Composite ionic compound, preparation method thereof and use for recovering metal ions

Abstract

The invention discloses a composite ionic compound which comprises a carrier, a bridging agent and an adsorbent, the bridging agent is grafted to the carrier, and the adsorbent is grafted to the bridging agent. In addition, the invention also provides a preparation method of the composite ionic compound and application of the composite ionic compound for recovering metal ions.

Description

Technical Field

[0001] The invention relates to a composite ion compound, a preparation method thereof and use thereof in recovering metal ions. Background Art

[0002] Lithium-ion batteries have long been a widely used source of electricity in people's daily lives due to their high energy density and ease of manufacture. Currently, the materials used for the positive electrode of lithium-ion batteries may include metal-containing materials such as lithium cobalt, lithium nickel, lithium nickel cobalt, and lithium nickel cobalt manganese. Since the natural minerals of metals (e.g., manganese, cobalt, nickel, and lithium) used for positive electrode materials are not inexhaustible, and these metals in discarded batteries may also cause harm to the environment, how to recycle metals in discarded batteries is indeed one of the important issues for the sustainable development of the earth's environment. Summary of the invention

[0003] The invention provides a composite ion compound, which is helpful for recovering metal ions.

[0004] The invention provides a method for preparing a composite ion compound, which is helpful for recovering metal ions.

[0005] The invention provides a use of a composite ion compound for recovering metal ions, which can simplify the recovery procedure of the metal ions and reduce the recovery cost of the metal ions.

[0006] The composite ion compound of the present invention comprises: a carrier; a bridging agent grafted to the carrier; and an adsorbent grafted to the bridging agent.

[0007] In one embodiment of the present invention, the carrier includes C:Na-Ni / Al2O3 composite powder.

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

[0009] In one embodiment of the present invention, the adsorbent includes 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 invention discloses a method for preparing a composite ionic compound, comprising the following steps: grafting a bridging agent onto a carrier; and grafting an adsorbent onto the bridging agent to form a composite ionic compound.

[0011] In one embodiment of the present invention, the preparation method of the above-mentioned composite ionic compound also includes forming a carrier, wherein the forming of the carrier includes: placing Na-Ni / Al2O3 powder in a reactor; and passing carbon dioxide and hydrogen into the reactor, wherein the temperature in the reactor is 400°C to 800°C, so as to reduce the carbon dioxide to carbon, and allow the carbon to be adsorbed on the 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 bridging agent comprises a low carbon number chlorinated siloxane as shown in the following formula (1):

[0013]

[0014] Here, each R is independently an alkyl group having 1 to 6 carbon atoms.

[0015] In one embodiment of the present invention, the above-mentioned adsorbent is grafted onto the chlorine (Cl) end of the bridging agent.

[0016] In one embodiment of the present invention, the adsorbent includes 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.

[0017] The use of a composite ion compound of the present invention for recovering metal ions includes: adding the above-mentioned composite ion compound to a recovery solution containing metal ions so that the composite ion compound adsorbs metal ions; separating the composite ion compound that adsorbs metal ions; using a solvent to extract the composite ion compound that adsorbs metal ions so that the metal ions are separated from the composite ion compound and the metal ions are extracted into the solvent; and purifying the metal ions in the solvent.

[0018] In one embodiment of the present invention, the recovery solution is a lithium-ion battery recovery solution.

[0019] 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.

[0020] In one embodiment of the present invention, the above-mentioned “separating the composite ion compound that adsorbs metal ions” is performed by using a magnetic substance to attract the composite ion compound.

[0021] In one embodiment of the present invention, the solvent includes ethyl acetate or methanol.

[0022] Based on the above, the adsorbent of the composite ion compound of the present invention can adsorb metal ions, can be used for separation and extraction of metal ions, and thus contribute to the recovery of metal ions. In addition, the composite ion compound of the present invention is magnetic and easy to extract, so that the method for recovering metal ions of the present invention can not only greatly simplify the recovery procedure of metal ions, but also reduce the recovery cost of metal ions.

[0023] To further understand the features and technical contents of the present invention, please refer to the following detailed description and drawings of the present invention. However, the drawings provided are only for reference and description and are not intended to limit the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic flow chart of a method for preparing a composite ionic compound according to an embodiment of the present invention.

[0025] Figure 2 The figure shows the decomposition potentials of two different metal ions A and metal ion B.

[0026] Figure 3 Schematic diagram of the circuit for controlling the potential of the electrolytic separation method. DETAILED DESCRIPTION

[0027] Hereinafter, embodiments of the present invention will be described in detail. However, these embodiments are illustrative only, and the present invention is not limited thereto.

