JPWO2015083292A1 - Rare earth ion separation method and separation apparatus - Google Patents

Abstract

A method and apparatus for easily separating neodymium ions and dysprosium ions are provided. An organic molecule that forms a complex with these ions is added to an aqueous solution containing neodymium ions and dysprosium ions to form a complex. Are separated by liquid chromatography. As the organic molecule, ethylenediaminetetraethylamine, ethylenediaminetetraethanol, ethylenediaminetetraacetic acid, ethylenediaminetetraacetamide is used. Liquid chromatography is performed by column chromatography or thin layer chromatography using silica gel as a stationary phase and water or a mixed solvent of water and acetone as a mobile phase.

Description

  The present invention relates to a separation method and a separation apparatus for separating neodymium and dysprosium, which are rare earth elements.

In recent years, the demand for neodymium magnets has increased as motor performance and size have decreased. Neodymium magnets are extremely strong magnets with the composition of Nd ₂ Fe ₁₄ B, and because they are easy to downsize and thin, they are being applied to hard disk drive motors, hybrid vehicle motors, etc. Is increasing.

Neodymium magnets are powerful magnets, but have the disadvantage that their coercivity decreases at high temperatures. The coercive force generation mechanism of neodymium magnets is not necessarily clarified at present, but empirically high dysprosium Dy with high magnetic anisotropy is added to neodymium magnets at several to several tens percent to maintain coercivity at high temperatures. It has been found that the decrease in magnetic force can be suppressed. However, since Dy is a rare element and the production area is unevenly distributed, securing its stability is an issue, and the coercivity of the magnet is maintained while reducing the amount of Dy added to the neodymium magnet. Technology to recycle Dy added to neodymium magnets is being developed.
In order to recycle Dy added to the neodymium magnet, it is necessary to separate Nd and Dy contained in the neodymium magnet. However, Nd and Dy are elements of the same lanthanoid series, which have similar chemical properties and are difficult to separate from each other.

  The separation methods of Nd and Dy known so far include a physicochemical method, a biological method, and a chemical method.

  The physicochemical method is a method of separating Nd and Dy by utilizing the difference in physicochemical properties of Nd and Dy or their compounds. As the physicochemical method, a solvent extraction method, an ion exchange resin method, and an ion trap method are known. The solvent extraction method is a method for separating Nd and Dy by utilizing the distribution of organic molecular complexes of Nd and Dy at different concentrations between two immiscible solvents. Regarding solvent extraction methods, there are Non-Patent Document 1, Patent Documents 1 and 2.

  In the ion exchange resin method, an aqueous solution containing Nd and Dy ions is passed through a column packed with a cation exchange resin that adsorbs cations, and then a solution of complex-forming molecules such as ethylenediaminetetraacetic acid (EDTA) is applied to the column. In this method, Nd and Dy ions adsorbed on the cation exchange resin are dissolved and developed, and these ions are separated. In the ion exchange resin method, these ions are separated by utilizing the fact that Nd and Dy ions adsorbed on the cation exchange resin have different complexing ability with respect to organic molecules. As for the ion exchange resin method, there is Patent Document 3.

The ion trap method is a method for separating Nd and Dy ions by utilizing the property that a polymer having an amine-based side chain selectively traps Dy ions. There is Patent Document 4 regarding a method using an ion trap.
There is Patent Document 5 as a biological method. In this method, bacteria that selectively aggregate Dy are cultured and grown, and a solution containing Nd and Dy is added to the bacterial medium to selectively aggregate Dy inside the bacteria.

  Although the separation of Nd and Dy is not described, there is Patent Document 6 as a chemical method for separating lanthanoid ions. This method utilizes the fact that when a complex of a lanthanoid ion and a cyclic organic molecule is reacted in a salicylic aldehyde and acetonitrile solvent, the product varies depending on the type of ion, and the solubility of the product in the solvent varies depending on the type of ion. Thus, this is a method for separating lanthanoid ions.

JP 2010-270359 A Japanese Patent Laid-Open No. 5-320092 JP 63-270312 A JP 2012-30139 A JP 2012-244914 A Japanese Unexamined Patent Publication No. 7-315836

Hisamura Imura, Latest Separation, Purification, and Detection Methods-From Principles to Applications-NTN Corporation, Tokyo (1997)

  Thus, various methods have been proposed for the separation of Nd and Dy. However, among the physicochemical methods, the solvent extraction method and the ion exchange resin method require a large amount of solvent. These approaches requiring large amounts of solvent are undesirable from an environmental protection standpoint.

  On the other hand, the ion trap method does not require a large amount of solvent, but has a drawback that it takes time to separate ions. The method of Patent Document 5 using a biological method does not require a large amount of solvent and has a small environmental load, but requires a medium for culturing bacteria that isolates Dy, and is a biological process. Therefore, there is a drawback that it takes time to separate ions. Since the method of Patent Document 6 using a chemical method includes a crystallization process, it is not suitable for rapidly separating Nd and Dy. Thus, it has been difficult for conventional techniques to separate a large amount of Nd and Dy quickly and easily.

  The object of the present invention is to easily and quickly separate Nd and Dy ions.

  Traditional techniques using physicochemical techniques take advantage of the slight difference in physicochemical properties of Nd and Dy, which requires a large amount of solvent, and the ion trap method does not require a large amount of solvent, but the ion There was a drawback that it took time to separate. Similarly, biological methods and chemical methods have the drawback of requiring time to separate ions.

If the difference between the physicochemical properties of Nd and Dy can be amplified in some form, it is considered that separation of Nd and Dy can be performed without using a large amount of solvent in the physicochemical method. From this point of view, the inventor conducted a molecular orbital calculation on the differences in the physicochemical properties of various organic molecules and complexes of Nd ⁺³ and Dy ⁺³ ions. It was found that the dipole efficiency of the complex in aqueous solution varies greatly depending on the type of ion.

  Specific organic molecules include ethylenediaminetetraethylamine (EDTEA) having a molecular structure of Formula 1, ethylenediaminetetraethanol (EDTEOH) having a molecular structure of Formula 2, ethylenediaminetetraacetic acid (EDTA) having a molecular structure of Formula 3, and Ethylenediaminetetraacetamide (EDTAA) having the molecular structure of Chemical Formula 4.

  Molecules with different dipole efficiency can be separated using liquid chromatography. The inventors paid attention to this point, and devised a method and an apparatus for separating these complexes by liquid chromatography using a mobile phase containing water after forming complexes of these organic molecules and Nd and Dy ions in an aqueous solution. did.

To give a typical example of the method for separating rare earth ions of the present invention, an aqueous solution containing neodymium ion Nd ⁺³ and dysprosium ion Dy ⁺³ has the ability to form a complex with these ions that are soluble in the aqueous solution. A step of forming a complex of ions and organic molecules in an aqueous solution by adding organic molecules, and a step of separating the formed Nd ⁺³ complex and Dy ⁺³ complex by liquid chromatography using silica gel as a stationary phase And.

As an example of the rare earth ion separation apparatus of the present invention, a column packed with silica gel powder and an aqueous solution containing a complex of Nd ⁺³ and Dy ⁺³ ions and organic molecules at the top of the column. Means for introducing, means for continuously flowing a liquid chromatography mobile phase liquid into the upper part of the column, and a container for receiving the moving bed liquid flowing out from the lower part of the column, wherein said container flows out from the lower part of the column When filled with a phase liquid, another container moves under the column to receive the mobile phase liquid that flows out, and a device for irradiating the container located under the column with ultraviolet light and generated from the container This is a rare-earth ion separation device that includes a device that detects fluorescence and that is installed in a darkroom.

