JP3493752B2 - Method for producing a carrier in which a compound having a hydroquinone skeleton is supported on a porous carrier - Google Patents

Description

Detailed Description of the Invention

The present invention relates to an aqueous solution containing metal ions,
For example, using copper or mercury compounds, metal ion-containing wastewater discharged from the process of manufacturing compounds containing these metals, metal ion-containing wastewater discharged when manufacturing electronic components, or using industrial catalyst From the viewpoint of resources, from the wastewater containing the metal ions discharged from the treatment of the catalyst and the wastewater of the fixing solution containing the metal complex salt such as silver discharged from the photographic industry,
The present invention relates to a method for producing a supported material in which a compound having a hydroquinone skeleton, which is useful as a metal ion treating agent for recovering economically valuable metals, is supported on a porous carrier. in particular,
The present invention relates to a method for producing a treating agent useful for recovering heavy metal ions such as copper and mercury contained in an aqueous solution and / or so-called precious metal ions such as gold, silver, platinum, palladium, rhodium and ruthenium.

[0002]

2. Description of the Related Art In recent years, Japan has been relying on imports for most of its metals, especially for use in electronic parts, industrial catalysts such as industrial oxidation catalysts and reduction catalysts used in the oxidation treatment of automobiles and industrial exhaust gas, and the photographic industry. A large amount of noble metal is used as the sensitizer, and accordingly, wastewater containing heavy metal or noble metal ion is discharged during the production or recovery of these, and a large amount of the fixing process is also performed in the photographic industry. Wastewater containing precious metal resources is discharged, and in Japan, where resources are scarce, it is important to recover and reuse these metal resources.

Most of these metals are contained in an aqueous medium such as an aqueous solution as metal ions or metal complex ions (hereinafter, both of them are collectively referred to as metal ions). As a method of recovering this metal ion, for example, (1)
A method of producing a precipitate from an aqueous solution by insoluble salt or reduction, separating impurities and metals such as precious metals, and purifying and recovering them, (2) a method of adsorbing on an ion exchange resin or a chelate resin and recovering , (3) a method of adsorbing and recovering with a redox resin, and (4) a method of electrolytically reducing metal ions to obtain them as a metal [eg, Austi
n C. Cooley, J .; Imaging Sci
ence Technology, Vol. 37, No. 4, 37
4 to 379 (1993)].

In the method (1), there is a high possibility that metal will be entrained in the waste liquid, and the recovery rate of metal is not very good.
The methods (2) have the drawback that the selectivity is not so high when several kinds of metal ions coexist, and the chelate resin is difficult to remove when the metal ions are in a complex. The method (3) does not have a practical method for directly alkylating or alkenylating quinones such as anthraquinone even when producing a monomer as a raw material for producing a redox resin, such as monovinylanthraquinone. , Requires many steps and becomes very expensive. Moreover, when the monomer is used and polymerized with, for example, divinylbenzene, it has a drawback that it is unlikely to form beads, and a practical product has not been produced. The method (4), that is, the electrolysis method is effective in recovering high-concentration metal ions, but in the case of low-concentration metal ions, the current efficiency is poor and the amount of metal is less than a few ppm in drainage regulations. It is practically impossible to process up to the metal ion concentration.

Regarding a method of reducing a polyvalent metal ion using a hydroquinone-quinone type redox reaction reagent in an aqueous solution, a solution of a hydroquinone type organic solvent of an anthraquinone derivative excluding anthraquinone is used,
A method is known in which polyvalent metal ions in an aqueous solution are reduced to metals such as copper, silver and mercury, separated and recovered (US Pat. No. 3,820,979). The redox reaction reagent used here is once completely oxidized, and then hydrogenated again to be recycled and reused as an organic solvent solution of the redox reaction reagent. The behavior of the putative representative hydroquinone-quinone type redox reaction reagent is as shown in [Chemical Formula 1].

[0006]

[Chemical 1]

All of these redox reaction reagents are conventionally used in a state of being dissolved in a solution, and there is a drawback that they are lost together with the solution. Examples of redox reaction reagents for anthraquinone and its derivatives include, for example, anthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-propylanthraquinone, 2-isopropylanthraquinone, 2-t-butylanthraquinone, 2-amylanthraquinone, tetrahydroanthraquinone, 2-Substituted tetrahydroanthraquinone and the like are known, and any of them can be synthesized by a condensation reaction between butadiene or a diene compound having a substituent and naphthoquinone, or a condensation reaction between phthalic anhydride and a corresponding alkylbenzene.

The above-mentioned US Pat. No. 3,820,979 gives examples of these anthraquinone derivatives excluding anthraquinone and an organic solvent solution used in combination therewith. As a solvent used for dissolution, there is a drawback that a mixture of a high-boiling point nonpolar or polar solvent is required. For example, as the non-polar organic solvent, alkyltoluene, alkylnaphthalene, or diphenyl, as the polar solvent, octanol, ethylhexanol, or diisobutyl ketone, other dialkyl phthalate, diallyl phthalate, alkyl benzoate, benzyl acetate, etc. The use of esters is mentioned.

In the above-mentioned US Pat. No. 3,820,979, in order to utilize the redox reaction reagent as an organic solvent solution, there is a danger or disadvantage in use such as flammability or evaporation loss. It is necessary to overcome it, and it is difficult to separate the coexisting aqueous phase, organic solvent phase, and solid phase that is reduced and recovered into a metal in the process, and the redox reaction reagent lost with the residue of the solid phase There was a problem that the amount had a significant impact on the economics of the process. Further, when it is used for the recovery treatment of copper ions in waste water, the removal of copper ions is insufficient, and a part of them is reduced to a metal, resulting in a drawback that the redox reaction reagent is excessively consumed.

