JP2016151026A - Palladium extraction agent, and method for extraction separation of palladium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a palladium extraction agent which allows palladium to be extracted with high selectivity, and a method for extraction separation of palladium.SOLUTION: The present invention provides a palladium extraction agent comprising a cyclic phenol sulfide derivative represented by formula (1), and a method for extraction separation of palladium using the same. (Rand Rindependently represent H or a C 1-5 hydrocarbon group; Z is a sulfide group, sulfinyl group or sulfonyl group).SELECTED DRAWING: Figure 1

Description

  The present invention relates to a palladium extractant and a method for extracting and separating palladium using the same.

  Rare metals (for example, cobalt (Co), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), zinc (Zn), yttrium (Y), zirconium (Zr), niobium (Nb), cadmium (Cd), lanthanum (La), cerium (Ce), neodymium (Nd), europium (Eu), terbium (Tb), mercury (Hg), uranium (U), platinum (Pt), palladium (Pd), rhodium (Rh), ruthenium (Ru), iridium (Ir), osmium (Os), etc.) are indispensable for our daily lives, including many of today's precision instruments such as automobile catalysts, fuel cells, and super-strong magnets. Used in products. However, Japan relies on imports for most of these metals, and the recycling of rare metals is an important technology from the viewpoint of stable supply of resources and environmental protection. Above all, palladium is a small amount of metal compared to gold, and it is not only rare as a metal used in decorative products, but also has a lot of industrial demand such as automobile catalysts. In the competition for resource acquisition, prices are rising, and recycling technology is anxious.

  For the recycling of rare metals, a solvent extraction method from a rare metal-containing aqueous solution is generally used, and various extractants have been developed and used. For example, Patent Document 1 describes that an extraction experiment of a metal containing chromium and nickel, which are rare metals, was performed using a cyclic phenol sulfide having an aminoalkyl group. Patent Document 2 describes that a rare metal extraction experiment was performed using a cyclic phenol sulfide derivative having a thiocarbamoyl group.

JP 2000-178271 A Japanese Patent No. 5344430

  However, in the extraction experiment described in Patent Document 1, extraction is performed for each solution containing a single type of metal, and any metal is extracted at a high extraction rate. For this reason, it has been insufficient for application as a rare metal recycling technique that requires selective and efficient separation and recovery of rare metals from a mixture of a plurality of types of metals. According to the cyclic phenol sulfide derivative described in Patent Document 2, it is possible to extract and separate palladium with high efficiency, but a plurality of types of metals are extracted at the same time, and extraction with further enhanced selectivity to palladium. There was a need for the development of agents.

  Then, this invention makes it a subject to provide the palladium extraction agent and the extraction separation method of palladium which can extract palladium highly efficiently and highly selectively from the solution containing multiple types of metals.

  The present inventors conducted an extraction experiment on a solution containing a plurality of types of metals including palladium using a cyclic phenol sulfide having a phosphono group, and extracted and separated palladium with high efficiency and high selectivity. Identified what can be done.

  That is, the first aspect of the present invention is a palladium extractant containing a cyclic phenol sulfide derivative represented by the following general formula (1).

(In Formula (1), R < ¹ >, R < ² >, R < ³ > is respectively independently a hydrogen atom or a C1-C5 hydrocarbon group, and Z is either a sulfide group, a sulfinyl group, and a sulfonyl group. .)

  Moreover, the second aspect of the present invention comprises a step of bringing a cyclic phenol sulfide derivative represented by the following general formula (1) into contact with a solution containing a plurality of types of metals including palladium. Extraction separation method.

(In Formula (1), R < ¹ >, R < ² >, R < ³ > is respectively independently a hydrogen atom or a C1-C5 hydrocarbon group, and Z is either a sulfide group, a sulfinyl group, and a sulfonyl group. .)

In the first and second embodiments of the present invention, R ¹ in the general formula (1) is a hydrogen atom or a linear or branched alkyl group having 1 to 5 carbon atoms, and R ² and R ³ are each independently carbon. A linear or branched alkyl group having 1 to 5 is preferable.

