled water at a flow rate within a specified range, and aluminum can be effectively desorbed. Therefore, the recovery of metals from lithium secondary batteries can be continuously carried out.

[0026] According to an exemplary embodiment, no additional substances or processes are required for the recovery of the treatment liquid for desorbing aluminum from the aluminum adsorption resin column. Therefore, metals from lithium secondary batteries can be recovered in an environmentally friendly and effective manner. Description of the drawings

[0027] Figure 1 is a schematic flow chart for explaining a method for recovering metals from lithium secondary batteries according to an exemplary embodiment.

[0028] Figure 2 and Figure 3 is a schematic diagram for explaining a system for recovering metals from lithium secondary batteries according to an exemplary embodiment.

[0029] [Description of reference numerals]

[0030] 100: Aluminum adsorption resin column 110: Flow rate control unit

[0031] 120: Distilled water supply unit 150: Evaporation treatment unit

[0032] 155: Discharge unit 200: Distilled water regeneration unit Detailed implementation manners

[0033] Embodiments of the present invention provide a method for recovering metals from a lithium secondary battery, the method including adsorption and desorption of aluminum using an aluminum adsorption resin column. In addition, a system for recovering metals from a lithium secondary battery using an aluminum adsorption resin column is provided.

[0034] Hereinafter, with reference to the drawings, exemplary embodiments of the present invention will be described in more detail. However, the drawings in this specification are used to illustrate preferred embodiments of the present invention and, together with the above-described summary of the invention, serve to further understand the technical idea of the present invention. Therefore, the present invention should not be construed as being limited to the content described in the drawings.

[0035] The term "precursor" used in this specification generally refers to a compound containing a specific metal in order to provide the specific metal contained in the electrode active material.

[0036] In this specification, "first", "second", "third", etc. are used to distinguish each substance, rather than to distinguish the importance, order, etc. of each substance.

[0037] The "treatment liquid" in this specification is used as a term designating a substance and does not limit the phase of each substance. For example, the treatment liquid may include solid, liquid, and / or gas phases.

[0038] Figure 1 is a schematic flowchart for explaining a method for recovering metals from a lithium secondary battery according to an exemplary embodiment.

[0039] Figure 2 and Figure 3 is a schematic diagram for explaining a system for recovering metals from a lithium secondary battery according to an exemplary embodiment.

[0040] Refer to Figure 1 to prepare a lithium-containing positive electrode active material mixture (e.g., process S10).

[0041] The lithium-containing positive electrode active material mixture can be collected from the positive electrode of a lithium secondary battery. The lithium secondary battery may include an electrode assembly including a positive electrode, a negative electrode, and a separator. The positive electrode and the negative electrode may include a positive electrode current collector, a positive electrode active material layer coated on the positive electrode current collector, a negative electrode current collector, and a negative electrode active material layer coated on the negative electrode current collector, respectively.

[0042] According to an exemplary embodiment, the positive electrode active material mixture may contain an oxide containing lithium and a transition metal.

[0043] For example, the positive electrode active material mixture may contain a lithium-nickel metal oxide. The lithium-nickel metal oxide may further contain at least one of cobalt (Co), manganese (Mn), and aluminum (Al).

[0044] In some embodiments, the lithium-nickel metal oxide may comprise a layered structure or a crystal structure represented by Chemical Formula 1 below.

[0045] [Chemical Formula 1]

[0046] Li x Ni a M b O 2+z

[0047] In Chemical Formula 1, 0.9 ≤ x ≤ 1.2, 0.6 ≤ a ≤ 0.99, 0.01 ≤ b ≤ 0.4, and -0.5 ≤ z ≤ 0.1. As described above, M may comprise Co, Mn, and / or Al.

[0048] The chemical structure represented by Chemical Formula 1 represents the bonding relationship included in the layered structure or crystal structure of the positive electrode active material, and does not exclude other additional elements. For example, M may comprise Co and / or Mn, and Co and Mn may be provided together with Ni as the main active elements of the positive electrode active material. Chemical Formula 1 is provided to represent the bonding relationship of the main active elements, and it should be understood that Chemical Formula 1 is a formula including the introduction and substitution of additional elements.

[0049] In some embodiments, the main active elements may further comprise auxiliary elements. The auxiliary elements may comprise, for example, at least one of Na, Mg, Ca, Y, Ti, Hf, V, Nb, Ta, Cr, Mo, W, Fe, Cu, Ag, Zn, B, Al, Ga, C, Si, Sn, Sr, Ba, Ra, P, or Zr.

