Complex ionic compound, its preparation method, and its use in recovery of metal ions

Abstract

To provide a complex ionic compound for recovery of metal ions, capable of simplifying the recovery process of metal ions and reducing the recovery cost of metal ions, its preparation method, and its use in the recovery of metal ions.SOLUTION: A complex ionic compound comprises a carrier including C:Na-Ni / Al2O3 composite powder, a crosslinking agent including halogen-containing siloxane of low molecular weight, and an adsorbent including 1-butyl-3-methylimidazolium hexafluorophosphate or the like, wherein the crosslinking agent is grafted onto the carrier, and the adsorbent is grafted onto the crosslinking agent.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to complex ionic compounds, methods for their preparation, and their use in the recovery of metal ions. [Background technology]

[0002] Lithium-ion batteries have long been a common power source in our daily lives, thanks to their high energy density and ease of manufacture. Currently, the cathode materials of lithium-ion batteries include metal-containing materials such as lithium cobalt, lithium nickel, lithium nickel cobalt, and lithium nickel cobalt manganese. The metals employed in the cathode materials (e.g., manganese, cobalt, nickel, and lithium) are derived from depleting natural resources, and the metals contained in discarded batteries may pose a danger to the environment. How to recover the metals contained in discarded batteries is one of the key challenges in the environment and sustainable development. Summary of the Invention [Problem to be solved by the invention]

[0003] The present invention provides complex ion compounds that facilitate the recovery of metal ions.

[0004] The present invention provides a method for producing complex ion compounds to enhance the recovery of metal ions.

[0005] The present invention provides the use of complex ion compounds for the recovery of metal ions, which can simplify the recovery process of metal ions and reduce the cost of recovering metal ions. [Means for solving the problem]

[0006] The composite ionic compound of the present invention includes a support, a cross-linking agent grafted to the support, and an adsorbent grafted to the cross-linking agent.

[0007] The support of an embodiment of the present invention comprises C:Na-Ni / Al2O3 composite powder.

[0008] In one embodiment of the present invention, the crosslinker comprises a low molecular weight halogen-containing siloxane.

[0009] In one embodiment of the invention, the adsorbent comprises at least two of 1-butyl-3-methylimidazolium hexafluorophosphate, 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium hexafluorophosphate, 1-butyl-3-methylimidazolium acetate, choline chloride, and glycerol.

[0010] The method for preparing the composite ionic compound of the present invention includes the steps of grafting a cross-linking agent onto a support, and grafting an adsorbent onto the cross-linking agent to form the composite ionic compound.

[0011] In one embodiment of the present invention, the method for preparing the composite ion compound further includes forming a carrier, which includes: putting Na-Ni / Al2O3 powder into a reactor, supplying carbon dioxide and hydrogen into the reactor, and adjusting the temperature in the reactor to 400℃-800℃ to reduce the carbon dioxide to carbon, and adsorbing the carbon to Ni atoms in the Na-Ni / Al2O3 powder to form C:Na-Ni / Al2O3 composite powder.

[0012] In one embodiment of the present invention, the crosslinker comprises a low carbon number chlorine-containing siloxane represented by the following formula (1): [ka] In the formula, each R is independently alkyl having 1 to 6 carbon atoms.

[0013] According to one embodiment of the present invention, the adsorbent is grafted to the chlorine (Cl) terminus of the crosslinker.

[0014] In one embodiment of the invention, the adsorbent comprises at least two of butyl-3-methylimidazolium hexafluorophosphate, 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium hexafluorophosphate, 1-butyl-3-methylimidazolium acetate, choline chloride, and glycerol.

[0015] The use of the complex ion compound in the recovery of metal ions of the present invention includes adding the above-mentioned complex ion compound to a recovery liquid containing metal ions so that the complex ion compound can adsorb the metal ions, separating the complex ion compound having the metal ions adsorbed thereon, extracting the complex ion compound having the metal ions adsorbed thereon with a solvent to separate the metal ions from the complex ion compound, extracting the metal ions into the solvent, and purifying the metal ions in the solvent.

[0016] In one embodiment of the present invention, the recovery solution is a lithium ion battery recovery solution.

[0017] In one embodiment of the present invention, the metal ions include manganese (Mn) ions, cobalt (Co) ions, nickel (Ni) ions, lithium (Li) ions, or a combination thereof.

