Metal separation method

Abstract

In one embodiment there is provided a metal separation method that can efficiently separate and / or recover, from a metal-containing aqueous solution, a metal for which separation and / or recovery is desired.　In one embodiment, the present disclosure relates to a metal separation method for separating, or separating and recovering, a metal from a metal-containing aqueous solution, wherein the metal separation method comprises a step for bringing a metal-containing aqueous solution into contact with a metal separation agent containing a salt (component A) represented by formula (I), thiocyanic acid (component B), and a water-insoluble organic solvent (component C), and separating a metal from the aqueous phase into the organic phase. In formula (I), R1 is a C6-C22 hydrocarbon group which may have an ester group, an amide group, and / or an ether group; R2 and R3 are each independently a C6-C22 hydrocarbon group which may have an ester group, an amide group, and / or an ether group, or a C1-C4 alkyl group which may have a hydroxyl group; R4 is a C1-C6 alkyl group or a hydrogen atom; and X- is an anion.

Description

Metal separation method

[0001] The present disclosure relates to a metal separation method for separating or separating and recovering a metal from an aqueous solution containing the metal, a metal separator kit, a metal recovery method, a method for producing a lithium ion battery, and a metal separator.

[0002] Rare and precious metals are important metals due to their widespread use in commerce and industry. However, efficient recycling processes for these metals in industrial products must be developed to avoid the discharge of hazardous residues. Metal recovery from e-waste and natural resources is typically achieved through pyrometallurgical and hydrometallurgical processes. However, pyrometallurgical methods consume large amounts of energy and generate polluting gases during the process, which can be highly damaging to humans and the environment. Hydrometallurgical methods involve dissolving the desired metals through alkaline or acid leaching. After the leaching process, the resulting metal solution is subjected to further separation processes such as chemical precipitation, solvent extraction, and electrolytic deposition. Among these, solvent extraction is the most efficient and commonly used method. Solvent extraction uses a metal capture agent (metal separator) to capture the metals in aqueous solution. Nitrogen-containing compounds such as amine compounds are commonly used as metal capture agents.

[0003] For example, Japanese Patent Laid-Open Publication No. 2015-183282 (Patent Document 1) discloses a technique for extracting cobalt using a tertiary amine as an extractant and an aromatic hydrocarbon solvent as a diluent in order to separate and recover cobalt from a cobalt-containing aqueous nickel chloride solution in the production of metallic nickel and metallic cobalt by a hydrometallurgical process, and in the examples, tri-normal-octylamine is used as the tertiary amine.

[0004] Japanese Patent Laid-Open Publication No. 2015-168858 (Patent Document 2) discloses a solvent extraction method for extracting cobalt from an aqueous solution containing cobalt ions, in which the solubility of a quaternary ammonium ionic liquid in water is significantly reduced by mixing it with a certain organic solvent, and ions are extracted from the aqueous solution containing cobalt using the quaternary ammonium ionic liquid as an extractant. In the examples, trioctylmethylammonium chloride is used.

[0005] In one aspect, the present disclosure relates to a metal separation method for separating or separating and recovering a metal from an aqueous solution containing the metal, the metal separation method comprising a step of contacting an aqueous solution containing the metal with a metal separating agent comprising a salt represented by the following formula (I) (component A), thiocyanic acid (component B), and a water-insoluble organic solvent (component C), and separating the metal from the aqueous phase into an organic phase: In formula (I), R 1 is a hydrocarbon group having 6 to 22 carbon atoms which may have an ester group, an amide group, and / or an ether group, and R 2 and R 3 are each independently a hydrocarbon group having 6 to 22 carbon atoms which may have an ester group, an amide group and / or an ether group, or an alkyl group having 1 to 4 carbon atoms which may have a hydroxyl group, R 4 is an alkyl group having 1 to 6 carbon atoms or a hydrogen atom, and X - is an anion.

[0006] In one aspect, the present disclosure relates to a metal separating agent kit for separating or separating and recovering a metal from an aqueous solution containing the metal, the metal separating agent kit comprising a first agent containing a salt represented by the following formula (I) (component A) and a second agent containing thiocyanic acid (component B): In formula (I), R 1 is a hydrocarbon group having 6 to 22 carbon atoms which may have an ester group, an amide group, and / or an ether group, and R 2 and R 3are each independently a hydrocarbon group having 6 to 22 carbon atoms which may have an ester group, an amide group and / or an ether group, or an alkyl group having 1 to 4 carbon atoms which may have a hydroxyl group, R 4 is an alkyl group having 1 to 6 carbon atoms or a hydrogen atom, and X - is an anion.

[0007] In one aspect, the present disclosure relates to a metal recovery method for separating and recovering metals from an aqueous solution containing the metal, the method including the steps of contacting the aqueous solution containing the metal with an agent comprising the metal separating agent kit of the present disclosure to separate the metal from the aqueous phase into an organic phase, and recovering the metal from the organic phase.

[0008] In one aspect, the present disclosure relates to a method for manufacturing a lithium ion battery, comprising the steps of contacting an aqueous solution containing a metal with an agent comprising the metal separating agent kit of the present disclosure to separate the metal from the aqueous phase into an organic phase, recovering the metal from the organic phase, and manufacturing a battery using the metal recovered in the above step.

[0009] In one aspect, the present disclosure relates to a metal separating agent for separating or separating and recovering a metal from an aqueous solution containing the metal, the metal separating agent comprising a salt (component A) represented by the following formula (I) and thiocyanic acid (component B).In one aspect, the present disclosure relates to a metal separating agent for separating or separating and recovering a metal from an aqueous solution containing the metal, the metal separating agent comprising a salt (component A) represented by the following formula (I) and thiocyanic acid (component B). In formula (I), R 1 is a hydrocarbon group having 6 to 22 carbon atoms which may have an ester group, an amide group, and / or an ether group, and R 2 and R 3 are each independently a hydrocarbon group having 6 to 22 carbon atoms which may have an ester group, an amide group and / or an ether group, or an alkyl group having 1 to 4 carbon atoms which may have a hydroxyl group, R 4 is an alkyl group having 1 to 6 carbon atoms or a hydrogen atom, and X - is an anion.

[0010] In one aspect, the present disclosure relates to a metal separation method for separating a metal from an aqueous solution containing the metal, the metal separation method comprising the step of contacting the aqueous solution containing the metal with the metal separating agent of the present disclosure and separating the metal from the aqueous phase into an organic phase.

[0011] In one aspect, the present disclosure relates to a metal recovery method for separating and recovering metals from an aqueous solution containing the metals, the method including the steps of contacting the aqueous solution containing the metals with the metal separating agent of the present disclosure to separate the metals from the aqueous phase into an organic phase, and recovering the metals from the organic phase.

[0012] However, alkylammonium salts such as trioctylmethylammonium chloride tend to exhibit poor cobalt separation and recovery performance when the hydrochloric acid concentration is low or in the presence of sulfate ions. High-concentration hydrochloric acid also places a heavy burden on the environment and is difficult to dispose of. Furthermore, the change in separation and recovery performance depending on the type of acid present reduces the versatility of the extractant.

[0013] Therefore, the present disclosure provides a metal separation method that can efficiently separate and / or recover a metal that is to be separated and / or recovered from an aqueous solution containing the metal.

[0014] According to one aspect of the present disclosure, a metal separation method can be provided that can efficiently separate and / or recover a metal to be separated and / or recovered from an aqueous solution containing the metal.

[0015] [Metal Separation Method] The present disclosure is based on the finding that by using a metal separating agent containing a salt represented by the above formula (I) (component A), thiocyanic acid (component B), and a water-insoluble organic solvent (component C), or a metal separating agent containing a salt represented by the above formula (I) (component A) and thiocyanic acid (component B), it is possible to efficiently separate and / or recover a metal to be separated and / or recovered from an aqueous solution containing the metal.

[0016] That is, in one aspect, the present disclosure relates to a metal separation method for separating or separating and recovering a metal from an aqueous solution containing the metal, the metal separation method including a step (hereinafter also referred to as the "metal separation method of the present disclosure") of contacting the aqueous solution containing the metal with a metal separating agent (hereinafter also referred to as the "metal separating agent of the present disclosure") comprising a salt represented by formula (I) above (component A), thiocyanic acid (component B), and a water-insoluble organic solvent (component C) to separate the metal from the aqueous phase into an organic phase (hereinafter also referred to as the "contacting step"). According to the metal separation method of the present disclosure, in one or more embodiments, a metal separation method can be provided that can efficiently separate and / or recover a metal to be separated and / or recovered from an aqueous solution containing the metal. According to the metal separation method of the present disclosure, in one or more embodiments, a metal separation method that has excellent metal separation and recovery performance from an aqueous solution containing the metal can be provided.