[0050] According to an exemplary embodiment, the positive electrode active material mixture may be obtained from the positive electrode of a waste lithium battery or a positive electrode that has been damaged or defective during the manufacturing process of a lithium secondary battery.

[0051] According to an exemplary embodiment, the positive electrode active material mixture may be obtained by pulverizing the positive electrode. The positive electrode active material mixture may be obtained in the form of a powder.

[0052] The positive electrode active material mixture may refer to a raw material substance obtained by substantially removing the positive electrode current collector from the positive electrode.

[0053] In some embodiments, the positive electrode active material mixture may further comprise substances included in the manufacturing process of the positive electrode. For example, it may comprise a part of the components derived from the binder or the conductive material. In one embodiment, the positive electrode active material mixture may also consist essentially of a lithium-nickel metal oxide.

[0054] According to an exemplary embodiment, the positive electrode active material mixture may be heat-treated before generating a lithium precursor from the positive electrode active material mixture as described below.

[0055] The heat treatment may be performed, for example, at about 100 - 500 °C or about 350 - 450 °C. Within the above range, impurities contained in the positive electrode active material mixture can be removed while decomposition and damage of the lithium-nickel metal oxide can be prevented.

[0056] The positive electrode active material mixture may be subjected to a reduction reaction in a reactor to generate a lithium precursor (e.g., process S20). A lithium precursor and a transition metal or a transition metal oxide can be generated through the reduction reaction.

[0057] For example, the positive electrode active material mixture may be included in a fluidized bed reactor, and a reducing gas may be injected into the interior of the fluidized bed reactor to perform the reduction reaction.

[0058] The fluidized bed reactor refers to a reactor in which a fluid (gas or liquid) is passed through the injected positive electrode active material mixture to fluidize the positive electrode active material mixture.

[0059] In some embodiments, the reducing gas may be supplied from the lower part of the reactor and come into contact with the positive electrode active material mixture.

[0060] For example, the reducing gas may be hydrogen, an inert gas, or a mixed gas thereof. The inert gas may include helium (He), nitrogen (N2), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), etc.

[0061] In some embodiments, the reduction reaction may be a hydrogen reduction reaction or a carbon reduction reaction.

[0062] In some embodiments, the hydrogen reduction reaction may be performed at 400 °C to 700 °C or 450 °C to 550 °C. In some embodiments, the carbon reduction reaction may be performed at 400 °C to 800 °C. Within the above reaction temperature range, re-aggregation and re-combination of the lithium precursor, transition metal, and transition metal oxide can be inhibited, and the reduction reaction can be promoted.

[0063] According to an exemplary embodiment, the lithium precursor generated through the reduction reaction may include one or more of lithium hydroxide, lithium oxide, and lithium carbonate.

[0064] In some embodiments, the lithium precursor may be formed in the form of lithium hydroxide. The pH of the following aqueous solution of the lithium precursor can be adjusted by lithium hydroxide.

[0065] For example, the transition metal or transition metal oxide may include Ni, Co, NiO, CoO, MnO, etc.

[0066] The lithium precursor can be dissolved in water to form an aqueous solution of the lithium precursor (e.g., process S30).

[0067] According to an exemplary embodiment, the lithium precursor can be washed with water, and through the water washing treatment, the lithium precursor contacts with water, thereby forming an aqueous solution of lithium hydroxide dissolved in water.

[0068] According to an exemplary embodiment, the transition metal or transition metal oxide can be dispersed by washing with water and separated in a slurry state.

[0069] For example, through the water washing treatment, the transition metal or the transition metal oxide does not dissolve in water, so that a slurry can be formed in a dispersed state, and the slurry can be separated from the aqueous solution of the lithium precursor.

[0070] In some embodiments, the transition metal or transition metal oxide contained in the slurry can react with an acid solution to form a transition metal precursor. For example, the transition metal precursor may include NiSO4, MnSO4, CoSO4, etc.

[0071] According to an exemplary embodiment, the aqueous solution of the lithium precursor may contain aluminum. For example, the aluminum may exist in the form of aluminum ions through the water washing treatment.

[0072] For example, the aluminum in the aqueous solution of the lithium precursor may be in the form of Al 3+ , Al(OH) 2+ , Al(OH)2 + , Al(OH)3, Al(OH)4 - and other various forms.

[0073] According to an exemplary embodiment, the pH of the aqueous solution of the lithium precursor may be 6 or more. According to an exemplary embodiment, the pH of the aqueous solution of the lithium precursor may be 7 or more, 7.5 or more, 8 or more, or 8.5 or more.

[0074] According to the pH of the aqueous solution of the lithium precursor, the form in which aluminum ions exist in the solution may be different, and thus, there are differences in the amount of aluminum removed.