In the first and second embodiments of the present invention, R ¹ is a hydrogen atom, R ² and R ³ are each independently a linear or branched alkyl group having 1 to 3 carbon atoms, and Z is a sulfide group. Preferably there is.

    In the second aspect of the present invention, the solution may contain aluminum, barium, cerium, lanthanum, platinum, rhodium, yttrium, or zirconium in addition to palladium.

  According to the present invention, palladium can be extracted with high efficiency and high selectivity from a solution containing a plurality of types of metals.

It is a figure which shows the result of the extraction rate of Example 1. FIG. It is a figure which shows the influence which the extraction time calculated | required in Example 2 has on the extraction rate. It is a figure which shows the influence which pH calculated | required in Example 3 has on extraction rate. FIG. 6 is a diagram showing a JOB's plot of the cyclic phenol sulfide derivative (2a) -Pd (II) complex obtained in Example 4.

1. Palladium extractant The palladium extractant according to the first aspect of the present invention contains a cyclic phenol sulfide derivative represented by the following general formula (1).

In the general formula (1), R ¹ is a hydrogen atom or a hydrocarbon group having 1 to 5 carbon atoms, preferably a hydrogen atom or a linear or branched alkyl group having 1 to 5 carbon atoms, More preferably. Specific examples of the linear or branched alkyl group having 1 to 5 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, and n-pentyl group. Groups and the like.

In the general formula (1), R ² and R ³ are each independently a hydrogen atom or a hydrocarbon group having 1 to 5 carbon atoms, preferably a linear or branched alkyl group having 1 to 5 carbon atoms. More preferably, it is a linear or branched alkyl group having 1 to 3 carbon atoms. Examples of the alkyl group include the same groups as those exemplified for R ¹ above.

  In the general formula (1), Z is any of a sulfide group, a sulfinyl group, and a sulfonyl group. Among these, Z is preferably a sulfide group. In this case, the compound of the formula (1) is called a thiacalix [4] arene derivative.

The compound of the general formula (1) has a structure in which four phenol derivative skeletons are cyclically linked by Z, but the substituents R ¹ , R ² and R ³ of the four phenol derivative skeletons are the same or different. The four Zs may be the same or different. From the viewpoint of ease of production and palladium extraction characteristics of the resulting compound, it is preferable that R ¹ , R ² , R ³ and four Zs of the four phenol derivative skeletons are the same.

The cyclic phenol sulfide derivative represented by the general formula (1) can be synthesized by a known method. For example, starting from an alkylphenol in which the 4-position is R ¹ (excluding a hydrogen atom) and reacting this with simple sulfur in the presence of an alkali metal reagent or an alkaline earth metal reagent, It can be obtained by obtaining a cyclic phenol sulfide linked with an alkylphenol, and then converting the phenolic hydroxyl group into a phosphono group having R ² and R ³ . In addition, before converting a phenolic hydroxyl group into a phosphono group, you may dealkylate cyclic phenol sulfide in presence of catalysts, such as aluminum chloride.

  Examples of the alkali metal reagent and alkaline earth metal reagent used when synthesizing the cyclic phenol sulfide include simple metals, hydrides, halides, oxides, carbonates, and alkoxides. Moreover, as a conversion method to a phosphono group, the method of making a cyclic phenol sulfide and a phosphoric acid compound react is mentioned. Although it will not specifically limit as a phosphoric acid compound if the cyclic phenol sulfide derivative represented by General formula (1) can be given, Halogenated phosphoric acid dialkyl ester is preferable. As the halogenated phosphoric acid dialkyl ester, diethyl chlorophosphate is preferable from the viewpoint of availability and reactivity. The sulfide group of the cyclic phenol sulfide, that is, Z in the general formula (1) is converted to a sulfinyl group or a sulfonyl group by oxidizing with an oxidizing agent such as hydrogen peroxide or sodium perborate as necessary. be able to.

