JP2014133227A - Platinum separating agents and platinum ion separating methods - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a separating agent and a platinum ion separation method that enable platinum ions to be separated from a solution containing low to high concentration of platinum ions in a short time and with high selectivity.SOLUTION: A separating agent represented by general formula (1), in which a functional group is attached to a carrier, is used to separate platinum ions. (In the formula, R represents an optionally substituted chain hydrocarbon group with 1 to 18 carbon atoms, an alicyclic hydrocarbon group with 3 to 10 carbon atoms, an aromatic hydrocarbon group with 6 to 14 carbon atoms, a heterocyclic group with 3 to 12 carbon atoms, a carboxymethyl group, or a carboxyethyl group; and n represents an integer from 1 to 4.)

Description

  The present invention relates to a separating agent that selectively adsorbs platinum or platinum ions from a solution containing a plurality of metal ions and enables separation and recovery of platinum, and a method for separating platinum ions.

  Industrial catalysts, automobile exhaust gas purification catalysts and many electrical appliances use noble metals such as palladium, platinum and rhodium. Since these noble metals are expensive and useful as resources, they are conventionally collected and reused after use, that is, recycled. Recently, demands for resource conservation have increased, and the importance of recycling precious metals has increased.

  In order to recover precious metals, methods such as precipitation separation, ion exchange, electrolytic deposition, solvent extraction, and adsorption have been developed. Of these, solvent extraction is economical and easy to use. Widely adopted.

  The solvent extraction method includes an extraction step of extracting platinum ions to the organic phase side by bringing the aqueous phase in which platinum ions are dissolved into contact with the organic phase in which the platinum ion extractant is dissolved, and extraction to the organic phase side. It consists of the back extraction process which back-extracts platinum ion to the water phase side by making platinum ion and the aqueous phase which the back extractant melt | dissolved contacted.

  According to this method, platinum ions can be recovered with a high selectivity, and thus are used industrially (see, for example, Patent Document 1).

  However, since the solvent extraction method uses a large amount of an organic solvent, there are problems in terms of safety and environmental load. In addition, in the method using an extraction solvent such as tributyl phosphate generally used in the extraction method, the extraction rate of low concentration platinum ions is insufficient, and the extraction rate is high even with a high concentration platinum solution. Since it is slow, it has problems such as low productivity.

  Therefore, it is desired to develop a separating agent capable of separating platinum from a low-concentration to high-concentration platinum ion solution in a short time and with high selectivity, and a method for separating platinum ions using the separating agent. .

  The present applicant has applied for a patent for a platinum group metal adsorbent having a specific amide-containing sulfur functional group on the surface of the support (see Patent Document 2). However, even if this adsorbent is applied to a solution containing palladium, platinum, and rhodium, since palladium is preferentially adsorbed, it is referred to as a separating agent and separation method capable of separating platinum with high selectivity. It was not enough in terms yet.

Japanese Patent Publication No.1-30896 JP 2011-41918 A

  The present invention has been made in view of the above-mentioned background art, and is a separating agent capable of separating platinum from a platinum solution in a low concentration range to a high concentration range in a short time and with high selectivity, and the separation thereof. It is an object to provide a method for separating platinum ions using an agent.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have used a novel separating agent shown in the present invention in a short time from a platinum solution in a low concentration to a high concentration range, and The inventors have found that platinum can be separated with high selectivity, and have completed the present invention.

  That is, the present invention has the following gist.

  [1] A platinum separating agent in which a functional group represented by the following general formula (1) is bonded to a carrier.

（式中、Ｒは、置換基を有してもよい炭素数１〜１８の鎖式炭化水素基、炭素数３〜１０の脂環式炭化水素基、炭素数６〜１４の芳香族炭化水素基、炭素数３〜１２の複素環基、カルボキシメチル基、又はカルボキシエチル基を表し、ｎは１〜４の整数を表す。Ｚはアミド結合を表す。）
［２］一般式（１）で示される官能基が、一般式（２）で示される官能基であることを特徴とする上記［１］に記載の分離剤。

(In formula, R is a C1-C18 chain hydrocarbon group which may have a substituent, a C3-C10 alicyclic hydrocarbon group, and a C6-C14 aromatic hydrocarbon. A group, a C3-C12 heterocyclic group, a carboxymethyl group, or a carboxyethyl group, n represents an integer of 1 to 4. Z represents an amide bond.)
[2] The separating agent as described in [1] above, wherein the functional group represented by the general formula (1) is a functional group represented by the general formula (2).

（式中、Ｒは、置換基を有してもよい炭素数１〜１８の鎖式炭化水素基、炭素数３〜１０の脂環式炭化水素基、炭素数６〜１４の芳香族炭化水素基、炭素数３〜１２の複素環基、カルボキシメチル基、又はカルボキシエチル基を表し、ｎは１〜４の整数を表す。）
［３］一般式（１）又は（２）で示される官能基が、メチレン基、エチレン基、炭素数３〜８の直鎖、分岐若しくは環状のアルキレン基、又は炭素数６〜１４のアリーレン基を介して担体に結合していることを特徴とする上記［１］又は［２］に記載の分離剤。

(In formula, R is a C1-C18 chain hydrocarbon group which may have a substituent, a C3-C10 alicyclic hydrocarbon group, and a C6-C14 aromatic hydrocarbon. Group, a C3-C12 heterocyclic group, a carboxymethyl group, or a carboxyethyl group, and n represents an integer of 1-4.)
[3] The functional group represented by the general formula (1) or (2) is a methylene group, an ethylene group, a linear, branched or cyclic alkylene group having 3 to 8 carbon atoms, or an arylene group having 6 to 14 carbon atoms. The separating agent according to [1] or [2], wherein the separating agent is bound to a carrier via

  [4] The separating agent according to any one of [1] to [3], wherein the carrier is an inorganic carrier.

  [5] A method for adsorbing platinum ions, comprising contacting the separating agent according to any one of [1] to [4] above with a solution containing platinum (II) ions.