[0010]

The problem to be solved by the present invention, however, is to select metal ions in an aqueous solution, particularly heavy metals such as copper ions and mercury ions, and noble metal ions composed of gold, silver and platinum elements. In addition, it can be efficiently recovered, and further, the aqueous solution, for example, the metal ions in the waste water can be treated to a harmless concentration or less, and the raw materials can be easily obtained, and can be simply produced. As a result, it is possible to manufacture economically relatively inexpensively,
In particular, it is to provide a method for producing a supported material in which a compound having a hydroquinone skeleton, which is useful as a treating agent for metal ions in an aqueous solution, is supported on a porous carrier.

[0011]

[MEANS FOR SOLVING THE PROBLEMS] A redox reaction reagent is used as a metal ion treating agent to perform reduction trapping treatment of metal ions in wastewater repeatedly completely or economically advantageously, and to facilitate its handling. As a result of extensive studies, as a redox reaction reagent, a compound having a hydroquinone skeleton was supported on a solid porous carrier, and a container storing the compound was connected in series or in parallel to treat a divalent metal ion to be treated. Introducing a raw aqueous solution containing the same into a redox reaction reagent carried on a solid porous carrier stored in a container, and sequentially reacting the redox reaction reagent to selectively reduce the monovalent metal ion to obtain a solid porous carrier. The solution is completely separated and captured on the carrier, and if necessary, after the reaction, a solution for eluting the monovalent metal ions separated and deposited on the solid porous carrier is circulated to be eluted out of the system. I By circulating a reducing solution in the vessel, the reducing agent is returned to the reduction reaction treatment system as a treating agent for the metal ions in the wastewater, and the divalent metal ions in the wastewater are repeatedly selected as monovalent metal ions. Succeeded in preparing a metal ion treating agent that recovers the metal ion in the wastewater as a monovalent metal ion by reduction treatment, and using this metal ion treating agent, the metal ion in the wastewater The invention was completed by finding a concrete implementation system for recovering the above, and a patent application has already been filed (Japanese Patent Application No. 5-222951).
issue).

Further, as a result of intensive studies to solve the above problems, the present inventors have found that the redox reaction reagent,
That is, when an aqueous solution containing a metal ion, particularly a noble metal ion, is treated with a support material in which a compound having a hydroquinone skeleton is adsorbed and fixed on a solid porous carrier, the noble metal ion is selectively reduced, and the support material has a valence of 0 We found that it was captured as a metal and its selectivity was better than that of conventional resins, and we have already filed a patent application (Japanese Patent Application No.
323045).

Further, as a result of further studying a method for supporting a compound having a hydroquinone skeleton, which is useful as a metal ion treating agent, on a porous carrier, the carrier is brought into contact with a solution of the above compound in an organic solvent, and adsorption is carried out. In the method of loading, for example, anthrahydroquinone is a compound that is very easily oxidized and is unstable, so that it is adsorbed in the anthraquinone type and then reduced. On the other hand, this anthraquinone has a drawback that its solubility in organic solvents such as alcohol is low. However, when the present inventors have brought an aqueous solution of a water-soluble salt such as an alkali metal salt of an anthrahydroquinone compound in a reduced form into contact with a porous carrier such as activated carbon, the reduced compound is adsorbed as it is, The present invention has been completed by finding that the carrier is easily and stably supported on the carrier by washing treatment.

That is, in the present invention, an aqueous solution of a water-soluble salt of a compound having a hydroquinone skeleton is brought into contact with a porous carrier,
A method for producing a supported material, which comprises supporting a compound having a hydroquinone skeleton on a porous carrier, which comprises adsorbing the compound on the porous carrier, separating the porous carrier, and then performing a washing treatment.

Examples of the compound having a hydroquinone skeleton include hydroquinone (1,4-dihydroxybenzene), naphthohydroquinone (1,4-dihydroxynaphthalene) and anthrahydroquinone (9,10-dihydroxyanthracene), hydrogenated compounds thereof, and the like. A monocyclic or polycyclic hydroquinone compound selected from the above-mentioned substitution products (hereinafter, unless otherwise specified, a monocyclic or polycyclic hydroquinone compound is simply referred to as a hydroquinone compound).

Examples of the substituent in the above-mentioned hydroquinone compound substitution product include an alkyl group, an alkenyl group, an alkoxyl group, a phenyl group, an alkylamino group,
Examples thereof include relatively hydrophobic substituents such as halogen groups. The number of carbon atoms in the alkyl group, alkenyl group and alkoxyl group is 1 to 10, practically 5 or less, and the alkyl group may be linear or branched.

As long as the use of the carrier of the present invention is not hindered, a substituent containing a sulfonic acid group, a sulfonic acid amide group or a carboxyl group can be adopted as the substituent of these hydroquinone compounds. Since the metal ion treating agent, which is the main application of the present invention, is used in an aqueous solution, a reducing compound having a hydrophobic substituent which generally does not elute in the aqueous solution is preferable.

The compound having these substituents includes
For example, 2-methylhydroquinone, 2-ethylhydroquinone, 2,3,5-trimethylhydroquinone, 2-methylnaphthohydroquinone, 2-ethylnaphthohydroquinone,
2-propylnaphthohydroquinone, 2-methylanthrahydroquinone, 2-ethylanthrahydroquinone, 2-
Alkylated hydroquinone compounds such as amylanthrahydroquinone, 2-t-butylanthrahydroquinone and 2- (4-methylpentyl) anthrahydroquinone; 2-
Alkenylated hydroquinone compounds such as (4-methyl-pentenyl) anthrahydroquinone; alkoxylated hydroquinone compounds such as 1-methoxyanthrahydroquinone and 1,5-dimethoxyanthrahydroquinone; 2-N,
Examples include alkylaminated hydroquinone compounds such as N-dimethylaminoanthrahydroquinone; halogenated hydroquinone compounds such as 2-chlorohydroquinone, 2,3-dichloronaphthohydroquinone, 1-chloroanthrahydroquinone, and 2-chloroanthrahydroquinone.