2. Extraction and separation method of palladium The extraction and separation method of palladium according to the second aspect of the present invention includes a cyclic phenol sulfide derivative represented by the general formula (1) and a solution containing a plurality of types of metals including palladium. The process of making these contact.

  In carrying out the method for extracting and separating palladium according to the present invention, the cyclic phenol sulfide derivative represented by the general formula (1) is usually a solution, and palladium is added to the solution (hereinafter referred to as an extractant solution). By contacting a dissolved solution (hereinafter referred to as a palladium solution), palladium moves to the extractant solution side and palladium is extracted. As the solvent used for the extractant solution and the solvent used for the palladium solution, solvents that are hardly soluble in each other are used. The solvent used for each solution may be a mixture of two or more solvents. Among these solvent combinations, a combination in which the solvent of the extractant solution is a water-insoluble solvent and the solvent of the palladium solution is an aqueous solution is particularly preferable.

  The water-insoluble solvent is not particularly limited as long as it can dissolve the cyclic phenol sulfide derivative represented by the general formula (1); mineral oil such as petroleum and kerosene; aliphatic carbonization such as hexane, heptane and octane Hydrogen; aromatic hydrocarbons such as toluene and xylene; halogenated solvents such as carbon tetrachloride, methylene chloride, chloroform, and ethylene chloride.

  When the solvent of the palladium solution is an aqueous solution, the aqueous solution preferably contains an acid. The acid is not particularly limited as long as it is water-soluble, and an organic acid or an inorganic acid can be used. Examples of organic acids include formic acid, acetic acid, oxalic acid, citric acid, and inorganic acids include hydrochloric acid, hydrobromic acid, hydroiodic acid, hypochlorous acid, chlorous acid, sulfuric acid, nitric acid, phosphorus An acid, hydrogen peroxide, etc. are mentioned. An inorganic acid is preferable from the viewpoint of solubility of the metal, and hydrochloric acid is preferable as the inorganic acid from the viewpoint of solubility of the metal. Two or more kinds of acids may be contained.

  When the palladium solution contains an acid, the pH of the solution is preferably 0 or more, 7 or less, more preferably 2 or more and 6 or less, and further preferably 3 or more and 5 or less.

  Since the palladium solution contains an acid and the pH is in the above range, palladium is stably present in the aqueous solution, and reacts with the phosphorus and sulfur of the cyclic phenol sulfide derivative to form a complex, thereby more efficiently. It becomes possible to extract palladium.

The concentration of the cyclic phenol sulfide derivative represented by the general formula (1) in the extractant solution is not particularly limited except that the upper limit is limited by the solubility of the cyclic phenol sulfide derivative. Since the extraction effect cannot be obtained, it is usually used in the range of 1 × 10 ^{−6 to} 1M. The concentration of palladium in the palladium solution is not particularly limited, and is usually about 1000 ppm.

  The extraction temperature is not particularly limited as long as it is equal to or lower than the boiling point of the solvent to be used, and is usually performed around room temperature. The extraction operation is performed by bringing the extractant solution and the palladium solution into contact with each other by shaking or stirring. Shaking is usually performed about 100 to 500 times per minute. The shaking time is preferably 24 hours or more from the viewpoint of increasing the extraction rate because the extraction rate is low at 24 hours or less and no change in the extraction rate is observed after 24 hours.

  In the present invention, the plurality of types of metals contained in the solution are not particularly limited, and may include alkali metals, alkaline earth metals, transition metals, 3B metals, and the like. Among these, the method for extracting and separating palladium of the present invention is particularly preferably used for extracting palladium from a rare metal-containing solution. For example, palladium can be extracted and separated with high efficiency and high selectivity from a PGM (Platinum-Group Metals) solution containing aluminum, barium, cerium, lanthanum, platinum, rhodium, yttrium, or zirconium in addition to palladium. Thereby, the rare and useful palladium can be recycled. Moreover, since the amount of palladium contained in the PGM solution after separating palladium can be greatly reduced, it can also be used as an operation for removing palladium. Therefore, this invention can be utilized also as a pre-processing at the time of isolating useful metals other than palladium from a PGM solution.

