JP2006183106A - Apparatus for separating and collecting metal, and method for separating and collecting metal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus which easily, quickly and safely extracts a metal from a metal-containing substance, and further selectively and continuously separates each component from the other and collects it at a high yield, and to provide a method for separating and collecting the metal. <P>SOLUTION: The method for separating and collecting the metal comprises: the first step of extracting the objective metal from the metal-containing substance by contacting it with a supercritical fluid or liquid (particularly preferably, supercritical carbon dioxide); and the second step of separating each component from the metal-containing extract by using a pseudo-moving-bed type separating means. The apparatus for separating and collecting the metal suits for the above method. In the first step, it is preferable to contact the metal-containing substance with the supercritical fluid or liquid containing a complexing agent and an oxidizing agent. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a metal separation and recovery apparatus and a metal separation and recovery method.

Metal ores, heterogeneous catalysts, printed circuit boards, etc. contain metals such as precious metals, from which separation and recovery of metals is important. At present, however, poisons such as strong acids and cyanide compounds are used to dissolve the contained metals, so handling with great care and special equipment are required. In addition, the metal-dissolved solution and the pulverized rock or ceramic carrier slurry are sludged, and there is a problem that solid-liquid separation is not easy. Although there is a method of melting metal at high temperature, a special furnace is required, and establishment of a safe and simple method for separating metal from rocks and carriers is required.
In the refining and plating industries, a large amount of metal-containing waste liquid is generated. If the metal-containing waste liquid flows into the environment such as rivers, lakes, and seas, heavy metal contamination may occur. Therefore, it is required to separate and recover the metal from the metal-containing waste liquid. However, since they usually contain a plurality of metals, it is desired from the viewpoint of effective use of resources that each of them is separated and recovered as a single body and recycled. . The amount of precious metals such as gold, platinum, palladium, and rhodium is very small, and because the mining sites are limited, they are expensive and valuable. These precious metals are also contained in the high-level radioactive nitric acid waste liquid of spent nuclear fuel, and a technique for recovering from the high-level radioactive nitric acid waste liquid before solidification treatment with molten glass is required. Furthermore, since there was no excellent method for separating the catalyst and the organic product in the homogeneous metal catalyst reaction liquid, and only those that could be separated by distillation could not be industrialized, it was possible to establish a method for separating the metal catalyst and the organic product from this reaction liquid. It has been demanded.

Conventional metal dissolution / extraction methods include the addition of strong acids to metal-containing materials and the addition of an oxidizing agent in the case of noble metals, followed by filtration of insoluble materials, and the addition of complexing agents to aqueous solutions in which metals are dissolved. A two-phase separation using a solvent and extracting a metal complex into an organic phase, and a method of recovering a metal component by melting a metal-containing material in a high-temperature furnace are common. However, in recent years, studies have been conducted on extraction of metals as complexes with supercritical fluids that can be easily separated from extraction residues and between extraction solvents and metal complexes. Methods for obtaining noble metal oxides by supercritical water oxidation (eg, non-patented) Reference 1), a method of extracting a noble metal complex with supercritical carbon dioxide and a chelating agent (see, for example, Non-Patent Document 2), a method of extracting a metal complex from a metal oxide with supercritical carbon dioxide, a chelating agent, and an oxidizing agent ( For example, see Patent Document 1). However, although it is possible to extract a plurality of metals from a material containing a plurality of metals, it is necessary to separate the metals into each other.
Examples of the metal separation method include a classic precipitation method and an electrodeposition method in which precipitation and dissolution by complex formation are repeated. In recent years, highly selective metal extractants have been developed, and many patents for solvent extraction methods using the metal extractants have been filed. In addition, a method in which a metal is adsorbed on an anion exchange resin and then selectively eluted by devising an elution method, a method in which a metal is adsorbed on a chitosan derivative that is a chelate resin, and a method for selective elution are proposed. Furthermore, there is a method of separating a metal complex by a chromatographic method. However, all of these methods have to be purified many times, and the separation takes a long time. In addition, there are problems of low yield, high cost, and discontinuity.
Therefore, a method of applying a simulated moving bed method by high yield, low cost, continuous size exclusion chromatography, specifically, using a halogen solution as an eluent and a hydrophilic such as polysaccharide or polyacrylamide as a filler. A method for separating and recovering a metal from a metal halogeno complex containing a noble metal or a base metal halide using a reactive gel (see, for example, Patent Documents 2 to 4) has been proposed.
Japanese Patent No. 2813551 U.S. Pat. No. 4,885,143 Japanese Patent No. 3291203 Japanese National Patent Publication No. 2001-516808 Piers Grummet, Platinum Metals Rev., 47, (4), 163-166 (2003) Motonobu Goto, Akio Kodama, Tsutomu Hirose, Abstracts of the 3rd Waste Treatment Science Research Presentation, 53-54, (2003)