[0017] In another aspect, the present disclosure relates to a metal separation method for separating a metal from an aqueous solution containing the metal, the metal separation method including a step (hereinafter also referred to as the "metal separation method of the present disclosure") of contacting the aqueous solution containing the metal with a metal separating agent (hereinafter also referred to as the "metal separating agent of the present disclosure") containing a salt represented by formula (I) (component A) and thiocyanic acid (component B) to separate the metal from the aqueous phase into an organic phase (hereinafter also referred to as the "contacting step"). The metal separation method of the present disclosure allows efficient separation of the desired metal from the aqueous solution containing the metal.

[0018] In one or more embodiments, the metal separation method of the present disclosure is excellent in cobalt recovery efficiency. Furthermore, in one or more embodiments, the metal separation method of the present disclosure is excellent in Co—Ni separation ability. That is, in one or more embodiments, the metal separation method of the present disclosure is a metal separation method for separating cobalt from an aqueous solution containing cobalt, or for separating and recovering cobalt. In one or more embodiments, the metal separation method of the present disclosure is a metal separation method for separating cobalt from an aqueous solution containing cobalt and nickel, or for separating and recovering cobalt.

[0019] Although the details of the mechanism of action by which the effects of the present disclosure are realized remain unclear, the following speculation is made. In an aqueous solution (aqueous phase), metal ions are stabilized by primarily receiving electrons from water molecules or other hydrophilic compounds. This stabilized structure is called a metal ion cluster. For metal ion clusters to migrate into oil (organic phase), greater stabilization is required. Because the salt represented by formula (I) (Component A) in the present disclosure is positively charged with a high charge density, electrostatic interactions occur with negatively charged metal ion clusters in the aqueous solution (aqueous phase), enabling the formation of more stable structures. Therefore, Component A in the present disclosure exhibits a certain degree of effectiveness as a metal separator in oil (organic phase). Furthermore, when used in combination with a thiocyanate (Component B), Component B forms complexes with each metal that have unique structures compared to common ligands. For example, it is said to form a linear bidentate complex with nickel and a tetrahedral tetradentate complex with cobalt. The difference in the structure of this thiocyanate complex creates differences in the reactivity of Component A with each metal, potentially enabling more accurate metal separation. In the present disclosure, the presence of component B in the oil (organic phase) traps metal ions in the oil (organic phase), and component A contributes to the stable presence of the metal ions and component B that have interacted in the oil (organic phase) in the oil (organic phase). It is believed that this allows for much more efficient extraction of specific metal ions than when using a salt represented by formula (I) (component A) or thiocyanic acid (component B) alone. The salt represented by formula (I) (component A) in the present disclosure may be an alkylammonium salt or amine salt having a polar group such as an ester group. When the alkylammonium salt or amine salt has a polar group, its electron-withdrawing properties may allow it to share electrons with the metal ion to form a more stable covalent bond. Since the rate of formation of this covalent bond differs for each type of metal ion, it is believed that selectivity is improved and negatively charged metal ion clusters can be separated. Therefore, when component A in the present disclosure has a polar group (specific alkylammonium salt or amine salt), it is believed that better metal separation and recovery capabilities can be provided. However, the present disclosure does not need to be interpreted as being limited to the above mechanism.

[0020] <Metal-Containing Aqueous Solution> In one or more embodiments, the "metal-containing aqueous solution" in the present disclosure may be obtained by treating electronic waste. In one or more embodiments, the electronic waste may be waste from electronic components of lithium-ion batteries. In one or more embodiments, the metal-containing aqueous solution may be an aqueous solution (leachate) obtained by treating waste electronic components with acid. The "metal-containing aqueous solution" obtained from electronic waste can be obtained, for example, by separating the positive electrode components of lithium-ion batteries into iron-based metals, plastics, electrode powder black matrix (BM), etc. by crushing or heat treatment, and then dissolving the electrode powder black matrix in a sulfuric acid or hydrochloric acid solution to form an acidic aqueous solution. The electrode powder black matrix contains, for example, lithium (Li), cobalt (Co), nickel (Ni), manganese (Mn), etc. In one or more embodiments, the metal-containing aqueous solution may be a cobalt-containing aqueous solution or a cobalt and nickel-containing aqueous solution. In the present disclosure, the metal-containing aqueous solution may be, for example, a leachate obtained by leaching battery sludge containing a positive electrode active material of a lithium-ion battery with an acidic aqueous solution.

[0021] <Contacting Step> In one or more embodiments, the contacting step is a step of separating metals from an aqueous phase by contacting an aqueous metal-containing aqueous solution with the organic phase of the metal separating agent of the present disclosure and distributing (extracting) the metal to be separated into the organic phase. The organic phase in the above step may be contained in an oil-continuous or bicontinuous emulsion system. In one or more embodiments, the metal separating agent of the present disclosure containing an organic phase contains a water-insoluble organic solvent (component C) described below. The operating procedure for the contacting step is not particularly limited, and known operating procedures used in liquid-phase extraction methods can be appropriately selected. For example, the aqueous metal-containing aqueous solution and the metal separating agent of the present disclosure containing an organic phase can be placed in a container, and the aqueous and organic phases can be thoroughly mixed using a shaker or the like, followed by phase separation by centrifugation. Alternatively, known extracting devices or extraction tools such as a countercurrent extractor or a separatory funnel can be used instead of the container.

[0022] The pH of the metal-containing aqueous solution is not particularly limited and can be appropriately selected depending on the type and purpose of the metal to be separated and / or recovered. In one or more embodiments, the pH of the metal-containing aqueous solution is usually 6.0 or less, preferably 5.5 or less, and more preferably 5.0 or less or 5 or less. For example, when the metal to be separated and / or recovered is cobalt (Co), the pH of the metal-containing aqueous solution is preferably 7.0 or less or 7 or less, and more preferably 4.0 or less or 4 or less. In the present disclosure, the pH of the aqueous solution is a value at 25°C and can be measured using a pH meter, specifically, by the method described in the Examples.

[0023] In the contacting step, the time for which the aqueous phase and the organic phase are brought into contact with each other is not particularly limited and can be appropriately selected depending on the purpose. The time for the contacting is, for example, 1 to 10 minutes.

[0024] In the contact step, the temperature at which the aqueous phase and the organic phase are brought into contact is not particularly limited, but from the viewpoint of the solubility of the metal separating agent, it is preferably 0° C. or higher, more preferably 10° C. or higher, and even more preferably 20° C. or higher, and from the viewpoint of handleability, it is preferably 100° C. or lower, more preferably 75° C. or lower, and even more preferably 50° C. or lower. More specifically, the temperature in the contact step is preferably 0° C. or higher and 100° C. or lower, more preferably 10° C. or higher and 75° C. or lower, and even more preferably 20° C. or higher and 50° C. or lower.

[0025] In one or more embodiments, the metal separating agent of the present disclosure that is brought into contact with the aqueous phase in the contacting step includes an organic phase, which is derived from the water-insoluble organic solvent (component C) of the metal separating agent of the present disclosure.

[0026] In the contacting step, the volume ratio of the aqueous phase to the organic phase to be contacted (aqueous phase volume / organic phase volume) is not particularly limited and can be appropriately selected depending on the purpose. It is usually 1 or more, and preferably 1 to 10.

[0027] The amount (mol%) of the salt represented by the formula (I) (component A) in the metal separating agent of the present disclosure to be contacted with the aqueous phase in the contact step is, from the viewpoint of the separability of the metal to be separated, preferably 100 mol% or more, more preferably 500 mol% or more, even more preferably 1000 mol% or more, and preferably 10000 mol% or less, more preferably 5000 mol% or less, and even more preferably 2500 mol% or less, relative to the concentration of the metal in the aqueous solution containing the metal, from the viewpoint of the separability of the metal to be separated. More specifically, the amount (mol%) of the salt represented by the formula (I) (component A) in the metal separating agent of the present disclosure is preferably 100 mol% or more and 10000 mol% or less, more preferably 500 mol% or more and 5000 mol% or less, and even more preferably 1000 mol% or more and 2500 mol% or less, relative to the concentration of the metal in the aqueous solution containing the metal, from the viewpoint of the separability of the metal to be separated.

