JP2000265224A - Method for refining zirconium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remove Ti in particular from a zirconium raw material. SOLUTION: This method for refining zirconium has the following steps: (1) a first step where a solution containing zirconium ions is prepared from a zirconium raw material; (2) a second step where a liquid mixture containing the solution, hydroxylcalyx[n]arene-p-sulfonate (nι2), trioctyl ammonium chloride and organic solvent; and (3) a third step where the liquid mixture is subjected to phase separation into a first aqueous phase and a first organic phase and the zirconium ions are recovered in the aqueous phase.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a novel method for purifying zirconium. In particular, T
i.

[0002]

2. Description of the Related Art Zirconium ores such as zircon sand and badderite usually contain 1 to 2% (in some cases, 1 to 4%).
%) Of hafnium (Hf). But,
When using Zr having a small thermal neutron absorption cross section as a reactor material, it is necessary to separate and remove Hf having a large thermal neutron absorption cross section. According to Japanese Industrial Standards, the Hf content in the Zr alloy for nuclear fuel coating is set to be 0.010% or less. However, Zr and Hf have an electronic structure and an atomic radius (Zr: 1.45 °, Hf: 1.44).
Å) and ion radius (Zr: 0.74Å, Hf: 0.7)
5)) are similar to each other, and their chemical properties are similar, making it difficult to separate them. Conventionally, as a method for separating Zr and Hf, for example, a solvent extraction method, a fractional precipitation method, an ion exchange method, and the like have been proposed. However, there are still problems in separability, economy, etc. Further improvements are desired.

Incidentally, Zr has recently been used for glass,
Applications as sensors, electronic materials, materials for fine ceramics and the like are increasing. In this type of application, there is no particular need to remove Hf from Zr. On the other hand, T which degrades product performance in these applications
It is necessary to remove i, Fe, etc. preferentially. In particular, Ti is a component that causes coloring in zirconia glass, and degrades product quality.

[0004]

The elements such as Ti and Fe are contained as trace components in zirconium ore in any locality, but a technique for effectively removing these elements from zirconium is still established. It is not at present.

Accordingly, an object of the present invention is to remove particularly Ti from a zirconium raw material.

[0006]

The present inventor has made extensive studies in view of the problems of the prior art, and as a result, found that hydroxycalix [n] arene-p-sulfonate (n ≧ 2) and trioctylammonium chloride. It has been found that the above object can be achieved by using in the purification of zirconium, and finally the present invention has been completed.

That is, the present invention relates to a method for purifying zirconium, wherein (1) a first step of preparing a solution containing zirconium ions from a zirconium raw material (2) the above solution, hydroxycalix [n] arene-p-sulfone A second step of preparing a mixed solution containing an acid salt (n ≧ 2), trioctylammonium chloride and an organic solvent; and (3) separating the mixed solution into a first aqueous phase and a first organic phase to remove zirconium ions. The present invention relates to a purification method characterized by having a third step of recovering in an aqueous phase.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (1) First Step In the first step, a solution containing zirconium ions is prepared from a zirconium raw material.

The zirconium raw material used in the first step of the present invention is not particularly limited, and not only zirconium ore but also zirconium reagents, zirconium compound reagents and the like can be used, and these can be purified by the method of the present invention. . The zirconium ore is not particularly limited in the kind of the ore, the place of production, and the like. For example, ores such as zircon sand and badderite produced in various parts of the world can be used as they are.

The method for preparing the solution is not particularly limited as long as zirconium can be finally turned into a solution (ionized), and a known method can also be used. For example, when zircon sand (ZrO ₂ · SiO ₂ ) is used as the zirconium raw material, the zircon sand is converted to an alkaline earth metal compound (N
a ₂ CO ₃ ) at a high temperature (up to 1000 ° C.), and dissolving the obtained zirconium compound (eg, Na ₂ ZrO ₃ ) in a mineral acid such as hydrochloric acid.
In this solution, zirconium ions and impurity metals (Ti, F) contained in zirconium are generally contained.
e, Al, etc.) are included as metal ions.

The zirconium ion concentration in the above solution is not particularly limited as long as it is stably present as zirconium ions, but it is usually 0.0001 to 1M (1M = 1).
It is preferably adjusted to about moldm ⁻³ ), particularly 0.05 to 0.5M. Zirconium ion concentration adjustment
For example, it can be suitably performed by mixing water.

