How to recover nickel

Abstract

To provide a method for efficiently recovering nickel from a nickel solution containing a nickel compound produced in an organic chemical reaction process.SOLUTION: A nickel recovery method includes the following steps of: (a) preparing a nickel solution containing a nickel compound produced in an organic chemical reaction process; (b) adjusting the pH of the nickel solution to 3 or more; and (c) adding an alkali metal sulfide to the nickel solution whose pH has been adjusted to 3 or more to obtain a nickel sulfide precipitate. The nickel recovery method is suitable when the nickel solution contains a nickel halide. Further, the nickel recovery method is suitable when the nickel solution contains an organic solvent.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for recovering nickel from nickel solutions produced in organic chemical reaction processes. [Background technology]

[0002] Non-Patent Document 1 describes a method for producing an organic compound, which is characterized by using a nickel compound as a catalyst.

[0003] Patent Document 1 describes a process for preparing a hydrophobic group-forming monomer (A) consisting of a single aromatic ring, or consisting of a divalent hydrocarbon group, a divalent silicon-containing group, a divalent nitrogen-containing group, a divalent phosphorus-containing group, a divalent oxygen-containing group, a divalent sulfur-containing group, or a plurality of aromatic rings bonded to each other via direct bonds, with two halogen atoms, pseudohalides, or boronic acid groups bonded to the aromatic rings; and (B) a process for preparing a hydrophobic group-forming monomer consisting of a single aromatic ring, or consisting of a divalent hydrocarbon group, a divalent silicon-containing group, a divalent nitrogen-containing group, a divalent phosphorus-containing group, a divalent oxygen-containing group, a divalent sulfur-containing group, or a plurality of aromatic rings bonded to each other via direct bonds, with two halogen atoms, pseudohalides, or boronic acid groups bonded to the aromatic rings. (C) preparing a hydrophilic group-forming monomer comprising a linking group which is a group containing a group, a divalent oxygen-containing group, or a divalent sulfur-containing group, and / or a plurality of aromatic rings bonded to each other via direct bonds, wherein two halogen atoms, pseudohalides, or boronic acid groups are bonded to the aromatic rings, and at least one of the linking groups or aromatic rings is bonded to an anion exchange group precursor functional group via a divalent saturated hydrocarbon group or a direct bond; and (D) preparing a hydrophilic group-forming monomer comprising bis(1,5-cyclooctadiene)nickel(0) as a polymerization accelerator and a co-polymerization catalyst. A method for producing an anion exchange resin, comprising: (a) a step of reacting the hydrophobic group-forming monomer with the hydrophilic group-forming monomer in the presence of 2,2'-bipyridine as a ligand to synthesize a polymer; and (b) a step of ionizing the anion exchange group precursor functional group to form an anion exchange group, wherein the number of moles of bis(1,5-cyclooctadiene)nickel(0) used in the step (C) is 1.2 to 1.8 times the total number of moles of the hydrophobic group-forming monomer and the hydrophilic group-forming monomer. The method for producing an anion exchange resin is described, characterized in that the number of moles of 2,2'-bipyridine used in the step (C) is 1.5 to 2.5 times the number of moles of bis(1,5-cyclooctadiene)nickel(0), and in the anion exchange resin, the residue of the hydrophobic group-forming monomer forms a divalent hydrophobic group, and the residue of the hydrophilic group-forming monomer having the anion exchange group forms a divalent hydrophilic group, and the hydrophobic group and the hydrophilic group are bonded via a direct bond.

