JPH02133532A - Separation of rare earth element from each other - Google Patents

Abstract

PURPOSE:To recover high-purity rare earth elements at a high recovery rate by using a spherical cation exchanger having a sulfonic acid group and a weakly acidic cation exchange group for the cation exchanger at the time of separating the rare earth elements from each other by using a complex forming agent and the cation exchanger. CONSTITUTION:The spherical cation exchanger having the sulfonic acid group and the weakly acidic cation exchange group is used for the cation exchanger at the time of subjecting the rare earth elements to a chromatographic sepn. by using the complex forming agent and the cation exchanger. The sphericity of >=90% of this cation exchanger is about <=2.0 and the average grain size thereof is about 20 to 300mu. The average grain size of >=80% of the entire particle is about 0.5 to 1.5 times the average grain size. The total cation exchange capacity is specified to about 0.5 to 10meq/g on a dry basis. The weakly acidic cation exchange group is preferably a carboxylic acid group and the exchange capacity thereof is preferably about 5 to 90% of the total cation exchange capacity. EDTA, HEDTA, DCPA, etc., are used for the complex forming agent and the pH of the aq. soln. thereof is specified to about 4 to 10.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for mutually separating rare earth elements by an ion exchange method. The present invention relates to a method for obtaining high purity rare earth elements from a mixture of elements with a high recovery rate.

Rare earth elements include lanthanide group elements, scandium (
It is a general term for 17 elements including Sc) and yttrium (Y). Currently, rare earth elements are widely used in phosphor materials, laser materials, permanent magnet materials, ceramic strength enhancers, catalysts, magnetic recording materials, hydrogen storage alloy materials, etc., and demand for them is expected to continue to grow. It is an element. For these applications, higher purity rare earth elements are required.

[Prior art and problems to be solved by the invention] Separation of each rare earth element from a mixture of rare earth elements
? J: There is an ion exchange method. In this method, a mixed solution of rare earth element salts is passed through a packed bed of strongly acidic cation exchange resin to form a rare earth element absorbing layer on top of the strongly acidic cation exchange resin bed, which is then washed with water. Next, a complex forming agent aqueous solution is poured, and chromatographic separation is performed by utilizing the significant difference in affinity between each rare earth element, the complex forming agent, and the ion exchange resin, thereby obtaining highly pure rare earth elements.

In this process, it has been desired to improve purity, yield, production rate, etc., that is, to improve economic efficiency, and the following improvements have been made.

(1) A method of separating rare earth elements from each other by combining two or more types of complex forming agents.

In this method, there is a risk that the two types of complex forming agents may be mixed with each other, and in that case, the mutual separability of the rare earth elements will be reduced. Moreover, the separation requires two or more stages, which is economically disadvantageous.

(2) The counter ion of the cation exchange resin is Cu (II),
A method of mutually separating rare earth elements into metal ions such as Fe (III).

This method requires the selection of metal ions depending on the composition of the mixed rare earth element solution and the type of target rare earth element, and requires separate equipment to recover and reuse the used metal ions. It is disadvantageous industrially. or,
There is also a problem in terms of product quality in that the metal ions used are mixed into the separated rare earth elements as impurities.

(3) A method for mutually separating rare earth elements by improving cation exchange resins.

As this improvement method, for example, Japanese Patent Application Laid-Open No. 5688826
As disclosed in Japanese Patent Application Laid-Open No. 57-35650, there is a method that limits the porosity, particle size distribution, etc. of the cation exchange resin to a specific range and separates rare earth elements more stably and at high speed. Can be mentioned.

However, the point of improvement is the support structure of the ion exchanger, and the essential improvement in separation performance has not been achieved.

Another example is a method of high-speed separation using a fibrous ion exchanger, as disclosed in Japanese Patent Application Laid-Open No. 58-45341. In this method, since the material is fibrous, pressure loss is low and high-speed separation is possible.