  [6] Contacting a separating agent adsorbing platinum (II) ions obtained by the platinum ion adsorption method described in [5] above with a desorbing agent to desorb the platinum (II) ions. A method for separating platinum ions.

  [7] The separation method according to [6], wherein the releasing agent is at least one selected from the group consisting of ammonia, thiourea, methionine, and ethylenediamine.

  [8] Use of the separating agent according to any one of the above [1] to [4] as an agent for adsorbing and separating platinum ions from a solution containing platinum (II) ions.

  The separating agent of the present invention can be used repeatedly and does not require an organic solvent. As a result, platinum or platinum ions can be separated and recovered economically without placing an environmental burden.

  Moreover, according to the separation method of the present invention, platinum can be separated from a platinum solution having a low concentration to a high concentration in a short time and with a high selectivity.

  Furthermore, according to the separation method of the present invention, platinum ions can be adsorbed and desorbed with high selectivity from a solution in which platinum ions and palladium ions coexist.

  Hereinafter, the present invention will be described in detail.

  The separating agent of the present invention is characterized in that the functional group represented by the general formula (1) is bonded to a carrier.

  Although it does not specifically limit as a functional group shown by the said General formula (1), For example, it is preferable that it is a functional group shown by the said General formula (2).

  In the functional group represented by the general formula (1), Z represents an amide bond. Here, the “amide bond” indicates a bond represented by —CO—NH—, and the direction of the bond is not particularly limited, but is preferably the direction represented by the general formula (2).

  The functional group represented by the general formula (1) or (2) is a methylene group, an ethylene group, a linear, branched or cyclic alkylene group having 3 to 8 carbon atoms, or an arylene group having 6 to 14 carbon atoms. And preferably bound to a carrier.

  Although it does not specifically limit as said C3-C8 linear or branched alkylene group, For example, a propylene group, a butylene group, a pentylene group, a hexylene group, a heptylene group, an octylene group etc. are mentioned. These may be linear or branched. The bonding position of the amide group is not particularly limited as long as it is on the carbon of the alkylene group.

  Examples of the cyclic alkylene group having 3 to 8 carbon atoms include a cyclopropylene group, a cyclobutylene group, a cyclopentylene group, a cyclohexylene group, a cycloheptylene group, a cyclooctylene group, a cyclohexenylene group, and a cyclohexadienylene group. , Cyclooctenylene group, cyclooctadienylene group and the like. The bonding position of the amide group is not particularly limited as long as it is on the carbon of the cycloalkylene group.

  Examples of the arylene group having 6 to 14 carbon atoms include a phenylene group, a naphthylene group, an anthrylene group, a tolylene group, a xylylene group, a cumenylene group, a benzylene group, a phenylene group, a styrylylene group, a cinnamylene group, a biphenylylene group, and a phenanthrylene group. Etc. The bonding position of the amide group is not particularly limited as long as it is on the carbon of the arylene group.

  Of these, the functional group represented by the general formula (1) or (2) is particularly preferably bonded to the carrier via an n-propylene group.

  In the functional group represented by the above general formula (1) or (2), R is a C1-C18 chain hydrocarbon group which may have a substituent, and a C3-C10 alicyclic carbonization. A hydrogen group, a C6-C14 aromatic hydrocarbon group, a C3-C12 heterocyclic group, a carboxymethyl group, or a carboxyethyl group is represented.

  Although it does not specifically limit as a C1-C18 chain hydrocarbon group, For example, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group Decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group (cetyl group), heptadecyl group, octadecyl group (stearyl group), oleyl group, elaidyl group, isopropyl group, isobutyl group, sec- Butyl group, tert-butyl group, isopentyl group, neopentyl group, tert-pentyl group, 2-ethylhexyl group, vinyl group, allyl group, 1-propenyl group, isopropenyl group, 1-butenyl group, 2-butenyl group, 2 -Methyl allyl group, 1-heptynyl group, 1-hexenyl group, 1-heptenyl group, - octenyl, 2-methyl-1-propenyl group. Of these, a chain hydrocarbon group having 1 to 4 carbon atoms is preferred.

  Examples of the alicyclic hydrocarbon group having 3 to 10 carbon atoms include, but are not limited to, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclononyl group, and cyclodecyl. Group, cyclohexenyl group, cyclohexadienyl group, cyclooctenyl group, cyclooctadienyl group and the like.

  Examples of the aromatic hydrocarbon group having 6 to 14 carbon atoms include, but are not limited to, phenyl group, naphthyl group, anthryl group, tolyl group, xylyl group, cumenyl group, benzyl group, phenethyl group, and styryl group. , Cinnamyl group, biphenylyl group, phenanthryl group and the like.

  The heterocyclic group having 3 to 12 carbon atoms is not particularly limited. For example, oxazolyl group, isoxazolyl group, thiazolyl group, isothiazolyl group, imidazolyl group, pyrazolyl group, pyrrolidinyl group, tetrahydrofuranyl group, tetrahydrothiophenyl Group, pyrrolyl group, furanyl group, five-membered heterocyclic group such as furanyl group, thiophenyl group, pyrazinyl group, morpholinyl group, thiazinyl group, pyrimidinyl group, pyridazinyl group, piperidinyl group, tetrahydropyranyl group, tetrahydrothiopyranyl group, pyridyl group, etc. 6-membered heterocyclic group, prynyl group, benzimidazolyl group, benzoxazolyl group, indolyl group, isoindolyl group, pteridinyl group, cinnolyl group, quinoxalinyl group, quinolyl group, isoquinolyl group, chromenyl group, isochromenyl group, acrylyl group Group, xanthenyl group, such as fused heterocyclic group and a carbazolyl group.

  Examples of the “substituent” in R in the general formula (1) or (2) include an alicyclic hydrocarbon group having 3 to 10 carbon atoms, an aromatic hydrocarbon group having 6 to 14 carbon atoms, and the number of carbon atoms. 3 to 12 heterocyclic groups are preferred. For these, specifically, the above-described “alicyclic hydrocarbon group having 3 to 10 carbon atoms”, “aromatic hydrocarbon group having 6 to 14 carbon atoms”, and “heterocyclic group having 3 to 12 carbon atoms”. The explanation of "can be used. Of these, heterocyclic groups are preferred.