[0004] Patent Document 2 describes a method for producing a hydrophobic group-forming monomer, which comprises (A) a single aromatic ring, or a divalent hydrocarbon group, a divalent silicon-containing group, a divalent nitrogen-containing group, a divalent phosphorus-containing group, a divalent oxygen-containing group, a divalent sulfur-containing group, or a plurality of aromatic rings bonded to each other via direct bonds, with two chlorine atoms bonded to the aromatic rings; and (B) a method for producing a hydrophobic group-forming monomer, which comprises a single aromatic ring, or a divalent hydrocarbon group, a divalent silicon-containing group, a divalent nitrogen-containing group, a divalent phosphorus-containing group, a divalent oxygen-containing group, a divalent sulfur-containing group, or a plurality of aromatic rings bonded to each other via direct bonds, with two chlorine atoms bonded to the aromatic rings. (C) preparing a hydrophilic group-forming monomer, which comprises a linking group which is a phosphorus-containing group, a divalent oxygen-containing group, or a divalent sulfur-containing group, and / or a plurality of aromatic rings bonded to each other via direct bonds, and two chlorine atoms are bonded to the aromatic rings, and at least one of the linking groups or aromatic rings is bonded to an anion exchange group precursor functional group via a divalent saturated hydrocarbon group or a direct bond; and (C) bis(1,5-cyclooctadiene)nickel as a catalyst. (C) is a process for producing an anion exchange resin, the process comprising: (a) reacting the hydrophobic group-forming monomer with the hydrophilic group-forming monomer in the presence of (C), 2,2'-bipyridine as a co-ligand, a bromide or iodide as a co-catalyst, and a reducing agent to synthesize a polymer; and (D) ionizing the anion exchange group precursor functional group to form an anion exchange group. The process is characterized in that the number of moles of bis(1,5-cyclooctadiene)nickel(0) used in the process (C) is 0.3 to 1.8 times the total number of moles of the hydrophobic group-forming monomer and the hydrophilic group-forming monomer, and in the anion exchange resin, the residue of the hydrophobic group-forming monomer forms a divalent hydrophobic group, and the residue of the hydrophilic group-forming monomer having the anion exchange group forms a divalent hydrophilic group, and the hydrophobic group and the hydrophilic group are bonded via a direct bond. [Prior art documents] [Patent documents]

[0005] [Non-Patent Document 1] Nature 2014,509,299-309. [Patent Document 1] Japanese Patent Publication No. 2022-18683 [Patent Document 2] Japanese Patent Publication No. 2022-24326 Summary of the Invention [Problem to be solved by the invention]

[0006] In the production methods described in Non-Patent Document 1 and Patent Documents 1 and 2, the nickel compound used as a catalyst or polymerization accelerator is not incorporated into the product, and therefore all of the nickel used in the reaction is contained in the waste liquid. There is a demand for recovering nickel from the waste liquid produced in such organic chemical reaction processes and reusing it as a new resource.

[0007] Therefore, an object of the present invention is to provide a method for efficiently recovering nickel from a nickel solution containing nickel compounds produced in an organic chemical reaction process. [Means for solving the problem]

[0008] In order to solve the above problem, the nickel recovery method according to claim 1 comprises: (a)Organic Manufacturing of polymer compounds providing a nickel solution containing nickel compounds produced in the process; (b) adjusting the pH of the nickel solution to 3 or more; (c) adding an alkali metal sulfide to the nickel solution adjusted to a pH of 3 or more to obtain a nickel sulfide precipitate; The present invention is characterized by having the following.

[0009] The invention described in claim 2 is the nickel recovery method described in claim 1, The nickel compound is a nickel halide. It is characterized by:

[0010] The invention described in claim 3 is the nickel recovery method described in claim 1 or 2, The nickel solution comprises an organic solvent. It is characterized by:

[0011] The invention described in claim 4 is the method for recovering nickel described in any one of claims 1 to 3, The alkali metal sulfide is sodium sulfide. It is characterized by:

[0012] The invention described in claim 5 is the method for recovering nickel described in any one of claims 1 to 4, In the step (b), sodium hydroxide is added to the nickel solution. It is characterized by:

[0014] Claim 6 According to the invention described in claim Any one of items 1 to 5 In the nickel recovery method described in The organic polymer compound is an ion exchange resin. It is characterized by:

[0015] Claim 7 According to the invention described in claim 6 In the nickel recovery method described in The ion exchange resin is an anion exchange resin. It is characterized by: [Effects of the Invention]

[0016] According to the present invention, nickel can be efficiently recovered from a nickel solution containing nickel compounds produced in an organic chemical reaction process. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a graph showing the relationship between the amount of nickel sulfide added and the pH of the nickel solution in Examples 1 and 2 and Comparative Examples 1 and 2. DETAILED DESCRIPTION OF THE INVENTION

[0018] The present invention is a method for efficiently recovering nickel from a nickel solution containing nickel compounds produced in an organic chemical reaction process. More specifically, nickel (Ni), which is widely used as a catalyst in organic chemical reaction processes, is recovered as nickel sulfide (NiS), which has an extremely small solubility product, from the waste solution after the process is completed. This makes it possible to recover nickel, which has previously been treated as waste liquid, and reuse it as a new resource.