However, since it is fibrous, the packing density is not stable, and the density gradually increases during use, resulting in an increase in pressure loss. Furthermore, the density varies depending on the location, resulting in a difference in density, and as a result, separation time, separation properties, etc. change. This tendency becomes stronger as the diameter of the packed column increases and the height of the column increases. Therefore, when using a fibrous ion exchanger, it is necessary to devise a packing method, a structure of a packed column, and a separation operation, and the equipment and operation become complicated.

As mentioned above, various improvements have been made to the ion exchange method, but no fundamental improvement has yet been achieved.Currently, a method for mutually separating rare earth elements with high purity, high recovery rate, and high speed is waiting. ing.

[1° 1 Aim of the present invention] The present invention is a method for mutually separating rare earth elements by ion exchange method, which solves the above-mentioned problems, that is, using a complex forming agent and a cation exchanger. The object of the present invention is to provide a method for mutual separation of rare earth elements that can obtain rare earth elements at a high recovery rate.

[Means for Solving the Problems] The present invention is a method for mutually separating rare earth elements using a complex forming agent and a cation exchanger, and the various physical properties of the cation exchanger and the separability of the rare earth elements have been intensively investigated. As a result of repeated research, the inventors discovered that by limiting the type and shape of the ion exchange groups of the cation exchanger, the mutual separation efficiency of rare earth elements could be dramatically improved, and the present invention was completed.

That is, the present invention provides a method for mutually separating rare earth elements using a complex forming agent and a cation exchanger, in which a spherical cation exchanger having a sulfonic acid group and a weakly acidic cation exchange group is used as the cation exchanger. This is a method for mutually separating rare earth elements.

According to the invention, high purity, i.e. purity 3N (99,9%
) or more, it is possible to easily obtain rare earth elements of 4N (99,99%) or more, and the yield is 70% or more, and even 9
It can be as high as 0% or more, and high-speed separation is also possible.

That is, the present invention is a method for mutually separating rare earth elements that is superior in terms of quality and economy.

The present invention will be explained in more detail below.

The cation exchanger used in the present invention is essentially a spherical cation exchanger having a sulfonic acid group and a weakly acidic cation exchange group. Even with only sulfonic acid groups or only weak acidic groups, the mutual separation effect of rare earth elements is insufficient. or,
When an ion exchanger consisting only of sulfonic acid groups and an ion exchanger consisting only of weakly acidic cation exchange groups are used in combination, a slight effect on improving separation property is observed, but the result is not satisfactory. , it is necessary that sulfonic acid groups and carboxylic acid groups coexist within the cation exchanger particles. The weakly acidic cation exchange group mentioned here includes a carboxylic acid group, a phosphoric acid group, a phenol group, etc., and these may be used alone or in combination. As the weakly acidic cation exchange group, a carboxylic acid group is particularly preferable, and the weakly acidic cation exchange capacity is preferably 5 to 90% of the total cation exchange capacity, more preferably 10 to 5% of the total cation exchange capacity.
A weakly acidic cation exchange capacity of 0% is particularly preferred.If the capacity is small, the separation effect will be small, and if it is large, the production efficiency will decrease.

Also, exchange of sulfonic acid groups with weakly acidic cations 11! ! ! As the total amount of groups, that is, the total cation exchange capacity, increases, the solubility of the cation exchanger IQ body in water increases, and some of the groups are dissolved. Therefore, the preferred total cation exchange capacity is 0.5 to 10 meq/g on a dry basis, more preferably 1
~5 meq/g.

The cation exchanger used in the present invention is spherical.