[0075] For example, when the pH of the aqueous solution of the lithium precursor is 5 or less, aluminum may exist in a large amount in the solution in the form of Al 3+ , and when the pH of the aqueous solution of the lithium precursor is 6, aluminum may be in the form of Al(OH) 2+ , Al(OH)2 +and in the form of Al(OH)3 in large quantities in the solution. For example, when the pH of the aqueous solution of the lithium precursor is above 7, aluminum can exist in the form of Al(OH)4 - in large quantities in the solution.

[0076] The large quantity of the form of aluminum means that the specific form based on the total molar number of aluminum is 50 mol% or more.

[0077] Within the above pH range, the aluminum contained in the aqueous solution of the lithium precursor can be adsorbed onto the aluminum adsorption resin column in the form of Al(OH)4 - onto the aluminum adsorption resin column.

[0078] According to an exemplary embodiment, the aqueous solution of the lithium precursor can be alkaline. Therefore, aluminum can be contained in large quantities in the form of Al(OH)4 - in large quantities.

[0079] The aqueous solution of the lithium precursor is passed through the aluminum adsorption resin column 100, so that the aluminum contained in the aqueous solution of the lithium precursor can be adsorbed onto the aluminum adsorption resin column 100 (for example, process S40).

[0080] A first treatment liquid containing distilled water is injected into the aluminum adsorption resin column 100 at a flow rate within a specified range, so that the aluminum in the aluminum adsorption resin column 100 can be desorbed (for example, process S50). A regenerated aluminum adsorption resin column can be obtained by desorbing aluminum.

[0081] The aluminum adsorption resin column 100 can include a column filled with an aluminum adsorption resin. For example, the volume of the column can be from 0.1 ml to 1000 L, and the column is filled with an aluminum adsorption resin, so that the aluminum adsorption resin can occupy a specified space.

[0082] The aluminum adsorption resin can include, for example, an ion exchange resin. For example, the aluminum adsorption resin can include a bead-shaped resin having a specified particle size.

[0083] According to an exemplary embodiment, the aluminum adsorption resin can be a chelating resin or an anion exchange resin.

[0084] For example, the aluminum adsorption resin can adsorb aluminum hydroxide in the form of Al(OH)4 - contained in the aqueous solution of the lithium precursor.

[0085] For example, when the aluminum adsorption resin is a cation exchange resin, since it does not adsorb aluminum hydroxide, aluminum may not be removed, and since it adsorbs lithium ions, the metal may not be recovered.

[0086] According to an exemplary embodiment, the aluminum adsorption resin can include an amino group and a hydroxyl group.

[0087] According to an exemplary embodiment, the aluminum adsorption resin may include an amino group and two or more hydroxyl groups.

[0088] According to an exemplary embodiment, the aluminum adsorption resin may include an amino group and three or more hydroxyl groups.

[0089] According to an exemplary embodiment, the aluminum adsorption resin may include an amphoteric resin containing an acidic group and a basic group.

[0090] For example, the aluminum adsorption resin may adsorb aluminum through hydroxyl groups. The aluminum adsorption resin containing two or more hydroxyl groups may stably adsorb aluminum in an aqueous solution of a lithium precursor.

[0091] According to an exemplary embodiment, the aluminum adsorption resin may include methylglucamine groups. For example, the aluminum adsorption resin may include AmberLite UP7530 of DuPont Company containing methylglucamine groups.

[0092] For example, the aluminum adsorption resin may adsorb aluminum in a form including the following Chemical Formula 2.

[0093] [Chemical Formula 2]

[0094]

[0095] In the Chemical Formula 2, the part represented by may be connected to the monomer part of the aluminum adsorption resin. For example, the monomer may include a phenyl structure, and the part represented by may be connected to the terminal part of the phenyl structure from which one hydrogen is removed.

[0096] According to an exemplary embodiment, the volume of the aluminum adsorption resin column 100 may be 1.0 L to 350 L.

[0097] According to an exemplary embodiment, an aqueous solution of a lithium precursor may be injected in a volume 5 times to 30 times the volume of the aluminum adsorption resin column 100.

[0098] According to an exemplary embodiment, the aqueous solution of the lithium precursor may be injected until an excessive amount of aluminum metal is generated. The excessive aluminum metal may refer to the aluminum metal generated exceeding the aluminum adsorption capacity of the aluminum adsorption resin.

[0099] However, it is not necessary to inject the aqueous solution of the lithium precursor until an excessive amount of aluminum metal is generated, and only the required volume of the aqueous solution of the lithium precursor may also be injected.