Further, as another example of the rare earth ion separation apparatus of the present invention, an optically transparent glass substrate having a fired silica gel thin film on one of its surfaces, an apparatus for irradiating the silica gel thin film with ultraviolet rays, A device for detecting fluorescence emitted from a silica gel thin film is provided, and the device for irradiating ultraviolet light and the device for detecting fluorescence are disposed so as to face above and below the silica gel thin film, respectively, and these devices are disposed on the glass substrate. The entire apparatus is installed in a dark room, and the silica gel thin film is prepared by ^converting an aqueous solution containing a complex of Nd ⁺³ and Dy ⁺³ ions and an organic molecule into a Nd ^{+ 3} is a separation device of the rare earth ion is one which is separated in the complex of the complex and Dy ^+3.

According to the present invention, Nd ⁺³ and Dy ⁺³ ions can be easily and rapidly separated. In the present invention, organic molecules and complexes of these ions can be separated using liquid chromatography using water as a developing solvent, and compared with solvent extraction methods and ion exchange resin methods that require large amounts of organic solvents. And is excellent. Further, it is superior to the ion trap method and biological method in that a large amount of Nd ⁺³ and Dy ⁺³ can be separated by column chromatography.

Explanatory drawing of the complex of EDTEA which is the organic molecule of this invention, and Nd ^{+ 3} ion. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram of a scheme for preparing an aqueous solution containing Nd ⁺³ and Dy ⁺³ EDTEA complexes from the neodymium magnet of Example 1. FIG. 4 is an explanatory diagram of an apparatus for separating a complex of an organic molecule of Example 2 and Nd ⁺³ and Dy ⁺³ ions by column liquid chromatography. Explanatory drawing of the scheme which isolate | separates the complex of the ion of Nd ^{+ 3} ion and Dy ^{+ 3 in} case the organic molecule of Example 2 is EDTEA, EDTEOH, or EDTAA. FIG. ³ is an explanatory diagram of a scheme for separating a complex of EDTA, Nd ⁺³ ion, and Dy ⁺³ ion of Example 2. FIG. 6 is an explanatory diagram of a scheme for fractionating Dy ⁺³ ions by liquid chromatography from an aqueous solution containing EDTEA molecules and Dy ⁺³ ions in Example 4. FIG. 10 is an explanatory diagram of an example in which a complex of EDTEA and Nd ⁺³ and Dy ⁺³ ions is separated by thin layer chromatography of Example 10. FIG. 6 is a cross-sectional view of the thin layer taken along line AB in Example 10. FIG. 4 is an explanatory diagram of a scheme for separating a complex of EDETA, Nd ⁺³ and Dy ⁺³ ions by thin layer chromatography of Example 10. FIG. 5 is an explanatory diagram of the separation state of the Nd ⁺³ complex and the Dy ⁺³ complex of EDTEA in Example 10. FIG. 11 is an explanatory diagram of an apparatus for clarifying the positions of the Nd ⁺³ complex and the Dy ⁺³ complex in the thin film of Example 11.

First, the principle of the present invention will be described in detail. FIG. 1 is a diagram showing the structure of a complex of EDTEA of formula 1 and Nd ⁺³ ion obtained by molecular orbital calculation. In aqueous solution, EDTEA forms a complex with Nd ⁺³ ions together with two water molecules.

In FIG. 1, 1 is an Nd ⁺³ ion, 2 is an EDTEA molecule, 3 is an N atom of the EDTEA molecule 2, 4 is an O atom of a water molecule that forms a complex with the Nd ⁺³ ion together with the EDTEA molecule 2, and 5 is an EDTEA molecule 2 C atoms. For simplicity of illustration, EDTEA and H atoms of water molecules are not shown. The Nd ⁺³ ion is coordinated to 6 N atoms 3 and 2 O atoms 4 constituting the EDTEA molecule 2, and the coordination number is 8.

The dipole efficiency of this Nd ⁺³ ion complex is calculated to be 7.4266 debye. Similarly, when the complex structure of Dy ⁺³ ion and EDETA and water is calculated, a structure similar to that of FIG. 1 is obtained, but the dipole efficiency of the complex is calculated to be 6.9883 Debye.

Thus, the dipole efficiency of the complex formed by EDETA, Nd ⁺³ and Dy ⁺³ ions in water varies depending on the type of ion.

Similar calculations are performed for the organic molecules of the present invention, EDTEOH of Formula 2, EDTA of Formula 3, and EDTAA molecules of Formula 4, and these molecules and water molecules form Nd ⁺³ and Dy ⁺³ ions. The dipole efficiency of the complex was calculated. In the case of EDTA, a structure in which the four carboxyl groups in Chemical Formula 3 were ionized negatively was used for the calculation.

Table 1 summarizes the dipole efficiency of each complex obtained by calculation. The dipole efficiency of the complexes formed by EDTEOH, EDTA, and EDTAA molecules with Nd ⁺³ and Dy ⁺³ ions in water varies with the type of ion.

Thus, the organic molecule of the present invention forms a complex with Nd ⁺³ and Dy ⁺³ in an aqueous solution, and the dipole efficiency of the complex varies depending on the type of ion.

The present invention makes use of such characteristics of the organic molecule of the present invention, so that a complex of Nd ⁺³ and Dy ^{+3 in} an aqueous solution can be separated by liquid chromatography.

The complex of the organic molecule of the present invention and Nd ⁺³ and Dy ⁺³ ions is formed by adding the organic molecule of the present invention to an aqueous solution containing Nd ⁺³ and Dy ⁺³ ions. However, the aqueous solution must be alkaline because, under acidic conditions, the N atom constituting the organic molecule of the present invention is protonated and the complexing ability of the molecule is lost.

Any aqueous solution containing Nd ⁺³ and Dy ⁺³ ions used in the present invention may be used. For example, a solution obtained by removing Fe ions from an aqueous solution obtained by treating a neodymium magnet with an acid can be used. This aqueous solution is obtained by adding hydroxide ions to an aqueous solution obtained by treating a neodymium magnet with an acid to precipitate Fe ions in the aqueous solution as Fe (OH) ₂ and removing the precipitate.

In the present invention, an aqueous solution containing the Nd ⁺³ and Dy ⁺³ ions is obtained from a neodymium magnet having a Dy composition ratio of 0.1 to 1.0.

In the present invention, hydrophilic silica gel is used for the fixed layer of liquid chromatography. In liquid chromatography using hydrophilic silica gel as the stationary phase, the complex with higher dipole efficiency is more strongly adsorbed by the silica gel that is the solid phase, so the organic molecule of the present invention and Nd ⁺³ and Dy are different due to the difference in dipole efficiency. ⁺³ complexes can be separated.

In the present invention, water or a mixed solvent of water and acetone is used for the mobile phase of liquid chromatography. This is because when the organic molecule of the present invention forms a complex with Nd ⁺³ and Dy ⁺³ ions, it forms a complex with water molecules.

In addition, the complex formed by the organic molecule of the present invention with Nd ⁺³ and Dy ⁺³ ions is ionic and dissolves well in these high dielectric constant solvents. In the present invention, water having a high dielectric constant (dielectric constant 80) and a mixed solvent of water and acetone (dielectric constant 50) having a mixing volume ratio of 1: 1 are used as chromatographic mobile phases. Nd + 3 ion complex and Dy ion complex can be separated efficiently.

Further, as described above, the organic molecule of the present invention loses the ability to form a complex with Nd ⁺³ and Dy ⁺³ ions under acidic conditions. In the present invention, using this property, after separating the organic molecule of the present invention from the complex of Nd ⁺³ and Dy ⁺³ ions by liquid chromatography, an acid is added to the solution containing these complexes to form the organic molecule and The ions were separated so that Nd ⁺³ and Dy ⁺³ ions could be obtained separately.