  EXAMPLES Hereinafter, although the Example demonstrates the palladium extractant of this invention and the extraction separation method of palladium further in detail, this invention is not limited to the following specific forms.

(Production Example 1)
<Production of cyclic phenol sulfide intermediate oligomer (A)>

In a 1000 mL three-necked flask, p-tert-butylphenol 300 g (2.0 mol), diphenyl ether (Ph ₂ O) 64.0 mL, and ethylene glycol 56.0 mL (1.0 mol) were placed, and heated and stirred under a nitrogen atmosphere. After reaching 60 ° C., 28.0 g (0.5 mol) of calcium oxide was added, and the temperature was raised to 120 ° C. in about 20 minutes and allowed to react for 2 hours. Thereafter, ethylene glycol and produced water were distilled off under reduced pressure. Diphenyl ether distilled off at the same time as distillation under reduced pressure was added, and the mixture was heated and stirred again under a nitrogen atmosphere. After reaching 100 ° C., 95.9 g (3.0 mol) of sulfur was added, and the temperature was raised to 230 ° C. And reacted for 3 hours. Then, it was allowed to cool and it was confirmed that the temperature reached 110 ° C., 250 mL of toluene was gradually added to lower the viscosity of the reaction solution, and this reaction solution was poured into 500 mL of 4N sulfuric acid to stop the reaction. The precipitated calcium sulfate was filtered, and the filtrate was washed with a saturated aqueous sodium sulfate solution, and then the filtrate was concentrated and heated to 80 ° C. This was poured into 1 L of acetic acid heated to 80 ° C. prepared separately, stirred at 80 ° C. for about 1 hour, and then allowed to stand overnight at room temperature. The precipitated precipitate was washed with distilled water and then dissolved in a large amount of chloroform in order to remove unwashed acetic acid and washed with an aqueous sodium sulfate solution. Thereafter, the organic phase was dried over sodium sulfate, concentrated, and dried under reduced pressure overnight to obtain a cyclic phenol sulfide intermediate oligomer (A). The yield of the cyclic phenol sulfide intermediate oligomer (A) was 67.8%.

(Production Example 2)
<Production of cyclic phenol sulfide (B)>

In a 500 mL three-necked flask, 30 g of the cyclic phenol sulfide intermediate oligomer (A) obtained in Production Example 1, 64.0 mL of diphenyl ether, 3.99 g of sodium hydroxide, and 1.62 g of acetic acid were put in this order. The mixture was heated and stirred under a nitrogen atmosphere, and 2.14 g of sulfur was added at 100 ° C., and the temperature was raised to 230 ° C. in about 1 hour, followed by reaction for 4 hours. Thereafter, the mixture was allowed to cool, and toluene was added to lower the viscosity of the reaction solution. Then, 2N sulfuric acid (100 mL) was poured into the reaction solution to stop the reaction. Thereafter, the aqueous phase was removed, washed with a saturated aqueous sodium sulfate solution and then with water, and after concentration, diphenyl ether in the concentrate was distilled off under reduced pressure. Thereafter, the product was washed with acetone, and the deposited precipitate was collected by filtration and dried under reduced pressure to obtain crude cyclic phenol sulfide crystals. The crude crystals were dissolved in chloroform and recrystallized to purify the cyclic phenol sulfide (B). The yield of the cyclic phenol sulfide (B) after purification was 4.162 g, and the yield was 13.90%.
In addition, cyclic phenol sulfide (B) (tetramer) and other multimers were separated by the difference in solubility.