Hydrogenated compounds of hydroquinone compounds include 1,4-dihydro-9,10-dihydroxyanthracene, 1,2,3,4-tetrahydroanthrahydroquinone, 1,2,3,4,5,6,7. , 8-octahydroanthrahydroquinone and the like.

Polycyclic aromatic quinones such as catechol, 4,4'-dihydroxybiphenyl (reduced form of diphenoquinone) and 1,4-dihydroxyanthracene, 9,10-dihydroxyphenanthrene, reduced form of anthanthrone, etc. The reducing compound corresponding to can also be mentioned. These compounds may be used alone or in combination of two or more.

In the present invention, the above-mentioned hydroquinone compound can be oxidized to the corresponding quinone compound by a known oxidizing agent such as oxygen and hydrogen peroxide. Therefore, if necessary, the supported hydroquinone compound can be oxidized. It can also be used as a supported material carrying a quinone compound.

In the present invention, the solid porous carrier may be a carbon product such as silicon dioxide, activated carbon or activated carbon fiber,
Alumina, organic synthetic polymer particles, for example, a so-called organic synthetic adsorbent styrene-divinylbenzene copolymer or a porous carrier that can carry a compound having the above-mentioned hydroquinone skeleton such as a molded product thereof. In addition, hydrophobically prepared carbon dioxide such as silicon dioxide and activated carbon, for example, an aqueous emulsion processed product of polytetrafluoroethylene (JP-A-53-92981) can be mentioned. In order to be suitably used for this porous carrier, the pore size is 5 angstroms, preferably 10 angstroms or more, and the specific surface area per gram is 50 to 1000 square meters for particles of silicon dioxide and synthetic polymer, and 1 for carbon products. A standard surface area of 1000 square meters per gram is standard. The activated carbon may be in any form such as powder or pellet, spherical or crushed carbon.

The smaller the particle size of pellets, spheres or crushed coal of the solid porous carrier, the better the contact efficiency, but when packed in a column or the like and continuously treated with an aqueous solution containing metal ions. In general, 0.4 to 0.8 mm is suitable for the synthetic polymer adsorbent and 0.3 to 2.5 mm is suitable for the activated carbon since the liquid resistance becomes large.

In the present invention, as the compound having a hydroquinone skeleton, any of the above compounds can be used as long as it is a compound that stably exhibits an aqueous solution of a water-soluble salt such as an alkali metal salt. However, a compound having an anthracene structure that does not easily undergo alteration such as polycondensation even in an alkaline solution is advantageously used. For example, as water-soluble salts of these compounds, anthrahydroquinone or the above-mentioned alkyl-substituted anthrahydroquinone, 1,4-dihydro-9,10-dihydroxyanthracene (1,4-dihydroanthrahydroquinone), or a dialkali of its alkyl-substituted compound is used. Water-soluble salts such as metal salts may be mentioned.

The water-soluble salt of the compound having a hydroquinone skeleton in the present invention is, for example, one or more selected from alkali metal salts and ammonium salts. Examples of the alkali metal salt include sodium salt, potassium salt, lithium salt and the like. As the ammonium salt, a normal ammonium (NH ₄ ⁺ ) salt, a tetramethylammonium salt, a tetraethylammonium salt,
Examples thereof include quaternary ammonium salts such as tetrapropylammonium salt and tetrabutylammonium salt.
However, an alkali metal salt is usually used, and particularly an inexpensive sodium salt is used.

In particular, the aqueous disodium salt solution of the 1,4-dihydro-9,10-dihydroxyanthracene compound is obtained by the Diels-Alder reaction of naphthoquinone and the corresponding 1,3-butadiene compound.
The 4,4a, 9a-tetrahydroanthraquinone compound is easily reacted with an aqueous solution of an alkali metal hydroxide in an equivalent amount (2 mol times or more, preferably 2 to 2.4 mol times) of the quinone compound. Since it is obtained, it can be industrially advantageously obtained. The concentration of the aqueous solution of the alkali metal salt of the compound having a hydroquinone skeleton used in the method of the present invention (the concentration is represented by weight% of the quinone compound such as anthraquinone) is 1 to 23% (in the present specification, "%" is Unless otherwise specified, "% by weight" is shown), preferably 2 to 22%, the temperature of the adsorption treatment is usually normal temperature, and the adsorption time is 30 minutes to 5 hours, preferably 1 to
4 hours.

The amount of the compound having a hydroquinone skeleton used varies depending on the kind of the solid porous carrier, but is not particularly limited as long as it is a solution having a solubility of the compound or less, and after the adsorption treatment. By adjusting the concentration of the obtained mother liquor again, it can be used for adsorption treatment.

The adsorption treatment is usually carried out in a batch (batch type) by a method in which a container containing a porous carrier and an aqueous solution of an alkali metal salt of a compound having a hydroquinone skeleton is gently rotated or left to stand to adsorb, or a packed tower or the like. It is also possible to employ a continuous contact method in which a porous carrier is filled in advance and an aqueous dialkali metal salt solution of a compound having a hydroquinone skeleton is circulated and immersed while being adsorbed.

As the solid porous carrier used in this method, the above-mentioned carriers can be mentioned, but a carbonaceous carrier such as activated carbon is particularly preferable because it is inexpensive and easy to handle and has a high loading rate.