  In the functional group represented by the general formula (1) or (2), R may be a methyl group, an ethyl group, a propyl group, a butyl group, an isopropyl group, a phenyl group, a benzyl group, or a pyridylmethyl group. Preferably, an ethyl group, a propyl group, an isopropyl group, a phenyl group, a benzyl group, and a pyridylmethyl group are more preferable, and an ethyl group, a propyl group, and a pyridylmethyl group are particularly preferable.

  In the functional group represented by the general formula (1) or (2), n represents an integer of 1 to 4, and is preferably 1.

  Any carrier that is insoluble in the solvent can be used without particular limitation. The carrier that can be used is not particularly limited. For example, in addition to inorganic carriers such as silica gel, alumina, titania, magnesia, zirconia, iron oxide, copper oxide, glass, silica sand, talc, mica, clay, and wollastonite. Polystyrene polymers such as styrene polymer and styrene-divinylbenzene crosslinked; polyolefins such as polyethylene, polypropylene and polyvinyl chloride; acrylic polymers such as polymethyl methacrylate and polyethyl acrylate; polylysine particles, polyvinylamine particles, poly Examples include organic carriers such as methyl glutamic acid and polyvinyl alcohol. Of these carriers, inorganic carriers are preferable in terms of chemical resistance and price, and silica gel is particularly preferable in terms of high versatility.

  The shape of the carrier is generally used as a separation substrate such as spherical (eg, spherical particles), granular, fibrous, granular, monolithic column, hollow fiber, membrane (eg, flat membrane), etc. Shape is available. Although not particularly limited, spherical, film-like, granular, granular or fibrous ones are preferable among these. Spherical, granular or granular carriers are particularly preferably used because their use volume can be arbitrarily set when used in the column method or batch method.

  The particle size of the spherical, granular or granular carrier is not particularly limited. For example, those having an average particle size in the range of 1 μm to 10 mm can be used, and among these, in terms of operability and adsorption capacity. The range of 2 μm to 1 mm is preferable.

  The element ratio (S / N) of the S element and the N element contained in the separating agent of the present invention can be calculated, for example, by performing elemental analysis. The element ratio (S / N) is not particularly limited, but is preferably in the range of 0.94 to 1.00. By making the element ratio (S / N) 0.94 or more, the selectivity of platinum ions is improved.

  The average pore diameter of the carrier can be calculated by, for example, a mercury intrusion method. The average pore diameter is not particularly limited, but is preferably 2 μm or more. By setting the average pore diameter of the carrier to 2 μm or more, the platinum ion adsorption amount is improved.

  Although it does not specifically limit as a manufacturing method of the separating agent of this invention, For example, the following method can be mentioned. That is, a carrier having an amino group described below (hereinafter referred to as “aminated carrier”) and a sulfide-containing carboxylic acid compound represented by the following general formula (3) are reacted (hereinafter referred to as “immobilization reaction”). Can be manufactured by.

（式中、Ｒ、ｎは上記と同じ定義である。）
上記一般式（３）で示されるスルフィド含有カルボン酸化合物としては、特に限定するものではないが、例えば、アンモニウム塩、アルカリ金属塩等のスルフィド含有カルボン酸塩、カルボン酸メチルエステル、カルボン酸エチルエステル等のエステル化物、２分子のスルフィド含有カルボン酸化合物が脱水縮合した酸無水物等が挙げられる。

(In the formula, R and n are as defined above.)
The sulfide-containing carboxylic acid compound represented by the general formula (3) is not particularly limited, but examples thereof include sulfide-containing carboxylates such as ammonium salts and alkali metal salts, carboxylic acid methyl esters, and carboxylic acid ethyl esters. And acid anhydrides obtained by dehydration condensation of two molecules of a sulfide-containing carboxylic acid compound.

  The amination carrier is not particularly limited, but examples thereof include amination silica, amination alumina, amination zirconia, amination titania, amination magnesia, amination glass and the like, amination styrene- Examples thereof include aminated organic carriers such as divinylbenzene crosslinked product, polyallylamine particles, polylysine particles, polyvinylamine particles, aminated polymethylglutamic acid, and aminated polyvinyl alcohol.

  A commercially available product can be used as the aminated carrier, and a carrier obtained by aminating the above-mentioned carrier by a generally known method can be used, and is not particularly limited.

  The method for aminating the carrier is not particularly limited. For example, the carrier and the silane coupling agent having an amino group described above are mixed and reacted (hereinafter referred to as “silane coupling reaction”). Can be manufactured by.

  Although it does not specifically limit as a silane coupling agent which has an amino group, For example, the silane coupling agent shown by following General formula (4) is mentioned.

（式中、Ｘは各々独立して、メチル基、エチル基、メトキシ基、又はエトキシ基を表し、そのうち少なくとも１つ以上がメトキシ基又はエトキシ基を表す。Ｙは炭素数が１〜１２であり、窒素数が１〜２からなるアミノアルキル基を表す。）
上記一般式（４）において、Ｙで表されるアミノアルキル基としては、特に限定するものではないが、例えば、２−アミノエチル基、３−アミノプロピル基、６−アミノヘキシル基、Ｎ−２−（アミノエチル）−３−アミノプロピル基、Ｎ−６−（アミノヘキシル）−３−アミノプロピル基等が挙げられる。

(In the formula, each X independently represents a methyl group, an ethyl group, a methoxy group, or an ethoxy group, and at least one of them represents a methoxy group or an ethoxy group. Y has 1 to 12 carbon atoms. And represents an aminoalkyl group having 1 to 2 nitrogen atoms.)
In the general formula (4), the aminoalkyl group represented by Y is not particularly limited, and examples thereof include a 2-aminoethyl group, a 3-aminopropyl group, a 6-aminohexyl group, and N-2. -(Aminoethyl) -3-aminopropyl group, N-6- (aminohexyl) -3-aminopropyl group and the like can be mentioned.