[0018] In one embodiment of the present invention, "separating the complex ionic compounds having adsorbed metal ions" is performed using a magnetic material that attracts the complex ionic compounds.

[0019] In one embodiment of the invention, the solvent comprises ethyl acetate or methanol. Effect of the Invention

[0020] The adsorbent in the composite ion compound of the present invention adsorbs metal ions, so it can be used to separate and extract metal ions to further promote the recovery of metal ions. Furthermore, the composite ion compound of the present invention has magnetic properties and is easy to extract. Therefore, the method for recovering metal ions of the present invention can greatly simplify the recovery process and reduce the recovery cost of metal ions.

[0021] In order to make the foregoing more easily understandable, several embodiments are described in detail below with reference to the drawings. [Brief description of the drawings]

[0022] The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the invention and, together with the description, serve to explain the principles of the invention. [Figure 1] 1 is a schematic flow chart illustrating a method for producing a composite ionic compound according to one embodiment of the present invention. [Diagram 2] The decomposition potentials of two different metal ions, metal ion A and metal ion B, are shown. [Diagram 3] FIG. 2 is a schematic diagram showing a potential control circuit used in electrolytic separation. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the following embodiments, which are merely illustrative and do not limit the scope of the present invention.

[0024] In this specification, the range indicated as "from a certain value to another value" is a general expression to avoid listing all the values ​​in this specification one by one. Therefore, the description of a specific numerical range covers any numerical value within that range and a smaller numerical range defined by any numerical value within that range, and is equivalent to specifying that numerical value and the smaller numerical range.

[0025] FIG. 1 is a schematic flow chart illustrating a method for producing a composite ionic compound according to one embodiment of the present invention.

[0026] Please refer to FIG. 1. In the present invention, the method for producing a composite ion compound includes the following steps, but the present invention is not limited thereto. First, in step S1, a carrier is formed. Next, in step S2, a crosslinking agent is grafted onto the carrier. In step S3, an adsorbent is grafted onto the crosslinking agent, so that the adsorbent and the carrier are bonded via the crosslinking agent to form a composite ion compound. The steps are described in detail as follows:

[0027] In the present invention, the order of grafting the crosslinker and the adsorbent is not particularly limited. In some embodiments, the adsorbent may be grafted to the crosslinker before the crosslinker bound to the adsorbent is grafted to the support via the crosslinker end.

[0028] In some embodiments, the support can be a C:Na-Ni / Al2O3 composite powder. In some embodiments, the C:Na-Ni / Al2O3 composite powder can be made by fixed bed reactor reduction. For example, forming the C:Na-Ni / Al2O3 composite powder can include placing the Na-Ni / Al2O3 powder in a reactor (e.g., a fixed bed reactor) and feeding carbon dioxide and hydrogen to the reactor. The temperature in the reactor can be between 400°C and 800°C, e.g., 500°C, 600°C, or 700°C, to reduce the carbon dioxide to carbon (C) and adsorb the carbon to the Na-Ni / Al2O3 powder. In some embodiments, the volume ratio of carbon dioxide to hydrogen is between 3:1 and 1:3. In some embodiments, the volume ratio of carbon dioxide to hydrogen is 1:1. In some embodiments, the time period for feeding carbon dioxide to the reactor is between 2 hours and 36 hours. In some embodiments, carbon is grafted to Ni (nickel) atoms in the Na-Ni / Al2O3 powder to form a C:Na-Ni / Al2O3 composite powder.

[0029] In some embodiments, forming the C:Na-Ni / Al2O3 composite powder further includes performing a sintering process to rearrange the lattice of the C:Na-Ni / Al2O3 composite powder. In some embodiments, the temperature of the sintering process is 500°C to 800°C, such as 550°C, 650°C, or 750°C. In some embodiments, the sintering process time is 1 hour to 2 hours, although the present invention is not limited thereto.

[0030] The crosslinker may be formed of a low molecular weight siloxane. In some embodiments, the crosslinker may be formed of a low molecular weight halogen-containing siloxane. In some embodiments, the crosslinker may include a low carbon number chlorine-containing siloxane. For example, the crosslinker may have a structure represented by formula (1): [ka] In the formula, each R may independently be alkyl having 1 to 6 carbon atoms.