Since a compound having a hydroquinone skeleton as a redox reaction reagent is generally an extremely weak acid, even if the support carrying an alkali metal salt of the compound is washed with an aqueous medium such as water, the salt can be treated. Can be hydrolyzed to replace its alkali metal ions with hydrogen ions. The aqueous medium is preferably an aqueous medium from which dissolved oxygen has been removed, such as demineralized water or deionized water, and the amount used may be an amount by which an alkali metal ion is replaced with a hydrogen ion. In this cleaning process, reduce the amount of cleaning water,
Alternatively, treatment with an acid aqueous solution is effective for ensuring replacement with hydrogen ions. The acid used for the washing treatment with the aqueous acid solution may be an organic or inorganic acid as long as it has an ability to liberate an alkali metal salt. Examples of the inorganic acid include sulfuric acid and hydrochloric acid, and examples of the organic acid include carboxylic acid such as acetic acid and sulfonic acid such as naphthalenesulfonic acid. The amount of this acid used may be such that the alkali metal ions in the obtained supported material are sufficiently replaced with hydrogen ions, and generally, the amount is equal to or more than the equivalent amount of the adsorbed compound, 2
It is 0 equivalent or less, and an aqueous solution having a concentration of 0.1 to 20% is used.

In this washing treatment, the above-mentioned washing treatment is not carried out in advance, and the application of using the carrier in the present invention,
For example, in the metal ion treatment, it is possible to combine both the washing treatment and the treatment of the metal ion with a neutral to acidic metal ion aqueous solution to be treated, but a compound having a hydroquinone skeleton, particularly an alkali metal of anthrahydroquinone Since salt is extremely easily oxidized and may generate heat or ignite when it comes into contact with an oxidizing agent such as air, it is preferable to carry out this washing treatment in advance for safety in storage and transportation.

To implement this method, the following is generally performed. For example, a container is charged with a predetermined amount of granular activated carbon, degassed under reduced pressure, and further sufficiently replaced with nitrogen,
Under a nitrogen atmosphere, a porous carrier is added to a predetermined amount of an alkali metal salt of a compound having a hydroquinone skeleton having a predetermined concentration, for example, an aqueous solution of a disodium salt of 1,4-dihydro-9,10-dihydroxyanthracene having a predetermined concentration, under reduced pressure. And contact them for adsorption for a predetermined time. The carrier is separated from the mixture in a separator such as a centrifuge under a nitrogen atmosphere and washed with an aqueous medium such as deoxygenated deionized water, or washed with a dilute acid such as 5 to 10% sulfuric acid. Then, the carrier (supported material) carrying the obtained compound having a hydroquinone skeleton is stored in deionized water that has been sufficiently deoxygenated. The supported amount of the obtained supported substance varies depending on the kind of the compound having a hydroquinone skeleton, the concentration of the salt aqueous solution thereof and the kind of the solid porous carrier, and for example, 1,4-dihydro-9,1.
When using the disodium salt of 0-dihydroxyanthracene and granular activated carbon, it is about 0.3 to about 1.0 mol / liter-carrier.

The thus obtained support composed of 1,4-dihydro-9,10-dihydroxyanthracene / activated carbon is useful, for example, as a metal ion treating agent, and when used for silver thiosulfate complex ions, for example. At the first time, the metal ion trapping efficiency per the same number of moles is 2 to 5 times higher than that of the compound having another hydroquinone skeleton.

In the present invention, when the supported material carrying the redox reaction reagent used in the present invention is used as a metal ion treating agent, the equilibrium oxidation-reduction potential (here, the equilibrium oxidation-reduction potential means under operating conditions). A divalent metal ion having a higher equilibrium oxidation-reduction potential of a divalent-monovalent metal ion in terms of the redox potential when the oxidant and the corresponding reductant maintain an equilibrium state. Copper ions or mercuric ions are selectively reduced to monovalent metal ions, for example, cuprous ions or mercuric ions, and the monovalent metal ions are added from an aqueous solution to the carrier of the present invention. It can be quantitatively separated on the top and deposited and captured, and the treatment liquid contains almost no metal ions.

Further, since this monovalent cuprous ion is soluble in hydrochloric acid and aqueous ammonia, it can be easily eluted and desorbed from the deposited and captured support of the present invention. The cuprous ion eluted with hydrochloric acid is almost colorless, but when the eluted aqueous solution is appropriately diluted and oxidized with air, the cuprous ion is oxidized to give a blue color characteristic of cupric ion.

In the redox reaction reagent supported on the solid porous carrier according to the present invention, that is, the supported material of the present invention, for example, divalent copper ions are selectively reduced and separated, and captured as monovalent copper ions. In contrast, the separation method using a solvent solution in the above-mentioned US Pat. No. 3,820,979 differs in that divalent copper ions are reduced to metallic copper. Therefore, in the present invention, the monovalent copper ions captured can be eluted and collected if necessary.

In the present invention, the metal ion trapped as a monovalent metal ion may be any metal ion trapped as a monovalent metal ion by the carrier in the present invention.
Although adopted, divalent copper ions and mercury ions are generally used. The corresponding anion is not particularly limited as long as it forms a water-soluble salt as a divalent metal salt and can be captured by the metal ion treating agent, and examples of the salt include cupric chloride and cupric bromide. Copper salts of inorganic acids such as dicopper and copper sulfate; copper salts of organic acids such as cupric acetate; copper salts such as complex salts of copper acetylacetonate, etc., or mercuric chloride, mercuric bromide, Examples thereof include mercuric salts of inorganic acids such as mercuric sulfate; mercuric salts of organic acids such as mercuric acetate.

The conditions for treating and using the supported material as a metal ion treating agent are not particularly limited as long as the metal ions are stably present, but the pH is in relation to the equilibrium oxidation-reduction potential and the target metal ion is Is selected from the conditions that can be captured by the metal ion treating agent, but generally 0-12, preferably 0-9 positions are selected. pH is 1
When it is 2 or more, a compound having a hydroquinone skeleton may be eluted, which is not preferable. The concentration of metal ions in the aqueous solution is generally 0.01 to 10000 ppm, preferably 0.1 to 1000 ppm, and the treatment temperature is generally 10 to 70 ° C., usually room temperature.