[0028] The amount of thiocyanate (component B) in the metal separating agent of the present disclosure to be contacted with the aqueous phase in the contact step is, from the viewpoint of the separability of the metal to be separated, preferably 100 mol% or more, more preferably 500 mol% or more, even more preferably 1000 mol% or more, and preferably 20,000 mol% or less, more preferably 10,000 mol% or less, and even more preferably 5,000 mol% or less, relative to the metal concentration (100 mol%) in the aqueous solution containing the metal. More specifically, the amount of thiocyanate (component B) in the metal separating agent of the present disclosure is preferably 100 mol% or more and 20,000 mol% or less, more preferably 500 mol% or more and 10,000 mol% or less, and even more preferably 1,000 mol% or more and 5,000 mol% or less, relative to the metal concentration (100 mol%) in the aqueous solution containing the metal.

[0029] The amount of the water-insoluble organic solvent (component C) in the metal separating agent of the present disclosure that is contacted with the aqueous phase in the contact step is, from the viewpoint of recovery efficiency of the metal to be recovered, preferably 1000 mol% or more, more preferably 5000 mol% or more, even more preferably 10,000 mol% or more, and preferably 100,000 mol% or less, more preferably 50,000 mol% or less, and even more preferably 25,000 mol% or less, relative to the metal concentration (100 mol%) in the aqueous solution containing the metal. More specifically, the amount of the water-insoluble organic solvent (component C) in the metal separating agent of the present disclosure is preferably 1000 mol% or more and 100,000 mol% or less, more preferably 5000 mol% or more and 50,000 mol% or less, and even more preferably 10,000 mol% or more and 25,000 mol% or less, relative to the metal concentration (100 mol%) in the aqueous solution containing the metal.

[0030] [Metal Separating Agent] In one aspect, the present disclosure relates to a metal separating agent for separating or separating and recovering a metal from an aqueous solution containing the metal, the metal separating agent comprising a salt represented by formula (I) above (component A) and thiocyanic acid (component B) (hereinafter also referred to as the “metal separating agent of the present disclosure”).

[0031] According to one or more embodiments of the present disclosure, a metal separating agent capable of efficiently separating and / or recovering a metal to be separated and / or recovered from an aqueous solution containing the metal can be provided. According to one or more embodiments of the present disclosure, a metal separating agent having excellent performance for separating and recovering metals from an aqueous solution containing the metal can be provided.

[0032] In one or more embodiments, the metal separating agent of the present disclosure is used to separate or separate and recover metals from an aqueous solution containing the metal. In one or more embodiments, the metal to be separated and / or recovered includes a catalytic metal for lithium ion batteries and the like. Examples of catalytic metals include fourth period metals, such as at least one metal selected from cobalt, nickel, and manganese. The metal in the aqueous solution is preferably in an ionic state. In particular, in one or more embodiments, the metal separating agent of the present disclosure has excellent cobalt recovery efficiency. Furthermore, in one or more other embodiments, the metal separating agent of the present disclosure has excellent Co—Ni separation ability. That is, in one or more embodiments, the metal separating agent of the present disclosure is a metal separating agent for separating or separating and recovering cobalt from an aqueous solution containing cobalt. In one or more embodiments, the metal separating agent of the present disclosure is a metal separating agent for separating or separating and recovering cobalt from an aqueous solution containing cobalt and nickel.

[0033] <Component A: Salt Represented by Formula (I)> The metal separating agent of the present disclosure contains a salt represented by the following formula (I) (hereinafter also referred to as "Component A"). 4 When R is an alkyl group having 1 to 6 carbon atoms, component A is a quaternary ammonium salt. 4 is a hydrogen atom, Component A is a tertiary amine salt. That is, Component A is a salt represented by formula (I) and includes a quaternary ammonium salt and a tertiary amine salt. Component A may be one type or a combination of two or more types.

[0034] In formula (I), R 1 is a hydrocarbon group having 6 to 22 carbon atoms which may have an ester group, an amide group, and / or an ether group, and R 2 and R 3 are each independently a hydrocarbon group having 6 to 22 carbon atoms which may have an ester group, an amide group and / or an ether group, or an alkyl group having 1 to 4 carbon atoms which may have a hydroxyl group, R 4 is an alkyl group having 1 to 6 carbon atoms or a hydrogen atom, and X- is an anion.

[0035] In the above formula (I), R 1 , R 2 and R 3 are each independently a hydrocarbon group having 6 to 22 carbon atoms which may have an ester group, an amide group, and / or an ether group, and R 1 , R 2 and R 3 The hydrocarbon group in R is a hydrocarbon group having 6 to 22 carbon atoms, preferably a hydrocarbon group having 8 to 18 carbon atoms, and more preferably a hydrocarbon group having 8 to 16 carbon atoms, from the viewpoint of the separability of the metal to be separated. The hydrocarbon group may be a straight chain or a branched chain, but preferably has a branched chain from the viewpoint of suppressing foaming when contacted with an aqueous solution. The hydrocarbon group may be a saturated chain or an unsaturated chain, but preferably has an unsaturated chain from the viewpoint of suppressing foaming when contacted with an aqueous solution. 1 , R 2 and R 3 From the viewpoint of the separability of the separated metals, at least one of R preferably has an ester group, an amide group and / or an ether group, more preferably has an ester group or an ether group, and even more preferably has an ester group. 1 , R 2 and R 3 In one or more embodiments, when the hydrocarbon group having 6 to 22 carbon atoms in 5 -X-R 6 and R 5 is an alkylene group having 1 to 4 carbon atoms, X is —O—C(═O)—, —NH—C(═O)—, or an oxygen atom, and from the viewpoint of the separation property of the metal to be separated, R 6 R is a hydrocarbon group having 6 to 18 carbon atoms. 5 The number of carbon atoms in R is preferably 1 or 2 from the viewpoint of the separation of the metal to be separated. 6 The number of carbon atoms in R is preferably 6 or more and 18 or less from the viewpoint of the separation of the metal to be separated. 6The hydrocarbon group may be saturated or unsaturated, but in one or more embodiments, it is preferable that it has an unsaturated chain from the viewpoint of suppressing foaming when contacted with an aqueous solution, and in one or more embodiments, X is preferably —O—C(═O)— from the viewpoint of the separability of the metal to be separated. 2 and R 3 In terms of the separation property of the metal to be separated, the alkyl group having 1 to 4 carbon atoms and optionally having a hydroxyl group in R is preferably an alkyl group having 1 to 3 carbon atoms and optionally having a hydroxyl group, more preferably an alkyl group having 1 or 2 carbon atoms and optionally having a hydroxyl group, and even more preferably a hydroxyethyl group. 4 From the viewpoint of the separation property of the metal to be separated, the alkyl group of X is an alkyl group having 1 to 6 carbon atoms or a hydrogen atom, preferably an alkyl group having 1 to 6 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms, even more preferably an alkyl group having 1 to 2 carbon atoms, and even more preferably a methyl group. - is a counter ion, and examples thereof include alkyl sulfate ions having 1 to 3 carbon atoms, sulfate ions, phosphate ions, carboxylate ions having 1 to 3 carbon atoms (formate ions, acetate ions, propionate ions), and halide ions. Among these, from the viewpoint of ease of production and availability of raw materials, X - is preferably at least one selected from the group consisting of methyl sulfate ion, ethyl sulfate ion, chloride ion, and bromide ion, and more preferably methyl sulfate ion. - may be one type alone or two or more types.