In the present invention, column chromatography or thin layer chromatography is used as a liquid chromatography method. Column chromatography is suitable for separating large amounts of Nd ⁺³ and Dy ⁺³ , and thin layer chromatography is suitable for separating small amounts of Nd ⁺³ and Dy ⁺³ .

  In column chromatography, silica gel powder packed in a column is used as a stationary phase, and water or a mixed solvent of water and acetone is used as a mobile phase.

When an aqueous solution containing an organic molecule of the present invention and a complex of Nd ⁺³ and Dy ⁺³ ions is introduced into the top of a column packed with silica gel powder, the complex is adsorbed and fixed on the silica gel.
Subsequently, when water, which is a mobile phase, or a mixed solvent of water and acetone is introduced from the top of the column, the mobile phase solvent falls toward the bottom of the column. Move towards. Among the complexes of Nd ⁺³ and Dy ⁺³ ions, the higher the dipole efficiency, the stronger the adsorption on silica gel, which is the stationary phase, and the lower the migration rate of the complex accompanying the movement of the mobile phase liquid. On the other hand, a complex having a smaller dipole efficiency is weakly adsorbed on silica gel, and thus the migration rate of the complex accompanying the mobile phase liquid is large. In this way, the complex of Nd ⁺³ and Dy ⁺³ ions has different dipole efficiency, and the moving speed in the column is different, so that the time of flowing out from the column is different and can be separated. Thus, Nd ⁺³ and Dy ⁺³ ion complexes can be separated by column chromatography based on the difference in dipole efficiency of these complexes.

A complex of Nd ⁺³ and Dy ⁺³ ions has a property of emitting fluorescence when irradiated with ultraviolet rays. The present invention makes use of this property of the complex to confirm these separated ions.

  In thin-layer chromatography, a glass substrate with silica gel sintered on its surface is used, and the silica gel thin film is used as a stationary phase, and water or a mixed solvent of water and acetone is used as a mobile phase.

An aqueous solution containing the organic molecule of the present invention and a complex of Nd ⁺³ and Dy ⁺³ ions is applied on the surface of the silica gel thin film about 1 cm from the edge of the substrate in a straight line so as to be parallel to the edge of the substrate. The complex inside is adsorbed and fixed on the silica gel surface.
Thereafter, the glass substrate portion between the edge of the substrate and the silica gel portion coated with the aqueous solution is water or a mobile phase so that the silica gel thin film portion coated with the aqueous solution containing the complex does not contact the liquid surface. When immersed under the surface of a mixed solvent of water and acetone, the mobile phase liquid rises in the silica gel thin film by capillary action.
Along with this, the complex adsorbed on the silica gel thin film also rises in the thin film, but the rate of increase is slower for the complex with higher dipole efficiency and strongly adsorbed by silica gel, and the dipole efficiency is smaller and weakly adsorbed by silica gel. The faster the complex.
Since the dipole efficiency of the organic molecule, Nd ⁺³ complex and Dy ⁺³ complex of the present invention varies depending on the type of ions, the moving speed in the thin film when the mobile phase rises in the silica gel thin film is different. Can be separated above.

In the present invention, by using the apparatus of the present invention described later, the Nd ⁺³ and Dy ⁺³ complexes separated on the silica gel thin film are irradiated with ultraviolet rays, and the position of the complex on the silica gel thin film is confirmed. .

In the present invention, the Nd ⁺³ ion complex and the Dy ⁺³ ion complex can be separated and obtained by peeling off the silica gel thin film at the position of the complex thus confirmed and washing with water. I did it.

In the present invention, as an apparatus for separating Nd ⁺³ ion complex and Dy ⁺³ complex by the above column chromatography, a column packed with silica gel powder as a stationary phase, and the above-mentioned column at the top of the column An apparatus for introducing an aqueous solution containing a complex of Nd ⁺³ and Dy ⁺³ ions, an apparatus for continuously supplying a liquid chromatography mobile phase liquid to the top of the column, and an outlet from the bottom of the column below the column An apparatus of the present invention has been devised comprising a container for receiving moving bed liquid.

  There are a plurality of containers for receiving the mobile phase liquid, and when filled with the mobile phase liquid flowing out from the lower part of the column, another container moves under the column and receives the mobile phase liquid flowing out.

This apparatus is provided with a device for detecting fluorescence emitted from the device and the vessel is irradiated with ultraviolet rays in a vessel located below the column, the presence or absence of fluorescence when irradiated with ultraviolet rays, the Nd ⁺³ ion complex The container in which the mobile phase liquid containing was separated or the container in which the mobile phase containing the Dy ⁺³ ion complex was separated can be discriminated.

An ultraviolet light transmission preventing filter is installed on the front surface of the detection unit of the apparatus that detects fluorescence. As a result, the apparatus for detecting fluorescence does not react to the ultraviolet light emitted by the apparatus that irradiates ultraviolet light, but reacts only to the fluorescence emitted by the Nd ⁺³ complex and the Dy ⁺³ complex.

  Further, the entire apparatus is installed in a dark room, and an apparatus for detecting fluorescence with light from outside does not operate.

Thus, in this apparatus, the container in which the complex of Nd ⁺³ and Dy ⁺³ ions is separated can be confirmed by fluorescence.

In the present invention, as a device for separating Nd ⁺³ complex and Dy ⁺³ complex separated by thin layer chromatography, the silica gel thin film is irradiated with ultraviolet rays to detect fluorescence emitted by these complexes. We have devised a device to clarify the position of these complexes on silica gel thin films.

  This apparatus includes means for irradiating a silica gel thin film used in thin layer chromatography with ultraviolet light and means for detecting fluorescence emitted from the silica gel thin film.

  The means for irradiating ultraviolet light and the means for detecting fluorescence are arranged so as to face the upper and lower sides of the silica gel thin film, respectively, and the means can move in parallel to the substrate carrying the silica gel glass thin film. It is like that.

  The means for irradiating ultraviolet rays irradiates only the portion of the silica gel thin film located under the means.

  The fluorescence emitted from the silica gel thin film passes through the glass substrate and is detected by means for detecting fluorescence.

  An ultraviolet light transmission preventing filter is disposed in front of the means for detecting fluorescence, and the means detects only the fluorescence emitted by the silica gel thin film.

  In addition, the entire apparatus is installed in a dark room, and means for detecting fluorescence with light from outside does not operate.

  When the silica gel thin film used in the thin layer chromatography is irradiated with ultraviolet light using this apparatus, the thin film does not emit fluorescence when the ultraviolet light is irradiated on the portion of the thin film where the complex has not moved.

  On the other hand, when ultraviolet rays are irradiated to the thin film portion where the complex has moved, the thin film emits fluorescence, and the fluorescence is detected by means for detecting the fluorescence through the glass substrate.

In this way, this device can know the position of the complex of Nd ⁺³ and D ^{y + 3} ions on the thin film by the presence or absence of fluorescence when the silica gel thin film used in thin layer chromatography is irradiated with ultraviolet rays. It can be done.

As described above, in thin layer chromatography, the smaller the dipole efficiency, the greater the amount of movement from the position where the complex was first applied, so the position of the Nd ⁺³ ion complex and the amount of movement Dy ⁺³ ion complex position can be identified.

  The means for irradiating ultraviolet rays and the means for detecting fluorescence constituting the apparatus of the present invention are not limited, and for example, a semiconductor laser and a photomultiplier can be used.

  Embodiments of the present invention will be described below with reference to the drawings.

This example relates to an example in which an aqueous solution containing Nd ⁺³ and Dy ⁺³ ions is prepared from a neodymium magnet, and an aqueous solution containing a complex of these ions and the organic molecule of the present invention is prepared.