The monovalent metal ion trapped on the carrier used as the metal ion treating agent can be eluted and recovered by a solution capable of eluting the monovalent metal ion, but the metal ion is trapped. The supported material can be incinerated by a known incineration method and recovered in the form of metal, oxide or salt. In particular, cuprous ion is insoluble in water, for example, as cuprous chloride and cuprous bromide salt, but is soluble in hydrochloric acid or ammonia water, and therefore, these aqueous solutions are used as elution solutions. It can be easily recovered by using it. This solution is selected from the concentration capable of dissolving these cuprous ions, but generally concentrated hydrochloric acid or concentrated ammonia water is used, and it may be appropriately diluted if necessary. Conditions for elution are generally at room temperature.

When a system is constructed in which the containers storing the carrier as the metal ion treatment agent are connected in series or in parallel, the divalent metal ions flowing through the system are transferred onto the carrier stored in the container. For example, in the case of a downward flow, the redox reaction reagent carried is sequentially contacted from the upper part of the layer to be reduced to a monovalent metal ion, which is quantitatively separated on the supported material to be deposited and captured, so that the divalent divalent The leakage amount of metal ions can be controlled, and further reduction reaction does not occur, so that metal ions can be treated extremely advantageously.

Furthermore, the supported material of the present invention can be converted to a zero-valent metal by a redox reaction from a metal ion contained in an aqueous solution, for example, a noble metal ion, and the metal material can be captured and recovered on the supported material. The metal ion to be subjected to the metal ion treatment is a metal ion-metal equilibrium redox potential higher than the equilibrium redox potential of the compound having a hydroquinone skeleton as a redox reaction reagent supported on the carrier of the present invention. Is limited to metal ions having. In the present invention, the metal ion may be a metal ion forming a complex. That is, this corresponds to a metal ion in which the metal ion is reduced to a zero-valent metal by the supported compound having a hydroquinone skeleton. For example, the metals corresponding to the metal ions are noble metals, that is, gold, silver and platinum group elements, and the platinum group elements include ruthenium, rhodium, palladium, osmium, iridium and platinum, and particularly gold. ,
Examples include silver, platinum, palladium, rhodium, and ruthenium.

Examples of metal complex ions include silver thiosulfate complex ions (also referred to as thiosulfato silver complex ions; compounds represented by the chemical formula shown in [Chemical Formula 2]), tetrachloroaurate ion and hexachloroplatinate ion. Is mentioned.

[0043]

[Chemical 2]

The method for treating the metal ion-containing aqueous solution in the present invention is as follows. The supported material prepared as described above is added to the metal ion in the metal ion-containing aqueous solution in an amount equal to or more than the reducing amount thereof and stirred. After this, a batch-type treatment method in which the supported material is filtered off by decantation or filtration can be adopted. Generally, the above-mentioned supported material is packed in a column (tower). Then, a method of passing a metal ion-containing aqueous solution through this is adopted.

The method of passing the liquid through the column is not particularly limited, and it can be carried out by a usual method, and a method such as an upward flow method or a downward flow method can be appropriately adopted. The pH of the liquid to be treated is influenced by the coexisting anions, but is not particularly limited as long as the metal ions are stably present in the aqueous solution. However, usually 0 to 1
A wide range of 2, preferably 0-9, and more preferably 0-8 is employed. The anion in the aqueous solution may be an anion such as an inorganic acid or an organic acid as long as the target metal ion is not precipitated. The concentration of the metal ion in the aqueous solution is not particularly limited as long as it is dissolved, but generally 0.01
-10,000 ppm, preferably 0.1-1000 pp
m, and the treatment temperature is generally 10 to 70 ° C., and usually ambient temperature.

In the case of treating the aqueous solution containing the above-mentioned noble metal ions, the supported material of the present invention loses its reducing ability, that is, the supported material as a metal ion treating agent which has passed through is treated with an aqueous sodium hydrosulfite solution or the like. After reduction treatment by various reduction methods capable of reducing a compound having a quinone skeleton in the present invention such as reduction by hydrogen and other nascent hydrogen to a compound having a hydroquinone skeleton,
The aqueous metal ion solution can be treated repeatedly by treating the aqueous solution containing the noble metal ion.

When a metal ion treating agent having an anthrahydroquinone compound supported on activated carbon is used to capture and recover silver metal from an aqueous solution containing silver thiosulfate complex ion on the supported material, the pH of the aqueous solution is recovered. Is adjusted to 7 or more, preferably 8 to 12, and more preferably 8 to 11, so that the amount of captured silver per unit supported material is increased.
The effect of this pH is more remarkable when the concentration is high, and is 10 ppm or more, and preferably 20 ppm or more as silver.
Generally, at about pH 8 and above, the maximum amount of captured silver is maximized.
From the economical viewpoint, the amount of alkali added is preferably not too large, and the pH is preferably 11 or less. If the pH is higher than 12, the compound having the supported hydroquinone skeleton elutes, which is not preferable.

A carrier (metal ion treating agent) that has lost its ability to be finally regenerated and has captured a metal uses an organic synthetic polymer adsorbent or a carrier that can be burned such as activated carbon and the like. In some cases, the supported material that has captured these metals can be easily recovered as a noble metal by incineration, for example. This incineration method is not particularly limited, and any type of incinerator such as a rotary kiln or a crucible type incinerator can be used as long as precious metals can be easily recovered from the incineration residue. You can

Further, if the captured metal is dissolved and recovered as a metal ion by an oxidizing agent such as nitric acid or aqua regia, this recovery method can also be adopted.