[0019] In the present invention, first, a nickel solution containing a nickel compound produced in an organic chemical reaction process is prepared (step (a)). The organic chemical reaction process may be a process for producing organic low molecular weight compounds and / or organic polymer compounds, but this method is suitable for a process for producing organic polymer compounds. Examples of organic polymer compounds include ion exchange resins, highly absorbent polymers, conductive polymers, piezoelectric polymers, self-healing polymers, general-purpose plastics, and engineering plastics. Among these, ion exchange resins are preferred, and anion exchange resins are more preferred. Examples of processes for producing anion exchange resins include polymer production processes based on cross-coupling using bis(1,5-cyclooctadiene)nickel(0) as a polymerization promoter (catalyst), as described in Patent Documents 1 and 2.

[0020] Nickel compounds produced in organic chemical reaction processes include nickel halides such as nickel fluoride, nickel chloride, nickel bromide, and nickel iodide, and inorganic nickel acids such as nickel nitrate and nickel sulfate. For example, the nickel compound produced in the polymer production processes described in the examples of Patent Documents 1 and 2 is nickel chloride.

[0021] The nickel solution containing the nickel compound is produced in an organic chemical reaction process and therefore typically contains an organic solvent. Examples of the organic solvent include alcohols such as methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutyl alcohol (2-methyl-1-propanol), and tert-butyl alcohol (2-methyl-2-propanol); ethers such as diethyl ether and tetrahydrofuran; ketones such as acetone and methyl ethyl ketone; halogenated hydrocarbons such as dichloromethane and chloroform; aliphatic hydrocarbons such as n-pentane, n-hexane, and n-heptane; aromatic hydrocarbons such as benzene, toluene, xylene, and chlorobenzene; nitrogen-containing organic solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone; and sulfur-containing organic solvents such as dimethyl sulfoxide, dimethyl sulfone, and sulfolane. For example, the nickel solution containing the nickel compound produced in the polymer production process described in the examples of Patent Documents 1 and 2 contains water and the organic solvent methanol as solvents.

[0022] The solvent contained in the nickel solution may be water, an organic solvent, or a mixed solvent of water and an organic solvent. When the solvent contained in the nickel solution is a mixed solvent of water and an organic solvent, the content of the organic solvent in the mixture is, for example, 0.1 vol% or more, preferably 50 vol% or more.

[0023] In the present invention, the pH of the nickel solution is then adjusted to 3 or higher (step (b)). If the pH of the nickel solution is less than 3 (particularly less than 2), hydrogen sulfide (HS) will be generated when an alkali metal sulfide is added in the next step (c), and the alkali metal sulfide will be consumed in excess, resulting in a reduced amount of nickel sulfide precipitate. In other words, if the pH of the nickel solution prepared in step (a) is less than 3, an alkali component should be added so that the pH becomes 3 or higher. Examples of the alkaline component to be added include alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide; and carbonates such as lithium carbonate, sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, cesium carbonate, magnesium carbonate, and calcium carbonate. Among these, alkali metal hydroxides are preferred, and sodium hydroxide is more preferred. It is not preferred to use alkali metal sulfides as the alkaline component.

[0024] In the present invention, an alkali metal sulfide is then added to the nickel solution whose pH has been adjusted to 3 or higher to obtain a precipitate of nickel sulfide (step (c)). In this way, nickel ions in the nickel solution react with alkali metal sulfides to precipitate nickel sulfide (NiS), which has an extremely small solubility product, making it possible to efficiently recover nickel. Examples of alkali metal sulfides include lithium sulfide (LiS), sodium sulfide (NaS), and potassium sulfide (KS). Among these, sodium sulfide is preferred.

[0025] When adding an alkali metal sulfide, it is advisable to check the pH of the nickel solution. The pH of the nickel solution rises slowly when the alkali metal sulfide is added, but the pH rises sharply once the nickel sulfide production reaction is complete, making it easy to determine the end point of the reaction. Alternatively, it is preferable to add the alkali metal sulfide in an amount 1.0 to 1.2 times the theoretical amount.