[0036] In one or more embodiments, component A is R 1 , R 2 and R 3 In one or more embodiments, Component A1 is a compound in which at least one of R in Formula (I) has an ester group having 6 to 22 carbon atoms (hereinafter also referred to as "Component A1"). 1 , R 2 and R 3 a compound in which at least two of R in formula (I) have an ester group having 6 to 22 carbon atoms; 1 , R2 and R 3 In one or more embodiments, component A1 is a compound having an ester group having 6 to 22 carbon atoms. 1 , R 2 and R 3 are hydrocarbon groups each having 6 to 22 carbon atoms and each having an ester group, 1 and R 2 are hydrocarbon groups each having 6 to 22 carbon atoms and each having an ester group, and R 3 is an alkyl group having 1 to 4 carbon atoms which may have a hydroxyl group, and examples thereof include methyltris-[ethyl 2-ethylhexyl]-ammonium salt and (2-hydroxyethyl)-methylbis-[ethyl 2-oleate]-ammonium salt. Counter ions of these salts include, for example, methyl sulfate ion, ethyl sulfate ion, chloride ion, bromide ion, and the like. Examples of component A1 include methyltris-[ethyl 2-ethylhexyl]-ammonium methyl sulfate and (2-hydroxyethyl)-methylbis-[ethyl 2-oleate]-ammonium methyl sulfate. The number of carbon atoms in the ester group and the hydrocarbon group interrupted by a nitrogen atom is not particularly limited, and examples thereof include 0 or more and 4 or less. In one or more embodiments, component A is a compound represented by the formula (I) 1 , R 2 and R 3 In one or more embodiments, Component A2 is a compound in which at least one of R in Formula (I) has an ether group having 6 to 22 carbon atoms (hereinafter also referred to as "Component A2"). 1 , R 2 and R 3is a hydrocarbon group having 6 to 22 carbon atoms and having an ether group, and examples thereof include tris[2-hexoxyethyl]-hexyl-ammonium salt. Counter ions of these salts include, for example, methyl sulfate ion, ethyl sulfate ion, chloride ion, bromide ion, and the like. Component A2 includes, for example, tris[2-hexoxyethyl]-hexyl-ammonium hydrochloride. The number of carbon atoms in the ether group and the hydrocarbon group interrupted by a nitrogen atom is not particularly limited, and examples thereof include 0 or more and 4 or less. In one or more embodiments, component A is a compound represented by the formula (I) 1 , R 2 and R 3 In one or more embodiments, Component A3 is a compound in which at least one of R in Formula (I) has an amide group having 6 to 22 carbon atoms (hereinafter also referred to as "Component A3"). 1 , R 2 and R 3 are hydrocarbon groups having 6 to 22 carbon atoms and each having an amide group, such as tris[2-(oleamido)ethyl]-methyl-ammonium methyl salt. Counter ions of these salts include, for example, methyl sulfate ion, ethyl sulfate ion, chloride ion, bromide ion, etc. Component A3 includes, for example, tris[2-(oleamido)ethyl]-methyl-ammonium methyl sulfate. The number of carbon atoms in the amide group and the hydrocarbon group interrupted by a nitrogen atom is not particularly limited, but may be 0 or more or 4 or less.

[0037] From the viewpoint of the separation property of the metal to be separated, Component A is preferably at least one selected from Component A1, Component A2, and Component A3, more preferably at least one selected from Component A1 and Component A2, and even more preferably Component A1. From the same viewpoint, Component A is preferably at least one selected from methyl tris-[ethyl 2-ethylhexylate]-ammonium salt, (2-hydroxyethyl)-methylbis-[ethyl 2-oleate]-ammonium salt, tris[2-hexoxyethyl]-hexyl-ammonium salt, and tris[2-(oleamido)ethyl]-methyl-ammonium methyl salt, and more preferably at least one selected from methyl tris-[ethyl 2-ethylhexylate]-ammonium salt, (2-hydroxyethyl)-methylbis-[ethyl 2-oleate]-ammonium salt, tris[2-hexoxyethyl]-hexyl-ammonium salt, and tris[2-(oleamido)ethyl]-methyl-ammonium methyl salt. At least one selected from methyltris-[ethyl 2-ethylhexyl]-ammonium salt and tris[2-hexoxyethyl]-hexyl-ammonium salt is more preferred, at least one selected from methyltris-[ethyl 2-ethylhexyl]-ammonium salt and (2-hydroxyethyl)-methylbis-[ethyl 2-oleate]-ammonium salt is even more preferred, methyltris-[ethyl 2-ethylhexyl]-ammonium salt is even more preferred, and methyltris-[ethyl 2-ethylhexyl]-ammonium methyl sulfate is even more preferred.

[0038] From the viewpoint of the separability of the metal to be separated, the amount (mass%) of component A in the metal separating agent of the present disclosure is preferably 1.0 mass% or more or 1 mass% or more, more preferably 5.0 mass% or more or 5 mass% or more, even more preferably 10.0 mass% or more or 10 mass% or more, and preferably 50 mass% or less, more preferably 40 mass% or less, and even more preferably 30 mass% or less. More specifically, the amount (mass%) of component A in the metal separating agent of the present disclosure is preferably 1.0 mass% or more and 50 mass% or less, or 1 mass% or more and 50 mass% or less, more preferably 5.0 mass% or more and 40 mass% or less, or 5 mass% or more and 40 mass% or less, and even more preferably 10.0 mass% or more and 30 mass% or less, or 10 mass% or more and 30 mass% or less. When component A is a combination of two or more types, the amount of component A refers to the total amount thereof.

[0039] In one or more embodiments, the metal separating agent of the present disclosure is a composition containing component A and component B.

[0040] <Thiocyanate (Component B)> In one or more embodiments, the metal separating agent of the present disclosure is composed of or contains a blend of component A and a thiocyanate (hereinafter also referred to as "component B") from the viewpoint of the separability of the metal to be separated. That is, in one or more embodiments, the metal separating agent of the present disclosure is composed of a blend of component A and a thiocyanate (component B). In one or more embodiments, component A and component B are present in a miscible state in the metal separating agent of the present disclosure. In the present disclosure, "combined" means that not only component A and thiocyanate (component B) but also optional components can be further blended as necessary. In the present disclosure, the blend amount of each component in the metal separating agent can be interpreted as the content of each component in the metal separating agent.

[0041] From the viewpoint of the separability of the metal to be separated, examples of component B include ammonium thiocyanate and sodium thiocyanate. Component B may be one type or a combination of two or more types.

[0042] From the viewpoint of the separability of the metal to be separated, the blending amount (mass%) of component B in the metal separating agent of the present disclosure is preferably 0.1 mass% or more, more preferably 0.5 mass% or more, even more preferably 1.0 mass% or more, and preferably 40 mass% or less, more preferably 20 mass% or less, and even more preferably 10 mass% or less. More specifically, the blending amount (mass%) of component B in the metal separating agent of the present disclosure is preferably 0.1 mass% or more and 40 mass% or less, more preferably 0.5 mass% or more and 20 mass% or less, and even more preferably 0.5 mass% or more and 10 mass% or less, or 1.0 mass% or more and 10 mass% or less. When component B is a combination of two or more types, the blending amount of component B refers to the total blending amount thereof.

[0043] The mass ratio A / B of component A to component B in the metal separating agent of the present disclosure (amount of component A blended / amount of component B blended) is preferably 0.01 or more, more preferably 0.1 or more, and even more preferably 1.0 or more, from the viewpoint of the separability of the metal to be separated, and from the same viewpoint, is preferably 50 or less, 40 or less, or 20 or less, more preferably 10 or less, and even more preferably 5.0 or less. More specifically, the mass ratio A / B (amount of component A blended / amount of component B blended) is preferably 0.01 or more and 50 or less, 0.01 or more and 30 or less, or 0.01 or more and 20 or less, more preferably 0.1 or more and 10 or less, and even more preferably 1.0 or more and 5.0 or less.

[0044] <Water-insoluble organic solvent (component C)> In one or more embodiments, the metal separating agent of the present disclosure is a blend of or contains component A, a thiocyanate (component B), and a water-insoluble organic solvent (component C).

[0045] In the present disclosure, the term "water-insoluble organic solvent" refers to a solvent having a solubility of 0.01 g or less in 100 g of water at 25°C. Examples of water-insoluble organic solvents (component C) include petroleum-based solvents such as kerosene; aliphatic hydrocarbon-based solvents such as hexane, isooctane, and dodecane; aromatic hydrocarbon-based solvents such as benzene, toluene, and xylene; halogenated solvents such as chloroform and dichloromethane; higher alcohol-based solvents such as dodecyl alcohol and octanol; and higher fatty acid-based solvents such as oleic acid. Among these, petroleum-based solvents such as kerosene are preferred from the viewpoint of the recovery efficiency of the metals to be recovered. Component C may be one type or a combination of two or more types (mixed solvent). In the present disclosure, the phase derived from component C when the metal separating agent of the present disclosure is mixed with an aqueous solution may be referred to as the "organic phase."

