JPS605655B2 - Separation method of yztrium - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for separating yttrium.

Yttrium (Y) (atomic number 39) is in increasing demand as a raw material for red phosphors for color televisions, optical lens materials, and electronics materials.
Conventional methods for separating Y and other rare earths include an extraction separation method using acidic phosphate ester as an extraction solvent, and an ion exchange method in which a mixed aqueous solution of Y and rare earth is passed through an ion exchange resin tower. This is known as a general method.

However, none of these methods can be said to be fully satisfactory as a method for separating Y.

That is, in the former case, separation of Y and light rare metals (from La to Eu) is performed well;
Regarding the separation of numbers 4 to 71, satisfactory results were not obtained.

In addition, in the case of the latter ion exchange method, the concentration of the purified Y aqueous solution obtained is small, large-scale equipment and heat sources are required for concentration, and the flow rate of the eluent flowing through the ion exchange resin tower is low, making production difficult. low gender.

The present inventors conducted research on a new separation method for Y and atomic numbers 64 to 71, and found that it is possible to separate Y and atomic numbers 64 to 71 more easily than conventional methods. He found a method, published it, and filed a patent application (Japanese Patent Application No. 68332/1983). The characteristics of the method of Machigao 1976-68332 are that jetylenetriaminepentaacetic acid (hereinafter referred to as "DTPA")
''), and Y and rare ± of atomic number 64-71.
By contacting the mixed aqueous solution containing
The point is that it effectively separates the 71 rare earths.

In order to improve the productivity of Y, the present inventors have conducted intensive studies on an extraction solvent system that accelerates the extraction rate of Y without reducing the separation efficiency between Y and dilute compounds with atomic numbers of 64 to 71. As a result, they discovered a solvent system with a faster extraction rate than conventional methods and achieved the following invention.

The present invention is characterized in that Y and diluted substances are separated by contacting a mixed aqueous solution containing DTPA and Y and diluted elements with atomic numbers 64 to 71 with a solution of Group D HPA. It is the same as 68332, but its characteristics are that D is a diluent for HPA, and at least one kind of organic compound selected from ■ aliphatic hydrocarbons having 10 to 14 carbon atoms, and ■ aliphatic alcohols having 6 to 10 carbon atoms. By using the above diluent solvent, the extraction rate of Y can be improved and productivity can be increased.

The present invention will be explained in detail below.

The object of the method of the present invention may be any mixture containing Y and at least one of rare earths having an atomic number of 64 to 71, but the present invention is particularly applicable to Y and Dy (atomic number 66) to Lu (atomic number 7).
Suitable for separation from heavy rare earth (1).

The aqueous solution containing Y and heavy rare earth applied to the method of the present invention is usually 0.005 to 2 M' and 0.05 to 0.5
A concentration of about M/M is used. In the method of the present invention, at least one of the following organic solvents is used as a diluting solvent for Group D HPA.

■ Aliphatic hydrocarbons having 10 to 14 carbon atoms.

■ Aliphatic alcohol with 6 to 10 carbon atoms.

When an aliphatic hydrocarbon with carbon number 9 or less is used, the extraction rate of Y is the same or lower than when kerosene, which is used in the conventional method, is used as a diluting solvent, making it ineffective. Aliphatic hydrocarbons with 15 or more carbon atoms have a high melting point (mplo.

0) and the viscosity increases, making it difficult to handle.

In addition, alcohols with carbon numbers of 5 or less have a considerably high solubility in water, which causes changes in the solvent composition during use, which is inconvenient, while alcohols with carbon numbers of 11 or more have a high melting point (mp 16.90) and are difficult to handle. be. It is preferable for the extraction operation to select the concentration of group D HPA in the organic solvent to be about 0.02 to 1.5 M', but the extraction rate of Y is lower than that of group D HPA.
The higher the concentration, the larger it becomes. On the other hand, in the method of the present invention, DTPA used dissolved in an aqueous solution is usually used in an amount equivalent to or more than the total amount of Y and the heavy diluted metal having an atomic number of 64 to 71 to be separated. It is used in an amount of about 0.4 to 1.5 times equivalent. An aqueous solution containing DTPA and containing Y and a dilute compound with an atomic number of 64 to 71 has a pH of
．． It is preferable to adjust the pH to 5 or more and 9 or less, and if the pH is 1.5 or less, a sufficient separation effect cannot be expected.