In the above solution, the concentration of hydrogen ions can be adjusted by adding an acid or an alkali such as hydrochloric acid or sodium hydroxide. The hydrogen ion concentration in the solution may be appropriately set according to the zirconium raw material to be used and the like, but is usually about 0.01 to 3M, preferably 0.5 to 1.5M. The solution may contain components other than these necessary components as long as the effects of the present invention are not impaired. (2) Second Step In the second step, the above solution, hydroxycalix [n]
A mixed solution containing arene-p-sulfonate (n ≧ 2), trioctylammonium chloride and an organic solvent is prepared.

[0013] This mixture is substantially composed of an aqueous phase and an organic phase. The volume ratio of the aqueous phase and the organic phase can be appropriately set according to the type and concentration of each component, but is usually 1: 0.
It may be about 5-5.

The content of each component in the mixture is not particularly limited as long as a desired effect can be obtained, and usually may be in the following range. The zirconium ion concentration may be generally adjusted to be about 5 × 10 ⁻⁵ M to 0.4 M in the aqueous phase. Hydroxycalix [n] arene-
The concentration of p-sulphonate is generally 5 × 10 ⁻⁴ M in the aqueous phase.
It may be adjusted so as to be about 1M. The concentration of trioctylammonium chloride may be generally adjusted to be about 5 × 10 ⁻³ M to 1 M in the organic phase.

The hydroxycalix [n] arene-p-sulfonate (hereinafter also referred to as “water-soluble calixarene”) has a structure represented by the following formula (for example, in the case of a sodium salt).

[0016]

Embedded image

The water-soluble calixarene used in the present invention is not particularly limited as long as it is soluble in water. Usually, at least one of an alkali metal salt and an alkaline earth metal salt is used.
Use seeds. Among these, it is particularly preferable to use an alkali metal salt (sodium salt, potassium salt, etc.). In addition, the water-soluble calixarene is particularly preferable when n in the above formula is 6
Or it is preferable to use the thing of 8. One or more of these water-soluble calixarenes can be used.

The water-soluble calixarene may be used in an amount sufficient to bind to the ions of the impurity metal present in the solution (hereinafter simply referred to as “metal ions”). That is, the chemical equivalent required for binding to the above-mentioned metal ion should be at least the chemical equivalent (at least one time the chemical equivalent), and preferably about 1 to 1.5 times the chemical equivalent.

When adding the water-soluble calixarene, it is preferable to gradually add it while stirring. Also,
A water-soluble calixarene aqueous solution may be prepared in advance, and this aqueous solution may be added. The concentration of the aqueous solution in this case is
What is necessary is just to adjust suitably according to the kind of water-soluble calix arene, etc.

The trioctylammonium chloride used in the present invention has the following structure.

[0021]

Embedded image

Trioctylammonium chloride is
A product prepared by a known production method or a commercially available product can also be used. As a commercially available product, for example, "Capricoat"
(Trade name, manufactured by Dojin Chemical Laboratory Co., Ltd.) and the like can be preferably used. The amount of trioctylammonium chloride used in the mixture may be at least the chemical equivalent required to associate with the water-soluble calixarene present in the mixture (that is, at least one time the chemical equivalent).
Preferably, it should be about 1 to 1.5 times the chemical equivalent.

The organic solvent is not particularly limited.
Preferably, a polar organic solvent such as chloroform and octanol can be used. In the present invention, chloroform is particularly preferred. In the present invention, it is preferable that trioctyl ammonium chloride is dissolved in an organic solvent in advance, and this solution is blended with each component. In this case, the concentration of trioctyl ammonium chloride in the organic solvent (in the organic phase) is not particularly limited as long as the trioctyl ammonium chloride is dissolved, and may be appropriately set according to the type of metal ion, the type of organic solvent, and the like. Good, but usually 0.01-2
It may be set to about M.

In the present invention, the order of mixing the components in preparing the mixed solution is not particularly limited. For example, after adding a water-soluble calixarene to the above solution, an organic solvent and trioctylammonium chloride (or a solution of trioctylammonium chloride dissolved in an organic solvent) are added, or the solution and the water-soluble calixarene are added. After mixing, a solution in which trioctyl ammonium chloride is dissolved in an organic solvent may be added. After the preparation of the mixture, the mixture may be further mixed and stirred as necessary.