[0028] In this article, the range expressed by "a value to another value" is a summary expression method to avoid listing all the values ​​in the range one by one in the specification. Therefore, the description of a specific numerical range covers any value in the numerical range and a smaller numerical range defined by any value in the numerical range, just as the arbitrary value and the smaller numerical range are written in the description text of the specification.

[0029] Figure 1 It is a schematic flow chart of a method for preparing a composite ionic compound according to an embodiment of the present invention.

[0030] Please refer to Figure 1 In the present invention, the preparation method of the composite ionic compound may include the following steps, but the present invention is not limited thereto. First, a carrier is formed in step S1. Then, a bridging agent is grafted onto the carrier in step S2. Then, an adsorbent is grafted onto the bridging agent in step S3, so that the adsorbent is connected to the carrier through the bridging agent to form a composite ionic compound. The above steps are described in detail below.

[0031] In the present invention, the order of grafting the bridging agent and the grafting the adsorbent is not particularly limited. In some embodiments, the adsorbent can be grafted onto the bridging agent first, and then the bridging agent connected to the adsorbent is grafted onto the carrier through the bridging agent end.

[0032] In some embodiments, the carrier may be a C:Na-Ni / Al2O3 composite powder. In some embodiments, the C:Na-Ni / Al2O3 composite powder may be prepared by a fixed bed reactor reduction method. For example, the step of forming a C:Na-Ni / Al2O3 composite powder may include placing the Na-Ni / Al2O3 powder in a reactor (e.g., a fixed bed reactor), and then passing carbon dioxide and hydrogen into the reactor, wherein the temperature in the reactor may be 400°C to 800°C, such as 500°C, 600°C, or 700°C, to reduce carbon dioxide to carbon (C), and adsorb carbon to the Na-Ni / Al2O3 powder. In some embodiments, the volume ratio of carbon dioxide to hydrogen is 3:1 to 1:3. In some embodiments, the volume ratio of carbon dioxide to hydrogen is 1:1. In some embodiments, the time for passing carbon dioxide into the reactor is 2 hours to 36 hours. In some embodiments, carbon is grafted to Ni (nickel) atoms in Na-Ni / Al2O3 powder to form a C:Na-Ni / Al2O3 composite powder.

[0033] In some embodiments, the step of forming the C:Na-Ni / Al2O3 composite powder further includes: performing a sintering treatment to rearrange the lattice of the C:Na-Ni / Al2O3 composite powder. In some embodiments, the sintering temperature is 500°C to 800°C, such as 550°C, 650°C or 750°C. In some embodiments, the sintering time is about 1 hour to 2 hours, but the present invention is not limited thereto.

[0034] The bridging agent may be formed by a low molecular weight siloxane. In some embodiments, the bridging agent may be formed by a low molecular weight halogen-containing siloxane. In some embodiments, the bridging agent may include a low carbon number chlorinated siloxane. For example, the bridging agent may have a structure shown in the following formula (1):

[0035]

[0036] Here, R may be independently an alkyl group having 1 to 6 carbon atoms.

[0037] The bridging agent can be grafted onto the outer surface of the carrier by adsorption or bonding. In some embodiments, the bridging agent is connected to the C:Na-Ni / Al2O3 carrier to form a structure as shown in the following formula (2):

[0038]

[0039] The adsorbent may be derived from a deep eutectic solvent (DES), which is often considered to be an ionic liquid, which may refer to a liquid ionic compound. In some embodiments, the adsorbent is a positively charged ionic compound, and the cationic portion contributing the positive charge may be an imidazole ion, a pyridine ion, a quaternary phosphonium ion, a quaternary ammonium ion, a guanidinium ion, a sulfonium ion, a choline ion, or a morpholinium ion.

[0040] In some embodiments, the adsorbent further comprises anions with strong metal adsorption efficiency, such as hexafluorophosphate ion (PF6), tetrafluoroborate ion (BF4), tetrachloroferrate ion (FeCl4) or acetate ion (OAc). In some embodiments, the adsorbent further comprises choline chloride and glycerol. The adsorbent can form a stable chelate structure with some metal ions, so it has high selectivity and good adsorption performance, and can be used for the detection and separation of metal ions.

[0041] In some embodiments, the adsorbent includes 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 adsorbent includes 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.