[0100] As Figure 2As shown, an aqueous solution of a lithium precursor can also be injected into one side of the aluminum adsorption resin column 100 through the flow path 101 for injecting the aqueous solution of the lithium precursor. The aqueous solution of the lithium precursor can be discharged through the composite flow path 104, and the composite flow path 104 is connected to the other side opposite to the side where the aqueous solution of the lithium precursor is injected. For example, in the aluminum adsorption resin column 100, the aqueous solution of the lithium precursor can flow unidirectionally.

[0101] A first treatment liquid containing distilled water can be injected into one side of the aluminum adsorption resin column 100 through the composite flow path 104. The first treatment liquid is injected into the aluminum adsorption resin column 100 in a state where the flow rate is controlled by the flow rate control unit 110. The first treatment liquid can desorb aluminum in the aluminum adsorption resin column 100 and be discharged through the treatment liquid discharge flow path 106, and the treatment liquid discharge flow path 106 is connected to the other side opposite to the side where the first treatment liquid is injected. For example, in the aluminum adsorption resin column 100, the first treatment liquid can flow unidirectionally.

[0102] For example, the flow path connected to the aluminum adsorption resin column 100 can be connected to the flow path 101 for injecting the aqueous solution of the lithium precursor and the treatment liquid discharge flow path 106.

[0103] For example, the flow path 101 for injecting the aqueous solution of the lithium precursor and the treatment liquid discharge flow path 106 connected to the aluminum adsorption resin column 100 can be distinguished by a valve (e.g., Figure 2 the part indicated by the dotted line in the figure).

[0104] For example, the aqueous solution of the lithium precursor can be injected and discharged in a state where the valve of the treatment liquid discharge flow path 106 is closed. Or, the treatment liquid can be injected and discharged in a state where the valve of the flow path 101 for injecting the aqueous solution of the lithium precursor is closed.

[0105] According to an exemplary embodiment, the flow path 101 for injecting the aqueous solution of the lithium precursor and the discharge flow path 105 for the aqueous solution of the lithium precursor can be distinguished from the flow path 102 for injecting the treatment liquid and the treatment liquid discharge flow path 106.

[0106] For example, by distinguishing the flow paths (101, 105) for the aqueous solution of the lithium precursor and the flow paths (102, 106) for the treatment liquid, the liquid remaining in the flow path can be distinguished, and thus the efficiency of aluminum adsorption and desorption can be improved.

[0107] For example, the injection and discharge of the aqueous solution of the lithium precursor and the injection and discharge of the first treatment liquid can be achieved sequentially. For example, through the injection and discharge of the treatment liquid, aluminum can be sufficiently adsorbed into the aluminum adsorption resin column 100, and then through the injection and discharge of the first treatment liquid, the aluminum adsorbed into the aluminum adsorption resin column 100 can be sufficiently desorbed.

[0108] According to an exemplary embodiment, the flow direction of the aqueous solution of the lithium precursor in the aluminum adsorption resin column 100 and the flow direction of the treatment liquid can be opposite to each other. For example, the aqueous solution of the lithium precursor can flow from the injection flow path 101 of the aqueous solution of the lithium precursor toward the composite flow path 104, and the treatment liquid can flow from the composite flow path 104 toward the treatment liquid discharge flow path 106.

[0109] The flow direction of the aqueous solution of the lithium precursor is opposite to the flow direction of the treatment liquid, so that a system for recovering metals from lithium secondary batteries can be effectively realized.

[0110] According to an exemplary embodiment, the first treatment liquid may contain distilled water. For example, based on the total weight, the first treatment liquid may contain 95% by weight or more, 98% by weight or more, or 99% by weight or more of distilled water.

[0111] Therefore, a wastewater treatment process caused by the use of acids or alkalis can be eliminated. In addition, a decrease in the capacity of the aluminum adsorption resin column 100 due to the solution remaining in the aluminum adsorption resin column 100 can be prevented. Therefore, even if the aqueous solution of the lithium precursor and the treatment liquid are repeatedly injected into the aluminum adsorption resin column 100, metals can be effectively recovered in terms of energy and cost.

[0112] The flow rate control unit 110 can control the flow rate of the treatment liquid injected into the aluminum adsorption resin column 100.

[0113] For example, the flow rate control unit 110 may include means for controlling the flow rate, such as valves, pumps, fans, blowers, etc., and the injection rate of the first treatment liquid injected into the aluminum adsorption resin column 100 can be adjusted through these means.

[0114] For example, the injection rate of the first treatment liquid can be controlled by adjusting the diameter, length, etc. of the flow path connecting the flow rate control unit 110 and the aluminum adsorption resin column 100.