The pH of the mixture is not particularly limited as long as the atmosphere allows the water-soluble calixarene to capture metal ions (particularly Ti ions), but is usually 7 or less, preferably 5 or less, more preferably 3 or less. good. By adjusting the pH within the above range, the extraction rate of Ti into the organic phase can be further increased. Adjustment of pH
For example, it can be carried out with an aqueous solution of hydrochloric acid, sodium hydroxide or the like. The concentration of these aqueous solutions may be generally used at about 0.1 to 3 mol / liter.

[0026] In the mixed solution, acetate ions may be present as necessary. The presence of acetate ions can increase the extraction rate of Ti into the organic phase. As a method for causing acetate ions to exist, for example, acetic acid or a salt thereof (Na salt, K salt, or the like) may be added to the mixture. The concentration of the acetate ion may be appropriately set according to the type of the metal ion and the like, but is usually about 0.01 to 0.05 M in the aqueous phase. (3) Third Step In the third step, the mixed solution is separated into a first aqueous phase and a first organic phase, and zirconium ions are recovered in the first aqueous phase. Thus, zirconium ions can be recovered in a state where metal ions (particularly Ti) as impurities have been removed.

The method for phase separation may be carried out by a known method for phase separation between an aqueous phase and an organic phase, and can be appropriately selected according to the extraction method and the like. For example, if it is a batch type solvent extraction method, a centrifugal separation method or the like can be adopted.

The method for recovering zirconium from the aqueous phase may be a known recovery method. For example, first, sulfuric acid and ammonia are added to the aqueous phase to generate a precipitate of zirconium sulfate, and after filtration, the precipitate is neutralized with ammonia to be recovered as zirconium hydroxide. (4) Fourth step In the present invention, the fourth step can be performed as necessary. In the fourth step, an acidic aqueous solution is added to the first organic phase.
The hydroxycalix [n] arene-p-sulfonate (n ≧ 2) or metal ions are recovered in the aqueous phase by mixing and then separating into a second aqueous phase and a second organic phase.

The acidic aqueous solution to be added to the first organic phase is not particularly limited, and examples thereof include aqueous solutions of hydrochloric acid, sulfuric acid, acetic acid and the like. The type and concentration of these aqueous solutions can be appropriately selected according to the type of the water-soluble calixarene used and the like. The concentration of the acidic aqueous solution can also be appropriately set according to the type of the water-soluble calixarene or the like to be used, but is usually about 0.01 to 20 N, preferably 1 to 10 N. After the addition of the acidic aqueous solution,
If necessary, stirring may be further performed.

The method for separating the second aqueous phase and the second organic phase and the method for recovering the metal from the second aqueous phase may be the same as those in the third step. (5) Fifth Step In the present invention, a fifth step can be further performed as necessary. In the fifth step, an acidic aqueous solution is added to and mixed with the second organic phase, and then separated into a third aqueous phase and a third organic phase, whereby hydroxycalix [n] arene-p is added.
Recover the sulfonate (n ≧ 2) in the third aqueous phase. FIG. 10 is a process chart showing an example of the purification method of the present invention including the fifth step and the circulation step.

The acidic aqueous solution to be added to the second organic phase is not particularly restricted but includes, for example, aqueous solutions of hydrochloric acid, sulfuric acid, acetic acid and the like. The type and concentration of these aqueous solutions can be appropriately selected according to the type of the water-soluble calixarene used and the like. The concentration of the acidic aqueous solution can also be appropriately set according to the type of the water-soluble calixarene or the like to be used, but is usually about 0.01 to 5N, preferably 0.01 to 0.1N. After the addition of the acidic aqueous solution, stirring may be further performed as necessary.

The method for separating the third aqueous phase and the third organic phase and the method for recovering the metal from the third aqueous phase may be carried out in the same manner as in the third step.

The third aqueous phase obtained here can be recycled to the first aqueous phase. Also, the third organic phase can be recycled to the first organic phase in a similar manner. By employing a circulation step of circulating in the first aqueous phase and / or the first organic phase, hydroxycalix [n] arene-sodium p-sulfonate and trioctylammonium chloride can be reused, and each metal (Ti
Etc.) can be increased.