[0026] The nickel sulfide precipitated in the nickel solution has an extremely small solubility product, and can therefore be easily recovered by filtration or the like. [Example]

[0027] Next, the present invention will be described based on examples and comparative examples, but the present invention is not limited to the following examples.

[0028] Example 1 As a simulated waste liquid, a nickel solution was prepared by adding nickel chloride (NiCl2) to 100 mL of a mixed solvent of 6 M hydrochloric acid and methanol in a 1:1 (volume ratio) ratio to a concentration of 42.1 mmol / L. Next, sodium hydroxide (NaOH) was added until the pH of the nickel solution reached 3.0. While stirring the resulting nickel solution at 500 rpm, 10 mL of a 31.25 mmol / L aqueous solution of sodium sulfide (NaS) was slowly added, resulting in the formation of a black precipitate of nickel sulfide (NiS). After that, 138 mL of sodium sulfide (NaS) aqueous solution was added, and the pH rose sharply, indicating that this was the end point of the reaction. The resulting black precipitate was filtered and dried under vacuum, recovering 349 mg (yield: 90.6%) of nickel sulfide.

[0029] <Example 2> The same procedure as in Example 1 was carried out, except that sodium hydroxide (NaOH) was added until the pH of the nickel solution reached 4.0. The amount of sodium sulfide (NaS) aqueous solution added until the pH suddenly increased was 135 mL, and 379 mg (yield: 99.2%) of nickel sulfide was recovered.

[0030] <Comparative Example 1> The same procedure as in Example 1 was carried out, except that sodium hydroxide (NaOH) was added until the pH of the nickel solution reached 1.0. The amount of sodium sulfide (NaS) aqueous solution added until the pH suddenly increased was 210 mL, and 306 mg (yield: 80.1%) of nickel sulfide was recovered. In addition, hydrogen sulfide (HS) was detected in the early stage of adding the sodium sulfide (NaS) aqueous solution.

[0031] <Comparative Example 2> The same procedure as in Example 1 was carried out, except that sodium hydroxide (NaOH) was added until the pH of the nickel solution reached 2.0. The amount of sodium sulfide (NaS) aqueous solution added until the pH suddenly increased was 139 mL, and 326 mg (yield: 85.3%) of nickel sulfide was recovered. Furthermore, hydrogen sulfide (HS) was detected in the early stage of adding the sodium sulfide (NaS) aqueous solution.

[0032] <Consideration> FIG. 1 is a graph showing the relationship between the amount of nickel sulfide added and the pH of the nickel solution in Examples 1 and 2 and Comparative Examples 1 and 2. In Examples 1 and 2, the pH rose significantly in the early stage after sodium sulfide was added, then rose slowly, and rose again significantly at the end of the reaction. In contrast, in Comparative Examples 1 and 2, the pH rose slowly in the early stage after sodium sulfide addition, then rose sharply, then rose slowly again, and then rose sharply again at the end of the reaction. It is believed that hydrogen sulfide (HS) was generated when the pH was rising slowly in the early stage of Comparative Examples 1 and 2. It is also presumed that sodium sulfide (NaS) was consumed in proportion to the hydrogen sulfide generated, which is why a large amount of sodium sulfide was added by the end of the reaction.

Claims

1. (a) preparing a nickel solution containing a nickel compound produced in a process for producing an organic polymer compound; (b) adjusting the pH of the nickel solution to 3 or more; (c) adding an alkali metal sulfide to the nickel solution whose pH has been adjusted to 3 or more to obtain a precipitate of nickel sulfide; have A method for recovering nickel.

2. The nickel compound is a nickel halide.

2. The method for recovering nickel according to claim 1.

3. The nickel solution comprises an organic solvent.

3. The method for recovering nickel according to claim 1 or 2.

4. The alkali metal sulfide is sodium sulfide.

4. The method for recovering nickel according to claim 1, wherein the nickel is extracted from the solution.

5. In the step (b), sodium hydroxide is added to the nickel solution.

5. The method for recovering nickel according to claim 1, wherein the nickel is extracted from the solution.

6. The organic polymer compound is an ion exchange resin.

6. The method for recovering nickel according to claim 1,

7. The ion exchange resin is an anion exchange resin.

7. The method for recovering nickel according to claim 6.

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