[0031] The cross-linking agent may be grafted to the outer surface of the support by adsorption or binding. In some embodiments, after the cross-linking agent is bound to the C:Na-Ni / Al2O3 support, the structure represented by formula (2) is formed. [ka]

[0032] The adsorbent may be derived from a deep eutectic solvent (DES). Deep eutectic solvents are generally considered to be a type of ionic liquid and refer to ionic compounds in a liquid state. In some embodiments, the adsorbent is an ionic compound having a positive charge. Cationic moieties that provide a positive charge include imidazole ions, pyridine ions, quaternary phosphonium ions, quaternary ammonium ions, guanidinium ions, sulfonium ions, choline ions, morpholinium ions, and the like.

[0033] In some embodiments, the adsorbent is, for example, hexafluorophosphate ion (PF6 - ), tetrafluoroborate ion (BF4 - ), ferric chloride ion (FeCl4 - ) or acetate ion (OAc - In some embodiments, the adsorbent may further include choline chloride and glycerol. This adsorbent can form a stable chelate structure with some metal ions, and therefore has high selectivity and ideal adsorption performance, and can be used for the detection and separation of metal ions.

[0034] In some embodiments, the sorbent comprises 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]), 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIM][BF4]), 1-ethyl-3-methylimidazolium hexafluorophosphate ([EMIM][PF6]), 1-butyl-3-methylimidazolium acetate ([BMIM][OAc]), choline chloride, glycerol, or a combination thereof. In some embodiments, the sorbent comprises at least two of 1-butyl-3-methylimidazolium hexafluorophosphate, 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium hexafluorophosphate, 1-butyl-3-methylimidazolium acetate, choline chloride, and glycerol.

[0035] The adsorbent may be grafted to the outer surface of the support by adsorption or binding. In some embodiments, the adsorbent is grafted to the support by grafting the adsorbent to a crosslinker, where one end of the crosslinker is connected to the support and the other end is connected to the adsorbent. In some embodiments, the adsorbent is grafted to the C:Na-Ni / Al2O3 support through the chlorine end of the crosslinker, thus forming a complex ionic compound, as represented by the following formula (3): [ka]

[0036] For example, the chlorine-containing siloxane (crosslinker) represented by formula (1) may be reduced under an acidic environment (pH=4-5) to have a hydroxyl group. The reduced chlorine-containing siloxane then reacts with C:Na-Ni / Al2O3 composite powder (carrier) to graft the chlorine-containing siloxane to the C:Na-Ni / Al2O3 composite powder via the hydroxyl group. Next, a deep eutectic solvent containing 1-butyl-3-methylimidazolium hexafluorophosphate and 1-ethyl-3-methylimidazolium tetrafluoroborate (adsorbent) is added in an acidic environment (pH=4-5). The 1-butyl-3-methylimidazolium hexafluorophosphate and 1-ethyl-3-methylimidazolium tetrafluoroborate react with the chlorine group of the chlorine-containing siloxane. Therefore, 1-butyl-3-methylimidazolium hexafluorophosphate and 1-ethyl-3-methylimidazolium tetrafluoroborate are grafted to chlorine-containing siloxane.Therefore, 1-butyl-3-methylimidazolium hexafluorophosphate and 1-ethyl-3-methylimidazolium tetrafluoroborate can be grafted to carrier through crosslinker.Therefore, the composite ion compound of the present invention is prepared. Alternatively, each of 1-butyl-3-methylimidazolium hexafluorophosphate and 1-ethyl-3-methylimidazolium tetrafluoroborate may also be grafted to the C:Na-Ni / Al2O3 composite powder via a chlorine-containing siloxane by reacting the 1-butyl-3-methylimidazolium hexafluorophosphate and the 1-ethyl-3-methylimidazolium tetrafluoroborate with a chlorine-containing siloxane to form an intermediate before reacting the intermediate with the C:Na-Ni / Al2O3 composite powder.

[0037] In some embodiments, the composite ionic compound includes a carrier, a crosslinker grafted to the carrier, and two types of adsorbents each grafted to the crosslinker. In some embodiments, two or more types of adsorbents are each grafted to the carrier under different reaction conditions, and the different adsorbents may involve different reactions, such as adsorption reactions or depolymerization reactions. In some embodiments, the weight ratio of adsorbent to carrier in the composite ionic compound is 1.8 or more and 3 or less.