[0034]

[Function] Hydroxycalix used as a metal ligand
[N] arene-p-sulfonic acid ion (l_n ^n-, N =
6, 8 etc.) are hydroxyl groups arranged at the lower edge of the cyclic molecule.
Coordinates with metal ions in solution to form phenolate complex
To achieve. Many metal ions have l_n ^n-And in alkaline solution
Form a phenolate-type complex with Ti (IV) and Fe (I
II) is exceptionally effective in acidic solutions (particularly around pH 2-3).
Respond. On the other hand, l_n ^n-Is trioctyl ammonium chloride
Ride (TMA⁺Cl^-) And an ion aggregate, forming an aqueous phase
Is extracted quantitatively into the organic phase. This extracted meeting
The body is TMA⁺Is mainly l_n ^n-Sulfonic acid group and ion association
Hydroxyl group that has the coordination ability of metal ions
Remains almost intact. Therefore, l
_n ^n-Is a phenolate that captures a metal ion with its hydroxyl group
TMA in the form of a complex⁺And extracted into the organic phase
Is done. In this case, Zr (IV) is not extracted into the organic phase,
Remains in the aqueous phase. As a result, Zr (IV) and other metal ions
Can be separated from each other.

[0035]

According to the method for purifying zirconia of the present invention, metal ions (particularly Ti ions) as impurities using hydroxycalix [n] arene-sodium p-sulfonate and trioctylammonium chloride.
Can be selectively extracted into the organic phase, so that the impurity metal can be reliably and efficiently removed from the zirconia raw material.

When the circulation step is adopted, it is possible to reuse sodium hydroxycalix [n] arene-p-sulfonate and trioctylammonium chloride, and to further increase the recovery rate of impurity metals. Can be.

[0037]

[Examples] Hereinafter, examples and the like will be shown to further clarify the features of the present invention.

[0038] Hydroxy calix [n] arene -p- sodium sulfonate used in Example (n is 6 or 8) is abbreviated as "Na _n l _n". Also, tri-octyl ammonium chloride ^- abbreviated as "TMA ⁺ Cl". Zr is Zr (IV), Ti is Ti (IV), Fe is Fe (II
I) and Al represent Al (III).

The quantitative and qualitative analysis of the zirconium ion concentration and the concentration of each metal ion in the solution is performed by an apparatus “SPS-1200VR type” according to a high frequency inductively coupled plasma emission spectroscopy (hereinafter abbreviated as “ICP-AES”) method.
(Seiko Electronics Co., Ltd.).

[0040] Preparation Example 1 (1) Preparation Na _n l _{n (n} = 6 or 8, made Sugaikagakukogyo) of each solution and TM
A model solution is prepared using A ⁺ Cl ⁻ (“Capricoat” manufactured by Dojindo Laboratories). Next, a phase separation operation is performed.

Firstly, Na _n l _n are water - was once recrystallized from methanol mixed solvent, and dried under reduced pressure in a vacuum desiccator. The Na ₆ l ₆ 8.32 g and Na ₈ l ₈ 11.0
8 g was dissolved in 500 ml of water, and 0.01M (1M =
1 moldm ^-3 ) Prepare aqueous solutions. Also, T
MA ⁺ Cl ^- was previously prepared by adding 7.80 g of chloroform to 100 m 2.
1M solution (TMA ⁺ Cl ^- solution)
Is prepared.

On the other hand, Zr, Fe and Al are chlorides of each metal ion (special grade reagent), and Ti is a 1000 ppm standard solution for atomic absorption analysis (manufactured by Wako Pure Chemical Industries, Ltd.) dissolved in water.
Prepare a 0.01 M solution of zirconium ions and each metal ion. After standardization by EDTA titration, it was diluted exactly 1/10 to obtain a 1 × 10 ⁻³ M aqueous solution. (2) metal ions Preparation and phase separation operations 50ml centrifuge settling tube model mixture solution 15ml and Na _n
The aqueous solution 15ml of l _n was taken, to which TMA ⁺ Cl ^- A solution 15ml, and the model mixture. The model mixture is shaken at 400 strokes per minute for 10 minutes to extract. Next, after centrifugation at 2000 rpm for 3 minutes,
Phase separated. PH and metal ion concentration [M] _{w, e}
Is measured.