  Although the amount of the silane coupling agent having an amino group in the silane coupling reaction is not particularly limited, for example, it is selected from a range of 0.1 to 10 mol with respect to 1 kg of the carrier. Among these, the range of 0.5-5 mol is preferable at the point of introduction efficiency and economical efficiency of an amino group.

  The above silane coupling reaction is usually performed in a solvent. The solvent is not particularly limited as long as it does not inhibit this reaction, but aromatic hydrocarbon solvents such as benzene, toluene, xylene and mesitylene are preferably used. Although the usage-amount of a solvent is not specifically limited, It is 2-40 weight part normally with respect to the silane coupling agent which has an amino group, Preferably it is the range of 4-15 weight part.

  The reaction temperature in the silane coupling reaction is preferably in the range of 0 to 200 ° C, more preferably 30 to 110 ° C. By setting it within this temperature range, the silane coupling reaction proceeds sufficiently.

  The reaction time in the silane coupling reaction varies depending on the concentration of the amino group-containing silane coupling agent, the reaction temperature, and the like, and is not particularly limited, but is usually performed in the range of several minutes to 24 hours.

  The aminated carrier obtained by the silane coupling reaction can be easily separated from other components in the reaction solution by filtration and washing operations.

  In the immobilization reaction, the use amount of the sulfide-containing carboxylic acid compound represented by the general formula (3) is preferably 1 to 10 times mol, and 1.2 to 3 times the nitrogen content of the amination carrier. Mole is more preferred. If the amount of the sulfide-containing carboxylic acid compound used is 1-fold mol or more with respect to the nitrogen content of the amination carrier, the immobilization reaction proceeds sufficiently, and if it is 10-fold mol or less, it is economically preferable.

  The immobilization reaction is usually performed in a solvent. The solvent is not particularly limited as long as it does not inhibit the reaction, but an organic solvent such as benzene, toluene, xylene, dichloromethane, chloroform, tetrahydrofuran, N, N-dimethylformamide is preferably used. Although the usage-amount of a solvent is not specifically limited, It is 2-40 weight part normally with respect to the sulfide containing carboxylic acid compound shown by the said General formula (3), Preferably it is the range of 3-15 weight part. .

  In the immobilization reaction, a reaction accelerator can be added to the reaction solution. The reaction accelerator is not particularly limited. For example, N, N′-dicyclohexylcarbodiimide, N, N′-diisopropylcarbodiimide, 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide, diphenylphosphoric acid Dehydrating condensing agents such as azide, benzotriazol-1-yloxy-trisdimethylaminophosphonium chloride, 4- (4,6-dimethoxy-1,3,5-triazin-2-yl) -4-methylmorpholinium chloride, Examples thereof include boronic acid derivatives such as 3,5-bis (trifluoromethyl) phenylboronic acid, 4-trifluoromethylphenylboronic acid, 3,4,5-trifluorophenylboronic acid, and 3-nitrophenylboronic acid. . As these dehydrating condensing agents or boronic acid derivatives, commercially available reagents can be used as they are.

  The amount of the dehydrating condensing agent to be used is not particularly limited. For example, the amount of the dehydrating condensing agent is usually selected from the range of 1 to 10 moles per mole of the sulfide-containing carboxylic acid compound represented by the general formula (3). From the point of reaction acceleration effect and economical efficiency, the range of 1-3 times mole is preferable. When a dehydrating condensing agent is used, additives such as 1-hydroxybenzotriazole, 1-hydroxy-7-azabenzotriazole, and N-hydroxysuccinimide may be added for the purpose of improving the reactivity.

  The amount of these additives used is not particularly limited, but for example, it is selected from a range of 1 to 10 moles per mole of the sulfide-containing carboxylic acid compound represented by the general formula (3). From the point of reaction acceleration effect and economical efficiency, the range of 1-3 times mole is preferable.

  The amount of the boronic acid derivative used is not particularly limited, but is selected from a range of 0.0001 to 1 mol per mol of the sulfide-containing carboxylic acid compound represented by the general formula (3). . The range of 0.001-0.5 times mol is preferable from the point of reaction promotion effect and economical efficiency, and the range of 0.005-0.1 times mol is more preferable.

  Although the reaction temperature in an immobilization reaction is not specifically limited, For example, the range of 0-200 degreeC is preferable and the range of 100-180 degreeC is more preferable.

  The reaction time in the immobilization reaction varies depending on the concentration of the sulfide-containing carboxylic acid compound represented by the general formula (3) and the reaction accelerator, the reaction temperature, and the like, but is usually in the range of several minutes to 24 hours.

  The separating agent of the present invention obtained by the above-mentioned immobilization reaction can be easily separated from other components in the reaction solution by operations such as filtration, washing, and drying.

  The separating agent of the present invention can also be produced by a production method other than the method described above.

  As a manufacturing method other than the above-described method, for example, the following general formula (5)

（式中、Ｒ、ｎは上記と同じ定義である。）
で示されるスルフィド含有アミン化合物とカルボキシル基を有する担体とを反応させる製造法が挙げられる。

(In the formula, R and n are as defined above.)
And a production method of reacting a sulfide-containing amine compound represented by the formula (1) with a carrier having a carboxyl group.

  The sulfide-containing amine compound represented by the general formula (5) is not particularly limited, and examples thereof include 2-aminoethyl methyl sulfide, 2-aminoethyl ethyl sulfide, and 3-aminopropyl methyl sulfide. .

  As the reaction conditions, general reaction conditions can be used, and the reaction conditions are not particularly limited, but it is preferable to employ the same reaction conditions as the above-described immobilization reaction conditions.

  The sulfide-containing amine compound represented by the general formula (5) may be used as salts such as hydrochloride and bromate.

  As the carrier having a carboxyl group, a known carrier having a carboxyl group may be used. In addition, a carrier having a carboxyl group introduced on the surface of a known carrier can be used by a known method. At this time, the carboxyl group may be esterified like a carboxymethyl group or a carboxyethyl group.