[0042] The adsorbent can be grafted onto the outer surface of the carrier by adsorption or bonding. In some embodiments, the adsorbent is grafted onto the bridging agent so that one end of the bridging agent is connected to the carrier and the other end is connected to the adsorbent, so that the adsorbent can be grafted onto the carrier. In some embodiments, the adsorbent is grafted onto the C:Na-Ni / Al2O3 carrier via the chlorine end of the bridging agent to form a composite ionic compound as shown in the following formula (3):

[0043]

[0044] For example, the chlorinated siloxane (bridging agent) shown in formula (1) can be reduced in an acidic environment (pH = 4-5) to have hydroxyl groups. The reduced chlorinated siloxane is then reacted with C:Na-Ni / Al2O3 composite powder (carrier) to graft the chlorinated siloxane onto the C:Na-Ni / Al2O3 composite powder via hydroxyl groups. 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), and 1-butyl-3-methylimidazolium hexafluorophosphate and 1-ethyl-3-methylimidazolium tetrafluoroborate react with the chlorine groups of the chlorinated siloxane and are grafted onto the chlorinated siloxane. In this way, 1-butyl-3-methylimidazolium hexafluorophosphate and 1-ethyl-3-methylimidazolium tetrafluoroborate can be grafted onto the carrier individually through a bridging agent to obtain the composite ion compound of the present invention. In addition, 1-butyl-3-methylimidazolium hexafluorophosphate and 1-ethyl-3-methylimidazolium tetrafluoroborate can also be reacted with chlorosiloxane to form an intermediate, and then the intermediate is reacted with C:Na-Ni / Al2O3 composite powder. In this way, 1-butyl-3-methylimidazolium hexafluorophosphate and 1-ethyl-3-methylimidazolium tetrafluoroborate can also be grafted onto C:Na-Ni / Al2O3 composite powder respectively through chlorosiloxane.

[0045] In some embodiments, the composite ionic compound includes: a carrier, a bridging agent grafted to the carrier, and two adsorbents grafted to the bridging agent. In some embodiments, two or more adsorbents are grafted to the carrier under different reaction conditions, wherein different adsorbents may have different effects, such as adsorption, depolymerization, etc. In some embodiments, the weight ratio of the adsorbent to the carrier in the composite ionic compound is greater than or equal to 1.8 and less than or equal to 3.

[0046] The composite ion compound of the present invention can be used to recover metal ions, such as 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 can be added to a lithium ion battery recovery solution so that the composite ion compound adsorbs metal ions in the lithium ion battery recovery solution, such as manganese ions, cobalt ions, nickel ions, lithium ions or a combination thereof. Then, since the composite ion compound is magnetic, a magnetic substance (such as a magnet) can be used to attract the composite ion compound that adsorbs metal ions, so that the composite ion compound that adsorbs metal ions adheres to the magnetic substance. Thereafter, the composite ion compound that adsorbs metal ions can be separated by filtering. In this way, the separation procedure of the composite ion compound can be greatly simplified.

[0047] In some embodiments, a solvent can be further used to wash off the metal ions adsorbed by the composite ion compound, and the composite ion compound after the metal ions are removed can be reused. In some embodiments, the various metal ions washed off can be individually separated and purified by electrochemical technology. For example, the metal ions adsorbed by the composite ion compound can be removed by solvent extraction. In some embodiments, a volatile organic solvent (such as ethyl acetate, methanol) can be used to perform solvent extraction on the composite ion compound that adsorbs metal ions, so as to separate the metal ions from the composite ion compound and extract the metal ions into the organic solvent. Subsequently, the metal ions in the solvent can be separated and purified by evaporation of the volatile solvent or other appropriate methods.

[0048] In some embodiments, metal ions in organic solvents can be separated and purified by electrolytic reduction. For example, metal ions in organic solvents can be used as electrolytes for electrolytic reduction. Through appropriate potential and electrolytic conditions, metal ions can be reduced to metals, so that purified metals can be collected from electrolytic electrodes.

[0049] In some embodiments, the metal ions in the organic solvent can be separated and purified by the electrochemical separation method (controlled potential electrolysis separation method) described below.

[0050] When there are two or more metal ions in a solution, if their reduction potentials are similar, such as Cu 2+ (standard electrode potential E° = +0.345 volts) and Bi 3+ (E°=+0.2V), they will be reduced and precipitated during electrolysis, and the purpose of separation cannot be achieved.

[0051] Figure 2 The figure shows the decomposition potentials of two different metal ions T and metal ion B. Please refer to Figure 2If the cathode potential is controlled to be potential b, the metal ion T can generate a current with a current intensity of d, and can be reduced; while the current intensity of the metal ion B is extremely small, that is, it can hardly be reduced. In this way, the separation purpose can be achieved, and T and B can be measured separately.