On the other hand, a chloroform phase as an organic phase was 10 m
l into another 50 ml centrifugal sedimentation tube.
l, shake at 400 strokes per minute for 60 minutes,
Perform the extraction. Next, after centrifuging at 2000 rpm for 3 minutes, the metal ion concentration in the aqueous phase is measured. From this, the metal ion concentration [M] _{o, e} in the organic phase was determined. The extraction rate (% E) of metal ions was determined by the following formula 1 when no precipitate such as hydroxide of metal ions was found in the positively extracted aqueous phase.

% E = ｛([M] _{w, i} − [M] _{w, e} ) /
[M] _{w, i} ｝ × 100 where [M] _{w, i} is the charged concentration of metal ions.

When no precipitates such as hydroxides of metal ions were found in the positively extracted aqueous phase, it was determined by the following equation (2).

% E = {[M] _{o, e} / [M] _{w, i} } × 100 Reference Example 1 The pH dependence of the extraction rate of Zr using Na _{6 16} and TMA ⁺ Cl ⁻ was examined.

Using each solution of Preparation Example 1, [Zr] _{w, i} =
2.10 × 10 ⁻⁴ M, [Na _{6 16} ] _{w , i} = 1.09 × 1
0 ^-3 M, TMA ⁺ Cl ⁻ concentration in the organic phase [TMA
⁺ Cl ⁻ ] _{o, i} = 0.0103M A model mixture was prepared, and the phases were separated according to Preparation Example 1. The pH was adjusted with an aqueous sodium hydroxide solution or an aqueous hydrochloric acid solution. The result is shown in FIG.

As shown in FIG. 1, Zr is N2 in the pH range of 2 to 12.
It can be seen that not at all extracted by a ₆ l _6.

Reference Example 2 The pH dependence of the extraction rates of Ti, Fe and Al using Na _{6 16} and TMA ⁺ Cl ⁻ was examined.

In the case of Ti, [Ti] _{w, i} = 2.09 ×
10 ⁻⁴ M, [Na _{6 16} ] _{w, i} = 1.09 × 10 ⁻³ M,
[TMA ⁺ Cl ^-] _o, addition to the i = 0.0103M is,
A model mixture was prepared according to Preparation Example 1, and extracted and phase-separated.

In the case of Fe, [Fe] _{w, i} = 2.09 ×
10 ⁻⁴ M, [Na _{6 16} ] _{w, i} = 1.09 × 10 ⁻³ M,
[TMA ⁺ Cl ^-] _o, addition to the i = 0.0103M is,
A model mixture was prepared according to Preparation Example 1, and extracted and phase-separated.

In the case of Al, [Al] _{w, i} = 2.09 ×
10 ⁻⁴ M, [Na _{6 16} ] _{w, i} = 1.09 × 10 ⁻³ M,
[TMA ⁺ Cl ^-] _o, addition to the i = 0.0103M is,
A model mixture was prepared according to Preparation Example 1, and extracted and phase-separated.

The results are shown in FIGS.
In the figures, ○ indicates a value calculated from Expression 2, and Δ indicates a value calculated from Expression 1 (the same applies hereinafter).

From the results shown in FIG. 2, it can be seen that Ti begins to be extracted in a range higher than pH 1.2, reaches a maximum at pH 2.3 to 3.0, and reaches about 80%. Also, from the results in FIGS. 3 and 4, when Na _{6 16} is used, Fe and A
In other words, 1 is not extracted.

Reference Example 3 The pH dependence of the extraction rate of Zr using Na _{8 18} and TMA ⁺ Cl ⁻ was examined.

[Zr] _{w, i} = 2.10 × 10 ⁻⁴ M, [N
_{a 8 l 8] w, i} = 1.09 × 10 -3 M, [TMA + Cl -]
_A model mixture was prepared according to Preparation Example 1 except that _{o, i was} 0.0155 M, and extraction and phase separation were performed. The result is shown in FIG.

As shown in FIG. 5, Zr is N in the pH range of 2 to 12.
It can be seen that not at all extracted by a ₈ l _8.

We examined each Ti, the pH dependence of the Fe and Al extraction rate using ^- [0058] Reference Example 4 Na ₈ l ₈ and TMA ⁺ Cl.