  Although it does not specifically limit as a support | carrier which has a well-known carboxyl group, For example, the silica gel which has a carboxyl group (specifically SC carboxyl group modification silica microsphere, the product made from a Nipple Technocluster company), has a carboxyl group An ion exchange resin etc. can be mentioned.

  Further, as a production method other than the above, for example, a method of chemically bonding a sulfide-containing carboxylic acid compound having a substituent represented by the general formula (1) or (2) to a carrier by a known method may be used. it can. For example, a method of reacting a reaction product of a sulfide-containing carboxylic acid compound represented by the general formula (3) and a silane coupling agent having an amino group represented by the general formula (4) with an inorganic carrier can be mentioned.

  Next, a method for adsorbing platinum ions using the separating agent of the present invention will be described.

  In the present invention, the method for adsorbing platinum ions is carried out by bringing the separating agent of the present invention into contact with a solution containing platinum (II) ions. Although the separating agent of the present invention also has the ability to adsorb platinum (0), it is more efficient to adsorb platinum (II) ions in view of separation and recovery.

  The method for bringing the solution containing platinum (II) ions into contact with the separating agent of the present invention is not particularly limited. For example, the solution containing platinum (II) ions and the separating agent of the present invention are combined. The method (fluidized bed) which prepares the mixed slurry and stirs this is mentioned. In addition, a method (fixed bed) in which the separation agent of the present invention is packed in a column or the like and a solution containing platinum (II) ions is circulated and brought into contact therewith can be mentioned.

  In the above platinum ion adsorption method, the solution containing platinum ions to be brought into contact with the separating agent of the present invention is not particularly limited. For example, a solution in which an automobile exhaust gas treatment catalyst or jewelry is dissolved, platinum A solution after acid leaching in the hydrometallurgy process of the group metals is mentioned. In such a solution, since platinum ions are usually present in a tetravalent state, it is preferable to reduce the solution to obtain a solution containing platinum (II) ions.

  The solution containing platinum (II) ions described above contains platinum group metal ions such as rhodium ions, base metal ions such as copper ions, iron ions, nickel ions and zinc ions in addition to platinum (II) ions. Also good. When this solution is separated by the platinum separation method of the present invention described later, platinum ions can be selectively separated.

  On the other hand, it is desirable that the solution containing platinum (II) ions described above does not substantially contain palladium ions. In a solution containing platinum ions and palladium ions, platinum ions are usually tetravalent and palladium ions are usually divalent. The separating agent of the present invention selectively adsorbs palladium (II) ions with platinum (IV) ions and palladium (II) ions. For this reason, in the case of selectively adsorbing platinum ions from a solution containing platinum ions and palladium ions, the solution is brought into contact with a palladium separating agent to adsorb and separate the palladium ions, and the palladium ions are separated in advance. Is preferably removed.

  In the present invention, “substantially no palladium ions” means that palladium ions are removed to such an extent that they do not adversely affect the adsorption of platinum (II) ions by the separating agent of the present invention.

  Here, it does not specifically limit as a palladium separating agent, For example, a conventionally well-known palladium separating agent can be used. In addition, a separating agent in which the functional group represented by the general formula (1) is bonded to a carrier can be used as a palladium separating agent.

  In the case where platinum ions are selectively adsorbed from a solution containing platinum ions and palladium ions using a separating agent in which the functional group represented by the general formula (1) is bonded to a carrier as a palladium separating agent For example, platinum (II) ions can be selectively adsorbed from this solution by performing the steps shown in the following (1) to (3).

(1) A solution containing platinum (IV) ions and palladium (II) ions is brought into contact with a palladium separating agent to adsorb and separate palladium (II) ions, and a solution containing platinum (IV) ions is obtained. Obtaining step,
(2) reducing a solution containing platinum (IV) ions to obtain a solution containing platinum (II) ions with a platinum valence of 2; and (3) a solution containing platinum (II) ions; A step of contacting the separating agent of the present invention.

  The solution containing platinum (II) ions is not particularly limited and may be either an aqueous solution or an organic solvent solution, but an aqueous solution is preferably used in terms of environmental load.

  Although it does not specifically limit as liquidity of the solution containing platinum (II) ion, For example, when it is aqueous solution, it is preferable that it is acidic. Although it does not specifically limit as an acid used in order to acidify the solution containing platinum (II) ion, For example, inorganic acids, such as hydrochloric acid, a sulfuric acid, nitric acid, are mentioned. Of these, hydrochloric acid is particularly preferred because it is also used as an acid leaching solution of palladium ions.

  Although it does not specifically limit as acid concentration in the solution containing platinum (II) ion, The range of 0.1-10 mol / L (liter) is preferable, and the range of 0.1-5 mol / L is more preferable. When the acid concentration is within this range, platinum (II) ions can be adsorbed without impairing the adsorption efficiency of the separating agent of the present invention.

  When the solution containing platinum (II) ions is an organic solvent solution, the type of the organic solvent is not particularly limited. For example, toluene, benzene, xylene, chloroform, dichloromethane, dichloroethane, chlorobenzene, hexane, tetrahydrofuran, N , N′-dimethylformamide, ethyl acetate, acetone, methanol, ethanol, and other common organic solvents can be used.

  In the platinum ion adsorption method, the separating agent of the present invention is used in an amount of sulfur of 0.1% in the separating agent of the present invention with respect to 1 mole of platinum (II) ions in the solution containing the platinum (II) ions. The amount is preferably 1 to 100 times mol, and more preferably 0.5 to 10 times mol.

  Next, a method for separating platinum ions using the separating agent of the present invention will be described.

  In the present invention, platinum ions are separated by contacting the separating agent of the present invention that has adsorbed platinum (II) ions with the desorbing agent by the platinum ion adsorption method described above, thereby desorbing platinum (II) ions. Is done.

  The method for bringing the separating agent of the present invention that has adsorbed platinum (II) ions and the releasing agent into contact with each other is not particularly limited, and examples thereof include a contact method under the same conditions as the platinum ion adsorption method. be able to.