The supercritical water oxidation method described in Non-Patent Document 1 requires a high-temperature and high-pressure state of 374 ° C. or higher and 221 bar or higher, and has a problem that it is necessary to take anti-corrosion measures for equipment materials due to its high corrosivity. In addition, when the extracted metal oxide is a plurality of metals, they cannot be separated from each other, and in the case of an organic compound generated in a metal catalytic reaction, there is a problem that the product is decomposed.
The supercritical carbon dioxide extraction method described in Non-Patent Document 2 and Patent Document 1 has the advantage that it can be carried out at a relatively low temperature and low pressure and is easy to separate from the extraction residue. Metals have the disadvantage that they cannot be separated from each other.
Moreover, the methods as described in Patent Documents 2 to 4 are gel permeation chromatographic methods using a halogen solution, and the material of the device must be acid and corrosion resistant, leading to a high device cost. It was not industrial. In addition, rhodium is difficult to dissolve in aqueous hydrochloric acid with noble metal recovery using chloro complexes, and tetrachlorogold (III) acid has a large partition coefficient and is difficult to elute, so it has to be removed by pretreatment. .

  The present invention has been made in view of the above circumstances, and it is possible to easily and quickly extract metals from metal-containing materials, and further to separate each component continuously from each other with high selectivity and high yield. An object of the present invention is to provide a metal separation and recovery apparatus and a metal separation and recovery method that can be recovered.

The method for separating and recovering a metal according to the present invention includes a first step of extracting a metal-containing material by bringing a supercritical fluid into contact therewith, and a second step of separating the metal-containing extract from each other by a simulated moving bed type separation means. Features.
The metal separation and recovery method of the present invention is characterized in that, in the first step, a complexing agent is brought into contact with the supercritical fluid.
The metal separation and recovery method of the present invention is characterized in that, in the first step, an oxidizing agent is brought into contact with the supercritical fluid and the complexing agent.
The metal separation and recovery method of the present invention is characterized in that the eluent used in the simulated moving bed type separation means in the second step is a supercritical fluid.
The metal separation and recovery method of the present invention is characterized in that the first step and the second step are connected to enable continuous operation.
The metal separation and recovery method of the present invention is characterized in that the metal-containing material is a metal catalyst-containing material.
The metal separation and recovery method of the present invention is characterized in that the metal catalyst-containing material is a heterogeneous solid catalyst and is before or after calcination.
The metal separation and recovery method of the present invention is characterized in that the metal-containing material is washed and / or pulverized as a pretreatment step.
The metal separation and recovery method of the present invention is characterized in that the supercritical fluid or liquid is carbon dioxide.
The metal separation and recovery apparatus of the present invention includes a first step of extracting a metal-containing material by bringing a supercritical fluid into contact therewith, and a second step of separating the metal-containing extract from each other by a simulated moving bed type separation means. Features.

  According to the metal separation and recovery apparatus and the metal separation and recovery method of the present invention, metals can be easily and quickly extracted from a metal-containing material, and each component is highly selective, high yield, and continuous. Can be separated from each other and the metal can be recovered.

An embodiment of the first step of the present invention will be described.
The embodiment example of the first step is a step of supercritical extraction of metal from the metal-containing material.