[0046] When the metal separating agent of the present disclosure contains component C, the blending amount (mass%) of component C in the metal separating agent of the present disclosure is, from the viewpoint of the recovery efficiency of the metal to be recovered, preferably 50 mass% or more, more preferably 60 mass% or more, even more preferably 70 mass% or more, and preferably 99.9 mass% or less, more preferably 99 mass% or less, and even more preferably 95 mass% or less. More specifically, the blending amount (mass%) of component C in the metal separating agent of the present disclosure is preferably 50 mass% or more and 99.9 mass% or less, more preferably 60 mass% or more and 99 mass% or less, and even more preferably 70 mass% or more and 95 mass% or less. When component C is a combination of two or more types, the blending amount of component C refers to the total blending amount thereof.

[0047] When the metal separating agent of the present disclosure contains component C, the mass ratio A / C of component A to component C in the metal separating agent of the present disclosure (amount of component A blended / amount of component C blended) is, from the viewpoint of the recovery efficiency of the metal to be recovered, preferably 0.01 or more, more preferably 0.05 or more, and even more preferably 0.1 or more, and from the same viewpoint, preferably 10 or less, more preferably 5.0 or less or 5 or less, and even more preferably 1.0 or less or 1 or less. More specifically, the mass ratio A / C (amount of component A blended / amount of component C blended) is preferably 0.01 or more and 10 or less, more preferably 0.05 or more and 5.0 or 0.05 or more and 5 or less, and even more preferably 0.1 or more and 1.0 or 0.1 or more and 1 or less.

[0048] When the metal separating agent of the present disclosure contains component C, the mass ratio B / C of component B to component C in the metal separating agent of the present disclosure (compound amount of component B / compound amount of component C) is, from the viewpoint of the recovery efficiency of the metal to be recovered, preferably 0.001 or more, more preferably 0.01 or more, and even more preferably 0.05 or more, and from the same viewpoint, is preferably 10 or less, more preferably 5 or less, and even more preferably 1 or less. More specifically, the mass ratio B / C (compound amount of component B / component C) is preferably 0.001 or more and 10 or less, more preferably 0.01 or more and 5 or less, and even more preferably 0.01 or more and 1 or less.

[0049] <Other Components> The metal separating agent of the present disclosure may contain other components as needed, as long as the effects of the present disclosure are not impaired. Examples of other components include an antifoaming agent and a demulsifier.

[0050] [Metal Separator Kit] In one aspect, the present disclosure relates to a metal separator kit for separating or separating and recovering metals from an aqueous solution containing the metals, the metal separator kit including a first agent including component A and a second agent including component B (hereinafter also referred to as the "metal separator kit of the present disclosure"). In one or more embodiments, the first agent and the second agent are mixed at the time of use. The first agent and the second agent may each contain the above-mentioned optional components (component C, other components) as necessary. In one or more embodiments, an agent obtained by blending the metal separator kit of the present disclosure, i.e., an agent obtained by mixing the first agent and the second agent, is the metal separator of the present disclosure. In one or more embodiments, the metal separator kit of the present disclosure is a kit for producing the metal separator of the present disclosure. In one or more embodiments, the metal separator kit of the present disclosure is a metal separator kit for separating or separating and recovering cobalt. In one or more embodiments, the metal separator kit of the present disclosure is a metal separator kit for separating or separating and recovering cobalt from an aqueous solution containing cobalt and nickel.

[0051] [Metal Recovery Method] In one aspect, the present disclosure relates to a metal recovery method for separating and recovering a metal from an aqueous solution containing the metal, the metal recovery method including a step of contacting the aqueous solution containing the metal with a metal separating agent of the present disclosure or an agent containing the metal separating agent kit of the present disclosure to separate the metal from the aqueous phase into an organic phase (hereinafter also referred to as the "contacting step"), and a step of recovering the metal from the organic phase (hereinafter also referred to as the "recovery step"). According to the metal recovery method of the present disclosure, it is possible to efficiently separate and recover a metal to be separated and recovered from an aqueous solution containing the metal (aqueous phase). Furthermore, in one or more embodiments, the metal recovery method of the present disclosure has excellent cobalt recovery efficiency. Furthermore, in one or more embodiments, the metal recovery method of the present disclosure has excellent Co—Ni separation ability. That is, in one or more embodiments, the metal recovery method of the present disclosure is a metal recovery method for separating and recovering cobalt from an aqueous solution containing cobalt. In one or more embodiments, the metal recovery method of the present disclosure is a metal recovery method for separating and recovering cobalt from an aqueous solution containing cobalt and nickel.

[0052] <Contacting Step> The contacting method and contacting conditions in the contacting step of the metal recovery method of the present disclosure may be the same as the contacting method and contacting conditions in the metal separation method of the present disclosure described above.

[0053] <Recovery Step> In the recovery step, examples of a method for recovering the metal separated (distributed, extracted) in the organic phase include crystallization and electrolysis.

[0054] <Liquid Separation Step and Stripping Step> In one or more embodiments, the metal separation method and metal recovery method of the present disclosure may further include the following liquid separation step (1) and stripping step (2): (1) a liquid separation step in which the aqueous phase contacted in the contacting step is separated from the organic phase; (2) a stripping step in which an aqueous phase other than the aqueous phase separated in the liquid separation step is contacted with the organic phase separated in the liquid separation step to perform stripping; The aqueous solution other than the aqueous solution separated in the liquid separation step (1) is not particularly limited as long as it can be used for stripping, but is preferably an acidic aqueous solution or an aqueous solution containing a complexing agent such as ethylenediaminetetraacetic acid (EDTA) or thiourea. In the case of an acidic aqueous solution, its pH is preferably adjusted to be lower than the pH of the aqueous solution used in the contacting step. In addition, the acid used is not particularly limited, but examples thereof include inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, phosphorous acid, and hypophosphorous acid.

[0055] <Preparation Step> In one or more embodiments, the metal separation method and metal recovery method of the present disclosure may further include a step of preparing a metal-containing aqueous solution (hereinafter also referred to as a "preparation step"). The preparation method is not particularly limited, and a metal-containing aqueous solution may be obtained, or the metal-containing aqueous solution may be prepared by the user. The metal-containing aqueous solution may be any solution containing the metal to be separated and / or recovered. Typically, the aqueous solution is prepared under conditions that allow the separation (extraction) of the metal to be separated and / or recovered (when the aqueous solution contains metals other than the metal to be separated and / or recovered, the conditions are such that the extraction rate of the metal to be separated and / or recovered differs from the extraction rate of the metals other than the metal to be separated and / or recovered). Preferably, the aqueous solution is prepared as an acidic aqueous solution. Examples of metal-containing aqueous solutions include those obtained by processing the electronic waste described above. When preparing an acidic aqueous solution containing the metal to be separated and / or recovered by the user, the preparation method is not particularly limited, and an acid may be added to the aqueous solution containing the metal to be separated and / or recovered (to adjust the pH), or the aqueous solution may be prepared as an acidic aqueous solution to dissolve the metal to be separated and / or recovered. The acid used to prepare the acidic aqueous solution may be, for example, an inorganic acid such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, phosphorous acid, or hypophosphorous acid.

[0056] [Method for Manufacturing Lithium-Ion Battery] In one aspect, the present disclosure relates to a method for manufacturing a lithium-ion battery (hereinafter also referred to as the "lithium-ion battery manufacturing method of the present disclosure"), including the steps of contacting an aqueous solution containing a metal with an agent containing the metal separator kit of the present disclosure to separate the metal from the aqueous phase to an organic phase (hereinafter also referred to as the "contacting step"), recovering the metal from the organic phase (hereinafter also referred to as the "recovery step"), and manufacturing a battery using the metal recovered in the contacting step. The contacting method and contacting conditions in the contacting step of the lithium-ion battery manufacturing method of the present disclosure may be the same as the contacting method and contacting conditions in the metal separation method of the present disclosure described above. The recovery method in the recovery step of the lithium-ion battery manufacturing method of the present disclosure may be the same as the recovery method in the metal recovery method of the present disclosure described above. In one or more embodiments, the lithium-ion battery manufacturing method of the present disclosure may further include the separation step (1) and the back-extraction step (2) described above. In one or more embodiments, the lithium-ion battery manufacturing method of the present disclosure may further include the preparation step described above.