FIG. 2 shows a scheme for preparing an aqueous solution containing Nd ⁺³ and Dy ⁺³ EDTEA complexes from a neodymium magnet using EDTEA which is an organic molecule of the present invention. Step 6 is a step of grinding a neodymium magnet, Step 7 is a step of dissolving the magnet powder obtained in Step 6 in sulfuric acid, Step 8 is a step of adding a sodium hydroxide aqueous solution to the sulfuric acid aqueous solution obtained in Step 7, Step 9 Is a step of removing the precipitate of Fe (OH) ₂ generated in the aqueous solution as a result of Step 8, and Step 10 is a step of adding EDTEA to the aqueous solution obtained in Step 9.

First, pulverize the neodymium magnet. Any means for pulverizing the magnet may be used. For example, a ball mill can be used. In this example, 1 gram of neodymium magnet was pulverized by a ball mill. A neodymium magnet having a Dy addition amount of 9% by weight was used. Since the composition of this neodymium magnet is Nd ₂ Dy _0.66 Fe ₁₄ B and the molecular weight is 1188.371, the amount of pulverized magnet is about 0.84 mmol.

Subsequently, the magnet powder obtained by pulverization is dissolved in an aqueous solution of sulfuric acid. In this example, magnet powder was dissolved in 6 ml of sulfuric acid aqueous solution having a concentration of 3 mol / liter and a normality of 6N. At this stage, the aqueous solution contains Nd ⁺³ , Dy ⁺³ , Fe ⁺² , and B (OH) ₄ − ions derived from the pulverized magnet.

Next, an aqueous sodium hydroxide solution was added to the sulfuric acid solution to neutralize the aqueous solution, and Fe ⁺² ions contained in the aqueous solution were precipitated as Fe (OH) ₂ . In this example, 54 ml of an aqueous sodium hydroxide solution having a concentration of 1 mol / liter and a normality of 1N was added to the aqueous sulfuric acid solution, and Fe ⁺² in the aqueous solution was precipitated as Fe (OH) ₂ . The amount of aqueous sodium hydroxide is an amount sufficient to neutralize hydrogen ions remaining in the aqueous solution and to precipitate Fe ⁺² ions in the aqueous solution.

Next, the precipitate of Fe (OH) ₂ is removed. In this example, Fe (OH) ₂ was removed by filtering the aqueous solution. Nd ⁺³ , Dy ⁺³ , and B (OH) ₄ ⁻ ions are present in the aqueous solution at this stage.

Finally, the organic molecule of the present invention is added to the aqueous solution. In this example, 2.5 mmol (0.58 g) of EDTEA (molecular weight 232.369) was added to the aqueous solution and stirred. As a result, Nd ⁺³ and Dy ⁺³ ions in aqueous solution form a complex with EDETA and become Nd ⁺³ -EDETA (H ₂ O) ₂ complex and Dy ⁺³ -EDETA (H ₂ O) ₂ complex, respectively. . Here, (H ₂ O) ₂ represents two water molecules that form a complex with these rare earth ions together with EDTEA.

In this manner, an aqueous solution containing Nd ⁺³ and Dy ⁺³ ions can be prepared from a neodymium magnet, and the organic molecule of the present invention can be added to the aqueous solution to produce an aqueous solution containing a complex of Nd ⁺³ and Dy ⁺³ ions.

The aqueous solution obtained by the above treatment contains not only the complex of Nd ⁺³ and Dy ⁺³ ions, but also EDTEA and B (OH) ₄ ⁻ ions that do not form a complex. (OH) ₄ ⁻ ions can be separated from complexes of Nd ⁺³ and Dy ⁺³ ions by liquid chromatography performed later.

In this example, an aqueous solution containing a complex of Nd ⁺³ and Dy ⁺³ ions was prepared using EDTEA, but the above-described organic molecules of the present invention, that is, EDTOH, EDTA, and EDTAA were also used in the same manner. Complexes of organic molecules with Nd ⁺³ and Dy ⁺³ ions can be obtained.

Note that the aqueous solution in the stage before Step 10 needs to be alkaline. This is because the organic molecule of the present invention has an N atom in the molecular skeleton, and this N atom is coordinated to Nd ⁺³ and Dy ⁺³ ions to form a complex. This is because the proton is protonated and the coordination ability of molecules to ions is lost. In this example, the pH of the aqueous solution after Step 9 is about 11, which satisfies this condition.

FIG. 3 shows an apparatus for separating a complex of an organic molecule of the present invention and Nd ⁺³ and Dy ⁺³ ions by column liquid chromatography. 11 is a column, 12 is silica gel, 13 is a glass apparatus for flowing an aqueous solution containing an organic molecule of the present invention and a complex of Nd ⁺³ and Dy ⁺³ ions into the column 11, and 14 is a mobile phase liquid for liquid chromatography. A tank for storing a certain water or a mixed solvent of water and acetone, 15 is a pump, 16 is a pipe connecting the tank 14 and the pump 15, 17 is a pipe for sending a liquid chromatography mobile phase liquid to the column 11, 18 Is a container that receives liquid chromatography moving bed liquid flowing out from the column 11 through the silica gel 12, 19 is a stage of the container 18, 20 is a semiconductor laser that irradiates the container 18 positioned below the column 11 with ultraviolet light, 21 Is a photomultiplier tube, 22 is an ultraviolet transmission preventing filter, and 23 is a dark room.

By flowing an aqueous solution containing the complex of Nd ⁺³ and Dy ⁺³ ions from the upper part of the glass apparatus 13, the aqueous solution containing the complex is injected into the silica gel 12, and the complex is adsorbed and fixed on the top of the silica gel 12. It is like that.

  The mobile phase liquid of liquid chromatography is stored in a tank 14, and is allowed to flow into the uppermost part of the silica gel 12 through the pipe 16, the pump 15, and the pipe 17 by operating the pump 15.

  The mobile phase liquid descends in the silica gel 12 and is dropped into the container 18 from the lower end of the column 11. The volume of the container 18 is sufficiently smaller than the volume of the moving bed liquid used in the whole process of liquid chromatography, and a plurality of containers 18 are prepared so as to receive all the moving bed liquid used in the liquid chromatography. The container 18 is disposed on the stage 19, and when one container 18 is filled with moving bed liquid, the stage slides to the left and another container 18 moves to the lower part of the column 11, and the column 11 The moving bed liquid dripped from the lower end of the liquid is received.

Since Nd ⁺³ complex and Dy ⁺³ complex have different dipole efficiency, they are adsorbed on silica gel 12 with different strengths. Therefore, the migration speed of these complexes in the silica gel 12 as the mobile phase liquid descends is different for each complex, and the Nd ⁺³ complex and the Dy ⁺³ complex are dripped from the lower tip of the column 11 at different timings and are different. The container 18 is separated.

The semiconductor laser 20 irradiates the container 18 disposed below the column 11 with ultraviolet light having a wavelength of 400 nm. If the mobile phase liquid dropped into the container 18 contains an Nd ⁺³ complex or a Dy ⁺³ complex, the liquid emits fluorescence, and the fluorescence operates the photomultiplier tube 21.

  On the other hand, if the mobile phase liquid dropped into the container 18 does not contain these complexes, fluorescence does not occur and the photomultiplier tube 21 does not operate.

  An ultraviolet transmission preventing filter 22 is installed on the light receiving surface of the photomultiplier tube 21 to prevent the ultraviolet light irradiated from the semiconductor laser 20 to the container 18 from being scattered and received by the photomultiplier tube 21. Yes.

  The entire apparatus is arranged in a dark room 23 so that the photomultiplier tube 21 does not operate with light from the outside.