In the present invention, the applied aqueous solution containing metal ions can be preferably applied to aqueous solutions of metal ions discharged from various industries, particularly noble metal-containing waste water from industries handling precious metals. For example, wastewater containing gold or silver ions or complex ions thereof discharged from an electronic component processing plant, or ions of palladium, ruthenium, rhodium, platinum, etc. discharged from a catalyst manufacturing plant or complex ions thereof Waste water and waste water containing silver thiosulfate complex ions discharged from the fixing solution of the photographic industry.

The carrier comprising the porous carrier carrying the compound having a hydroquinone skeleton, which is obtained by the present invention, can be used for the same purpose as the redox resin other than the metal ion treating agent. Furthermore, if necessary, a compound having a hydroquinone skeleton can be used by converting a hydroquinone body into a corresponding quinone body by a known oxidation method as described above.

[0052]

The function of immobilizing the compound having a hydroquinone skeleton on the solid porous carrier of the present invention is considered to be basically adsorbed. When this supported material is used as a metal ion treating agent to treat a metal ion, particularly an aqueous solution containing a noble metal ion, as described above, even when the noble metal ion forms a complex, the noble metal ion has a valence of 0 on the treating agent. It is reduced to the metal and selectively captured, and hardly detected in the treated water. When the carrier of the treating agent was a synthetic adsorbent, the treating agent capturing a noble metal such as silver exhibited a so-called metallic luster peculiar to the metal. When the treating agent that captured the noble metal was analyzed by the powder X-ray diffraction method, it was confirmed that it was captured as a metal.

The mechanism by which metal ions are trapped as a metal on the metal ion treating agent has not yet been clearly analyzed, but it is presumed from the viewpoint of phenomena that when the metal ion comes into contact with the treating agent, the metal ion is treated by the treating agent. Reduction by a compound having a supported hydroquinone skeleton to form a metal nucleus, through which electrons are transferred, electrons are stacked and grown, and a metal film is formed on the treating agent. Is estimated.

Electrons are transferred and received through the metal film laminated on the treating agent also during reduction regeneration, and the supported quinone compound is reduced to a hydroquinone type compound, thereby reducing the metal ion again. However, it is presumed that it is laminated on the treatment agent.

[0055]

EXAMPLES The present invention will be described in more detail by way of examples, but the present invention is not limited to the following examples unless it exceeds the gist. In the examples,
"%" Indicates "% by weight" unless otherwise specified.

[Example 1] [Preparation of supported material by supporting on activated carbon using an aqueous solution of an alkali metal salt of anthrahydroquinone compound and measurement of supported amount] (1) 1,4-dihydro-9,10-dihydroxy Anthracene (also referred to as 1,4-dihydroanthrahydroquinone; hereinafter abbreviated as "DDA") is prepared on activated carbon as described below. Was expressed by the concentration converted to anthraquinone), and an experiment of adsorbing it on activated carbon was conducted. (A) Coal-based granular activated carbon (manufactured by Mitsubishi Kasei Co., Ltd., trade name Diamond Hope C, particle size 1.0 to 2.5 mm) 100 m in which 500 ml eggplant type flask was impregnated with demineralized water and degassed.
1 (40 g) and 175 ml of demineralized water were added, and the mixture was allowed to stand under reduced pressure for 1 hour, then, under a nitrogen atmosphere, an aqueous solution of DDA disodium salt having a concentration of 22% (specific gravity: 1.17 (20 ° C)) 25
ml was added and adsorption was performed under reduced pressure for 2 hours. After separating the supernatant with a centrifuge in a nitrogen atmosphere, washing with 100 ml of 4% sulfuric acid aqueous solution while centrifuging, then 150 ml
It was filled in a sample bottle, filled with deionized water subjected to nitrogen bubbling treatment, and stored.

(B) 100 ml (40 g) of coal-based granular activated carbon (manufactured by Mitsubishi Kasei Co., Ltd., trade name Diamond Hope C) obtained by degassing a 500 ml eggplant-shaped flask by impregnating it with demineralized water.
After adding 160 ml of demineralized water and leaving it for 1 hour under reduced pressure, 40 ml of 22% concentration of DDA disodium salt aqueous solution (specific gravity 1.17 (20 ° C)) was added under nitrogen atmosphere, and then under reduced pressure for 2 hours. Adsorbed. After separating the supernatant with a centrifuge under nitrogen atmosphere, 10% while centrifuging
After washing with 100 ml of a sulfuric acid aqueous solution, it was filled in a 150 ml sample bottle and filled with deionized water subjected to nitrogen bubbling and stored.

(C) 100 ml (40 g) of coal-based granular activated carbon (manufactured by Mitsubishi Kasei Co., Ltd., trade name: Diamond Hope C) obtained by degassing a 500 ml eggplant-shaped flask by impregnating it with demineralized water.
After adding 140 ml of demineralized water and leaving it for 1 hour under reduced pressure, 60 ml of 22% concentration of DDA disodium salt aqueous solution (specific gravity 1.17 (20 ° C)) was added under a nitrogen atmosphere, and then under reduced pressure for 2 hours. Adsorbed. After separating the supernatant with a centrifuge under nitrogen atmosphere, 10% while centrifuging
After washing with 100 ml of a sulfuric acid aqueous solution, it was filled in a 150 ml sample bottle and filled with deionized water subjected to nitrogen bubbling and stored.