(Metal-containing material)
The metal-containing material may be solid, liquid, or slurry. A plurality of metal species may be contained. Here, the metal refers to B (boron), Si (silicon), As (arsenic), Te (tellurium), At (of periodic table 1-7 group A, group 8 and group 1-7 B excluding hydrogen. Among the elements on the left side of astatine), it is an element that can form a complex, and may be a metal compound, a metal salt, a metal complex, or the like.
Specific examples of the metal-containing material include a transition metal-containing material and a noble metal-containing material. The transition metal-containing material is an element of Group 3 to Group 7 A, Group 8 or Group 1 to Group B (transition metal). ) Is a substance containing at least one of the above, and the noble metal-containing substance is a group 8 platinum group Ru (ruthenium), Rh (rhodium), Pd (palladium), Os (osmium), Ir in the periodic table. (Iridium), Pt (platinum), and Group (B) Au (gold), Ag (silver) (above, noble metal).
The metal-containing material is, for example, a solid, a metal ore or a heterogeneous metal catalyst supported on a carrier, a substrate for electronic industry, jewelry, a dental material, a spent nuclear fuel, or the like. These are easy to extract if pulverized before supercritical extraction. Also, in liquid materials and slurries, metal catalyst manufacturing waste liquid, metal refining waste liquid, plating waste liquid, development waste liquid, nitric acid solution generated from reprocessing plant of spent nuclear fuel in light water reactor and fast reactor, radioactive process waste liquid, or metal catalyst reaction liquid, etc. It is.
Heterogeneous noble metal catalysts typified by automobile exhaust gas treatment catalysts can be divided into granular or monolith (honeycomb), but granular catalysts carry noble metals such as platinum, palladium and rhodium on the surface of granular carriers such as alumina. . The monolith catalyst is composed of a honeycomb carrier such as cordierite, a washcoat layer mainly composed of alumina, and a noble metal such as platinum, palladium, and rhodium supported thereon. In order to produce these catalysts by the impregnation method, for example, in the case of a monolith catalyst, after coating with alumina or the like to be a washcoat layer, the noble metal solution is impregnated with a carrier, filtered, dried, fired, and activated. And get.
In such precious metal recovery from heterogeneous metal catalysts, acid dissolution method or bluing method with aqua regia is usually used, but handling of the solution requires great care and makes the equipment material corrosion resistant. In addition, there must be a special safety device, which has the disadvantage of increasing the device cost, and is not industrial. Further, the slurry with the pulverized carrier becomes sludge, and there is a problem that solid-liquid separation is not easy. However, in the supercritical extraction method, separation from the carrier is very safe and easy.
Further, in the acid dissolution method, there is a problem that the washcoat layer and the alumina carrier are dissolved and separation from the noble metal becomes difficult, but in the supercritical extraction method, aluminum is not extracted, and the problem can be avoided.
Furthermore, these catalysts often contain rhodium, but only rhodium is difficult to dissolve in aqua regia, so it is difficult to recover by acid dissolution method, but rhodium can also be extracted by supercritical extraction method. I found an advantage.
In addition, when manufacturing heterogeneous metal catalysts, waste slurries in which the impregnating solution, which is a precious metal solution, and a washcoat layer are mixed, or defective products with non-uniform impregnation, etc. are generated. Precious metals are also recovered from these. However, if it is before firing, the precious metal exists on the surface as a complex, so that it can be extracted with only a supercritical fluid or liquid, or only with a supercritical fluid or liquid and a complexing agent, even without an oxidizing agent. I found out.
A used automobile exhaust gas treatment catalyst or the like has carbon and oil adhered thereto, and therefore, it is preferably cleaned as a pretreatment. As a cleaning method, high temperature steam or supercritical carbon dioxide, supercritical water, or a mixture of solvents such as ethanol may be used. Furthermore, when heavy metals such as iron and nickel are attached, it is convenient that only the noble metal of the catalyst remains if washed and removed with an acid such as hydrochloric acid or sulfuric acid.
Further, extraction can be facilitated by pulverization with a jet mill or the like, but the particle size to be pulverized is arbitrary.
Furthermore, the ceramic carrier which is the extraction residue after being extracted in the first step can be reused as a ceramic filler or building material.
Even when the metal-containing material is a liquid material or a slurry, it was found that only the metal complex and the organic material can be extracted, and separation from water and solid material is very easy. In particular, there was no method for separating the catalyst and the organic product from the homogeneous metal catalyst reaction liquid, and until now it was impossible to industrialize anything other than that which could be separated by distillation, but it was found that it can be easily separated by this method.