As described above, the present apparatus can separate the Nd ⁺³ and Dy ⁺³ complexes flowing into the upper part of the silica gel 12 into different containers 18 and distinguish the containers 18 containing these complexes.

FIG. 4 shows a scheme for separating complexes of Nd ⁺³ ions and Dy ⁺³ ions when the organic molecule is EDTEA, EDTOH, or EDTAA using the apparatus of FIG.

Step 24 is a step of passing a mobile phase liquid through silica gel 12, Step 25 is a step of introducing a complex of Nd ⁺³ and Dy ⁺³ ions into column 11, and Step 26 is a liquid chromatography mobile layer in column 11. The step of introducing a liquid, step 27 is a step of dispensing the complex of Dy ⁺³ into the container 18, and step 28 is a step of ^dispensing the complex of Nd ⁺³ into the container 18.

  In step 24, the mobile phase liquid of liquid chromatography stored in the tank 14 is introduced into the column 11 by the pump 15 through the pipe 16 and the pipe 17, and the silica gel 12 is passed through the mobile phase liquid.

In step 25, an aqueous solution containing a complex of EDTEA, EDTEOH, or EDTAA and Nd ⁺³ and Dy ⁺³ ions is introduced into the column 11 using the glass apparatus 13, and the complex is adsorbed on the top of the silica gel 12.

  In step 26, the pump 15 is operated, and the liquid chromatography liquid bed liquid is introduced from the tank 14 into the column 11 through the pump 15, the pipe 16, and the pipe 17. The mobile phase liquid flowing into the column 11 descends in the silica gel 12 and is dropped into the container 18 from the lower part of the column 11.

  When the moving bed liquid descends through the silica gel 12, the complex adsorbed on the silica gel 12 also moves toward the bottom of the column 11. The moving speed becomes slower as the complex is strongly adsorbed on the silica gel 12, and the strength of the adsorption is larger as the dipole efficiency of the complex is larger. Therefore, the complex having a higher dipole efficiency has a slower moving speed in the silica gel 12 and is dropped more slowly into the container 18.

Among the complexes of EDTEA, EDTEOH, and EDTAA with Nd ⁺³ and Dy ⁺³ ions, the Dy ⁺³ complex has a lower dipole efficiency. For this reason, the complex of Dy ⁺³ is dropped into the container 18 earlier, and then the complex of Nd ⁺³ is dropped into the container 18.

Here, if the volume of the container 18 is appropriately set, the container 18 into which the Dy ⁺³ complex is dropped and the container 18 into which the Nd ⁺³ complex is dropped can be made different.

The fractionation of Nd ⁺³ and Dy ⁺³ ion complexes is confirmed by irradiating the mobile phase liquid fractionated in the container 18 with ultraviolet light from the semiconductor laser 20 and judging the presence or absence of fluorescence by the operation of the photomultiplier tube 21. Is done.

FIG. 5 shows a scheme for separating complexes of EDTA and Nd ⁺³ ions and Dy ⁺³ ions using the apparatus of FIG.

Step 29 is a step of passing a mobile phase liquid through silica gel 12, Step 30 is a step of introducing a complex of Nd ⁺³ and Dy ⁺³ ions into column 11, and Step 31 is a liquid chromatography mobile bed in column 11. A step of introducing a liquid, step 32 is a step of dispensing the Nd ⁺³ complex into the container 18, and step 33 is a step of dispensing the complex of Dv ⁺³ into the container 18.

  The scheme of FIG. 5 is similar to the scheme of FIG. Step 29 is the same as Step 24, Step 30 is the same as Step 25, and Step 26 is the same as Step 31.

When the scheme of FIG. 5 is compared with the scheme of FIG. 4, the scheme of FIG. 5 is different from the scheme of FIG. 4 in that the Nd ⁺³ complex is fractionated first, followed by the Dy ⁺³ complex. . This is because, as shown in Table 1, in the EDTA complex, the Nd ⁺³ ion complex has a smaller dipole efficiency and a higher moving speed in the silica gel 12 than the Dy ⁺³ ion complex. is there.

The aqueous solution containing the complex of EDETA, Nd ⁺³ ion and Dy ⁺³ ion prepared in Example 1 was separated by liquid chromatography according to the scheme of FIG. 4 using the apparatus of FIG. Water was used as the mobile phase for liquid chromatography. As the column 11, a column having a diameter of 5 centimeters and a length of 5 meters was used. As silica gel 12, silica gel powder having a particle diameter of 210 micrometers was used.

When 50 liters of water is introduced into the column 11, the complex of Dy ⁺³ ions is separated into the container 18, and when 51.5 liters of water is introduced into the column 11, the complex of Dy ⁺³ ions is separated into the container 18. Was taken. The amount of water collected was 0.2 liter of mobile phase liquid containing a complex of Dy ⁺³ ions and 0.3 liter of mobile phase liquid containing a complex of Nd ⁺³ ions.

15 ml of 1N sulfuric acid solution is added to each of the aqueous solutions containing the complex of Dy ⁺³ ions separated in Example 3, and the N atoms of the EDTEA molecules constituting the complex are protonated to separate the EDTEA molecules from the Dy ⁺³ ions. did.

From an aqueous solution containing the separated EDTEA molecules and Dy ⁺³ ions were aliquoted Dy ⁺³ ions by liquid chromatography using the apparatus of FIG. FIG. 6 shows the preparative scheme.

Step 34 is a step of adding an acid to a solution containing a Dy ⁺³ complex, Step 35 is a step of passing water, which is a mobile phase of liquid chromatography, through silica gel 12, and Step 36 is an EDTEA separated using a glass apparatus 13. Step of introducing an aqueous solution containing molecules and Dy ⁺³ ions into the column 11, step 37 is a step of introducing water as a mobile phase into the column 11 from the tank 14 using the pump 15, pipe 16, and pipe 17, step 38 is This is a step of dispensing water containing Dy ⁺³ ions into the container 18.

In Step 36, when the separated aqueous solution containing EDTEA molecules and Dy ⁺³ ions is introduced into the column 11, the introduced EDTEA molecules and Dy ⁺³ ions are adsorbed on the top of the silica gel 12. In step 37, when water as a mobile phase is introduced into the column 11, the water descends through the silica gel 12 and is dropped into the container 18 from the lower part of the column 11. As water descends through the silica gel 12, the EDTEA molecules and Dy ⁺³ ions adsorbed on the silica gel 12 also descend through the silica gel 12 at different rates. This is because EDTEA molecules and Dy ⁺³ ions have different charge states and dipole efficiency.

In this example, a column having a diameter of 5 cm and a length of 5 m was used as the column 11, and silica gel powder having a particle diameter of 210 μm was used as the silica gel 12. At the stage where 49 liters of water was introduced into the column 11, Dy ⁺³ ions were separated into the container 18.

When the separated aqueous solution was dried, 128 mg of Dy ₂ (SO ₄ ) ₃ crystals were obtained. The Dy recovery efficiency from the neodymium magnet was 75%.

To the aqueous solution containing the Nd ⁺³ ion complex separated in Example 3, 5 ml of 1N sulfuric acid solution was added to protonate the N atoms of the EDTEA molecule constituting the complex to separate the EDTEA molecule and the Nd ⁺³ ion.

Using the same method as in Example 4 was fractionated by liquid chromatography using the apparatus of Figure 3 Nd ⁺³ ions from an aqueous solution containing the separated EDTEA molecules and Nd ⁺³ ions. In the liquid chromatography, Nd ⁺³ ions were fractionated into the container 18 when 48 liters of water as a mobile phase was introduced into the column 11.

When the separated aqueous solution was dried, 372 milligrams of Nd ₂ (SO ₄ ) ³ crystals were obtained, and the Nd recovery efficiency from the neodymium magnet was 77%.