(Production Example 3)
<Synthesis of cyclic phenol sulfide derivative (detert-butyl-TC4A)>

  In a 1000 mL two-necked flask, 15.0 g (20.8 mmol) of the cyclic phenol sulfide (B) obtained in Production Example 2 was added, 450 mL of toluene was added thereto, and the mixture was stirred for 30 minutes. ) Was dissolved. Next, 20.0 g (211.3 mmol) of phenol and 100 g (750.0 mmol) of aluminum chloride were added and reacted at 80 ° C. for 5 hours under a nitrogen stream. Thereafter, the reaction solution was allowed to cool to room temperature. In a 2000 mL Erlenmeyer flask, 900 mL of 2N hydrochloric acid was prepared, the reaction solution was slowly added in an ice bath, and the mixture was stirred overnight at room temperature to deactivate aluminum chloride. The resulting precipitate was filtered, and the resulting pale yellow powder was washed with 500 mL of water and then with 500 mL of acetone, and then the crude product collected by filtration was transferred to a 500 mL Erlenmeyer flask. After adding acetone and stirring, By drying with a vacuum dryer, a white powdered cyclic phenol sulfide derivative (detert-butyl-TC4A) was obtained. The yield was 6.99 g, and the yield was 68%.

(Production Example 4)
<Synthesis of cyclic phenol sulfide derivative (p-tert-butyl-TC4A diethyl phosphate derivative: 2a)>

Put 0.362 g (0.5 mmol) of the cyclic phenol sulfide (B) obtained above and 0.552 g (4 mmol) of potassium carbonate in a 100 mL two-necked flask, stir in a nitrogen atmosphere, and add acetone (20 mL). Add. Thereafter, 0.15 mL (8 mmol) of diethyl chlorophosphate dissolved in 10 mL of acetone is dropped, and the mixture is reacted for 10 hours under reflux. After completion of the reaction, the reaction is allowed to cool to room temperature and acetone is distilled off. Then, it is dissolved in chloroform (about 50 mL), washed once with 1N-HCl and washed three times with an aqueous sodium sulfate solution. The obtained organic layer is dried over sodium sulfate, concentrated and sufficiently dried under reduced pressure to obtain a crude product. The resulting composition organism was purified by recrystallization from a solution of chloroform: hexane = 1: 1 to obtain the desired product.
Yield: 0.52 g (Yield: 81.88%)
The target product was identified by ¹ H-NMR, FT-IR, TOF-MS, and elemental analysis.
¹ H NMR (600 MHz, CDCl ₃ ): 7.43 (s, 2H, Ar), 4.39-4.48 (m, 6H, P (O) CH ₂ CH ₃ ), 1.39 (t, 6H, P (O) CH ₂ CH ₃ ) 1.12 (s, 9H, tert.Bu.); FT-IR: 1282 (P = O); Maldi MS: 1264 (M ⁺ ), 1287 (M + Na). Anal.Calcd. For C ₅₆ H ₈₄ O ₁₆ P ₄ S ₄ (%): C, 53.14; H, 6.69.found: C, 52.99; H, 6.56.

(Production Example 5)
<Synthesis of cyclic phenol sulfide derivative (de-tert-butyl-TC4A diethyl phosphate derivative: 2b)>

Put 0.250 g (0.5 mmol) of de-tert-butyl-TC4A obtained above and 0.552 g (4 mmol) of potassium carbonate in a 100 mL two-necked flask, stir in a nitrogen atmosphere, and add acetone (20 mL). . Thereafter, 0.15 mL (8 mmol) of diethyl chlorophosphate dissolved in 10 mL of acetone is dropped, and the mixture is reacted for 10 hours under reflux. After completion of the reaction, the reaction is allowed to cool to room temperature and acetone is distilled off. Then, it is dissolved in chloroform (about 50 mL), washed once with 1N-HCl and washed three times with an aqueous sodium sulfate solution. The obtained organic layer is dried over sodium sulfate, concentrated and sufficiently dried under reduced pressure to obtain a crude product. The resulting composition organism was purified by recrystallization from a solution of chloroform: hexane = 1: 1 to obtain the desired product.
Yield: 0.39 g (Yield: 74.42%)
The target product was identified by ¹ H-NMR, FT-IR, TOF-MS, and elemental analysis.
¹ H NMR (600 MHz, CDCl ₃ ): 6.98 (s, 2H, Ar), 6.80 (d, 1H, Ar), 4.35-4.41 (m, 4H, P (O) CH ₂ CH ₃ ), 1.38 (t , 6H, P (O) CH ₂ CH ₃ ); FT-IR: 1266 (P = O); Maldi MS: 1040 (M ⁺ ), 1063 (M + Na). Anal. Calcd. For C ₄₀ H ₅₂ O ₁₆ P ₄ S ₄ (%): C, 46.15; H, 5.03.found: C, 45.90; H, 4.82.