(Supercritical fluid or liquid)
Supercritical fluid is a fluid that exceeds the critical point, has both gas diffusivity and liquid solubility, and it is easy to separate dissolved substances when returning to normal pressure after supercritical extraction. Has advantages. Water, carbon dioxide, ammonia, ethane, propane, dinitrogen monoxide, chlorotrifluoromethane, and the like are preferable, but carbon dioxide is harmless and inexpensive, is not corrosive, and can be used at a relatively low temperature and low pressure.
A liquid is a solvent that can dissolve a metal or metal complex in a metal-containing material, and an organic solvent such as alcohol, acetonitrile, acetone, n-hexane, liquid carbon dioxide, or a mixture thereof is preferably used. However, liquid carbon dioxide is preferred.
Among supercritical fluids or liquids, supercritical carbon dioxide is more preferable from the viewpoints of dissolving power, dissolution rate, corrosivity, and cost.

(Complexing agent)
In order to supercritically extract a metal from a metal-containing material, it is necessary to complex the metal. A complexing agent is mixed to form a complex. The complexing agents include tributyl phosphate (TBP), triphenyl phosphate (TPP), acetylacetone (AA), dialkyl sulfide (DAS), CYANEX272, CYANEX301, CYANEX302, various crown ethers. However, TBP and AA are preferable.

(Oxidant)
When supercritical extraction of a metal is performed, an oxidizing agent is added because a metal oxide or the like is not complexed only by a complexing agent. Examples of the oxidizing agent include nitric acid, hydrogen peroxide, and chlorine. Nitric acid is preferable because stainless steel can be used for the extraction container and the cost can be reduced.

(Supercritical extraction equipment)
FIG. 1 shows an example of a supercritical extraction apparatus. This apparatus includes a liquid feeding device P, a thermostatic chamber O, an extraction container E, a back pressure device V, and a collection device S. The liquid extraction solvent G introduced from the cylinder is cooled by the cooling pipe C and then pumped by the liquid feeding device P. The extraction container E installed in the thermostatic bath O is mixed with a complexing agent and an oxidizing agent M on the way. The liquid is sent to. Here, the complexing agent and the oxidizing agent M may be filled in E in advance. Further, it is better if there is a preheating tube H before being introduced into O, but the extraction solvent becomes a supercritical fluid with H or O and is introduced into E. The introduction method to E may be a downward flow or an upward flow, or may be introduced into the head space of E from the side and extracted. E contains a metal-containing material, but it may be solid, powder, liquid, or slurry. It is even better if E has a drift prevention device or a stirring device. Of the metal-containing materials, complexed metals and organic materials are dissolved in the supercritical fluid. The extracted supercritical fluid is brought to atmospheric pressure by the back pressure device V, the extraction solvent G becomes gaseous, the metal complex becomes solid, and the organic matter becomes liquid or solid and is collected by the collection device S. The extraction solvent G is preferably recycled. Further, before V, there may be an ultraviolet (UV) spectrophotometer D for monitoring the extraction.
Although the extraction time of E is arbitrary, it is preferable that the average residence time of the extraction solvent is 0.01 to 2 hours in the batch operation and 0.01 to 2 hours in the continuous operation. E may provide a plurality of tanks and perform a parallel extraction operation. At that time, for example, a batch operation in which all the tanks are operated in the same manner, an extraction operation and an extraction operation, and a refilling operation may be divided into, for example, three groups to perform a continuous extraction operation as a whole. In E, the extraction rate can be increased by reducing the pressure in the normal E after extraction and then re-extracting.
After V, metal complexes and organic substances are obtained as powders, which are dissolved and separated and purified in the second step. As the solvent to be dissolved, those mentioned as the eluent described later are preferable. Further, it is more preferable to connect to the second step using the supercritical fluid as an eluent without dissolving V or S and dissolving in the supercritical fluid because continuous operation is possible.