In the case of Ti, [Ti] _{w, i} = 2.09 ×
10 ⁻⁴ M, [Na ₈ l ₈ ] _{w, i} = 1.09 × 10 ⁻³ M,
[TMA ⁺ Cl ^-] _o, addition to the i = 0.0103M is,
A model mixture was prepared according to Preparation Example 1, and extracted and phase-separated.

In the case of Fe, [Fe] _{w, i} = 2.09 ×
10 ⁻⁴ M, [Na ₈ l ₈ ] _{w, i} = 1.09 × 10 ⁻³ M,
[TMA ⁺ Cl ^-] _o, addition to the i = 0.0103M is,
A model mixture was prepared according to Preparation Example 1, and extracted and phase-separated.

In the case of Al, [Al] _{w, i} = 2.09 ×
10 ⁻⁴ M, [Na ₈ l ₈ ] _{w, i} = 1.09 × 10 ⁻³ M,
[TMA ⁺ Cl ^-] _o, addition to the i = 0.0103M is,
A model mixture was prepared according to Preparation Example 1, and extracted and phase-separated.

The results are shown in FIGS.
In the drawing, ○ indicates a value calculated from Equation 2, and Δ indicates a value calculated from Equation 1.

From the results shown in FIG. 6, it can be seen that Ti begins to be extracted in a range higher than pH 1.2, becomes maximum at pH 2.3 to 3.0, and reaches about 80%. Further, from the results of FIGS. 7 and 8, in the case of using Na ₈ l _8, Fe is also extracted maximum at pH 3, alternative may reach about 60%.

Reference Example 5 The influence of acetate ions on the extraction rate of Ti was examined.

[Ti] _{w, i} = 2.09 × 10 ⁻⁴ M, [N
_{a n l n] w, i} (n is 6 or ^{8) = 1.1 × 10 -3 M} , p
A model mixture was prepared according to Preparation Example 1, except that H = 2.1 and [TMA ⁺ Cl ⁻ ] _{o, i} = 0.0155M.
Extraction and phase separation. Table 1 shows the results. Table 1 left column Na ₆ l _6, right column shows the results of Na ₈ l _8.

[0066]

[Table 1]

[0067] Table than one result, the extraction rate of the Ti by Na ₈ l ₈ is improved by the presence of acetic acid, if there are acetic acid 0.04 M, the extraction rate, if it does not exist (7
0%), which is significantly improved, and reaches 95.6%. This acetate ions additionally coordinated to Ti-l ₈ ^8- complex, results polarity of this complex is reduced, presumably because that is easily distributed into chloroform. On the other hand, the extraction ratio of Ti by Na ₆ l ₆ is lowered by the presence of acetic acid. This is a Ti-l ₆ ^6- complex molecules crowded, extra TMA ⁺ ions is considered can not be added.

[0068] Reference Example 6 Reference Example 5, using Na ₈ l _8, an acetate 0.05M
, The dependence of the Ti extraction rate on pH was examined. FIG. 9 shows the result. The results in FIG. 9 show a curve similar to that in the case where no acetic acid shown in FIG. 5 is present. However, the extraction ratio of Ti at pH 2 to 3 was increased by 10% or more, and almost quantitatively (98%) was extracted at pH 3. Have been.

Example 1 Zr was purified from a model mixture in which Zr, Ti, Al and Fe coexisted using Na _{8 18} .

The model mixture is [Zr] _{w, i} = [Ti]
_{w, i} = [Al] _{w, i} = [Fe] _{w, i} = 2.0 × 10 ⁻⁴ M,
_{[Na 8 l 8] w,} i = 1.1 × 10 -3 M, pH = 2.1,
_{^{[TMA + Cl -] o,}} i = 0.0155M, [CH 3 COO
H] _{w, i} = 0.05 M, except that it was prepared according to Preparation Example 1. Using this model mixture, extraction and phase separation were carried out in the same manner as in Preparation Example 1. Table 2 shows the results.

[0071]

[Table 2]

According to Table 2, the extraction rate of Zr was 5.0%,
Is 0%, which means that these are hardly extracted. On the other hand, the extraction ratio of Ti was 90% and the extraction ratio of Fe was 45%. As a result,
By one extraction operation, the purity of Zr with respect to Ti, Zr
/ Zr + Ti improved from 65% before extraction to 95%.