[0057] In one or more embodiments, the present disclosure further relates to the following metal separation method, metal separating agent kit, metal separating agent, and metal recovery method. <1> A metal separation method for separating a metal from an aqueous solution containing the metal, or for separating and recovering the metal, comprising the step of contacting the aqueous solution containing the metal with a metal separating agent containing a salt represented by the following formula (I) (component A), thiocyanic acid (component B), and a water-insoluble organic solvent (component C), and separating the metal from the aqueous phase into an organic phase. In formula (I), R 1 is a hydrocarbon group having 6 to 22 carbon atoms which may have an ester group, an amide group, and / or an ether group, and R 2 and R 3 are each independently a hydrocarbon group having 6 to 22 carbon atoms which may have an ester group, an amide group and / or an ether group, or an alkyl group having 1 to 4 carbon atoms which may have a hydroxyl group, R 4 is an alkyl group having 1 to 6 carbon atoms or a hydrogen atom, and X - is an anion. <2> Component A is a compound represented by R1 , R 2 and R 3 The metal separation method according to <1>, wherein at least one of the following is a compound having an ester group having 6 to 22 carbon atoms: 1 , R 2 and R 3 The metal separation method according to <1>, wherein at least two of the compounds are compounds having an ester group having 6 to 22 carbon atoms. <4> Component A is a compound represented by the formula (I) 1 , R 2 and R 3 is a compound having an ester group having 6 to 22 carbon atoms. 4is a methyl group. <6> The metal separation method according to any one of <1> to <5>, wherein the mass ratio A / B of component A to component B in the metal separating agent is 0.01 or more and 50 or less. <7> The metal separation method according to any one of <1> to <5>, wherein the mass ratio A / B of component A to component B in the metal separating agent is 0.01 or more and 30 or less, or 0.01 or more and 20 or less, or 0.1 or more and 10 or less, or 1.0 or more and 5.0 or less. <8> The metal separation method according to any one of <1> to <7>, wherein the content of component A in the metal separating agent is 1% by mass or more and 50% by mass or less. <9> The metal separation method according to any one of <1> to <7>, wherein the content of component A in the metal separating agent is 5.0% by mass or more and 40% by mass or less, or 5% by mass or more and 40% by mass or less, or 10% by mass or more and 30% by mass or less. <10> The metal separation method according to any one of <1> to <9>, wherein the content of component B in the metal separating agent is 0.5% by mass or more and 10% by mass or less. <11> The metal separation method according to any one of <1> to <9>, wherein the content of component B in the metal separating agent is 0.1% by mass or more and 40% by mass or less, or 0.5% by mass or more and 20% by mass or less, or 0.5% by mass or more and 10% by mass or less, or 1.0% by mass or more and 10% by mass or less. <12> The metal separation method according to any one of <1> to <11>, which is a metal separation method for separating, or separating and recovering, cobalt. <13> The metal separation method according to any one of <1> to <12>, which is a metal separation method for separating, or separating and recovering, cobalt from an aqueous solution containing cobalt and nickel. <14> A metal separating agent kit for separating a metal from an aqueous solution containing the metal, or for separating and recovering the metal, the metal separating agent kit comprising: a first agent containing a salt represented by the following formula (I) (component A); and a second agent containing thiocyanic acid (component B). In formula (I), R 1 is a hydrocarbon group having 6 to 22 carbon atoms which may have an ester group, an amide group, and / or an ether group, and R 2 and R 3are each independently a hydrocarbon group having 6 to 22 carbon atoms which may have an ester group, an amide group and / or an ether group, or an alkyl group having 1 to 4 carbon atoms which may have a hydroxyl group, R 4 is an alkyl group having 1 to 6 carbon atoms or a hydrogen atom, and X - is an anion. <15> Component A is a compound represented by R 1 , R 2 and R 3 <16> The metal separating agent kit according to <14>, wherein at least one of the following is a compound having an ester group having 6 to 22 carbon atoms: 1 , R 2 and R 3 The metal separating agent kit according to <14>, wherein at least two of the R 1 , R 2 and R 3 is a compound having an ester group having 6 to 22 carbon atoms. 4is a methyl group. <19> The metal separating agent kit according to any one of <14> to <18>, wherein the mass ratio A / B of component A to component B in the metal separating agent is 0.01 to 50, or 0.01 to 30, or 0.01 to 20, or 0.1 to 10, or 1.0 to 5.0. <20> The metal separating agent kit according to any one of <14> to <19>, wherein the content of component A in the metal separating agent is 1.0% by mass to 50% by mass, or 1% by mass to 50% by mass, or 5.0% by mass to 40% by mass, or 5% by mass to 40% by mass, or 10% by mass to 30% by mass. <21> The metal separating agent kit according to any one of <14> to <20>, wherein the content of component B in the metal separating agent is 0.1% by mass or more and 40% by mass or less, or 0.5% by mass or more and 20% by mass or less, or 0.5% by mass or more and 10% by mass or less, or 1.0% by mass or more and 10% by mass or less. <22> The metal separating agent kit according to any one of <14> to <21>, which is a metal separating agent kit for separating or separating and recovering cobalt. <23> The metal separating agent kit according to any one of <14> to <22>, which is a metal separating agent kit for separating or separating and recovering cobalt from an aqueous solution containing cobalt and nickel. <24> A metal recovery method for separating and recovering a metal from a metal-containing aqueous solution, comprising the steps of: contacting the metal-containing aqueous solution with an agent comprising the metal separating agent kit according to any one of <14> to <23> to separate the metal from the aqueous phase into an organic phase; and recovering the metal from the organic phase. <25> A method for producing a lithium ion battery, comprising the steps of contacting the metal-containing aqueous solution with an agent comprising the metal separating agent kit according to any one of <14> to <23> to separate the metal from the aqueous phase into an organic phase, recovering the metal from the organic phase, and manufacturing a battery using the metal recovered in the steps. <26> A metal separating agent for separating, or separating and recovering, a metal from a metal-containing aqueous solution, comprising a salt represented by the following formula (I) (component A) and thiocyanic acid (component B): In formula (I), R 1is a hydrocarbon group having 6 to 22 carbon atoms which may have an ester group, an amide group, and / or an ether group, and R 2 and R 3 are each independently a hydrocarbon group having 6 to 22 carbon atoms which may have an ester group, an amide group and / or an ether group, or an alkyl group having 1 to 4 carbon atoms which may have a hydroxyl group, R 4 is an alkyl group having 1 to 6 carbon atoms or a hydrogen atom, and X - <27> A metal separating agent for separating a metal from an aqueous solution containing the metal, or for separating and recovering the metal, the metal separating agent comprising a salt represented by the following formula (I) (component A) and thiocyanic acid (component B): In formula (I), R 1 is a hydrocarbon group having 6 to 22 carbon atoms which may have an ester group, an amide group, and / or an ether group, and R 2 and R 3 are each independently a hydrocarbon group having 6 to 22 carbon atoms which may have an ester group, an amide group and / or an ether group, or an alkyl group having 1 to 4 carbon atoms which may have a hydroxyl group, R 4 is an alkyl group having 1 to 6 carbon atoms or a hydrogen atom, and X - is an anion. <28> Component A is a compound represented by R 1 , R 2 and R 3 <29> The metal separating agent according to <26> or <27>, wherein at least one of the following is a compound having an ester group having 6 to 22 carbon atoms: 1 , R 2 and R 3 <30> The metal separating agent according to any one of <26> to <28>, wherein at least one of the following is a compound having an ester group having 6 to 22 carbon atoms: 1 , R 2 and R 3 The metal separating agent according to any one of <26> to <28>, wherein at least two of the R 1, R 2 and R 3 <32> The metal separating agent according to any one of <26> to <28>, wherein R in formula (I) is a compound having an ester group having 6 to 22 carbon atoms. 4is a methyl group. <33> The metal separating agent according to any one of <26> to <32>, wherein the mass ratio A / B of component A to component B is 0.01 or more and 50 or less. <34> The metal separating agent according to any one of <26> to <33>, wherein the mass ratio A / B of component A to component B is 0.01 or more and 30 or less, or 0.01 or more and 20 or less, or 0.1 or more and 10 or less, or 1.0 or more and 5.0 or less. <35> The metal separating agent according to any one of <26> to <34>, comprising a blend of component A, a thiocyanate (component B), and a water-insoluble organic solvent (component C). <36> The metal separating agent according to any one of <26> to <35>, wherein the content of component A is 1% by mass or more and 50% by mass or less. <37> The metal separating agent according to any one of <26> to <35>, wherein the content of component A in the metal separating agent is 5.0% by mass or more and 40% by mass or less, or 5% by mass or more and 40% by mass or less, or 10% by mass or more and 30% by mass or less. <38> The metal separating agent according to any one of <26> to <37>, wherein the content of component B is 0.5% by mass or more and 10% by mass or less. <39> The metal separating agent according to any one of <26> to <37>, wherein the content of component B in the metal separating agent is 0.1% by mass or more and 40% by mass or less, or 0.5% by mass or more and 20% by mass or less, or 0.5% by mass or more and 10% by mass or less, or 1.0% by mass or more and 10% by mass or less. <40> The metal separating agent according to any one of <26> to <39>, which is a metal separating agent for separating or separating and recovering cobalt. <41> The metal separating agent according to any one of <26> to <39>, which is a metal separating agent for separating cobalt from an aqueous solution containing cobalt and nickel, or for separating and recovering cobalt. <42> A metal separation method for separating a metal from an aqueous solution containing a metal, comprising a step of contacting the aqueous solution containing the metal with the metal separating agent according to any one of <26> to <41> and separating the metal from the aqueous phase into an organic phase. <43> A metal recovery method for separating and recovering a metal from an aqueous solution containing a metal, comprising a step of contacting the aqueous solution containing the metal with the metal separating agent according to any one of <26> to <41> and separating the metal from the aqueous phase into an organic phase, and a step of recovering the metal from the organic phase.