Cation exchangers other than spherical, such as fibrous or amorphous, cannot achieve the purpose of the present invention even if sulfonic acid groups and weakly acidic cation exchange groups coexist; that is, they cannot be used when packed in a packed column. , differences in packing density tend to occur between the upper and lower parts of the tower, between each part of the tower and the peripheral parts.As a result, when the complexing agent aqueous solution is passed through for chroma separation, one-sided flow of the liquid and non-uniform linear velocity of the liquid occur. This causes tailing and leading phenomena in the eluted rare earth elements, and as a result, it becomes difficult to obtain rare earth elements with high purity and high recovery rate. In addition, during use, the packing density increases, the pressure loss fluctuates, and it becomes difficult to maintain stable mutual contact. Furthermore, the gap in the upper part of the packed column becomes large, and the separation performance deteriorates. In the present invention, in which the cation exchanger is spherical, there is no such problem, the filling state is stable at the initial stage of use and during the use process, and the separation operation is easy and stable.

Furthermore, highly purified rare earth elements can be obtained with a high recovery rate, and fractions can be operated at high speed.

The spherical shape will be further explained. Sphericity is usually used as a measure of sphericity. Sphericity is the value of the ratio of the maximum diameter to the minimum diameter passing through the center of gravity of the spherical cation exchanger. The sphericity of the spherical cation exchanger is preferably 90% or more and 2.0 or less. When the sphericity exceeds 2.0, pressure loss within the packed bed increases, leading to a decrease in separation efficiency.

The physical properties of the spherical cation exchanger will be further explained below. Regarding the particle size distribution of the spherical cation exchanger, it is preferable that 80% or more of the total particles be 0.5r to 1.5 times the average particle size.By doing this, stable separation operation can be achieved. It is easy to carry out, and the separation and high-speed separation are improved.

In addition, the average particle size of the spherical cation exchanger is 20 to 300
) t m is preferable. If the average particle diameter is too small, the pressure loss within the column will increase, making high-speed separation difficult. If it is too large, the intraparticle diffusion rate will decrease, resulting in a decrease in separation efficiency. do.

Sphericity can be measured using an optical microscope or the like.

The average particle size and particle size distribution can be measured by generally known methods, such as optical head microscopy, sieving method, and electric conductivity displacement measurement type particle size distribution measurement method.

The spherical cation exchangers used in the present invention are preferably of the following four types.

The first is a cation exchanger in which a sulfonic acid group and a weakly acidic cation exchange IQ group are introduced into gel-type carrier particles.

For example, carboxylic acid groups are introduced into Amberlite 120B (manufactured by Orka Co., Ltd.), Diaion 5KIB (manufactured by Mitsubishi Kasei Corporation), etc.

The second is a cation exchanger in which a sulfuric acid group and a weakly acidic cation exchange group are introduced into bead-shaped carrier particles.

This type of cation exchanger is made by coating a thin layer of cross-linked polymer on the surface of a smooth core such as a glass bead, or by forming a chemical bond with a sulfonic acid group on the cross-linked polymer layer on the surface. Products with acidic cation exchange groups introduced. For example, Vericular Caddion (manufactured by Parian), Yanaco PE I-7
Products with carboxylic acid groups introduced into CX (Sho Yanagimoto), etc.

Third, a cation exchanger in which a sulfonic acid group and a weakly acidic cation exchange group are introduced into surface-porous support particles.This type of cation exchanger has a smooth core surface such as a glass bead. silica gel and alumina.

A porous VL-free material such as alumina silicate is adhered to a thick layer, and a sulfonic acid group and a weakly acidic cation exchange group are directly introduced into this porous inorganic material layer by adsorption 1 reaction, graft polymerization, etc. Coated with a polymer containing sulfonic acid groups and weakly acidic cation exchange groups.

A commercially available product, such as Zivax SCX (manufactured by DuPont), into which a weakly acidic cation exchange group is introduced may also be used.

Fourth, a cation exchanger in which a sulfonic acid group and a weakly acidic cation exchange group are introduced into fully porous support particles.

The base material of the carrier particles may be organic or inorganic, and examples of the inorganic base material include silica gel, alumina, porous glass, porous carbon, and zeolite. Examples of the organic base material include monomers and polymers having vinyl groups, and copolymers of monomers and crosslinked monomers.