[0038] The composite ion compound of the present invention can be used for recovering metal ions, for example, recovering metal ions in a lithium ion battery recovery solution. In some embodiments, the method for recovering metal ions may include the following steps. First, the composite ion compound is added to the lithium ion battery recovery solution so that the composite ion compound can adsorb metal ions, such as manganese ions, cobalt ions, nickel ions, lithium ions, or combinations thereof, in the lithium ion battery recovery solution. Second, since the composite ion compound has magnetic properties, the composite ion compound with the adsorbed metal ions can be attached to the magnetic material by attracting the composite ion compound with the adsorbed metal ions using a magnetic material (e.g., a magnet). Finally, the composite ion compound with the adsorbed metal ions may be separated by filtration. Thus, the separation process of the composite ion compound is greatly simplified.

[0039] In some embodiments, the metal ions adsorbed on the complex ion compound can be further washed away by using a solvent, and the complex ion compound from which the metal ions have been removed can be reused. In some embodiments, each type of washed metal ion can be separated and purified by electrochemical techniques. For example, the metal ions adsorbed on the complex ion compound can be extracted by solvent extraction. In some embodiments, a volatile organic solvent (e.g., ethyl acetate and methanol) can be used to perform solvent extraction on the complex ion compound adsorbing the metal ions to separate the metal ions from the complex ion compound and extract the metal ions into the organic solvent. The metal ions in the solvent can then be separated and purified by evaporation of the volatile solvent or other suitable methods.

[0040] In some embodiments, metal ions in an organic solvent may be separated and purified by electrolytic reduction. For example, metal ions in an organic solvent may be electrolyzed as an electrolyte. Under suitable potential and suitable electrolytic conditions, the metal ions are reduced to metal and the purified metal may be collected from the electrolytic electrodes.

[0041] In some embodiments, metal ions in an organic solvent may be separated and purified by electrochemical separation methods (potential-controlled electrolytic separation) described below.

[0042] For example, Cu 2+ (Standard electrode potential E 0 = +0.345 volts) and Bi 3+ (E 0 If there are two or more types of metal ions in a solution and the reduction potential of one of the metal ions is close to the reduction potential of the other metal ions, such as when the reduction potential of one metal ion is close to that of the other metal ions (e.g., +0.2 volts), the two or more metal ions will be reduced and precipitated during electrolysis, making it impossible to achieve the purpose of separation.

[0043] Figure 2 shows the decomposition potentials of two different metal ions, metal ion A and metal ion B. Please refer to Figure 2. When the cathode potential is controlled to potential b, metal ion T generates a current with a current intensity of d, so metal ion T is reduced. However, metal ion B has an extremely small current intensity and is hardly reduced. This allows metal ion T and metal ion B to be separated and measured, while achieving the purpose of separation.

[0044] In some embodiments, the reduction electrode is the cathode. To control the cathode potential, the applied voltage must be constantly adjusted. The electrode material is a corrosion-resistant and highly reactive material. Typically, platinum group metals are employed. Figure 3 is a schematic diagram showing a potential control circuit used in electrolytic separation. In Figure 3, electrode e1 is a platinum mesh cathode, electrode e2 is a platinum wire counter electrode, and electrode e3 is a reference electrode (e.g., a saturated calomel electrode). The potential of the selected electrode e1 (relative to electrode e3) can be read from potentiometer V. The electrolysis current can be read from milliammeter A. During the electrolysis process, resistor r is continuously adjusted to keep the cathode potential constant.

[0045] In some embodiments, the metal ions adsorbed by the composite ion compound may be separated by electrochemical metal selective separation techniques. For example, for a composite ion compound that adsorbs metal ions, sulfuric acid or hydrochloric acid may be used to dissolve the metal ions. Then, according to the difference in redox potential of each type of metal ion, each type of metal is selectively reduced in sequence by voltage control to achieve the purpose of metal separation. For example, the following formulas show the redox potentials of nickel (Ni), manganese (Mn), cobalt (Co), and lithium (Li) for separating Ni, Mn, Co, and Li:

number

[0046] The separation of metals can be carried out by the following steps.