[0052] In some embodiments, the reducing electrode is the cathode. In order to control the cathode potential, the external voltage needs to be adjusted at any time. The electrode material is selected from corrosion-resistant and highly reactive materials, and platinum metal is generally selected. Figure 3 Figure 1 is a schematic diagram of a potential-controlled circuit for electrolytic separation. Figure 3 In the process, 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 a potentiometer V, and the electrolysis current can be read from a milliammeter A. During the electrolysis process, the resistor r is continuously adjusted to keep the cathode potential constant.

[0053] In some embodiments, multiple metal ions adsorbed by a composite ion compound can be separated by electrochemical metal selective separation technology. For example, for a composite ion compound adsorbing multiple metal ions, the metal ions can be first dissolved with sulfuric acid or hydrochloric acid, and then the metals can be selectively reduced one by one by controlling the voltage according to the difference in the redox potential of each metal to achieve metal separation. For example, to separate nickel (Ni), manganese (Mn), cobalt (Co), and lithium (Li), the redox potentials of Ni, Mn, Co, and Li are shown in the following formulas.

[0054]

[0055]

[0056]

[0057]

[0058] The separation of these metals can be carried out according to the following steps.

[0059] In some embodiments, the voltage (E 0 ) is controlled to the range of -0.3V to -1.2V, and Ni and Co metals are deposited on the electrode surface.

[0060] In some embodiments, the voltage (E 0 ) is controlled to the range of -1.2V to -3V, and Mn metal is deposited on the electrode surface.

[0061] In some embodiments, the voltage (E 0 ) is controlled to the range of >-3V, and Li metal is deposited on the electrode surface.

[0062] Thus, by adjusting to different voltages (E 0 ) interval can achieve the effect of metal separation.

[0063] In summary, the adsorbent in the composite ionic compound of the present invention can form a chelating coordination with metal ions, and thus can be used for separation and extraction of metal ions, thereby facilitating the recovery of metal ions. Furthermore, since the composite ionic compound is magnetic and easy to separate, the method for recovering metal ions of the present invention can not only greatly simplify the recovery procedure of metal ions, but also reduce the recovery cost of metal ions.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A composite ionic compound, characterized in that include: Carrier; A bridging agent, grafted onto the carrier; as well as An adsorbent is grafted onto the bridging agent.

2. The composite ionic compound according to claim 1, characterized in that The carrier includes C:Na-Ni / Al2O3 composite powder.

3. The composite ionic compound according to claim 1, characterized in that The bridging agent includes a low molecular weight halogen-containing siloxane.

4. The composite ionic compound according to claim 1, characterized in that The adsorbent includes 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. A method for preparing a composite ionic compound, characterized in that: include: Grafting the bridging agent onto the carrier; as well as The adsorbent is grafted onto the bridging agent to form the composite ion compound.

6. The method for preparing the composite ionic compound according to claim 5, characterized in that: Also includes: forming the carrier, wherein forming the carrier comprises: placing Na-Ni / Al2O3 powder in a reactor; as well as Carbon dioxide and hydrogen are introduced into the reactor, wherein the temperature in the reactor is 400° C. to 800° C., so as to reduce the carbon dioxide to carbon, and allow the carbon to adsorb on Ni atoms in the Na-Ni / Al2O3 powder to form C:Na-Ni / Al2O3 composite powder.

7. The method for preparing a composite ionic compound according to claim 5, characterized in that: The bridging agent includes a low carbon number chlorinated siloxane as shown in the following formula (1): wherein R is each independently an alkyl group having 1 to 6 carbon atoms.

8. The method for preparing the composite ionic compound according to claim 7, characterized in that: The adsorbent is grafted onto the chlorine end of the bridging agent.

9. The method for preparing a composite ionic compound according to claim 5, characterized in that: The adsorbent includes 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. Use of a composite ionic compound for recovering metal ions, characterized in that: include: adding the composite ion compound as claimed in claim 1 to a recovery solution containing metal ions so that the composite ion compound adsorbs the metal ions; separating the composite ion compound adsorbing the metal ions; extracting the composite ion compound adsorbing the metal ions using a solvent to separate the metal ions from the composite ion compound and extracting the metal ions into the solvent; as well as The metal ions in the solvent are purified.

11. The use according to claim 10, characterized in that The recovery solution is a lithium ion battery recovery solution.

12. The use according to claim 10, characterized in that The metal ions include manganese ions, cobalt ions, nickel ions, lithium ions or a combination thereof.

13. The use according to claim 10, characterized in that The step of "separating the composite ion compound that adsorbs the metal ions" is performed by using a magnetic substance to attract the composite ion compound.

14. The use according to claim 10, characterized in that The solvent includes ethyl acetate or methanol.

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