Using the same method as in Example 1, an aqueous solution containing Nd ⁺³ and Dy ⁺³ ions was prepared from a neodymium magnet, and 2.5 mmol (0.59 g) of EDTEOH (molecular weight 236.308) was added to the aqueous solution to add Nd ⁺³ -EDTEOH. (H ₂ O) ₂ and Dy ⁺³ -EDTEOH (H ₂ O) ₂ complexes were prepared.

The prepared complexes of Nd ⁺³ ion and Dy ⁺³ ion were fractionated by liquid chromatography using water as a mobile phase in the same manner as in Example 3 using the apparatus shown in FIG. The amount of mobile phase liquid required for fractionation of Dy ⁺³ ion complex was 49.2 liters, and the amount of mobile phase liquid required for fractionation of Nd ⁺³ ion complex was 51.3 liters.

Next, using the same method as in Example 4, a complex of Sorted Dy ⁺³ ions separated into EDTEOH molecules and Dy ⁺³ ions, the mobile phase to water using the apparatus of FIG. 3 the liquid Dy ⁺³ ions were separated by chromatography. The amount of mobile phase required for fractionation was 49 liters.

When the separated aqueous solution was dried, 120 mg of Dy ₂ (SO ₄ ) ₃ crystals were obtained. The Dy recovery efficiency from the neodymium magnet was 70%.

Then using the same method as in Example 5, to separate the complex of Sorted Nd ⁺³ ions EDTEOH molecule and Nd ⁺³ ions, liquid mobile phase and water using the apparatus of FIG. Chromatography Nd ⁺³ ions were fractionated by chromatography. The amount of mobile phase required for fractionation was 48 liters.

When the separated aqueous solution was dried, 360 mg of Nd ₂ (SO ₄ ) ₃ crystals were obtained. The Nd recovery efficiency from the neodymium magnet was 74%.

In the same manner as in Example 1, an aqueous solution containing Nd ⁺³ and Dy ⁺³ ions was prepared from a neodymium magnet, 2.5 mmol (0.72 g) of EDTAA (molecular weight 288.304) was added to the aqueous solution, and Nd ⁺³ -EDTAA (H ₂ O) ₂ and Dy ⁺³ -EDTAA (H ₂ O) ₂ complexes were prepared.

The prepared complexes of Nd ⁺³ ion and Dy ⁺³ ion were fractionated by liquid chromatography using water as a mobile phase in the same manner as in Example 3 using the apparatus shown in FIG. The amount of mobile phase required for fractionation of Dy ⁺³ ion complex was 47 liters, and the amount of mobile phase required for fractionation of Nd ⁺³ ion complex was 49 liters.

Next, using the same method as in Example 4, a complex of Sorted Dy ⁺³ ions separated into EDTEAA molecules and Dy ⁺³ ions, the mobile phase to water using the apparatus of FIG. 3 the liquid Dy ⁺³ ions were separated by chromatography. The amount of mobile phase required for fractionation was 49 liters.

When the separated aqueous solution was dried, 137 milligrams of Dy ₂ (SO ₄ ) ₃ crystals were obtained. The Dy recovery efficiency from the neodymium magnet was 81%.

Then using the same method as in Example 5, to separate the complex of Sorted Nd ⁺³ ions EDTEAA molecule and Nd ⁺³ ions, liquid mobile phase and water using the apparatus of FIG. Chromatography Nd ⁺³ ions were fractionated by chromatography. The amount of mobile phase required for fractionation was 48 liters.

When the separated aqueous solution was dried, 432 milligrams of Nd ₂ (SO ₄ ) ₃ crystals were obtained. The Nd recovery efficiency from the neodymium magnet was 89%.

In the same manner as in Example 1, an aqueous solution containing Nd ⁺³ and Dy ⁺³ ions was prepared from a neodymium magnet, and 2.5 mmol (0.73 g) of EDTA (molecular weight 292.243) was added to the aqueous solution to add Nd ⁺³ − EDTA (H ₂ O) ₂ and Dy ⁺³ -EDTA (H ₂ O) ₂ complexes were made.

The prepared complexes of Nd ⁺³ ion and Dy ⁺³ ion were fractionated by liquid chromatography using water as a mobile phase in the same manner as in Example 3 using the apparatus shown in FIG. In the case of the EDTA complex, the Nd ⁺³ ion complex is fractionated prior to the Dy ⁺³ ion complex, so liquid chromatography was performed according to the scheme of FIG.

The amount of mobile phase required for fractionation of Nd ⁺³ ion complex was 45 liters, and the amount of mobile phase required for fractionation of Dy ⁺³ ion complex was 47 liters.

Next, using the same method as in Example 4, a complex of Sorted Dy ⁺³ ions separated into EDTA molecule and Dy ⁺³ ions, the mobile phase to water using the apparatus of FIG. 3 the liquid Dy ⁺³ ions were separated by chromatography. The amount of mobile phase required for fractionation was 49 liters.

When the separated aqueous solution was dried, 134 mg of Dy ₂ (SO ₄ ) ₃ crystals were obtained. The Dy recovery efficiency from the neodymium magnet was 79%.

Then using the same method as in Example 5, to separate the complex of Sorted Nd ⁺³ ions EDTEA molecule and Nd ⁺³ ions, liquid mobile phase and water using the apparatus of FIG. Chromatography Nd ⁺³ ions were fractionated by chromatography. The amount of mobile phase required for fractionation was 48 liters.

When the separated aqueous solution was dried, 403 mg of Nd ₂ (SO ₄ ) ₃ crystals were obtained. The Nd recovery efficiency from the neodymium magnet was 83%.

The complex of EDTEA and Nd ⁺³ and Dy ⁺³ ions prepared in Example 1 was separated by liquid chromatography in the same manner as in Example 3 using the apparatus shown in FIG. As a mobile phase for chromatography, a mixed solvent having a mixing volume ratio of acetone and water of 1: 1 was used. Liquid chromatography was performed according to the scheme of FIG.

At the stage when 49 liters of mobile phase liquid was introduced into column 11, the complex of Dy ⁺³ ions was fractionated into container 18, and then at the stage where 50 liters of mobile phase liquid was introduced into column 11, Nd ⁺³ ions Was dispensed into a container 18. The amount of the mobile phase separated was 30 ml of the mobile phase containing Dy ⁺³ ions and 35 ml of the mobile phase containing Nd ⁺³ ions.

Next, using the same method as in Example 4, a complex of Sorted Dy ⁺³ ions separated into EDTEA molecules and Dy ⁺³ ions, the mobile phase to water using the apparatus of FIG. 3 the liquid Dy ⁺³ ions were separated by chromatography. The amount of mobile phase required for fractionation was 49 liters.

The separated aqueous solution was dried to obtain 129 milligrams of Dy ₂ (SO ₄ ) ₃ crystals. The Dy recovery efficiency from the neodymium magnet was 75%.
Then using the same method as in Example 5, to separate the complex of Sorted Nd ⁺³ ions EDTEA molecule and Nd ⁺³ ions, liquid mobile phase and water using the apparatus of FIG. Chromatography Nd ⁺³ ions were fractionated by chromatography. The amount of mobile phase required for fractionation was 50 liters.

When the separated aqueous solution was dried, 399 milligrams of Nd ₂ (SO ₄ ) ₃ crystals were obtained. The Nd recovery efficiency from the neodymium magnet was 82%.