  The desorbing agent used in the platinum (II) ion separation method is not particularly limited, and examples thereof include ammonia, thiourea, methionine, and ethylenediamine. Of these, thiourea or methionine is preferred in terms of elimination efficiency and elimination rate. These releasing agents are preferably selected depending on the physical properties of the carrier.

  In the case of a liquid, the release agent can be a commercially available product as it is, or can be used as a solution dissolved in an arbitrary solvent. When used as a desorbing agent solution, although not particularly limited, for example, it can be used as an organic solution, an organic-water mixed solution, an aqueous solution, an acidic aqueous solution, or the like. Among these, it is preferable to use it as an aqueous solution or an acidic aqueous solution in terms of environmental load. Moreover, when it makes it acidic aqueous solution, although it does not specifically limit, For example, inorganic acids, such as hydrochloric acid, a sulfuric acid, nitric acid, can be used. As acid concentration of acidic aqueous solution, the range of 0.1-10 mol / L is preferable, and the range of 0.1-3 mol / L is more preferable.

  The concentration of the desorbing agent in the desorbing agent solution is not particularly limited, but is selected in the range of, for example, 1 to 99% by weight, preferably 1 to 10% by weight.

  The amount of the desorbing agent used is not particularly limited. For example, the amount of the desorbing agent is usually in the range of 2 to 10000 times mol with respect to 1 mol of sulfur in the separating agent of the present invention, and desorption efficiency and economic efficiency. In this respect, a range of 5 to 1000 times mol is preferable.

  By performing the above separation method, a desorbed liquid containing desorbed platinum ions (hereinafter referred to as “platinum ion desorbed liquid”) is obtained.

  Next, a method for recovering platinum from the platinum ion desorption solution will be described.

  The platinum ions in the platinum ion desorption solution can be precipitated as metal platinum or platinum complexes by a conventionally known method such as reduction treatment or addition of a chelating agent, and further recovered by a method such as filtration. be able to.

  There is no restriction | limiting in particular as a reduction process method of a platinum ion detachment | desorption liquid, According to the objective and equipment, various methods can be used. Examples thereof include an electrolytic reduction method by electrolysis and a chemical reduction method in which a reducing agent such as a boron hydride compound is added. Among these, the electrolytic reduction method by electrolysis is preferable from the viewpoint of ease of operation and cost.

  The reduction treatment of the platinum ion desorbed liquid can be carried out under any of acidic, neutral, or basic conditions. However, from the viewpoint of suppressing the reduction efficiency of platinum ions and the corrosiveness of the equipment, pH 6 or more and 8 The following neutral conditions are preferred. Although it does not specifically limit as a neutralizing agent of platinum ion detachment | desorption liquid, Inorganic base compounds, such as sodium hydroxide, potassium hydroxide, sodium bicarbonate, slaked lime, can be used preferably. Of these, sodium hydroxide is more preferably used as a neutralizing agent.

  The operation of reducing the platinum ion desorbing liquid is usually carried out under normal pressure and atmospheric atmosphere, but can also be carried out under pressurized or reduced pressure conditions and under an inert gas atmosphere. The operation of the reduction treatment is usually performed in a temperature range of 4 to 100 ° C., but a temperature range of 10 to 50 ° C. is more preferable.

  Examples of the method for filtering the metal platinum or platinum complex precipitate include a method using a membrane filter, filter paper, filter cloth, glass filter, and the like, and filtration with a membrane filter or filter paper is preferable from the viewpoint of ease of operation.

  The precipitate of metal platinum or platinum complex obtained by filtration can be separated as high-purity metal platinum of 99.9% or more by heating and melting to a melting point of platinum or higher.

  By the above operation, the separation and recovery of platinum is performed using the separation agent of the present invention.

  In the platinum ion separation method using the separation agent of the present invention, the separation agent is preferably packed in a column or the like from the viewpoints of operability, transportability, and repeated use.

  The column packed with the separating agent of the present invention is preferably made of a material excellent in acid resistance, base resistance and chemical resistance. For example, glass, acrylic resin, etc. are preferably used. A commercial item can be used as the column.

  In the platinum ion separation method of the present invention, the separation agent of the present invention can be used in combination with an existing or commercially available adsorption separation device, and can be arbitrarily used in combination with a liquid feeding device or the like. .

  The present invention will be specifically described below, but the present invention is not construed as being limited by these examples.

(Analysis method)
1. The platinum and palladium ion concentrations in the aqueous solution were measured with an ICP emission spectrophotometer (OPTIMA 3300 DV, manufactured by Perkin Elmaer). The metal concentration in the organic solvent was measured with an ICP emission spectroscopic analyzer after dissolving the residue obtained by distilling off the organic solvent in aqua regia.

  2. The nitrogen content was measured with a fully automatic elemental analyzer (2400II, manufactured by PerkinElmer Japan).

  3. The sulfur content was measured by ion chromatography. Ion chromatography measurement was performed with the following pretreatment, apparatus, and measurement conditions.

Pretreatment: The sample was introduced into an automatic sample combustion apparatus (AQF-100, manufactured by Mitsubishi Chemical Analytic Co., Ltd.), and SO ₄ ²⁻ produced by combustion was collected in an adsorbent (internal standard material PO ₄ ⁻ ).

Measuring device: IC-2001 manufactured by Tosoh Corporation
Separation column: TSKgel SuperIC-AP (4.6 mmΦ × 150 mm),
Detector: Electric conduction detector,
Eluent: 2.7 mmol / L NaHCO ₃ and 1.8 mmol / L Na ₂ CO ₃ .

  4). The average pore diameter of the separating agent was measured by a nitrogen adsorption method according to the BET method using a measuring device (model: BELSORP-mini) manufactured by Japan BEL.

  5. The average particle size of the separating agent was measured by a laser diffraction method using Microtrack MT3300 manufactured by Nikkiso Co., Ltd.