[0058] The present disclosure will be specifically described below using examples, but the present disclosure is not limited to these examples in any way.

[0059] 1. Preparation of Metal Separating Agent I (Organic Phase) A quaternary ammonium salt (Component A shown in Table 1) and an organic solvent (Component C shown in Table 1) were mixed at a mixing ratio of 0 to 30 vol%. Furthermore, ammonium thiocyanate (Component B shown in Table 1) was added to the mixture at a ratio of 0.5 mol / L to prepare Metal Separating Agent I (Examples 1 to 9, Comparative Examples 1 and 2). The blending amount (mass%) of each component in the metal separating agent of the present disclosure is shown in Table 1.

[0060] The following were used as components of the metal separating agent. (Component A) <Production Example of Triester Methylammonium Methyl Sulfate> Triester methylammonium methyl sulfate (compound name: methyltris-[ethyl 2-ethylhexyl]-ammonium methyl sulfate) [in formula (I), R 1 , R 2 , R 3 is ethyl 2-ethylhexylate, and R 4 A compound in which X is methyl and X is methyl sulfate was obtained as follows. 2-Ethylhexyl acid, triethanolamine, hypophosphorous acid as a catalyst, and butylhydroxytoluene as an antioxidant were charged into a four-neck flask connected to a condenser, and after purging with nitrogen, the temperature was raised to 170°C over 1.5 hours and then stirred for 2 hours. The pressure was then reduced to 13.3 kPa over 1.5 hours, and the mixture was aged for 7 hours, and then cooled to obtain an esteramine. The obtained esteramine was charged into a 2-L separable flask, and after purging with nitrogen, dimethyl sulfate was added dropwise over 1 hour while the mixture was heated to 65°C, and the mixture was aged at 65°C for 4 hours. The mixture was then cooled to room temperature to obtain triestermethylammonium methylsulfate. <Production Example of Diestermethylammonium Methylsulfate> Diestermethylammonium methylsulfate (compound name: (2-hydroxyethyl)-methylbis-[2-ethyl oleate]-ammonium methylsulfate) [R in formula (I)] 1 , R 2 is ethyl oleate, and R 3 is hydroxyethyl, and R4 A compound in which R is methyl and X is methyl sulfate] was obtained as follows. A four-necked flask connected to a condenser was charged with oleic acid, triethanolamine, hypophosphorous acid as a catalyst, and butylhydroxytoluene as an antioxidant. After purging with nitrogen, the temperature was raised to 170°C over 1.5 hours and the mixture was stirred for 2 hours. The pressure was then reduced to 13.3 kPa over 1.5 hours, and the mixture was aged for 7 hours, followed by cooling to obtain an esteramine. The obtained esteramine was charged into a separable flask, and after purging with nitrogen, dimethyl sulfate was added dropwise over 1 hour while the mixture was heated to 65°C, and the mixture was aged at 65°C for 4 hours. The mixture was then cooled to room temperature to obtain diestermethylammonium methyl sulfate. <Production Example of Trietherhexylammonium Hydrochloride> Trietherhexylammonium hydrochloride (compound name: tris[2-hexoxyethyl]-hexyl-ammonium hydrochloride) [R in formula (I)] 1 , R 2 , R 3 is hexoxyethyl, and R 4A compound in which X is hexyl and X is chloride was obtained as follows. Triethanolamine, hexanol, and sodium hydroxide were charged into a four-neck flask, and after purging with nitrogen, the temperature was raised to 160°C. After heating, the pressure was reduced to 1.3 kPa or less and stirring was continued for 24 hours. The mixture was then cooled to room temperature, and water was added to terminate the reaction, yielding trietheramine. The obtained trietheramine was charged into a separable flask, and after purging with nitrogen, hexyl chloride was added dropwise over 1 hour while the mixture was heated to 65°C, and the mixture was then aged at 65°C for 4 hours. The mixture was then cooled to room temperature, yielding trietherhexylammonium hydrochloride. The synthetic raw materials used in the production of the above component A are shown below. <Synthetic Raw Materials> Triethanolamine [manufactured by Tokyo Chemical Industry Co., Ltd.] 2-Ethylhexyl acid [manufactured by Tokyo Chemical Industry Co., Ltd.] Oleic acid [manufactured by Tokyo Chemical Industry Co., Ltd.] Hypophosphorous acid [manufactured by Sigma-Aldrich] BHT [manufactured by Tokyo Chemical Industry Co., Ltd.] Dimethyl sulfate [manufactured by Tokyo Chemical Industry Co., Ltd.] Hexanol [manufactured by Tokyo Chemical Industry Co., Ltd.] Sodium hydroxide [manufactured by Tokyo Chemical Industry Co., Ltd.] Hexyl chloride [manufactured by Tokyo Chemical Industry Co., Ltd.] <Trioctylmethylammonium methyl sulfate> A compound obtained by washing trioctylmethylammonium hydrochloride with an aqueous methyl sulfate solution and converting it to a methyl sulfate (Component B) Ammonium thiocyanate [manufactured by Tokyo Chemical Industry Co., Ltd.] (Component C) Kerosene [manufactured by Tokyo Chemical Industry Co., Ltd.]

[0061] 2. Preparation of Aqueous Solution II (Aqueous Phase, Aqueous Solution Containing Metals) Co sulfate and Ni sulfate were dissolved in 1 mol / L sulfuric acid to prepare Aqueous Solution II containing Co and Ni (Co concentration: 3.0 g / L, Ni concentration: 3.0 g / L). The pH of Aqueous Solution II is shown in Table 1. The contents of each metal in Aqueous Solution II were 0.3 mass% Co and 0.3 mass% Ni.

[0062] [pH Measurement Method] The pH of Aqueous Solution II was measured at 25°C using a pH meter (HM-30G, manufactured by Toa Denpa Kogyo Co., Ltd.) one minute after the electrode was immersed in the polishing composition. The results are shown in Table 1.

[0063] 3. Evaluation of Metal Separating Agents (Examples 1 to 9, Comparative Examples 1 and 2) Metal separating agent I (organic phase) was contacted with aqueous solution II (aqueous phase), and the Co extraction ability and Co—Ni separation ability were evaluated. Specific procedures are as follows. [Metal Extraction Method] Metal separating agent I (organic phase) and aqueous solution II (aqueous phase) were placed in a separatory funnel and contacted by shaking at 20°C for 10 minutes, and the metal was transferred (distributed) to the metal separating agent I (organic phase), thereby extracting (separating) the metal. The volume ratio (volume of aqueous phase / volume of organic phase) of the aqueous solution II (aqueous phase) to the metal separating agent I (organic phase) to be contacted was 1.0. The blending amounts of each component in the metal separating agent I to be contacted with aqueous solution II were 1500 mol% for component A, 2500 mol% for component B, and 25000 mol% for component C, relative to the Co concentration in aqueous solution II. The Co and Ni concentrations in the metal separating agent I (organic phase) and aqueous solution II (aqueous phase) after extraction were quantitatively analyzed using ICP-OES, and the Co extraction rate and Co-Ni separation ability were calculated. The results are shown in Table 1. The Co extraction rate and Co-Ni separation ability are defined as follows: [Co extraction rate] The Co extraction rate is the Co concentration (g / L) in the metal separating agent I after extraction divided by the initial (before extraction) Co concentration (g / L) in aqueous solution I. Co extraction rate = (Co concentration in metal separating agent I after extraction) / (Co concentration in aqueous solution I before extraction). Note that values ​​below the detection limit by ICP-OES are indicated as "below detection limit" in Table 1. [Co-Ni Separation Ability] The Co-Ni separation ability was calculated by dividing the ratio Co / Ni of the Co concentration (g / L) to the Ni concentration (g / L) in the metal separating agent I after extraction by the ratio Co / Ni of the Co concentration (g / L) to the Ni concentration (g / L) in the aqueous solution II after extraction. Co-Ni separation ability = (Co / Ni concentration ratio in the metal separating agent I after extraction) / (Co / Ni concentration ratio in the aqueous solution II after extraction). Note that the Co-Ni separation ability was not calculated for Examples 2 and 5, and therefore is indicated as "-" in Table 1.