[0115] According to an exemplary embodiment, the first treatment liquid can be injected into the aluminum adsorption resin column 100 at a flow rate of 100 L / hour to 1200 L / hour, 500 L / hour to 1200 L / hour, or 1000 L / hour to 1200 L / hour.

[0116] According to an exemplary embodiment, the first treatment liquid can be injected into the aluminum adsorption resin column 100 at a linear velocity of 1 m / hour to 13 m / hour, 8 m / hour to 12.6 m / hour, or 10.4 m / hour to 12.48 m / hour.

[0117] According to an exemplary embodiment, the liquid hourly space velocity (LHSV) of the distilled water may be 1 or more and 10 or less, 1.5 or more and 9 or less, or 4 or more and 8 or less. Herein, the LHSV may represent the flow rate of the first treatment liquid relative to the volume of the aluminum adsorption resin column 100.

[0118] For example, when the injection rate of the first treatment liquid exceeds the above range, the aluminum in the aluminum adsorption resin may not be sufficiently desorbed, and the removal of aluminum from the re-injected aqueous solution of the lithium precursor may not be fully achieved. In addition, due to the physical force according to the flow rate of the first treatment liquid, the inside of the aluminum adsorption resin column may be damaged, reducing the regeneration efficiency of the aluminum adsorption resin.

[0119] For example, when the injection rate of the first treatment liquid is less than the above range, the first treatment liquid may be difficult to penetrate into the aluminum adsorption resin column, or due to the reversible reaction of the aluminum adsorption resin, the aluminum may not be sufficiently desorbed. Therefore, the removal of aluminum from the re-injected aqueous solution of the lithium precursor may not be fully achieved.

[0120] According to an exemplary embodiment, the aluminum content of the first treatment liquid may be 15 ppm or less. According to an exemplary embodiment, the aluminum content before the aluminum in the distilled water injected into the aluminum adsorption resin column 100 is desorbed may be 10 ppm or less.

[0121] According to an exemplary embodiment, the first treatment liquid may desorb the aluminum in the aluminum adsorption resin column 100, thereby generating a second treatment liquid containing the desorbed aluminum.

[0122] According to an exemplary embodiment, the pH of the first treatment liquid may be 6.5 to 7.5 or 6.7 to 7.3.

[0123] Within the above pH range, the aluminum adsorbed in the aluminum adsorption resin column can be effectively desorbed without additional chemicals.

[0124] For example, when the first treatment liquid is acidic, the functional groups of the aluminum adsorption resin cannot be restored, and the capacity retention rate of the aluminum adsorption resin decreases, so that the metal cannot be repeatedly recovered from the lithium precursor.

[0125] For example, when the first treatment liquid is alkaline, the aluminum bound to the aluminum adsorption resin is firmly bound to the aluminum adsorption resin in the form of Al(OH)4 - , thereby possibly reducing the desorption efficiency of aluminum in the aluminum adsorption resin. Therefore, the metal cannot be repeatedly recovered from the lithium precursor.

[0126] According to an exemplary embodiment, the capacity retention rate of the aluminum adsorption resin column 100 based on the first treatment liquid may be 70% or more or 75% or more.

[0127] For example, the capacity retention rate refers to the ratio of the exchange capacity after regenerating the aluminum adsorption resin column with the first treatment liquid to the exchange capacity after regenerating the aluminum adsorption resin column with an aqueous sulfuric acid solution and an aqueous sodium hydroxide solution.

[0128] According to an exemplary embodiment, the content of aluminum contained in the second treatment liquid may be 200 ppm or more, or 210 ppm or more.

[0129] For example, when the content of aluminum contained in the second treatment liquid is less than the above range, the desorption efficiency of aluminum in the re-injected aqueous lithium precursor solution may decrease.

[0130] Such as Figure 2 and Figure 3 As shown, the aluminum adsorption resin column 100 can be connected to the evaporation treatment unit 150 through a flow path. The evaporation treatment unit 150 can be connected to the discharge unit 155 for discharging aluminum. In addition, the evaporation treatment unit 150 can be connected to the distilled water regeneration unit 200 through a flow path. The distilled water regeneration unit 200 can be connected to the distilled water supply unit 120 connected to the flow rate control unit 110.

[0131] According to an exemplary embodiment, the second treatment liquid can be evaporated by the evaporation treatment unit 150 to generate a third treatment liquid that does not contain aluminum.

[0132] According to an exemplary embodiment, the evaporation treatment unit 150 can evaporate the distilled water contained in the second treatment liquid. The evaporation method is not particularly limited. For example, the distilled water can be evaporated by methods such as direct heating, indirect heating, electricity, and microwave.