An embodiment of the second step of the present invention will be described.
The embodiment example of the second step is a step of separating each component from the metal-containing material by a simulated moving bed type separation means.
(Metal separation and recovery equipment)
The metal separation and recovery apparatus has a simulated moving bed type separation means.
The simulated moving bed type separation means is a device in which a plurality of columns filled with a filler are connected in an endless manner in series, and liquid can be discharged from each column while liquid can be introduced into each column.
FIG. 2 shows an example of the simulated moving bed type separation means. The simulated moving bed type separation means 1 includes eight columns (packed beds) 11a to 11h that are filled with a filler and connected endlessly in series, a metal-containing solution transfer pipe 21 that transfers a metal-containing solution, An eluent transfer pipe 22 for transferring an eluent, an extract transfer pipe 23 for transferring an extract discharged from each column, a raffinate transfer pipe 24 for transferring a raffinate discharged from each column, a column 11a and a column 11h, And a recycling pipe 25 for guiding the liquid discharged from the column 11h to the column 11a, connection pipes 40a to 40g for connecting adjacent columns, and a pump 50 provided in the recycling pipe 25. Is done. A flow path formed by the columns 11a to 11h, the recycle pipe 25, and the connection pipes 40a to 40g is referred to as a circulation flow path 70.
Here, the eluent is a mobile phase that moves through the circulation channel 70 by the pump 50 and causes the metal-containing solution introduced into the circulation channel 70 to flow, and the extract is adsorbed by the filler. The raffinate is a solution containing a component that is difficult to adsorb on the filler.

  The metal-containing solution transfer pipe 21 and the columns 11a to 11h are connected by metal-containing solution introduction pipes 31a to 31h, respectively. The eluent transfer pipe 22 and the columns 11a to 11h are respectively connected to eluent introduction pipes 32a to 32h. The extract transfer pipe 23 and the columns 11a to 11h are connected by extract discharge pipes 33a to 33h, respectively. The raffinate transfer pipe 24 and the columns 11a to 11h are connected by raffinate discharge pipes 34a to 34h, respectively. Has been. Further, each of the metal-containing solution introduction pipes 31a to 31h, the eluent introduction pipes 32a to 32h, the extract discharge pipes 33a to 33h, and the raffinate discharge pipes 34a to 34h was set so as to be appropriately opened and closed by sequence control or the like. Solenoid valves 35a to 35h (solenoid valves for introducing metal-containing solutions), 36a to 36h (solenoid valves for introducing eluent), 37a to 37h (solenoid valves for discharging exhaust), 38a to 38h (solenoid valves for discharging raffinate) Is provided. The recycle pipe 25 is preferably provided with a measuring device 60 for measuring ultraviolet (UV) absorption of the solution flowing through the recycle pipe 25.

[column]
The packing material filled in the columns 11a to 11h may be any material that can distribute the metal complex to the packing material by passing the metal solution. For example, in the case of an inorganic filler, silica, alumina, magnesia, titanium oxide, silicate, diatomaceous earth, aluminosilicate, layered compound, zeolite, activated carbon, graphite and the like can be used. The surface may be modified with various coupling agents, for example, a silane coupling agent such as octadecylsilane (ODS), but commercially available ODS fillers are preferred.
In the case of an organic filler, a functional monomer polymer is cross-linked with a cross-linkable monomer. The functional monomer includes unsaturated carboxylic acid, (meth) acrylic acid ester, (meth) acrylamide derivative, styrene derivative. , Vinyl esters, allyl alcohol derivatives, other vinyl compounds, chitosan derivatives, etc., which have introduced a functional group having ion exchange ability, chelate ability, hydrogen bonding ability, and hydrophobic binding ability. You may utilize the size exclusion capability of hydrophilic gels, such as a polysaccharide and polyacrylamide. Examples of the crosslinkable monomer include aliphatic or aromatic vinyl monomers such as ethylene glycol dimethyl acrylate, N, N′-methylenebisacrylamide, and divinylbenzene. Moreover, when a functional monomer is a chitosan derivative, what cross-linked by epichlorohydrin etc. and what introduce | transduced the functional group into this can be used.

  Commercially available ion exchange resins and chelate resins include Diaion WA20, Diaion SA10A, Diaion CR20 (manufactured by Mitsubishi Chemical Corporation), Sumichel CR-2 (manufactured by Sumitomo Chemical Co., Ltd.), Amberlite IRA400, Amberlite XAD4 Amberlyst A26 (Rohm & Haas, USA), Dowex Marathon A, Dowex Marathon C (Dow Chemical, USA), Chelate Chitopearl CS-03 (Fuji Boseki Co., Ltd.), and the like.