Example 1 Preparation of separating agent used in Examples 2-7.
A separating agent represented by the following formula (6) schematically including the bonding of the functional group to the carrier was prepared according to the following method.

ディーン・スターク装置付き５００ｍＬナス型フラスコに、シリカゲル（富士シリシア化学社製、商品名：ＰＳＱ６０Ｂ）１００ｇ、水５ｇ、及びｏ（オルト）−キシレン ２００ｇを量り取り、６０℃で激しく攪拌しながら、予め調製しておいた３−アミノプロピルトリメトキシシラン ３５．９ｇとｏ−キシレン ３５．９ｇの混合溶液を１０分間かけて滴下した後、９０℃まで昇温し、１時間攪拌した。次に、１１０℃まで昇温し、１．５時間攪拌した。ディーン・スターク装置に溜まったメタノール、ｏ−キシレン、及び水の混合溶液は系外に廃棄した。

In a 500 mL eggplant type flask equipped with a Dean-Stark apparatus, 100 g of silica gel (manufactured by Fuji Silysia Chemical Ltd., trade name: PSQ60B), 5 g of water, and 200 g of o (ortho) -xylene are weighed and stirred in advance at 60 ° C. A prepared mixed solution of 35.9 g of 3-aminopropyltrimethoxysilane and 35.9 g of o-xylene was added dropwise over 10 minutes, and then the mixture was heated to 90 ° C. and stirred for 1 hour. Next, it heated up to 110 degreeC and stirred for 1.5 hours. The mixed solution of methanol, o-xylene, and water collected in the Dean-Stark apparatus was discarded outside the system.

  Next, 0.005 g of 3,5-bis (trifluoromethyl) phenylboronic acid and 48 g of (ethylthio) acetic acid were weighed and heated to reflux for 24 hours with vigorous stirring. After cooling to room temperature, the reaction mixture was filtered, and the collected solid was washed with methanol to obtain a separating agent having the following characteristics.

Sulfur content 1.34 mmol / g, nitrogen content 1.43 mmol / g,
Average pore diameter 4 μm, average particle diameter 60 μm.

  Using the obtained separating agent, the platinum adsorption rate, the platinum adsorption amount to the separating agent, and the platinum selectivity were evaluated as shown below.

  The adsorbents A and B used for the evaluation of the separation performance are as follows.

Adsorbent A: 5.5 M hydrochloric acid solution containing 764 mg / L of platinum (II) ions,
Adsorbing solution B: 1M hydrochloric acid solution containing 820 mg / L of platinum (II) ions and 100 mg / L of rhodium (III) ions,
Adsorbing solution C: 1M hydrochloric acid solution containing 200 mg / L of palladium (II) ions and 200 mg / L of platinum (IV) ions.

  The platinum adsorption rate was calculated by the following formula.

    Platinum adsorption rate (%) = platinum ion concentration in liquid after platinum adsorption by separating agent ÷ platinum ion concentration in adsorbed liquid × 100%.

  The platinum selectivity was calculated by the following calculation formula.

    Platinum selectivity (%) = amount of platinum ions in the column effluent ÷ (amount of palladium ions in the column effluent + amount of platinum ions in the column effluent + amount of rhodium ions in the column effluent) × 100%.

Example 2 to Example 3.
The separating agent and adsorbent A obtained in Example 1 were precisely weighed into a 30 mL glass container and stirred for a predetermined time. Next, the platinum ion concentration in the obtained solution was measured, and the platinum adsorption rate was calculated. The results are also shown in Table 1.

表１から分かるように、１時間程度の吸着期間で９９．９％以上の白金を吸着できた。

As can be seen from Table 1, 99.9% or more of platinum could be adsorbed in an adsorption period of about 1 hour.

Example 4
After 0.1 g of the separating agent obtained in Example 1 was dispersed in water, it was packed in a glass column (inner diameter 5 mm, length 100 mm). 20 mL of adsorbent B was passed from the top of the column at a flow rate of 13 mL / hour. Next, after 20 mL of water was passed at a flow rate of 13 mL / hour to wash the column, a 1 mol / L aqueous hydrochloric acid solution containing 5% by weight of thiourea was passed from the top of the column at a flow rate of 13 mL / hour. Then, the metal ions adsorbed on the separating agent were desorbed. As a result of calculating the platinum selectivity from the platinum ion concentration and the rhodium ion concentration in the column effluent obtained, it showed 99.9%, and platinum could be selectively separated.

Example 5 FIG.
First step: 0.1 g of the separating agent obtained in Example 1 was dispersed in water and then packed into a glass column (inner diameter 5 mm, length 100 mm). Next, 40 mL of adsorbent C was passed from the top of the column at a flow rate of 13 mL / hour, and the effluent was collected.

Second step: SO ₂ gas was blown into the effluent obtained in the first step, and platinum ions in the effluent were divalently reduced.

  Third step: 0.1 g of the separating agent obtained in Example 1 was dispersed in water and then packed into a glass column (inner diameter 5 mm, length 100 mm). Next, the entire amount of the liquid obtained in the second step was passed from the top of the column at a flow rate of 3 mL / hour.

  Next, after 20 mL of water was passed at a flow rate of 13 mL / hour to wash the column, a 1 mol / L aqueous hydrochloric acid solution containing 5% by weight of thiourea was passed from the top of the column at a flow rate of 13 mL / hour. Then, the metal ions adsorbed on the separating agent were desorbed. As a result of calculating the platinum selectivity from the platinum ion concentration and the palladium ion concentration in the column effluent obtained, it was 99.2%, and platinum could be selectively separated.

Example 6
Platinum (0) 1,3-divinyl-1-1,1,3,3-tetramethyldisiloxane was dissolved in toluene to prepare 20 mL of a toluene solution containing 200 mg / L of platinum. 0.12 g of the separating agent prepared in Example 1 was added and stirred at room temperature for 24 hours. As a result of obtaining the platinum adsorption rate from the residual metal concentration and the initial concentration, the platinum adsorption rate was 75.1%.