Monomers include styrene and methylstyrene.

Styrene derivatives such as ethylstyrene, chlorostyrene, vinylstyrene; acrylic acid; methacrylic acid; acrylic acid esters such as methyl acrylate and ethyl acrylate;
Methacrylic acid esters such as methyl methacrylate, cyclohexyl methacrylate, and glycidyl methacrylate; diethyl maleate.

Diethyl fumarate; acrylonitrile derivatives, etc.

Examples of the crosslinking monomer include divinylbenzene, divinyltoluene, divinylsulfone, ethylene glycol methacrylate, triethylenediamine methacrylate, diallyl phthalate, and the like.

When producing a copolymer, a diluent such as toluene is used to adjust the pore size.

Suspension polymerization is preferred as a method for producing the copolymer. When using an oil-soluble monomer, O/W type suspension is carried out, and when using a water-soluble monomer, A W2O type suspension is carried out. At this time, particle size etc. can be controlled by conditions such as stirring speed and temperature.

As a method for introducing a sulfonic acid group and a weakly acidic cation exchange group, generally known methods are used. For example,
Journal of Applied Polymer Science (
Journal of Applied Polym
er 5science) Dan 13-22 (19
There is a method of simultaneously introducing sulfonic acid groups and carboxylic acid groups by treating fully porous carrier particles, which are copolymers of styrene, divinylbenzene, and acrylonitrile, with chlorosulfonic acid, as described in 84). .

In addition, carboxylic acid is introduced by treating a fully porous strongly acidic cation exchange resin, which is a copolymer based on ester acrylate or methacrylic ester, with an acid or alkaline aqueous solution to hydrolyze the ester. There are ways.

Furthermore, carboxylic acid groups can be introduced by treating a cation exchanger having a sulfonic acid group with an oxidizing agent such as hypochlorous acid or a salt thereof. In this case, it is necessary to pay attention to the amount introduced since the carrier particles themselves will be partially destroyed.

In the present invention, an ion exchanger made of bead-type carrier particles 6 surface porous carrier particles or fully porous carrier particles with a high ion exchange rate is preferable, and the base material of the carrier particles is organic. Fully porous cation exchange resins, which are particularly preferred, have a large cation exchange capacity that can be introduced, and the volumetric porosity can be easily controlled. The volume porosity of the fully porous cation exchange resin is preferably 40% to 80%. If the 0 volume porosity is too small, the diffusion rate of resin particles becomes slow and the separation efficiency decreases. On the other hand, if the volumetric porosity is too large, the cation exchange capacity that can be introduced into the resin becomes small and the amount of resin used increases.

Next, a method for separating ζ rare earth elements using an ion exchange compound using a spherical cation exchanger having a sulfonic acid group and a weakly acidic cation exchange group and a complex forming agent will be described.

When performing ion exchange chromatography, the counter ions of the cation exchanger packed in the column are H'', NH4, Cu
(n) ion, Fe (II) ion.

Fe (I[[) ion, Zn(II) ion, rare earth element (I[[) ion, Pb(II) ion, P
d(II) ion, Ni(II) ion, Na(
I) Ion.

Examples include K (Il ion), but if metal ions are used, there is a risk that they may be mixed into the rare earth elements that are eluted.5Also, these metal ions must be collected for reuse of the used chemicals. This makes the operation complicated.For this reason, H+ ions.

NH,'' ion, Na (I> ion, K (I)
ions are preferred, and H+ ions, NH,+ ions are particularly preferred.

It is preferable that the counter ion of the cation exchanger is substantially 11" type from the direction in which the complex forming agent passes through the column.
Substantially here means the part where H+ is adsorbed (hereinafter referred to as
The ratio of H+ to the counter ion of the H″ adsorption layer is 8.
0% or more, which can be easily seen from the adsorption equidistant diagram and breakthrough curve. In addition, counter ions other than H+ are hereinafter referred to as M ions, that is, the column is not made to exist in a layered manner in the order of H+ adsorption layer and M ion adsorption layer from the direction in which the aqueous complexing agent solution is passed through the cation exchanger. Prepare.