Examples of the shape of the filler include a granular shape and a monolithic shape, and a granular shape is preferable, and a spherical shape is preferable among the granular shapes. In that case, the particle size is preferably 1 to 2000 μm, and more preferably 5 to 100 μm in order to further increase the degree of separation.
The exchange capacity when the filler is an ion exchange resin does not need to be large for use as a chromatographic filler, but rather is preferably small, preferably 0.001 to 10 meq./g, more preferably 0.01. ~ 1 meq./g. Moreover, if a cation exchange resin and an anion exchange resin are mixed or each column is connected and used at the same time, both the cation and the anion can be separated from each other.

[Eluent]
The eluent is a fluid that can dissolve the complex / organic matter extracted in the first step and can elute the adsorbed material on the filler, and must not dissolve or swell the filler to increase the pressure loss. There is no particular limitation, and a supercritical fluid may be used. For example, water, aqua regia, acidic aqueous solutions such as hydrochloric acid, nitric acid and sulfuric acid, various alkaline aqueous solutions such as ammonia water, various salt aqueous solutions such as potassium chloride, sodium cyanide and sodium thiocyanate, alcohol, acetonitrile, acetone and n-hexane An organic solvent such as the above or a mixture thereof can be suitably used. Halogen-based eluents can be used for separation of halogeno complexes and the like, but are not preferable because of the problem of device corrosion. Supercritical fluids include water, carbon dioxide, ammonia, ethane, propane, dinitrogen monoxide, and chlorotrifluoromethane that exceed the critical point, but carbon dioxide is harmless and inexpensive, and can be used at relatively low temperatures and low pressures. Therefore, it is preferable. A ligand may be exchanged by adding a complexing agent to the eluent.

  When the eluent is a liquid, the temperature and pressure are within the usable range of the filler, the temperature is 0 to 100 ° C., more preferably 20 to 60 ° C., and the pressure is normal pressure to 300 atmospheres, more preferably 50 to 200 atmospheres. A complexing agent such as citric acid or a reducing agent may be added to the eluent. When the eluent is a supercritical fluid, it may be above the critical point. In the case of carbon dioxide, the temperature is 31 to 300 ° C, more preferably 40 to 100 ° C, and the pressure is 73 to 400 atmospheres, more preferably 75 to 300 atmospheres. It is. The flow direction of the eluent is arbitrary.

(Metal separation and recovery method)
Next, an example of a method for separating and recovering a metal from a multiple metal-containing solution containing two kinds of metals using the above-described simulated moving bed type separation means will be described.
First, the pump 50 is operated to cause the eluent to flow into the circulation channel 70. Along the flow direction of the circulating fluid, (1) an eluent inlet, (2) an extract outlet for extracting a liquid (extract) containing metal that is easily adsorbed by the filler, (3 The electromagnetic valve is opened and closed so that the multiple metal-containing solution inlet and (4) the raffinate outlet for extracting the liquid (raffinate) containing the metal that is difficult to adsorb to the filler are arranged in this order. The electromagnetic valve opens and closes so that each of these inlets or outlets moves intermittently and sequentially in the direction of fluid flow in the columns 11a to 11h. For example, the solenoid valves 36a, 37a, 35b, and 38b are opened, and the multiple metal-containing solution is introduced into the column 11b from the multiple metal-containing solution transfer pipe 21 through the multiple metal-containing solution introduction pipe 31b. The introduced multiple metal-containing solution is introduced into the column 11b and flows in the column 11b. At that time, since the adsorptivity to the filler in 11b is different between the two types of metals, the solution (raffinate) containing a metal that is difficult to adsorb flows quickly in the column 11b, and a liquid containing an easily adsorbed metal (extract ) Flows slowly. By utilizing such a difference in adsorptivity, it can be separated into raffinate and extract.

  Next, the solenoid valves 36a, 37a, 35b, and 38b are closed, and the solenoid valves 36b, 37b, and 35c are passed through the vicinity of the outlet of the solenoid valve 35c in the connecting pipe 40b until the extract peak reaches after the raffinate peak passes. , 38c are opened. Then, the raffinate is discharged from the column 11c prior to the extract, and then extracted to the raffinate transfer pipe 24 via the raffinate discharge pipe 34c. At the same time, the eluent is passed through the column 11b, and the extract is extracted to the extract transfer pipe 23 via the discharge pipe 33b. By such a series of steps, two kinds of metals can be separated and recovered.