(D) Coal-based granular activated carbon (trade name: Diamond Hope C, manufactured by Mitsubishi Kasei) in a 500 ml eggplant-shaped flask.
After adding 100 ml (40 g) and reducing the pressure, the operation of blowing nitrogen was repeated to replace oxygen in the activated carbon pores with nitrogen, and then under a nitrogen atmosphere, an aqueous solution of DDA disodium salt having a concentration of 22% (specific gravity 1.17) was used. (20 ° C.)) (200 ml) was added, and adsorption was performed under reduced pressure for 2 hours. After separating the supernatant with a centrifuge under a nitrogen atmosphere, 5% while centrifuging
After washing with 200 ml of a sulfuric acid aqueous solution, the solution was further impregnated with 100 ml of a 5% sulfuric acid aqueous solution, the supernatant was separated again by a centrifuge, filled in a 150 ml sample bottle, and filled with nitrogen-bubbled demineralized water for storage.

(2) Measurement of loading amount DDA loaded on the loading material prepared in (1) above
The method of measuring the supported amount of is as follows. That is, 10 ml of each of the four types of the supported materials a to d was subjected to Soxhlet extraction with a mixed solvent of acetone: methanol (1: 1), and then switched to toluene and extracted again. The extract was dried up, weighed, converted to anthraquinone, and the adsorption amount was calculated.

The results are shown in "Table 1". As a result,
When Diahope C was used as the carrier, the maximum was about 0.8 mol / min even when 22% DDA disodium salt solution was used.
The limit was liter-carrier.

[0062]

[Table 1]

[Example 2] [Preparation of a carrier carrying DDA or anthrahydroquinone on activated carbon and treatment of its silver complex ion aqueous solution] (1) Preparation of a carrier carrying DDA or anthrahydroquinone on activated carbon (a) [Supporting DDA] 50 ml (20 g) of coal-based granular activated carbon (manufactured by Mitsubishi Kasei Co., Ltd., trade name Diamond Hope C), which had been degassed after being moistened with demineralized water, was added to a 200 ml eggplant-shaped flask, and 40 ml of demineralized water was further added. After standing under reduced pressure for 1 hour, under nitrogen atmosphere, 200m aqueous solution of DDA disodium salt having a concentration of 10%
1 was added. Adsorption was carried out for 4 hours under a nitrogen atmosphere with occasional stirring. The supernatant was decanted under a nitrogen atmosphere and packed in a 22 mmφ × 300 mm glass column.
Wash with 150 ml of demineralized water in which dissolved oxygen was replaced with nitrogen,
The mixture was transferred to a 150 ml sample bottle under a nitrogen atmosphere, and the supernatant was decanted and stored. The adsorbed amount of this supported material was measured in the same manner as in Example 1 and found to be 0.53 mol / liter-activated carbon.

(B) [Support of anthrahydroquinone] Sodium hydroxide 2.4 was added to a 200 ml eggplant-shaped flask.
g, 8.5 g of sodium hydrosulfite and 50 ml of demineralized water were added to 50 ml of activated carbon (manufactured by Mitsubishi Kasei Co., Ltd., trade name Diamond Hope C) moistened with sufficiently degassed demineralized water under a nitrogen atmosphere and stirred. After that, add 6 g of anthraquinone crushed at room temperature, leave for 4 hours,
Adsorbed. Then, it was filtered under a nitrogen atmosphere, washed with 50 ml of 5% diluted sulfuric acid, and bubbling nitrogen with deionized water 50 m.
It was washed 3 times with 1, and transferred to a 150 ml sample bottle and stored under a nitrogen atmosphere. The adsorption amount of this supported material was measured in the same manner as in Example 1 and was 0.41 mol / liter-activated carbon.

(2) Treatment of metal ion-containing aqueous solution when the above-described supported material is used as a metal ion treating agent [Preparation of waste water for fixing washing model] Ammonium thiosulfate 200 g, anhydrous sodium sulfite 15
g and 15 ml of acetic acid were added and dissolved, and then diluted with demineralized water to make 1 liter. A solution prepared by dissolving 7.2 g of silver chloride in a dark room was used as a stock solution, and a solution obtained by diluting the stock solution 100 times was used as a fixing wastewater model wastewater (dissolved as silver thiosulfate complex ion, silver concentration 50 ppm, pH 5.0). did.

[Treatment of Metal Ion Aqueous Solution] (a) 10 ml of the supported material (DDA-activated carbon supported material) prepared in the above (1) -a was sampled and 11 mmφ × 150 mm
Column, and the fixing wastewater model wastewater was adjusted to pH 8.2 by adding a 20% sodium hydroxide solution, and then the S. V. The solution was passed at 2 / hr (20 ml / hr). The results of the treatment are shown in "Table 2". (B) Since 10 ml of the loaded material (DDA-activated carbon supported material) prepared in (1) -a above was collected in a 100 ml Erlenmeyer flask, it may have been oxidized during the storage period.
4% sodium hydrosulfite (Na ₂ S ₂ O ₄ )
After adding 100 ml of the aqueous solution, sealing the container and leaving it for 30 minutes,
Packed in a column of 11 mmφ x 150 mm, and demineralized water 50
After washing with ml, the fixing wastewater model wastewater was adjusted to pH 8.2 by adding a 20% sodium hydroxide solution, and then the S. V. The solution was passed at 2 / hr (20 ml / hr). The results of the treatment are shown in "Table 2". (C) 10 ml of the supported material (anthrahydroquinone-activated carbon supported material) prepared in the above (1) -b was sampled and 11 mm
It was packed in a column of φ × 150 mm, and the fixing wastewater model wastewater was added with 20% sodium hydroxide solution to pH 8.2.
After adjusting to S. V. 2 / hr (20 ml
/ Hr). The results of the treatment are shown in "Table 2".