The preparation method is not particularly limited, but for example, -
Examples include the following methods. First, prepare a column filled with a cation exchanger, pass an aqueous solution containing M ions through it, adsorb the M ions, and wash with water.Next, by passing an acid through the top of the column, 1 is adsorbed. let me,
The counter ions of the cation exchanger are arranged in a column that is not prepared in such a way that substantially H+ is formed from the direction in which the aqueous complex forming agent solution flows, that is, an H+ absorption layer and a layer that adsorbs M ions other than H+ in the order of stacking. You can create existing columns. This stacked state can be easily known by determining the one-product diagram and breakthrough curve for adsorption of H'' and M ions.Next, connect a column to which a mixed rare earth element has been adsorbed in advance. Then, a complexing agent is passed through the column from the tip of the column adsorbing the mixed rare earth elements to separate the rare earth elements from each other.

Another method is to fill a column packed with a cation exchanger with M
An aqueous solution containing ions is passed through the column, and the M ions are adsorbed and washed with water.Next, an aqueous solution of mixed rare earth elements whose pH has been adjusted is passed from the top of the column, and a mixed rare earth element is passed from the direction in which the aqueous complex forming agent solution is passed through. Adsorption layer 1 ("Adsorption layer, H'") A column is created in which M ions other than H' are present in a product I- shape in nI"i of the M ion adsorption layer. Next, a complex forming agent is passed through the column tip, and rare earth Perform mutual separation of elements.

The H+ adsorption layer has an H' ratio of '6' expressed by the following formula.
! ≦~80% equivalent is preferred.

H” ratio = ([H”]×100)/(
[H”] 10 [N ions]) [H”]: Ion exchange exercise body + amount (g equivalent) [M ions]: Ion exchange IQ 4 M ions in the body! (g equivalent) Among these, the amount of H' in the ion exchanger and the amount of M in the ion exchanger
The amount of ions is 1 adsorbed on the strongly acidic cationic Ti group.
11, and refers to the M ion, and also refers to 1 (
“The area does not include H in the M ion adsorption layer, H1
If the ratio is lower than this, the mutual component property of the rare earth elements will deteriorate significantly, making it impossible to obtain high purity rare earth elements. Furthermore, if the H+ ratio is higher than this, highly pure rare earth elements may be obtained, but the recovery rate will be reduced.

The aqueous solution of mixed rare earth elements used in the present invention is not particularly limited, and may be, for example, an aqueous solution obtained by decomposing ores such as xenotime, monazite, bastnaesite, etc. with a mineral acid or an alkali such as caustic soda, or an aqueous solution thereof. Examples include aqueous solutions in which rare earth element oxides, hydroxides, etc. obtained by rough purification from water/8 liquid by extraction methods, crystallization methods, etc. are dissolved with mineral acids. The aqueous solution preferably has a pH of 0.5 to 4.0,
Furthermore, the pH is preferably 1.0 to 3.0; if the pH is too low, the adsorption rate of rare earth elements will decrease. On the other hand, if the temperature increases, hydroxides of rare earth elements will precipitate.

In addition, rare earth element ions have a concentration of 5 to 50 with respect to all counter ions.
It is preferable to use equivalent %; if it is less than this, a huge amount of resin will be required when carried out on an industrial scale, and
The concentration of rare earth elements in the resulting eluate becomes very low.

Moreover, if the amount is more than this, sufficient separation will not be carried out, and the amount is more preferably 10 to 40 equivalent %.

Ethylenediaminetetraacetic acid (EDTA) is used as the saw-forming agent that passes through the tip of the mixed rare earth element adsorption zone.