[0133] The aluminum can be removed through the distilled water portion of the second treatment liquid, and the aluminum can be collected after evaporating the second treatment liquid.

[0134] According to an exemplary embodiment, the distilled water portion can be 0.01 wt% to 5 wt% relative to the total weight of the distilled water contained in the second treatment liquid.

[0135] For example, the distilled water portion contains aluminum, and the distilled water portion containing aluminum flows into the discharge unit 155, so that the aluminum can be removed.

[0136] Through the distilled water portion, the aluminum can be discharged at the discharge unit 155, and the third treatment liquid free of impurities can be supplied to the distilled water regeneration unit 200. Therefore, the purity of the water contained in the third treatment liquid can be increased, and the third treatment liquid can be recovered into the first treatment liquid.

[0137] For example, when the distilled water portion is within the above range, aluminum can be sufficiently discharged while improving the recovery efficiency of the treatment liquid passing through the third treatment liquid.

[0138] According to an exemplary embodiment, the third treatment liquid evaporated from the evaporation treatment unit 150 may flow into the distilled water regeneration unit 200 in the form of water vapor. The flowing-in third treatment liquid is cooled in the distilled water regeneration unit 200, and thus can be recovered as distilled water.

[0139] According to an exemplary embodiment, the distilled water cooled in the distilled water regeneration unit 200 may be re-injected into the flow rate control unit 110 through the distilled water supply unit 120.

[0140] The treatment liquid recovered after desorbing aluminum in the aluminum adsorption resin column 100 can be re-injected into the aluminum adsorption resin column 100 without undergoing a separate chemical treatment or additional process, thereby enabling effective regeneration of the aluminum adsorption resin column 100.

[0141] According to an exemplary embodiment, the distilled water regeneration unit 200 may maintain a temperature range of 10°C to 40°C. Within the above temperature range, the flowing-in third treatment liquid can be recovered as distilled water.

[0142] According to an exemplary embodiment, the distilled water regeneration unit 200 may be connected to the flow rate control unit 110 through the distilled water supply unit 120.

[0143] For example, the distilled water supply unit 120 may include a pump, a control valve, etc. The distilled water can be moved into the flow rate control unit 110 through the distilled water supply unit 120.

[0144] Through the distilled water supply unit 120, it can be re-injected into the aluminum adsorption resin column 100 after passing through the flow rate control unit 110 with the impurities of the treatment liquid removed, and thus the above effects can be repeatedly achieved.

[0145] Hereinafter, specific experimental examples for helping to understand the present invention are presented, but these are only for illustrating the present invention and not for limiting the scope of rights. Various changes and modifications can be made to the embodiments within the scope and technical idea of the present invention, which are obvious to those skilled in the art, and such changes and modifications also belong to the scope of rights.

[0146] Example 1

[0147] 1 kg of the positive electrode material separated from a waste lithium secondary battery was heat-treated at 450°C for 1 hour. The heat-treated positive electrode material was cut into small units and pulverized by grinding to collect a sample of the Li-Ni-Co-Mn oxide positive electrode active material mixture.

[0148] A 0.2 kg sample of the collected positive electrode active material mixture was added to a fluidized bed reactor, and a mixed gas (reducing gas) of 20 vol% hydrogen / 80 vol% nitrogen was injected through a gas inlet located at the lower part of the fluidized bed reactor for 4 hours. Fluidization was carried out in the fluidized bed reactor to react it with hydrogen, thereby forming a lithium precursor containing lithium hydroxide. At this time, the internal temperature of the fluidized bed reactor was maintained at 460 °C.

[0149] Water and nitrogen were added to the lithium precursor collected from the reactor outlet, thereby forming and collecting a primary precursor mixture in a slurry state. Further water was added to the collected primary precursor mixture in the slurry state, and then a water washing treatment was carried out to obtain an aqueous solution of the lithium precursor.

[0150] The aqueous solution of the lithium precursor was passed through an 180 L aluminum adsorption resin column (chamber) containing 125 L of aluminum adsorption resin (AmberLite UP7530 from DuPont). By passing the aqueous solution of the lithium precursor, aluminum ions were adsorbed onto the aluminum adsorption resin column.

[0151] Thereafter, a treatment liquid was added to the aluminum adsorption resin column at a flow rate of 1000 L / h for 70 minutes to desorb the aluminum adsorbed on the aluminum adsorption resin column.

[0152] Example 2

[0153] The adsorbed aluminum was desorbed by the same method as in Example 1, except that distilled water was added to the aluminum adsorption resin column at a flow rate of 1200 L / h for 60 minutes so that the amount of distilled water added to the aluminum adsorption resin column was the same.