[0067]

[Table 2]

[Example 3] [Preparation of supported material carrying DDA on activated carbon and treatment of photographic fixing washing wastewater (60 ppm of silver)] (1) Preparation of supported material carrying DDA on activated carbon [supporting DDA] 100 ml (39 g) of coal-based granular activated carbon (manufactured by Mitsubishi Kasei Co., Ltd., trade name: Diamond Hope C) that was degassed in a 500 ml eggplant-shaped flask after being moistened with demineralized water.
The sample was collected, and the operation of decompressing and decompressing with nitrogen was repeated to replace oxygen in the pores of the activated carbon with nitrogen, 200 ml of a 22% aqueous solution of DDA disodium salt was added, and adsorption was carried out under reduced pressure for 1 hour. After suction filtration under a nitrogen atmosphere, the supported material was washed with 200 ml of demineralized water in which dissolved oxygen was replaced by nitrogen, transferred to a 150 ml sample bottle under a nitrogen atmosphere, filled with demineralized water in which nitrogen was replaced, and stored. The adsorbed amount of this supported material was measured in the same manner as in Example 1 and found to be 0.53 mol / liter-activated carbon.

(2) Waste water for photographic fixing washing (60 ppm of silver)
Treatment of the carrier prepared in (1) above (DDA-activated carbon carrier)
5 ml was sampled and packed in a column of 12 mmφ × 150 mm, and the photographic fixing water washing waste water (silver 60 ppm) was adjusted to pH 8.5 with a 20% sodium hydroxide solution, and then S. V. The solution was passed at 4 / hr (20 ml / hr).
The results of the treatment are shown in "Table 3". The silver concentration in the treated water was 0.1 ppm or less.

[0070]

[Table 3]

[Example 4] [Preparation of a supported material in which DDA was supported on a porous silica or a synthetic polymer adsorbent and palladium ion (palladium chloride aqueous solution) using this supported material as a metal ion treating agent]
Treatment of (1) Preparation of Supported Material in which DDA is Supported on Porous Silica or Synthetic Polymer Adsorbent [Supported on DDA] A 300 ml eggplant-shaped flask is wetted with demineralized water, and then degassed to form a columnar shape (3 mmφ × 8m
m) porous silica (manufactured by JGC Chemical Co., Ltd., trade name N-
608, data measured by mercury porosimetry: average pore diameter 120 Å, cumulative pore volume 0.59 cc
/ G, cumulative pore specific surface area 97.6 m ² / g) and 50 g of each synthetic polymer adsorbent (trade name “SP207” manufactured by Mitsubishi Kasei) degassed after being moistened with demineralized water. , 100 ml each of demineralized water was added, and each operation of decompressing and substituting with nitrogen was repeated. After substituting oxygen in the carrier with nitrogen, 40 ml of 22% DDA disodium salt aqueous solution was added under a nitrogen atmosphere, and 2 under reduced pressure. Adsorbed for a time. After suction filtration under a nitrogen atmosphere, the supported material was washed with 100 ml of deionized water in which dissolved oxygen was replaced by nitrogen, washed with 100 ml of a 10% sulfuric acid aqueous solution under a nitrogen atmosphere, and washed with 150 ml of deionized water replaced with nitrogen. 150 in the atmosphere
It was transferred to a ml sample bottle, and the supernatant was decanted and stored. The adsorption amount of these supported materials was measured in the same manner as in Example 1, and was 0.24 mol / liter for the porous silica carrier and 0.22 for the synthetic polymer adsorbent carrier.
Mol / liter-carrier.

(2) Treatment of Palladium Ion Model Wastewater Each one of palladium ion model wastewater (215 ppm as Pd) prepared with palladium (II) chloride and demineralized water.
In 00 ml, 10 g of the two types of supported materials prepared in (1)
The supernatant was sampled at 6 hours and 24 hours, and the concentration of palladium remaining in the supernatant and the amount of palladium captured by the carrier were measured by IPC emission spectrometry. The results are shown in "Table 4".

[0073]

[Table 4]

[0074]

INDUSTRIAL APPLICABILITY According to the present invention, a quinone compound, which is an oxide corresponding to the compound having a hydroquinone skeleton applied for previously, is dissolved in an organic solvent, and a solid porous carrier is brought into contact with this solution to carry it. , Compared with the method of producing a supported material of a compound having a hydroquinone skeleton by reducing the supported material carrying the quinone type compound, the hydroquinone skeleton is difficult to handle in an aqueous solution without using a combustible organic solvent. Since the compound possessed is easily supported on the porous carrier and the supported compound is already in the reduced form, there is an advantage that it is not necessary to reduce the supported substance again when it is used as a metal ion treating agent which is a main application. . Also, DD
The supported material in which A is supported on the porous carrier has an effect of exhibiting about 2 to 5 times the ability of capturing metal ions in the first treatment as compared with the supported materials supporting other anthrahydroquinone compounds.

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) C02F 1/70 C02F 1/62 C09K 3/00

Claims (6)

(57) [Claims] 1. A method in which an aqueous solution of a water-soluble salt of a compound having a hydroquinone skeleton is brought into contact with a porous carrier, the compound is adsorbed to the porous carrier, the porous carrier is separated, and then washed. A method for producing a supported material, comprising a porous carrier on which a compound having a hydroquinone skeleton is carried. 2. The method according to claim 1, wherein the compound having a hydroquinone skeleton is an anthrahydroquinone compound. 3. The anthrahydroquinone compound is 1,4
A process according to claim 2 which is -dihydro-9,10-dihydroxyanthracene. 4. The method according to claim 1, wherein the water-soluble salt is one or more water-soluble salts selected from alkali metal or ammonium salts. 5. The method according to claim 1, wherein the cleaning treatment is a cleaning treatment with an aqueous medium or a treatment with an acid aqueous solution. 6. A metal ion in an aqueous solution, wherein the supported material converts a metal ion (including a metal complex ion; the same applies hereinafter) contained in the aqueous solution into a 0-valent metal or a 1-valent metal ion by a redox reaction. 2. The method according to claim 1, which is a metal ion treatment agent comprising capturing a metal on a carrier.