FIG. 7 is an explanatory diagram of an example in which a complex of EDTEA and Nd ⁺³ and Dy ⁺³ ions is separated by thin layer chromatography. 38 is a silica gel thin film surface fired on a glass substrate, 39 is a lower end portion of the silica gel thin film, 40 is an upper end portion of the silica gel thin film, and 41 is an aqueous solution containing a complex of EDTEA, Nd ⁺³ and Dy ⁺³ A coated portion of the silica gel thin film surface 38, 42 is water which is a mobile phase liquid for liquid chromatography, and 43 is a container for storing the mobile phase liquid 42. Of the silica gel thin film surface 38, the portion between the lower end 39 and the coating portion 41 is infiltrated under the liquid surface of the mobile phase liquid 42 so that the coating portion 41 does not contact the liquid surface of the mobile phase liquid 42. It has become.

  FIG. 8 is a cross-sectional view of the AB plane of the thin layer. 44 is a glass substrate. The silica gel thin film surface 38 is sintered on the glass substrate 44.

FIG. 9 is a scheme of a method for separating a complex of EDETA, Nd ⁺³ and Dy ⁺³ ions by thin layer chromatography. Step 45 is a step of applying an aqueous solution containing the complex of Nd ⁺³ and Dy ⁺³ ions to the application part 41. A step of immersing in 42, step 47 is a step of raising the mobile phase liquid 42 to the upper end portion 40 by capillary action, and step 48 is a step of removing the silica gel thin film surface 38 and the glass substrate 44 from the mobile phase liquid 42.

In step 45, the complex of EDTEA, Nd ⁺³ and Dy ⁺³ ions is adsorbed and fixed on the coating portion 41. By the processing of step 46, the mobile phase liquid 42 starts to rise in the silica gel thin film surface 38 by capillary action, and liquid chromatography using the silica gel thin film surface 38 as a stationary phase and the mobile phase liquid 42 as a mobile phase is started.

As the mobile phase liquid 42 rises in the silica gel thin film surface 38 beyond the coating portion 41, the complex of Nd ⁺³ and Dy ⁺³ fixed to the coating portion 41 also rises in the silica gel thin film surface 38. The rate of rise is different for each complex, and the Dy ⁺³ complex with a smaller dipole efficiency is weakly adsorbed by the silica gel thin film surface 38, so the rate of rise is faster than that of the Nd ⁺³ complex. As a result, the complex of Nd ⁺³ ion and the complex of Dy ⁺³ ion are separated on the silica gel thin film surface 38.

  In step 45, the mobile phase liquid 42 reaches the upper end 40, and the liquid chromatography ends.

  In step 47, the silica gel thin film surface 38 and the glass substrate 44 are taken out from the mobile phase liquid 42.

FIG. 10 is an explanatory diagram of the separation state of ETDEA Nd ⁺³ complex and Dy ⁺³ complex obtained by carrying out the above scheme.

49 Nd ⁺³ portion of the silica gel thin surface 38 moves complexes result Nd ⁺³ liquid chromatography, 50 in Dy ⁺³ portion of the silica gel thin surface 38 complex results Dy ⁺³ liquid chromatography has moved is there. Since the complex of Dy ⁺³ ions has a smaller dipole efficiency than the complex of Nd ⁺³ ions, the rate of rise in liquid chromatography is greater than that of Nd ⁺³ ions, and the Dy ⁺³ moiety 50 is Nd ⁺³ Located on part 49.

Thus, Nd ⁺³ complex and Dy ⁺³ complex of EDTA can be separated on the silica gel thin film surface 38 by thin layer chromatography.

In this example, Nd ⁺³ and Dy ⁺³ complexes of EDTEA were separated, but EDTOH, EDTA, and EDTAA complexes can also be separated by a similar scheme.

In the case of the EDTA complex, the Nd ⁺³ complex has a smaller dipole efficiency than the Dy ⁺³ complex. Therefore, when the Nd ⁺³ complex and the Dy ⁺³ complex of EDTA are separated by the above method, the result is that the portion containing Nd ⁺³ is located above the portion containing Dy ⁺³ .

FIG. 11 shows the fluorescence emitted from these complexes by irradiating Nd ⁺³ complex and Dy ⁺³ complex separated on a silica gel thin film by thin layer chromatography, and the position of these complexes in the thin film is determined. It is explanatory drawing of the apparatus clarified.

38 is a silica gel thin film, 39 is a lower end portion of the silica gel thin film 38, 40 is an upper end portion of the silica gel thin film 38, 41 is a silica gel thin film 38 coated with an aqueous solution containing Nd ⁺³ ion complex and Dy ⁺³ ion complex of EDETA Coated part, 44 is a glass substrate, 49 is a Nd ⁺³ part of silica gel thin film 38 containing Nd ⁺³ ion complex separated by chromatography, 50 is a silica gel containing Dy ⁺³ ion complex separated by chromatography Dy ⁺³ portion of the thin film 38, 51 is a semiconductor laser, 52 is a photomultiplier tube, 53 is an ultraviolet light transmission preventing filter, and 54 is a dark room. The structure of the silica gel thin film 38 and the glass substrate 44 that supports the silica gel thin film 38 is the CD plane cross-sectional structure of FIG.

The semiconductor laser 51 and the photomultiplier tube 52 are arranged to face each other and can move in parallel with the silica gel thin film 38 and the glass substrate 44. The semiconductor laser 51 irradiates the silica gel thin film 38 with ultraviolet light having a wavelength of 400 nm. When the semiconductor laser 51 is positioned above the Nd ⁺³ portion 49 or Dy ⁺³ portion 50, ultraviolet rays are irradiated to the complex contained in the Nd ⁺³ portion 49 or Dy ⁺³ portion 50, the complex fluoresces. Fluorescence is detected by the photomultiplier tube 52 that passes through the glass substrate 44 and faces it.

On the other hand, when the semiconductor laser 51 is positioned above the silica gel thin film 38 other than the Nd ⁺³ portion 49 and the Dy ⁺³ portion 50, the semiconductor laser 51 irradiates the silica gel thin film 38 with ultraviolet light, but fluorescence does not occur.

As described above, in the apparatus of this embodiment, the positions of the Nd ⁺³ portion 49 and the Dy ⁺³ portion 50 can be known based on the presence or absence of fluorescence when the silica gel thin film 38 is irradiated with ultraviolet rays.

  An ultraviolet transmission preventing filter 53 is disposed in front of the photomultiplier tube 52 so that the photomultiplier tube 52 is not operated by the ultraviolet light emitted from the semiconductor laser 51.

  The entire apparatus is installed in a dark room 54 so that the photomultiplier tube 52 does not operate with light from the outside.

Silica gel was baked to a thickness of 1 mm on an optically transparent glass substrate having a width of 10 cm, a height of 50 cm, and a thickness of 5 mm, and thin film chromatography was performed according to the method of FIG. 7 and the scheme of FIG. Went. As an aqueous solution containing a complex of Nd ⁺³ ions and Dy ⁺³ ions, 5 ml of the aqueous solution prepared in Example 1 was used. Liquid chromatography was performed according to the scheme of FIG. 9 using water as the mobile phase.

As a result of liquid chromatography, it was confirmed with the apparatus of FIG. 11 that the complex of Nd ⁺³ ion and the complex of Dy ⁺³ ion were separated on the silica gel thin film. The Rf values of these complexes (ratio of the amount of movement of the complex to the amount of movement of the mobile phase liquid) were 0.21 and 0.26, respectively.

The portion of the silica gel thin film 38 (Dy ⁺³ portion 50 in FIG. 11) to which the Dy ⁺³ ion complex was transferred was peeled from the glass substrate with a spatula, and the peeled silica gel thin film was washed with 5 ml of 1N sulfuric acid solution.

Thus, a complex of Dy ⁺³ ions separated into EDTEA molecules and Dy ⁺³ ions, dissolved in the solution. Dy ⁺³ ions were fractionated from the obtained solution by liquid chromatography using the apparatus of FIG. 3 and water as the mobile phase in the scheme of FIG. The amount of mobile phase liquid required for fractionation was 49 liters.