[0154] Example 3

[0155] The adsorbed aluminum was desorbed by the same method as in Example 1, except that distilled water was added to the aluminum adsorption resin column at a flow rate of 200 L / h for 350 minutes so that the amount of distilled water added to the aluminum adsorption resin column was the same.

[0156] Example 4

[0157] The adsorbed aluminum was desorbed by the same method as in Example 1, except that distilled water was added to the aluminum adsorption resin column at a flow rate of 500 L / h for 140 minutes so that the amount of distilled water added to the aluminum adsorption resin column was the same.

[0158] Comparative Example 1

[0159] The adsorbed aluminum was desorbed by the same method as in Example 1, except that distilled water was added to the aluminum adsorption resin column at a flow rate of 1500 L / h for 47 minutes so that the amount of distilled water added to the aluminum adsorption resin column was the same.

[0160] Comparative Example 2

[0161] The adsorbed aluminum was desorbed by the same method as in Example 1, except that an aqueous sulfuric acid solution was added to the aluminum adsorption resin column at a flow rate of 1000 L / h for 70 minutes.

[0162] Comparative Example 3

[0163] The adsorbed aluminum was desorbed by the same method as in Example 1, except that an aqueous sodium hydroxide solution was added to the aluminum adsorption resin column at a flow rate of 1000 L / h for 70 minutes.

[0164] Comparative Example 4

[0165] The adsorbed aluminum was desorbed by the same method as in Example 1, except that distilled water, an aqueous sulfuric acid solution, distilled water, an aqueous sodium hydroxide solution, and distilled water were sequentially added at a flow rate of 1000 L / h for 70 minutes.

[0166] Experimental Example 1. Evaluation of regeneration of aluminum adsorption resin column (1)

[0167] According to Example 1, the aluminum adsorbed on the aluminum adsorption resin column was desorbed to regenerate the aluminum adsorption resin column, and then the aluminum concentration in the distilled water over time was analyzed. The analysis results are shown in Table 1 below.

[0168] [Table 1]

[0169]

[0170] As shown in Table 1, until 20 minutes, the aluminum ions in the distilled water increased, and from 20 minutes, the aluminum in the treatment solution remained constant, so it could be confirmed that the aluminum adsorbed on the aluminum adsorption resin column was desorbed. In addition, after 70 minutes, almost no aluminum concentration was detected in the treatment solution, so it could be confirmed that the regeneration of the aluminum adsorption resin column was completed.

[0171] Experimental Example 2. Evaluation of regeneration of aluminum adsorption resin column (2)

[0172] According to the above Examples and Comparative Examples, the aluminum adsorbed on the aluminum adsorption resin column was desorbed, and then the aluminum concentration of the solution after each treatment was confirmed.

[0173] In addition, an aqueous solution of a lithium precursor with an aluminum concentration of 40 ppm was used to evaluate the exchange capacity (eq / L) of the aluminum adsorption resin column before and after aluminum adsorption and desorption in the aluminum adsorption resin column. The capacity retention rate (%) was evaluated as follows: based on the above exchange capacity of Comparative Example 4 in which sulfuric acid aqueous solution, distilled water, and sodium hydroxide aqueous solution were used to desorb aluminum, the respective exchange capacities according to the above Examples and Comparative Examples were compared.

[0174] The evaluation results are shown in Table 2 below.

[0175] [Table 2]

[0176]

[0177] Referring to Table 2, it can be confirmed that according to Example 1 and Example 2, when the flow rate of distilled water was set to 1000 L / hour or 1200 L / hour to regenerate the aluminum adsorption resin column, the exchange capacity of the aluminum adsorption resin column was high, so that metals could be repeatedly recovered from the lithium secondary battery. In addition, it was also confirmed that the capacity retention rate was 75% or more and the desorption efficiency of aluminum was high.

[0178] According to Example 3 and Example 4, when the flow rate of distilled water was set to 200 L / hour or 500 L / hour to regenerate the aluminum adsorption resin column, the concentration of aluminum contained in the treated solution was 100 ppm or more. However, due to insufficient linear velocity, distilled water could not penetrate sufficiently between the aluminum adsorption resin columns, and metal ions remained in the state of being attached to the functional groups, so the exchange capacity of the aluminum adsorption resin decreased compared with Example 1 and Example 2, and the capacity retention rate was less than 75%.

[0179] According to Comparative Example 1, when the flow rate of distilled water was set to 1500 L / hour to regenerate the aluminum adsorption resin, the concentration of aluminum contained in the treated solution decreased due to the flow rate, and the desorption time was insufficient due to the fast flow rate, so the exchange capacity and the capacity retention rate decreased significantly.