Example 2 Zr was purified from a model mixture in which Zr was present in excess of Ti, Al and Fe using Na ₈ l ₈ .

The model mixture is [Zr] _{w, i} = 5.9 ×
10 ⁻⁴ M, [Ti] _{w, i} = 7.0 × 10 ⁻⁵ M, [Al]
_{w, i} = 7.3 × 10 ⁻⁵ M, [Fe] _{w, i} = 8.2 × 10 ⁻⁵
M, [Na ₈ l ₈ ] _{w, i} = 1.1 × 10 ⁻³ M, pH = 2.
^{1, [TMA + Cl -]} o, i = 0.0155M, [CH 3 C
OOH] _{w, i} = 0.05 M, except that it was prepared according to Preparation Example 1. Using this model mixture, extraction and phase separation were carried out in the same manner as in Preparation Example 1. Table 2 shows the results.

[0075]

[Table 3]

As shown in Table 3, since the concentration of Zr is high,
r and l ₈ ^8- precipitated in water as a sulfonic acid type phenolate type mixing conformation complex of _{(ZrO) 7 (l 8 H} -6) · 16H 2 O. As a result, liquid-liquid extraction in a homogeneous solution system could not be performed, and the Zr concentration in the aqueous phase after the extraction was apparently reduced. T
i was extracted into the organic phase, and the purity of Zr relative to Ti, including precipitated Zr, Zr / Zr + Ti was improved from 94% before extraction to 99%.

Example 3 Zr was purified from the model mixture in the same manner as in Example 2 except that sulfate ions were present.

The model mixture is [Zr] _{w, i} = 5.9 ×
10 ⁻⁴ M, [Ti] _{w, i} = 7.0 × 10 ⁻⁵ M, [Al]
_{w, i} = 7.3 × 10 ⁻⁵ M, [Fe] _{w, i} = 8.2 × 10 ⁻⁵
M, [Na ₈ l ₈ ] _{w, i} = 1.1 × 10 ⁻³ M, pH = 2.
^{1, [TMA + Cl -]} o, i = 0.0155M, [CH 3 C
OOH] _{w, i} = 0.05 M, [Na ₂ SO ₄ ] _{w, i} = 0.0
Except for 1M, it was prepared according to Preparation Example 1. Using this model mixture, extraction and phase separation were carried out in the same manner as in Preparation Example 1. Table 4 shows the results.

[0079]

[Table 4]

From Table 4, the extraction rates of Ti and Fe were 77.7% and 36.1%, respectively. This is slightly lower than when no sulfate ion is present. On the other hand, most of Zr remains in the aqueous phase, and it can be seen that the presence of sulfate ions enables solvent extraction in a homogeneous solution system. In this case, Zr and T
A 66-fold difference is seen in the distribution ratio of i, which indicates that the two can be separated from each other.

[0081] Because of the high concentration of Zr, Zr and l ₈ ^8-
Is a sulfonic acid type phenolate type mixed conformation complex (Zr
_{O) 7 (l 8 H -8} ) · 16H precipitated in water as ₂ O.
As a result, liquid-liquid extraction in a homogeneous solution system could not be performed, and the Zr concentration in the aqueous phase after the extraction was apparently reduced. Ti is extracted into the organic phase and contains Zr,
The purity of Zr / Zr + Ti was increased from 94% before extraction to 99%.

[0082] using various mineral acid shown in Reference Example 6 in Table 5 as a stripping agent were back extracted with l _n ^n-and Ti in chloroform, were examined their recovery.

The model mixture is a metal ion solution of T
Except for using the i-ion solution, it was prepared according to Preparation Example 1, and extraction and phase separation were performed. Next, extraction and phase separation were performed in the same manner as in Preparation Example 1, using 10 ml of each of the mineral acids shown in Table 5 as a back-extracting agent for 10 ml of the separated chloroform phase. The T ion concentration in the aqueous phase obtained here was measured. The recovery was determined with the amount of ions in the chloroform phase as 100. Table 5 shows the results.