The separated aqueous solution was dried to obtain 41.78 mg of Dy ₂ (SO ₄ ) ₃ crystals. The Dy recovery efficiency from the neodymium magnet was 59%.

The portion of the silica gel thin film 38 to which the Nd ⁺³ ion complex was transferred (Nd ⁺³ portion 49 in FIG. 11) was peeled off from the glass substrate with a spatula, and the peeled silica gel thin film was washed with 5 ml of 1N sulfuric acid solution.

The obtained solution was subjected to liquid chromatography using water as a mobile phase according to the same scheme as in FIG. 6 using the apparatus shown in FIG. 3 to fractionate Nd ⁺³ ions. The amount of mobile phase liquid required for fractionation was 50 liters.

The separated aqueous solution was dried to obtain 131.19 milligrams of Nd2 ₂ (SO ₄ ) ₃ crystals. The Dy recovery efficiency from the neodymium magnet was 65%.

1 Neodymium atom
2 EDTEA molecule
3 Nitrogen atom
4 oxygen atom
5 carbon atoms
11 columns
12 Silica gel
13 Glassware
14 tanks
15 Pump
16 pipes
17 Pipe
18 containers
19 stages
20 Semiconductor laser
21 Photomultiplier tube
22 UV transmission filter
23 Darkroom
38 Silica gel surface
39 Lower end of silica gel thin film
40 Upper edge of silica gel thin film
41 Application part of aqueous solution containing complex of EDETA and Nd ^{+ 3} and Dy ^{+ 3}
42 Water (mobile phase liquid)
43 Water container
44 Glass substrate
Nd ⁺³ part of a complex of 49 Nd ⁺³ has moved
50 Dy ⁺³ complex transferred Dy ⁺³ part
51 Semiconductor laser
52 Photomultiplier tube
53 UV transmission filter
54 Darkroom

Claims (14)

An organic molecule soluble in aqueous solution and capable of forming a complex with these ions is added to an aqueous solution containing neodymium ion Nd ⁺³ and dysprosium ion Dy ⁺³ to form a complex of ions and organic molecules in the aqueous solution And steps to
Separating the formed Nd ⁺³ complex and Dy ⁺³ complex by liquid chromatography using silica gel as a stationary phase;
Method for separating rare earth ions containing The method for separating rare earth ions according to claim 1,
An aqueous solution containing Nd ⁺³ and Dy ⁺³ is added to an aqueous solution obtained by treating a neodymium magnet having a composition of Nd _2−x Dy _x Fe ₁₄ B with an acid, and hydroxide ions are added to add Fe ^{+2 in the} aqueous solution. A method for separating rare earth ions, which is an aqueous solution obtained by precipitating ions as Fe (OH) ₂ . The method for separating rare earth ions according to claim 2,
The neodymium magnet is a rare earth ion separation method in which the Dy composition ratio is 0.1 to 1.0. The method for separating rare earth ions according to claim 1,
The organic molecule is ethylenediaminetetraethylamine having a molecular structure of Chemical Formula 1, ethylenediaminetetraethanol having a molecular structure of Chemical Formula 2, ethylenediaminetetraacetic acid having a molecular structure of Chemical Formula 3, or ethylenediamine 4 having a molecular structure of Chemical Formula 4. A method for separating rare earth ions which are complex amides.

The method for separating rare earth ions according to claim 1,
A method for separating rare earth ions, wherein the mobile phase of the liquid chromatography is water or a mixed solvent of water and acetone. The method for separating rare earth ions according to claim 5,
A method for separating rare earth ions, wherein the mixing volume ratio of a mixed solvent of acetone and water is 1: 1. The method for separating rare earth ions according to claim 1, further comprising:
After separating the Nd ⁺³ complex and the Dy ⁺³ complex, the separated complex is treated with an acid to separate Nd ⁺³ and the organic molecule, and Dy ⁺³ and the organic molecule. Separation method. The method for separating rare earth ions according to claim 1,
In the step of separating by liquid chromatography, after introducing an aqueous solution containing the Nd ⁺³ complex and the Dy ⁺³ complex into the top of a column packed with silica gel powder, water or water is introduced from the top of the column. Introduce a mixed solvent of acetone and perform liquid chromatography using silica gel as the stationary phase and water or a mixed solvent of water and acetone as the mobile phase to separate the Nd ⁺³ complex from the Dy ⁺³ complex. Separation method. The method for separating rare earth ions according to claim 1,
A method for separating rare earth ions, wherein the separation of these complexes is confirmed by the fluorescence generated when the separated Nd ⁺³ and Dy ⁺³ complexes are irradiated with ultraviolet rays. The method for separating rare earth ions according to claim 1,
In the step of separating by liquid chromatography, silica gel is baked as a thin film on a glass substrate, and the Nd ⁺³ complex and the Dy ⁺³ complex are formed on the silica gel thin film at an inner position from one end of the glass substrate. After applying an aqueous solution containing a straight line so as to be parallel to the edge of the glass substrate,
Capillaries are formed by immersing the portion between the edge of the glass substrate and the silica gel thin film coated with the aqueous solution under the liquid surface of water or a mixed solvent of water and acetone so that the silica gel thin film portion does not contact the liquid surface. Penetration of water or a mixed solvent of water and acetone into the silica gel thin film due to the phenomenon,
Separation method of rare earth ions by separating Nd ⁺³ complex and Dy ⁺³ complex on silica gel thin film by liquid chromatography using silica gel thin film as stationary phase and water or mixed solvent of water and acetone as mobile phase. The method for separating rare earth ions according to claim 10,
After separating Nd ⁺³ and Dy ⁺³ ion complexes on a silica gel thin film, the silica gel thin film is irradiated with ultraviolet rays, and the fluorescence of the Nd ⁺³ and Dy ⁺³ complexes emits these complexes on the silica gel thin film. A method for separating rare earth ions by confirming the position and separating the complex by separating the silica gel thin film at the moving position from the glass substrate and washing with water. A column packed with silica gel powder;
Means for introducing an aqueous solution containing a complex of Nd ⁺³ and Dy ⁺³ ions and an organic molecule at the top of the column;
Means for continuously flowing a liquid chromatography mobile phase liquid into the top of the column;
A container for receiving the moving bed liquid flowing out from the bottom of the column;
When the container is filled with mobile phase liquid flowing out from the bottom of the column, another container moves under the column and receives mobile phase liquid flowing out,
A device for irradiating the container located under the column with ultraviolet light, and a device for detecting fluorescence generated from the container;
A rare earth ion separation device in which these devices are entirely installed in a darkroom. An optically transparent glass substrate having a fired silica gel thin film on one of its surfaces;
An apparatus for irradiating the silica gel thin film with ultraviolet rays;
Equipped with a device to detect the fluorescence emitted from the silica gel thin film,
The apparatus for irradiating the ultraviolet light and the apparatus for detecting fluorescence are arranged so as to face the upper and lower sides of the silica gel thin film, respectively, and these apparatuses are movable in parallel to the glass substrate,
These entire devices are installed in a darkroom,
The silica gel thin film is an apparatus for separating rare earth ions, wherein an aqueous solution containing a complex of Nd ⁺³ and Dy ⁺³ ions and an organic molecule is separated into an Nd ⁺³ complex and a Dy ⁺³ complex by liquid chromatography. The rare earth ion separator according to claim 12 or 13,
An apparatus for separating rare earth ions, in which the apparatus for irradiating ultraviolet rays is a semiconductor laser and the apparatus for detecting fluorescence is a photomultiplier tube.

Images