[0047] In some embodiments, the voltage (E 0 ) is controlled to be between -0.3V and -1.2V, and metallic Ni and Co are precipitated on the electrode surface.

[0048] In some embodiments, the voltage (E 0 ) is controlled to be −1.2 V to −3 V, and metallic Mn is precipitated on the electrode surface.

[0049] In some embodiments, the voltage (E 0 ) is controlled to be >-3V, and metallic Li is deposited on the electrode surface.

[0050] Therefore, the different voltages (E 0 ) spacing, separation of the metals is achieved.

[0051] Considering the above, the adsorbent in the composite ion compound of the present invention interacts with metal ions and brings about chelate coordination, so that the adsorbent can be used for separation and extraction of metal ions to further promote the recovery of metal ions. Moreover, the composite ion compound has magnetic properties and is easy to separate, so that the recovery method of metal ions of the present invention can greatly simplify the recovery process and reduce the recovery cost of metal ions. [Industrial Applicability]

[0052] The composite ion compound and the method for producing the same of the present invention can be applied to the recovery of metal ions.

[0053] It will be apparent to one skilled in the art that various modifications and variations can be made to the disclosed embodiments without departing from the scope or spirit of the invention. In view of the above, it is intended that the present invention cover modifications and variations provided they come within the scope of the following claims and their equivalents. [Explanation of symbols]

[0054] S1, S2, S3: Steps

Claims

1. A carrier; A crosslinker grafted to the support; and an adsorbent grafted to the crosslinker.

2. The support is C:Na-Ni / Al ２ O ３ The complex ionic compound of claim 1 comprising a complex powder.

3. The complex ionic compound of claim 1 , wherein said crosslinker comprises a low molecular weight halogen-containing siloxane.

4. 2. The complex ionic compound of claim 1, wherein the adsorbent comprises at least two of 1-butyl-3-methylimidazolium hexafluorophosphate, 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium hexafluorophosphate, 1-butyl-3-methylimidazolium acetate, choline chloride, and glycerol.

5. grafting a crosslinker onto the support; and grafting an adsorbent onto a cross-linking agent to form said composite ionic compound.

6. forming the carrier; forming the carrier Na-Ni / Al ２ O ３ placing the powder in a reactor; Carbon dioxide and hydrogen are supplied to the reactor, and the temperature in the reactor is set to 400° C. to 800° C. to reduce the carbon dioxide to carbon, which is then converted into the Na—Ni / Al ２ O ３ C:Na-Ni / Al was adsorbed onto the Ni atoms in the powder. ２ O ３ forming a composite powder; The method for producing the composite ionic compound according to claim 5, comprising:

7. The method for producing a composite ionic compound according to claim 5 , wherein the crosslinking agent contains a chlorine-containing siloxane having a low carbon number represented by the following formula (1): 【Chemistry 1】 In the formula, each R is independently alkyl having 1 to 6 carbon atoms.

8. The method for producing a composite ionic compound according to claim 7, wherein the adsorbent is grafted to the chlorine end of the crosslinking agent.

9. The method for producing a composite ion compound according to claim 5, wherein the adsorbent comprises at least two of 1-butyl-3-methylimidazolium hexafluorophosphate, 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium hexafluorophosphate, 1-butyl-3-methylimidazolium acetate, choline chloride, and glycerol.

10. 1. Use of a complex ion compound in the recovery of metal ions, comprising: adding the composite ionic compound according to claim 1 to a recovery solution containing metal ions so that the composite ionic compound can adsorb the metal ions; separating the composite ion compound having adsorbed the metal ions; extracting the composite ion compound having the metal ions adsorbed thereon with a solvent to separate the metal ions from the composite ion compound and extract the metal ions into the solvent; purifying the metal ions in the solvent; Use including.

11. The use according to claim 10, wherein the recovery solution is a lithium ion battery recovery solution.

12. 11. The use of claim 10, wherein the metal ions comprise manganese ions, cobalt ions, nickel ions, lithium ions, or a combination thereof.

13. The use according to claim 10, wherein the separation of the complex ionic compounds with adsorbed metal ions is carried out using a magnetic material which adsorbs the complex ionic compounds.

14. The use according to claim 10, wherein the solvent comprises ethyl acetate or methanol.

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