[0084]

[Table 5]

[0085] From the results of Table 5, l ₆ ^6- are 3M sulfuric acid, l ₈ ^8-
Can be almost quantitatively recovered using 4M hydrochloric acid. on the other hand,
even under the condition that l ₆ ^6- can be quantitatively recovered, the recovery rate of l ₈ ^8- -Ti complex was 88.4%. Also, in 6M hydrochloric acid,
Conversely, it showed a low value. L ₈ ^8- -Ti complex by reverse extraction with 3M sulfuric acid in place of hydrochloric acid could be recovered 81.6%. In contrast, back extraction of l ₈ ^8- itself is only 1.34%, it can be seen that most of remains in the chloroform phase. This was back extracted with First 3M sulfuric chloroform phase, only the metal ions were recovered, and then replace it can be back extracted to recover l ₈ ^8- with 4M hydrochloric acid.

[Brief description of the drawings]

FIG. 1 is a diagram showing the results of a study on the pH dependence of the extraction rate of Zr using Na _{6 16} and TMA ⁺ Cl ⁻ in Reference Example 1.

FIG. 2 is a view showing the result of examining the pH dependence of the Ti extraction rate using Na _{6 16} and TMA ⁺ Cl ⁻ in Reference Example 2.

FIG. 3 is a graph showing the result of examining the pH dependence of the Fe extraction rate using Na _{6 16} and TMA ⁺ Cl ⁻ in Reference Example 2.

FIG. 4 is a diagram showing the results of examining the pH dependence of the Al extraction rate using Na _{6 16} and TMA ⁺ Cl ⁻ in Reference Example 2.

FIG. 5 is a diagram showing the results of examining the pH dependence of the Zr extraction rate using Na _{8 18} and TMA ⁺ Cl ⁻ in Reference Example 3.

FIG. 6 is a graph showing the result of examining the pH dependence of the Ti extraction rate using Na _{8 18} and TMA ⁺ Cl ⁻ in Reference Example 4.

FIG. 7 is a diagram showing the results of examining the pH dependence of the Fe extraction rate using Na _{8 18} and TMA ⁺ Cl ⁻ in Reference Example 4.

FIG. 8 is a diagram showing the results of examining the pH dependence of the Al extraction rate using Na _{8 18} and TMA ⁺ Cl ⁻ in Reference Example 4.

In Figure 9 reference example 6, using Na ₈ l _8, by fixing the acetic acid and 0.05 M, is a diagram showing the results of examining the dependency of Ti extraction rate by the pH.

FIG. 10 is a process chart showing an example of the purification method of the present invention including the fifth step and the circulation step.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Munehiro Wakita 1-1-C4-8 Momoyamadai, Suita-shi, Osaka F-term (reference) 4K001 AA31 BA04 DB04 DB11 DB23 DB25

Claims (9)

[Claims] 1. A method for purifying zirconium, comprising: (1)
First step of preparing a solution containing zirconium ions from zirconium raw materials (2) A mixed solution containing the above solution, hydroxycalix [n] arene-p-sulfonate (n ≧ 2), trioctylammonium chloride and an organic solvent A purification method comprising: a second step of preparing; and (3) a third step of separating the mixed solution into a first aqueous phase and a first organic phase, and recovering zirconium ions in the aqueous phase. 2. The method according to claim 1, wherein the organic solvent is chloroform. 3. Hydroxycalix [n] arene-p
The purification method according to claim 1, wherein the sulfonate is a sodium salt (n is 6 or 8). 4. The purification method according to claim 1, wherein the pH of the mixture is 7 or less. 5. The method according to claim 1, wherein the mixed solution contains acetate ions. 6. An acidic aqueous solution is added to and mixed with the first organic phase,
Then, the second aqueous phase and the second organic phase are separated, whereby hydroxycalix [n] arene-p-sulfonate (n ≧ 2) and / or metal ions are recovered in the second aqueous phase. The purification method according to claim 1, further comprising a step. 7. An acidic aqueous solution is added to and mixed with the second organic phase.
Next, the method further comprises a fifth step of recovering hydroxycalix [n] arene-p-sulfonate (n ≧ 2) in the third aqueous phase by separating into a third aqueous phase and a third organic phase. Item 7. The purification method according to Item 6. 8. The method according to claim 7, wherein the third aqueous phase is circulated to the first aqueous phase.
Purification method as described. 9. The purification method according to claim 7, wherein the third organic phase is circulated to the first organic phase.