Example 7
Platinum (II) acetylacetonate was dissolved in toluene to prepare 20 mL of a toluene solution containing 200 mg / L of platinum. 0.06 g of the platinum separating agent prepared in Example 1 was added and stirred at room temperature for 1 hour. As a result of obtaining the platinum adsorption rate from the residual metal concentration and the initial concentration, the platinum adsorption rate was 52.5%.

Example 8 FIG.
A separating agent represented by the following formula (7) schematically including a bond of a functional group to a carrier was prepared according to the following method.

ディーン・スターク装置付き５０ｍＬナス型フラスコに、予め３−アミノプロピルトリメトキシシランで処理して３−アミノプロピル基を固定化したシリカゲル（窒素含有量１．５７ｍｍｏｌ／ｇ）５．００ｇ、３，５−ビス（トリフルオロメチル）フェニルボロン酸 ０．０２２ｇ、及び２．９２ｇの３−フェニル−３−チアプロパン酸、及びｏ（オルト）−キシレン ３５ｇを量り取り、激しく攪拌しながら、２４時間加熱還流した。室温まで冷却した後、反応混合物をろ過し、ろ取した固体をメタノールで洗浄して分離剤を得た。

Silica gel (nitrogen content 1.57 mmol / g) 5.00 g, 3, 5 treated in advance with 3-aminopropyltrimethoxysilane and fixed with 3-aminopropyl group in a 50 mL eggplant type flask equipped with a Dean-Stark apparatus -0.022 g of bis (trifluoromethyl) phenylboronic acid and 2.92 g of 3-phenyl-3-thiapropanoic acid and 35 g of o (ortho) -xylene were weighed and heated to reflux for 24 hours with vigorous stirring. . After cooling to room temperature, the reaction mixture was filtered, and the collected solid was washed with methanol to obtain a separating agent.

Sulfur content 1.18 mmol / g, nitrogen content 1.42 mmol / g,
Average pore diameter 4 μm, average particle diameter 60 μm.

Example 9
A separating agent of the following formula (8) schematically shown including the bonding of the functional group to the carrier was prepared according to the following method.

ディーン・スターク装置付き５０ｍＬナス型フラスコに、予め３−アミノプロピルトリメトキシシランで処理して３−アミノプロピル基を固定化したシリカゲル（窒素含有量１．５７ｍｍｏｌ／ｇ）５．００ｇ、３，５−ビス（トリフルオロメチル）フェニルボロン酸 ０．０２２ｇ、４．７３ｇの４−（２−ピリジル）−３−チアブタン酸、及びｏ（オルト）−キシレン ３５ｇを量り取り、激しく攪拌しながら、２４時間加熱還流した。室温まで冷却した後、反応混合物をろ過し、ろ取した固体をメタノールで洗浄して白金分離剤を得た。

Silica gel (nitrogen content 1.57 mmol / g) 5.00 g, 3, 5 treated in advance with 3-aminopropyltrimethoxysilane and fixed with 3-aminopropyl group in a 50 mL eggplant type flask equipped with a Dean-Stark apparatus -Weigh out 35 g of bis (trifluoromethyl) phenylboronic acid 0.022 g, 4.73 g of 4- (2-pyridyl) -3-thiabutanoic acid and o (ortho) -xylene for 24 hours with vigorous stirring. Heated to reflux. After cooling to room temperature, the reaction mixture was filtered, and the collected solid was washed with methanol to obtain a platinum separating agent.

Sulfur content 1.10 mmol / g, nitrogen content 2.33 mmol / g,
Average pore diameter 4 μm, average particle diameter 60 μm.

Example 10
Platinum (II) acetylacetonate was dissolved in toluene to prepare 20 mL of a toluene solution containing 200 mg / L of platinum. 0.08 g of the separating agent prepared in Example 9 was added and stirred at room temperature for 1 hour. As a result of obtaining the platinum adsorption rate from the residual metal concentration and the initial concentration, the platinum adsorption rate was 45.3%.

  The separation agent of the present invention can separate platinum ions from a solution containing platinum ions in a short time with high selectivity, and can be used repeatedly, and is widely used in the field of precious metal recovery from economical and environmental conservation viewpoints. Can be used for

Claims (8)

A platinum separating agent in which a functional group represented by the following general formula (1) is bonded to a carrier.

(In formula, R is a C1-C18 chain hydrocarbon group which may have a substituent, a C3-C10 alicyclic hydrocarbon group, and a C6-C14 aromatic hydrocarbon. A group, a C3-C12 heterocyclic group, a carboxymethyl group, or a carboxyethyl group, n represents an integer of 1 to 4. Z represents an amide bond.) The separating agent according to claim 1, wherein the functional group represented by the general formula (1) is a functional group represented by the general formula (2).

(In formula, R is a C1-C18 chain hydrocarbon group which may have a substituent, a C3-C10 alicyclic hydrocarbon group, and a C6-C14 aromatic hydrocarbon. Group, a C3-C12 heterocyclic group, a carboxymethyl group, or a carboxyethyl group, and n represents an integer of 1-4.) The functional group represented by the general formula (1) or (2) is via a methylene group, an ethylene group, a linear, branched or cyclic alkylene group having 3 to 8 carbon atoms, or an arylene group having 6 to 14 carbon atoms. The separating agent according to claim 1 or 2, wherein the separating agent is bound to a carrier. The separating agent according to any one of claims 1 to 3, wherein the carrier is an inorganic carrier. A method for adsorbing platinum ions, comprising contacting the separating agent according to any one of claims 1 to 4 with a solution containing platinum (II) ions. A separation agent obtained by adsorbing platinum (II) ions obtained by the platinum ion adsorption method according to claim 5 and a desorbing agent are brought into contact with each other to desorb the platinum (II) ions. A method for separating platinum ions. The separation method according to claim 6, wherein the releasing agent is at least one selected from the group consisting of ammonia, thiourea, methionine, and ethylenediamine. Use of the separating agent according to any one of claims 1 to 4 as an agent for adsorbing and separating platinum ions from a solution containing platinum (II) ions.