[0064]

[0065] As shown in Table 1, Examples 1 to 9, which used a quaternary ammonium salt represented by formula (I) (component A) and ammonium thiocyanate (component B), all had Co extraction rates of 94% or higher. Furthermore, Examples 1, 3-4, and 6-9 had better Co-Ni separation ability than Comparative Examples 1 and 2, which did not use component B. Furthermore, the Co-Ni separation ability of Examples 1, 3, and 4 was superior to that of Example 9. Thus, the metal separating agents of Examples 1 to 9 were confirmed to have high separation and recovery performance. In particular, Example 1, which used triestermethylammonium methyl sulfate as component A, had a Co extraction rate of 99% or higher and a separation ability of 1,300 or higher, demonstrating higher separation and recovery performance.

[0066] The metal separating agent of the present disclosure can be used as a recovery agent for rare metals and precious metals.

Claims

1. A metal separation method for separating a metal from an aqueous solution containing the metal, or for separating and recovering the metal, comprising the step of contacting the aqueous solution containing the metal with a metal separating agent containing a salt represented by the following formula (I) (component A), thiocyanic acid (component B) and a water-insoluble organic solvent (component C) to separate the metal from the aqueous phase into an organic phase. In formula (I), R 1 is a hydrocarbon group having 6 to 22 carbon atoms which may have an ester group, an amide group, and / or an ether group; R 2 and R 3 each independently represents a hydrocarbon group having 6 to 22 carbon atoms which may have an ester group, an amide group and / or an ether group, or an alkyl group having 1 to 4 carbon atoms which may have a hydroxyl group; R 4 is an alkyl group having 1 to 6 carbon atoms or a hydrogen atom; X - is an anion.

2. Component A is R in formula (I). 1 , R 2 and R 3 2. The method for separating metals according to claim 1, wherein at least one of the above is a compound having an ester group having 6 to 22 carbon atoms.

3. Component A is R in formula (I). 1 , R 2 and R 3 3. The method for separating metals according to claim 1 or 2, wherein at least two of the above are compounds having an ester group having 6 to 22 carbon atoms.

4. Component A is R in formula (I). 1 , R 2 and R 3 The method for separating metals according to any one of claims 1 to 3, wherein the compound has an ester group having 6 to 22 carbon atoms.

5. A metal separation method according to any one of claims 1 to 4, wherein the mass ratio A / B of component A to component B in the metal separating agent is 0.01 or more and 50 or less.

6. A metal separation method described in any one of claims 1 to 5, wherein the content of component A in the metal separating agent is 1 mass% or more and 50 mass% or less.

7. A metal separation method according to any one of claims 1 to 6, wherein the content of component B in the metal separating agent is 0.5 mass% or more and 10 mass% or less.

8. A metal separation method according to any one of claims 1 to 7, which is a metal separation method for separating or separating and recovering cobalt.

9. A method for separating metals according to any one of claims 1 to 8, which is a method for separating or separating and recovering cobalt from an aqueous solution containing cobalt and nickel.

10. A metal separating agent kit for separating or separating and recovering a metal from an aqueous solution containing the metal, the metal separating agent kit comprising a first agent containing a salt represented by the following formula (I) (component A) and a second agent containing thiocyanic acid (component B). In formula (I), R 1 is a hydrocarbon group having 6 to 22 carbon atoms which may have an ester group, an amide group, and / or an ether group; R 2 and R 3 each independently represents a hydrocarbon group having 6 to 22 carbon atoms which may have an ester group, an amide group and / or an ether group, or an alkyl group having 1 to 4 carbon atoms which may have a hydroxyl group; R 4 is an alkyl group having 1 to 6 carbon atoms or a hydrogen atom; X - is an anion.

11. The metal separator kit according to claim 10, which is a metal separator kit for separating or separating and recovering cobalt.

12. The metal separator kit according to claim 10 or 11, which is a metal separator kit for separating or separating and recovering cobalt from an aqueous solution containing cobalt and nickel.

13. A metal recovery method for separating and recovering a metal from an aqueous solution containing the metal, comprising the steps of: contacting the aqueous solution containing the metal with an agent comprising a metal separating agent kit according to any one of claims 10 to 12, thereby separating the metal from the aqueous phase into an organic phase; and recovering the metal from the organic phase.

14. A method for manufacturing a lithium ion battery, comprising the steps of: contacting an aqueous solution containing a metal with an agent comprising a metal separating agent kit according to any one of claims 10 to 12, thereby separating the metal from the aqueous phase into an organic phase; recovering the metal from the organic phase; and manufacturing a battery using the metal recovered in the above step.

15. A metal separating agent for separating or separating and recovering a metal from an aqueous solution containing the metal, the metal separating agent comprising a salt represented by the following formula (I) (component A) and thiocyanic acid (component B). In formula (I), R 1 is a hydrocarbon group having 6 to 22 carbon atoms which may have an ester group, an amide group, and / or an ether group; R 2 and R 3 each independently represents a hydrocarbon group having 6 to 22 carbon atoms which may have an ester group, an amide group and / or an ether group, or an alkyl group having 1 to 4 carbon atoms which may have a hydroxyl group; R 4 is an alkyl group having 1 to 6 carbon atoms or a hydrogen atom; X - is an anion.

16. A metal separating agent for separating or separating and recovering metals from an aqueous solution containing the metal, comprising a salt represented by the following formula (I) (component A) and thiocyanic acid (component B): In formula (I), R 1 is a hydrocarbon group having 6 to 22 carbon atoms which may have an ester group, an amide group, and / or an ether group; R 2 and R 3 each independently represents a hydrocarbon group having 6 to 22 carbon atoms which may have an ester group, an amide group and / or an ether group, or an alkyl group having 1 to 4 carbon atoms which may have a hydroxyl group; R 4 is an alkyl group having 1 to 6 carbon atoms or a hydrogen atom; X - is an anion.

17. Component A is R in formula (I). 1 , R 2 and R 3The metal separating agent according to claim 15 or 16, wherein at least one of the above is a compound having an ester group having 6 to 22 carbon atoms.

18. A metal separating agent according to any one of claims 15 to 17, wherein the mass ratio A / B of component A to component B is 0.01 or more and 50 or less.

19. A metal separating agent according to any one of claims 15 to 18, comprising a blend of component A, a thiocyanate salt (component B), and a water-insoluble organic solvent (component C).

20. A metal separating agent described in any one of claims 15 to 19, wherein the content of component A is 1 mass% or more and 50 mass% or less.

21. A metal separating agent according to any one of claims 15 to 20, wherein the content of component B is 0.5 mass % or more and 10 mass % or less.

22. The metal separating agent according to any one of claims 15 to 21, which is a metal separating agent for separating or separating and recovering cobalt.

23. The metal separating agent according to any one of claims 15 to 22, which is a metal separating agent for separating or separating and recovering cobalt from an aqueous solution containing cobalt and nickel.

24. A method for separating a metal from an aqueous solution containing the metal, comprising the steps of contacting the aqueous solution containing the metal with the metal separating agent according to any one of claims 15 to 23, and separating the metal from the aqueous phase into an organic phase.

25. A metal recovery method for separating and recovering a metal from an aqueous solution containing the metal, comprising the steps of: contacting the aqueous solution containing the metal with the metal separating agent described in any one of claims 15 to 23 to separate the metal from the aqueous phase into an organic phase; and recovering the metal from the organic phase.

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