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JP-7855961-B2 - Metal salt extractant, composition, method for recovering metal salts, and method for producing metal salts

JP7855961B2JP 7855961 B2JP7855961 B2JP 7855961B2JP-7855961-B2

Inventors

  • 近藤 慎一
  • 高野 美優
  • 平澤 学

Assignees

  • 株式会社レゾナック

Dates

Publication Date
20260511
Application Date
20220727

Claims (8)

  1. A metal salt extractant that extracts at least one of a divalent cobalt salt and a divalent nickel salt, and is a compound represented by the following general formula (1). (In general formula (1), R1 and R2 are each independently a hydrogen atom, an alkyl group, an aryl group, a heteroaryl group, an alkoxy group, a hydroxyl group, or a group represented by -NHR', R' is a hydrogen atom, an alkyl group, an aryl group, a heteroaryl group, an alkoxy group, or a hydroxyl group, and X1 and X2 are each independently an oxygen atom or a sulfur atom.)
  2. The metal salt extractant according to claim 1, wherein the compound is represented by the following general formula (2). (In general formula (2), R3 and R4 are each independently a hydrogen atom, an alkyl group, an aryl group, a heteroaryl group, an alkoxy group, or a hydroxyl group, and X1 and X2 are each independently an oxygen atom or a sulfur atom.)
  3. The metal salt extractant according to claim 2, wherein in the general formula (2), R3 and R4 are each independently an n-butyl group, a tert-butyl group, or a phenyl group.
  4. The metal salt extractant according to claim 2, wherein in the general formula (2) above, X1 and X2 are sulfur atoms.
  5. A composition comprising a metal salt extractant and a non-aqueous solvent according to any one of claims 1 to 4.
  6. A method for recovering a metal salt using the metal salt extractant described in any one of claims 1 to 4.
  7. A method for separating at least one of a divalent cobalt salt and a divalent nickel salt from a metal salt-containing material to produce at least one of a divalent cobalt salt and a divalent nickel salt, A method for producing a metal salt, comprising the steps of: preparing a mixture containing the metal salt-containing material, a metal salt extractant according to any one of claims 1 to 4, and a non-aqueous solvent; and separating the mixture into solid and liquid phases to obtain a metal salt-containing liquid.
  8. A method for separating at least one of a divalent cobalt salt and a divalent nickel salt from a metal salt-containing material to produce at least one of a divalent cobalt salt and a divalent nickel salt, A step of preparing a mixture comprising the metal salt-containing material, the metal salt extractant according to any one of claims 1 to 4, and a non-aqueous solvent. A method for producing a metal salt, comprising the steps of: separating the mixture into solid and liquid phases to obtain a metal salt-containing liquid; and recovering the metal salt extractant from the metal salt-containing liquid.

Description

One embodiment of the present invention relates to a metal salt extractant, a composition, a method for recovering a metal salt, and a method for producing a metal salt. The automotive industry, information and communication technology industry, and other sectors utilize large amounts of metal resources. However, concerns exist that increasing global demand for metal resources and the uneven distribution of reserves may lead to a reduction in the supply and price increases of these resources. Therefore, attempts are being made to extract and recycle metal resources from industrial waste. Recycling allows for the extraction of individual metal resources with high purity, enabling the provision of products that meet the requirements of various industrial sectors. Among metallic resources, transition metals share a common electron configuration in their outermost shell, resulting in similar properties. Therefore, the technology for extracting a single transition metal from multiple types of transition metals is complex. When transition metals form metal salts rather than elemental metals, recovering the transition metal in salt form allows for the direct recycling of the recovered transition metal salt. However, the technology for sorting and recovering transition metal salts based on differences in metal species during metal salt recycling is even more complex. Cobalt and nickel are widely used as cathode materials in lithium-ion batteries. Given the rapid increase in capacity of lithium-ion batteries in recent years, particularly in electric vehicles, there is a growing need to establish methods for selectively and efficiently recovering these metal salts. Chemical separation is a technology used to extract metal resources from materials, and it is possible to extract metal resources with high purity using chemical reactions, electrolysis, etc. Among these methods, the method of separating metals using extractants in a solvent can precisely separate specific metals. On the other hand, one technique for recovering ions from a solvent is to capture anions in the solvent using anion receptors. The molecular structure of the anion receptor allows for selective capture of the target ion species. Non-patent documents 1 and 2 disclose anion receptors having a urea group at the 8,8'-position of a 2,2'-binaphthyl group. S. Kondo, H. Sonoda, T. Katsu, and M. Unno, Sens. Actuators B, 160, 684-690 (2011).S. Kondo, M. Nagamine, S. Karasawa, M. Ishihara, M. Unno, and Y. Yano, Tetrahedron, 67, 943-950 (2011). The following describes one embodiment of the present invention, but the present invention is not limited by the following examples. "Metal salt extractants" One embodiment of the metal salt extractant is a metal salt extractant that extracts at least one of a divalent cobalt salt and a divalent nickel salt, and is a compound represented by the following general formula (1). (In general formula (1), R1 and R2 are each independently a hydrogen atom, an alkyl group, an aryl group, a heteroaryl group, an alkoxy group, a hydroxyl group, or a group represented by -NHR', R' is a hydrogen atom, an alkyl group, an aryl group, a heteroaryl group, an alkoxy group, or a hydroxyl group, and X1 and X2 are each independently an oxygen atom or a sulfur atom.) Hereinafter, compounds represented by general formula (1) will be collectively referred to as metal salt extractants. This metal salt extractant is capable of capturing at least one of divalent cobalt salts and divalent nickel salts in a non-aqueous solvent and can be used to extract at least one of divalent cobalt salts and divalent nickel salts from a non-aqueous solvent. In particular, this metal salt extractant is excellent at selectively capturing chloride ions that are released in a non-aqueous solvent, and by capturing them together with at least one of their counterions, divalent cobalt ions and divalent nickel ions, it becomes possible to extract at least one of nickel II chloride ( CoCl₂ ) and nickel II chloride ( NiCl₂ ). An anion receptor having a urea group at the 8,8'-position of the 2,2'-binaphthyl group exhibits excellent anion-capturing ability due to its rigid structure resulting from the 2,2'-binaphthyl group and the presence of urea groups at both ends. This compound is represented by the following general formula (10). (In general formula (10), R is an n-butyl group, a tert-butyl group, or a phenyl group.) Unlike compounds represented by general formula (10), compounds represented by general formula (1) have a structure in which the binaphthalene skeleton is replaced with a skeleton having an aliphatic chain and an oxygen atom (O) or a sulfur atom (S). Due to its flexible structure, it is thought to exhibit high solubility in non-aqueous solvents. In compounds represented by general formula (1), the amide bonds at both ends are expected to associate with anions, particularly halide ions such as chloride ions. Furthermore, in general formula (1), R1 and R2 a