As described above, if Y is purified according to the present invention, high-purity Y can be extracted by using one type of extraction solvent (D-bait HPA) to separate heavy oxidants and Y, and compared to conventional methods, , Y can be extracted at a high speed, so that the productivity of Y can be increased.

The present invention will be explained in more detail below using examples.

Example 1 0.05M/YC13, 0.05M/ErC1
3, containing 0.11 M/its DTPA and the pH of the solution
HCI-CH3COONH4 buffer (
Boat 3.
0.9M/that D on the feed liquid 100 adjusted to 3.
Extraction was performed using a 100% decane solution containing HPA.

Extraction times were 5 and 15 minutes. FIG. 1 shows the total extraction rate and the extraction rates of Y and Er at each extraction time. In FIG. 1, curve 1 represents the extraction rate of Y, curve 5 represents the total extraction rate, and curve 8 represents the extraction rate of Ed. Comparative Example 1 Feed liquid 100' with the same composition as Example 1 was added to 0.5M
Extraction was carried out under the same extraction conditions as in Example 1 using the following three solvents containing HPA: nonane, octane, and kerosene 100.

The extraction time was 5 minutes and 18 minutes in both cases. FIG. 1 shows the total extraction rate and the extraction rates of Y and Er for each extraction time. In Figure 1, "Curve 2, Curve 6 and Curve 10 are the Y when nonane is used as a diluting solvent."
Curve 4 represents the extraction rate of Er, the total extraction rate and the extraction rate of Er.
, curve 7 and curve 11 represent the extraction rate of Y, total extraction rate and extraction rate of Er when octane is used as the diluting solvent, respectively, and curve 3, curve 6 and curve 9 are respectively when kerosene is used as the diluting solvent. The extraction rate of Y, the total extraction rate, and the extraction rate of Er are shown for each case.

Example 2 0.5M of feed liquid 100 with the same composition as Example 1
'The D group was extracted using 100 ml of n-hexanol solution containing HPA.

The extraction times were 5 minutes, 30 minutes and 90 minutes. The total extraction rate and each extraction rate of Y and Er for each extraction time are
As shown in the figure. In FIG. 2, L curve 12, curve 14, and curve 15 represent the Y extraction rate, the total extraction rate, and the Er extraction rate, respectively. Comparative Example 2 Feed liquid 100 with the same composition as Example 1 with Z of 0.5M
/The D was extracted using 100 volumes of kerosene solution containing HPA.

The extraction times were 5 minutes, 3 minutes, and 90 minutes. The total extraction rate and each extraction rate of Y and Er for each extraction time are
As shown in the figure. In FIG. 2, curve 13 represents the Y extraction rate, curve I6 represents the total extraction rate, and curve 17 represents the Ed output rate.

[Brief explanation of the drawing]

Figure 1 shows the results of Example 1 and Comparative Example 1, with the vertical axis representing the extraction rate and the axis representing the extraction time. Figure 2 similarly shows the results of Example 2 and Comparative Example 2. It is something. Evening/Picture soup 2

Claims (1)

[Claims] 1 In extracting and separating yttrium from an aqueous solution containing diethylenetriaminepentaacetic acid and also containing yttrium and a rare earth with an atomic number of 64 to 71 using di-(2-ethylhexyl) phosphoric acid as an extractant, di-(2- A method for separating yttrium, characterized in that phosphoric acid (ethylhexyl) is diluted with at least one organic solvent selected from aliphatic hydrocarbons having 10 to 14 carbon atoms and aliphatic alcohols having 6 to 10 carbon atoms.