Example 1
<Preparation of PGM aqueous solution>
A PGM (Platinum-Group Metals) solution in which waste containing several types of rare metals discharged from the factory was made into an aqueous solution by acid treatment was diluted 10 times with distilled water and used. Each metal concentration of 10 times diluted PGM aqueous solution is shown below.

<Palladium Extraction Separation Using Cyclic Phenol Sulfide Derivatives (2a) and (2b)>
Using the cyclic phenol sulfide derivative (2a) or (2b) obtained in Production Example 4, a palladium extraction experiment was performed. First, 10 mL of an organic layer in which the cyclic phenol sulfide derivative (2a) or (2b) is dissolved in chloroform to a concentration of 1.0 mM and the 10-fold diluted PGM aqueous solution are placed in a 50 mL centrifuge tube, and 300 strokes / Shake for 24 h at min. After standing, the metal concentration in the aqueous layer was analyzed with an ICP emission spectrometer (SPS3000, manufactured by SII), and the extraction rate (E%) was calculated by the following formula (I) based on the obtained results. Asked. The cyclic phenol sulfide derivative and the metal concentration in the aqueous solution were set to a molar ratio of 1: 1.
(E%) = (C ₀ −C) / C ₀ × 100 (I)
However, _C0 : Metal concentration (ppm) in the water layer before extraction, C: Metal concentration (ppm) in the water layer after extraction
The extraction results are shown in Table 2 and FIG.

[result]
From Table 2 and FIG. 1, the cyclic phenol sulfide derivatives (2a) and (2b) both had an extraction rate of about 85%, and palladium was extracted at a high extraction rate. In addition, when the cyclic phenol sulfide derivative (2a) is used, the metal extracted together with palladium is only one kind of zirconium, and when the cyclic phenol sulfide derivative (2b) is used, only palladium is extracted. It was done. That is, it was shown that the palladium extractant of the present invention has high selectivity for palladium.

(Example 2)
<Investigation of the effect of extraction time on extraction rate>
Using the cyclic phenol sulfide derivative (2a), the influence of the extraction time on the extraction rate was investigated.
10 mL of an organic layer having a concentration of 1.0 mM by dissolving cyclic phenol sulfide derivative (2a) in chloroform and 10 mL of 1 mM palladium chloride hydrochloric acid solution (pH 3) are placed in a 50 mL centrifuge tube, and the shaking time is 1 to The pressure was changed in the range of 42 h and shaken at 300 strokes / min. After standing, the metal concentration in the aqueous layer was analyzed in the same manner as in Example 1, and the extraction rate (E%) was determined by the above formula (I) based on the obtained results. The cyclic phenol sulfide derivative and the metal concentration in the aqueous solution were set to a molar ratio of 1: 1.
The results are shown in FIG.

[result]
As shown in FIG. 2, the extraction rate increased as the extraction time increased, and reached 100% in 24 hours. From this result, it was shown that the extraction time is preferably 24 hours or longer when extraction is performed using the cyclic phenol sulfide derivative (2a).

(Example 3)
<Investigation of the effect of pH on extraction rate>
Using the cyclic phenol sulfide derivative (2a), the influence of the pH of the palladium solution on the extraction rate was investigated.
An extraction experiment was performed in the same manner as in Example 2 except that the pH of the palladium solution was changed between 0 and 5 and the shaking time was fixed at 24 h.
The results are shown in FIG.