N-Hydroxyethylethylenediaminetriacetic acid (HED)
TA), 1,2-diaminocyclohexanepentaacetic acid a (D
CPA), diethylenetriaminepentaacetic acid (DTPA),
Nitrilotriacetic acid (NTA).

Aminopolyacetic acids such as iminodiacetic acid (IMPA), oxycarboxylic acids such as enoic acid, lactic acid, glycolic acid, malic acid, tartaric acid, etc. are preferred, and aminopolyacetic acids are particularly preferred, as they improve the mutual separation of rare earth elements.

The concentration of the complexing agent aqueous solution is not particularly limited as long as it does not precipitate in the column at the temperature during elution, but if it is too low, production efficiency will deteriorate. In addition, ρ■(
is preferably 4 to 10, and aqueous ammonia is preferable for this pH1li adjuster.

When carrying out the present invention, if the temperature is low, the saw-forming agent in the complex-forming agent aqueous solution may precipitate, and if the temperature is high, the cation exchanger may deteriorate and the stability of the saw-forming agent may decrease. Yes, and since high pressure operation is required, 20 to 120℃
It is preferable to develop and elute at 30
~80°C.

In addition, in the present invention, mineral acids such as hydrochloric acid and sulfuric acid are used as acids for regenerating the cation exchanger, adjusting the adsorption amount of H+, and adjusting the pH of the solution, and sodium hydroxide, aqueous ammonia, etc. are used as the alkalis. It can be used.

[Effect of the invention] As is clear from the above explanation, in the method for mutually separating rare earth elements, a spherical cation exchanger having a sulfonic acid group and a weakly acidic cation exchange group is used as a cation exchanger. The effects of using it are listed below.

(1) Rare earth elements of higher purity, that is, 3N or higher, even 4N or higher, can be easily obtained.6 (2) The recovery rate of high purity rare earth elements can be as high as 70% or higher, and even 90% or higher.

(3) High-speed separation is possible and production efficiency can be increased.

(4) Rare earth elements can be separated from each other with simple operations.

(5) Rare earth elements can be separated from each other in a stable state at all times.
Operation management and quality control are easy.

Examples and comparative examples will be shown below, but the present invention is not limited to these methods.

Example 1 Fully porous carrier particles were produced by suspension polymerization using glycidyl methacrylate as a monomer, ethylene glycol methacrylate as a crosslinked monomer, and toluene as a diluent. Holder particles at 70°
The sample was treated with an aqueous sodium sulfite solution for 17 hours at C17 to introduce sulfonic acid groups, and then treated with an IN aqueous sodium hydroxide solution at 70° C. day and night to introduce carboxylic acid groups. The resulting fully porous cation exchange resin was washed, dried, and classified. As a result, the average particle size was 50 μm, and 1.95% or more of the particles were 25 to 75 μm. Also, the sphericity is 95
% or more and 2.0 or less, the volume porosity was 51%, the total cation exchange capacity was 3.0 meq/g, and the neutral salt decomposition capacity was 2.1 meq/g. After filling this fully porous cation exchange resin into a filter-equipped glass packed column with an inner diameter of 15φ and a length of 300 mrn, I
A solution of N-HCl was passed through the solution, followed by washing with water, followed by a solution of IN-NH2OI and washing with water, so that the counter ion of the sulfonic acid group was changed to the NH4+ type.

Next, 111 ml of mixed rare earth element water/B solution (pH 1,54) containing 8 mmol/1 each of Sm, Nd, and Pr was passed through the top of the packed column and washed with water to form a rare earth element adsorption zone. Thereafter, a 0.25 W/V% EDTA, pH 8.5 aqueous solution was added from the top of the packed column at 05 m I/rn in
The liquid was passed at a speed of . The temperature of the packed column was 60°C.

The effluent flowing out from the packed tower was divided into fractions and analyzed for rare earth elements using an ICP emission spectrometer. As a result, the recovery rate of rare earth elements with a purity of 3N (99.9%) or higher was 92 Sm. %, 91% for Nd and 93% for Pr.