[0180] According to Comparative Example 4, when sulfuric acid aqueous solution and sodium hydroxide aqueous solution were used simultaneously to regenerate the aluminum adsorption resin, aluminum in the aluminum adsorption resin could be desorbed by the sulfuric acid aqueous solution, and the functional groups of the aluminum adsorption resin could be regenerated by the sodium hydroxide aqueous solution, thus showing high exchange capacity and capacity retention rate. However, since sulfuric acid aqueous solution and sodium hydroxide aqueous solution were used, waste water containing sulfate ions, ammonium ions, etc. was generated, so the respective aqueous solutions and distilled water could not be used again. In addition, further water washing was required between adding the sulfuric acid aqueous solution and adding the sodium hydroxide aqueous solution, so the total amount of waste water also increased.

[0181] According to Comparative Example 2, when only an aqueous sulfuric acid solution was added, although the aluminum in the aluminum adsorption resin column could be desorbed, the functional groups of the adsorption resin could not be restored, so the metal could not be repeatedly recovered from the aqueous solution of the lithium precursor.

[0182] According to Comparative Example 3, when only an aqueous sodium hydroxide solution was added, the aluminum in the aluminum adsorption resin column was not desorbed due to the pH.

Claims

1. A method for recovering metals from a lithium secondary battery, comprising: A step of preparing a positive electrode active material mixture containing lithium; A step of reducing the positive electrode active material mixture to generate a lithium precursor; A step of dissolving the lithium precursor in water to form an aqueous solution of the lithium precursor; A step of passing the aqueous solution of the lithium precursor through an aluminum adsorption resin column, thereby adsorbing aluminum onto the aluminum adsorption resin column; And A step of injecting a first treatment liquid containing distilled water into the aluminum adsorption resin column at a flow rate of 100 L / hour to 1200 L / hour to obtain a regenerated aluminum adsorption resin column from which aluminum has been desorbed.

2. The method for recovering metals from a lithium secondary battery according to claim 1, wherein, The step of using the regenerated aluminum adsorption resin column to adsorb the aluminum again.

3. The method for recovering metals from a lithium secondary battery according to claim 1, wherein, In the step of obtaining the regenerated aluminum adsorption resin column, a second treatment liquid containing the desorbed aluminum is generated in the first treatment liquid.

4. The method for recovering metals from a lithium secondary battery according to claim 3, wherein, The content of aluminum contained in the second treatment liquid is 200 ppm or more.

5. The method for recovering metals from a lithium secondary battery according to claim 3, wherein, The method for recovering metals from a lithium secondary battery further includes: A step of generating a third treatment liquid formed by evaporating the second treatment liquid; and A step of recovering the third treatment liquid into the first treatment liquid.

6. The method for recovering metals from a lithium secondary battery according to claim 5, wherein, The step of generating the third treatment liquid includes simultaneously removing a specified portion of distilled water and the desorbed aluminum in the second treatment liquid.

7. The method for recovering metals from a lithium secondary battery according to claim 6, wherein, The amount of the distilled water portion is 0.01 wt% to 5 wt% relative to the total weight of the distilled water contained in the second treatment liquid.

8. The method for recovering metals from a lithium secondary battery according to claim 1, wherein, The first treatment liquid is injected at a flow rate of 1000 L / hour to 1200 L / hour.

9. The method for recovering metals from a lithium secondary battery according to claim 1, wherein, The first treatment liquid is injected at a linear velocity of 8 m / hour to 13 m / hour.

10. The method for recovering metals from a lithium secondary battery according to claim 1, wherein, The aluminum adsorption resin column contains a resin containing an amino group and a hydroxyl group.

11. The method for recovering metals from a lithium secondary battery according to claim 10, wherein, The resin containing an amino group and a hydroxyl group contains methylglucamine.

12. A system for recovering metals from a lithium secondary battery, comprising: An aluminum adsorption resin column; A flow rate control unit for supplying distilled water to the aluminum adsorption resin column; An evaporation treatment unit for evaporating the distilled water passing through the aluminum adsorption resin column to generate water vapor; A distilled water regeneration unit for collecting distilled water from the water vapor generated by the evaporation treatment unit; and A distilled water supply unit for supplying the regenerated distilled water from the distilled water regeneration unit to the flow rate control unit.

13. The system for recovering metals from a lithium secondary battery according to claim 12, wherein The evaporation treatment unit includes a discharge unit for discharging a portion of distilled water and aluminum that have not been treated as water vapor.

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