[result]
From FIG. 3, it was confirmed that the extraction rate was higher as the pH was higher in the range of pH 0 to 3, and the extraction rate was 100% in the range of pH 3 to 5. From this result, it was shown that the pH is preferably 3 or more when extraction is performed using the cyclic phenol sulfide derivative (2a).

Example 4
<Creation of JOB's plot of cyclic phenol sulfide derivative (2a) -Pd (II) complex>
The mode of complex formation between the cyclic phenol sulfide derivative (2a) and palladium ion (Pd (II)) was specified using the JOB continuous change method.
A plurality of 20 mL of a solution in which a cyclic phenol sulfide derivative (2a) was dissolved in chloroform to have a concentration of 1.0 mM and a 1.0 mM palladium chloride hydrochloric acid solution (pH 3) were mixed at different ratios were prepared. Each of these solutions was placed in a 50 mL centrifuge tube and shaken at 300 strokes / min for 24 hours. After standing, the organic layer was separated, and the absorbance at 438 nm was determined using ultraviolet, visible, and near infrared spectroscopy. FIG. 4 shows a plot of the absorbance against the molar fraction of the cyclic phenol sulfide derivative (2a).

[result]
From FIG. 4, the absorbance of the cyclic phenol sulfide derivative (2a) -Pd (II) complex becomes maximum when the molar fraction of the cyclic phenol sulfide derivative (2a) is 0.5, and the cyclic phenol sulfide derivative ( 2a) and palladium ions were found to form a 1: 1 complex.

  While the present invention has been described in connection with embodiments that are presently the most practical and preferred, the present invention is not limited to the embodiments disclosed herein. However, the present invention also includes a palladium extractant and a method for extracting and separating palladium, which can be changed as appropriate without departing from the spirit or concept of the invention that can be read from the claims and the entire specification. Should be understood as being included in the technical scope of

  INDUSTRIAL APPLICABILITY The present invention can be suitably used as a method for selectively recovering and reusing palladium from a metal that is often contained in precision instruments such as used electrical appliances, in particular, a solution containing rare metals.

Claims (7)

A palladium extractant containing a cyclic phenol sulfide derivative represented by the following general formula (1).
(In Formula (1), R < ¹ >, R < ² >, R < ³ > is respectively independently a hydrogen atom or a C1-C5 hydrocarbon group, and Z is either a sulfide group, a sulfinyl group, and a sulfonyl group. .) The R ¹ is a hydrogen atom or a linear or branched alkyl group having 1 to 5 carbon atoms, and the R ² and R ³ are each independently a linear or branched alkyl group having 1 to 5 carbon atoms, Item 2. The palladium extractant according to Item 1. The R ¹ is a hydrogen atom, the R ² and R ³ are each independently a linear or branched alkyl group having 1 to 3 carbon atoms, and the Z is a sulfide group. Palladium extractant. A method for extracting and separating palladium, comprising a step of bringing a cyclic phenol sulfide derivative represented by the following general formula (1) into contact with a solution containing a plurality of types of metals including palladium.
(In Formula (1), R < ¹ >, R < ² >, R < ³ > is respectively independently a hydrogen atom or a C1-C5 hydrocarbon group, and Z is either a sulfide group, a sulfinyl group, and a sulfonyl group. .) The R ¹ is a hydrogen atom or a linear or branched alkyl group having 1 to 5 carbon atoms, and the R ² and R ³ are each independently a linear or branched alkyl group having 1 to 5 carbon atoms, Item 5. The palladium extraction and separation method according to Item 4. The R ¹ is a hydrogen atom, the R ² and R ³ are each independently a linear or branched alkyl group having 1 to 3 carbon atoms, and the Z is a sulfide group. Of palladium by extraction. The method for extracting and separating palladium according to any one of claims 4 to 6, wherein the solution contains aluminum, barium, cerium, lanthanum, platinum, rhodium, yttrium, or zirconium in addition to palladium.