Example 2 Gel-type carrier particles were produced using glycidyl methacrylate as the 〈mi body and ethylene glycol methacrylate-1 as the crosslinked Llk. This gel-type support particle is
Sulfonic acid groups were introduced by treatment with 7 volumes of sodium sulfite aqueous solution at 0° C. for 7 hours, and then, carboxylic acid groups were introduced by treatment with IN sodium hydroxide aqueous solution at 70° C. day and night.

The resulting gel-type cation exchanger tlnh)1 is washed, dried, and classified.

As a result, the average particle size was 50 μm, and 95% or more of the particles were
It was 5 to 75 μm. In addition, the sphericity is 95°g or more and 2.0 or less, and the specific ion exchange capacity is 3.2me
q/g, and the neutral salt decomposition capacity was 2.3+neq/g. After filling this gel-type cation exchange resin into a filter-equipped glass packed column with an inner diameter of 15φ and a length of 300 mm, IN-MCI was passed through the top of the packed column, washed with water, and IN-NH and CI were poured. It was cleared and washed with water, and the counter ion of the sulfonic acid group was changed to NH4+ type.

Next, a mixed rare earth element aqueous solution (pH 1,54>117 ml) containing 8 mmol/1 each of Sm, Nd, and Pr was passed through the top of the packed column and washed with water to form a rare earth element adsorption zone. A similar operation was performed.As a result,
The recovery rate of rare earth elements with a purity of 3N or higher is 45% for Sm and 45% for N.
d was 25%, and 4Pr was 40%.

Comparative Example 1 Suspension polymerization was carried out using glycidyl methacrylate as a monomer, ethylene glycol methacrylate 1 to 1 as a crosslinking monomer, and 1 to luene as a diluent to produce fully porous carrier particles. Next, this fully porous support particle was
A sulfonic acid group was introduced by treatment with an aqueous sodium sulfite solution at 0'C for 17 hours. The resulting fully porous cation exchange resin was washed, dried, and classified. As a result, the average particle diameter was 50 μm, and 95% or more of the particles were 25 to 75 μm. In addition, the sphericity is 95% or more and 2.0 or less, the volume porosity is 49%, and the relative ion exchange container is 2.1me.
q/g. This fully porous cation exchange resin is packed with a glass filter with an inner diameter of 15φ and a length of 300mm.
After filling the 5 columns, the same operation as in Example 1 was performed. As a result, the recovery rate of rare earth elements with a purity of 3N (99.9%) or higher was 8091% for S m, 71% for Nd, and 71% for P r. 82L:'i.

Comparative Example 2 As a medium tr water, 1-remethacrylate/remethacrylate 1, cross-linked ν-form 1-rengelicol methacrylate-1
Gel-type carrier particles were manufactured using the following methods. Next, the gel-type carrier particles were treated with an aqueous solution of sulfite triuno at 70° C. for 17 hours to introduce sulfonic acid groups, and the resulting gel was washed with a cation exchange resin, dried, and classified.

As a result, the average particle size was 50 μm, particles of 95?6 or more -F or 25 to 75, Z]I+. Also, the sphericity is
952 was also greater than or equal to 2.0, and the specific ion exchange capacity was 2.3 meq/g.

This gel-type cation exchange (51 fat, inner diameter 15φ, length 3
After filling a glass packed column with a 00 mm filter, the same operation as in Example 2 was performed, and as a result, the recovery rate of rare earth elements with a purity of 3N or higher was 3,196 for Sm and 8 for Nd.
? ≦, Pr was 33%.

Claims (1)

[Claims] A method for mutually separating rare earth elements using a complexing agent and a cation exchanger, characterized in that a spherical cation exchanger having a sulfonic acid group and a weakly acidic cation exchanger is used as the cation exchanger. Mutual separation method of rare earth elements