  In this metal separation / recovery method, after the above-described steps are completed, the column for metal separation / recovery is changed in order. That is, after the metal is separated and recovered by the column 11b, the metal is separated and recovered in the order of the column 11c, the column 11d,. In addition, since the columns 11a to 11h are connected in series endlessly, after the metal is separated and recovered by the column 11h, the metal is separated and recovered by the column 11a. In addition, since the discharge | emission state of raffinate and an extract can be confirmed by the measurement of UV absorption etc., the timing which changes a column can be determined based on the result.

After separating and recovering the extract and raffinate as described above, the metal is recovered from each of them. As a method for recovering the metal from the extract or raffinate, for example, an electrodeposition method in an electrolytic cell, a method of adding a reducing agent to precipitate as metal black, a combustion method, a method combining these, or the like can be applied. Among these, in the method of adding a reducing agent and precipitating, hydrazine, formaldehyde, formic acid, sodium borohydride, potassium and other metals, hydrogen, and the like can be used as the reducing agent. In the combustion method, firing may be performed at 300 ° C. or higher, preferably 350 to 700 ° C., and performed in a hydrogen stream.
When the metal catalyst and the organic product are recovered from the metal catalyst reaction liquid, the organic product may be purified by distillation.

  In the embodiment example of the second step described above, since the plurality of metals are separated from the plurality of metal-containing solutions using the simulated moving bed type separation means, the selectivity and the yield are high. As a result, the purification process can be omitted. In addition, the simulated moving bed type separation means is efficient because it separates and recovers the metal continuously, and it is not necessary to use a halogen solution as the metal-containing solution. Can be lowered.

  In addition, this invention is not limited to the example mentioned above. In the example described above, the simulated moving bed type separation means has eight columns, but is not limited thereto, and preferably four or more columns are appropriately selected. As the simulated moving bed, for example, U.S. Pat. No. 2,985,589 which performs two-component separation, Japanese Patent Publication No. 42-15681, Japanese Patent No. 890042, Japanese Patent Laid-Open No. 2002-82106, Patent No. which performs multi-component separation. No. 2740780, Japanese Patent No. 2965747, Japanese Patent No. 1954744, Japanese Patent No. 200200292, Japanese Patent No. 20000830 with four columns, Japanese Patent No. 2964348 with a supercritical fluid as an eluent, For example, those described in Table 07-700771, other US Pat. No. 5,422,2007 and US Pat. No. 6,712,973 can be used.

It is a schematic diagram of the supercritical extraction device in this embodiment. It is a schematic diagram which shows an example of the pseudo | simulation moving bed type | mold separation means in this embodiment.

Explanation of symbols

1 ... Simulated moving bed type separation means

Claims (10)

A metal separation and recovery method comprising: a first step of extracting a metal-containing material by bringing a supercritical fluid or liquid into contact therewith; and a second step of separating the metal-containing extract from each other by a simulated moving bed type separation means. . The metal separation and recovery method according to claim 1, wherein a complexing agent is contacted in addition to the supercritical fluid or liquid in the first step. The method for separating and recovering a metal according to claim 2, wherein in the first step, the supercritical fluid or liquid is contacted with an oxidizing agent in addition to the complexing agent. 4. The method for separating and recovering a metal according to claim 1, wherein the eluent used in the simulated moving bed type separation means in the second step is a supercritical fluid. The method for separating and recovering a metal according to any one of claims 1 to 4, wherein the first step and the second step are connected and can be continuously operated. 6. The metal separation and recovery method according to claim 1, wherein the metal-containing material is a metal catalyst-containing material. 7. The method for separating and recovering a metal according to claim 6, wherein the metal catalyst-containing material is a heterogeneous solid catalyst, and includes a product before firing and a defective product. The metal separation and recovery method according to claim 1, wherein the metal-containing material is washed and / or pulverized as a pretreatment step. The method for separating and recovering a metal according to any one of claims 1 to 8, wherein the supercritical fluid or liquid is carbon dioxide. The apparatus which isolate | separates and collects a metal by the method in any one of Claims 1-9.

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