JPH0448038A - Method for separating indium and method for separating indium and gallium - Google Patents

Abstract

PURPOSE:To effectively separate In and Ga by bringing a metallic salt water soln. into contact with a dialkylphosphoric acid-contg. solvent to selectively extract In (III) and furthermore back-extracting it with an acid water soln. CONSTITUTION:A metallic salt water soln. contg. In (III), Ga (III) or the like is mixedly brought into contact with an extractant contg. dialkylphosphoric acid shown by the formula as an extracting agent to selectively extract In (III). The extractant carrying In (III) is mixedly brought into contact with a water soln. contg. an inorganic acid as back extraction agent to back-extract In (III) into the water soln. The metallic water soln. in which In is separated is mixedly brought into contact with an extractant contg. substituted quinolinol as an extracting agent to extract Ga (III). This extractant is mixedly brought into contact with the inorganic acid water soln. to strip out Ga (III) into the water soln. This back extraction can be executed at high yield.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention is directed to the treatment of In(m) produced by wet metal processing.
), Ga(m), or other metal ions, selectively extracts In(III) from an aqueous metal salt solution containing
The present invention relates to a method for separating and recovering In.

Furthermore, the present invention selectively extracts Ga(III) from the metal salt aqueous solution from which In(III) has been extracted, and
It relates to a method for separating and recovering.

(Prior Art) In and Ga are raw materials for manufacturing compound semiconductors such as In-P and Ga-As, and their demand has been increasing in recent years. However, there are no ores on earth that contain these metals as main components, and they are only contained as trace components in bauxite and some zinc ores.

For this reason, small amounts of In are contained in solutions and precipitates discharged from various metal refining processes and other chemical processing processes.
It is important to collect and use 6a.

For example, In is recovered from compound semiconductor scrap, zinc ore leaching residue, and the like. The aqueous solution obtained by treating these with an inorganic acid contains other metal ions as well as In. In particular, it often contains Ga. A solvent extraction method is known as a method for recovering In and Ga from such metal salt aqueous solutions. For example, In, Ga, and a large amount of A obtained by acid treatment of zinc ore leaching residue
There is a method in which an aqueous sulfate solution containing I% Zn or the like is treated with an extraction solvent containing a higher carboxylic acid extractant (for example, manufactured by Shell Chemical Co., Ltd., trade name Versatic 10). According to this method, In and Ga can be separated from other base metals and extracted into an extraction solvent. However, with this method, In and Ga cannot be separated, and the ability to separate In and Ga from other base metals is not sufficient. Furthermore, since the extractant has high water solubility, the extractant is eluted into the aqueous phase, resulting in a decrease in separation performance and economical problems due to the loss of the extractant, which cannot be ignored.

As a method for separating In and Ga extracted by the above method, In and Ga are back-extracted from the extraction solvent supporting In and Ga using hydrochloric acid, and the obtained In and Ga are chlorinated. Ga was extracted from the aqueous solution with isopropyl ether, and I was extracted with tributyl phosphate.
There is a method to extract n. However, in this method, sulfuric acid cannot be used, and hydrochloric acid, which is highly corrosive to equipment, must be used. Furthermore, isopropyl alcohol has a large water solubility and has the problem of being eluted into metal salt aqueous solutions.

Di-2-ethylhexyl phosphoric acid (DEHPA) can also be used as an extractant that can selectively extract In from a metal salt aqueous solution containing In and Ga. When this extractant is used, In is removed from the extraction solvent. When back-extracting, sulfuric acid has insufficient back-extraction ability and it is necessary to use highly concentrated hydrochloric acid.Therefore, it may corrode the anti-extraction equipment, so it is not an industrially suitable method. I can not say.

In order to solve the drawbacks of solvent extraction methods using higher carboxylic acid extractants, a method has been devised in which In and Ga are adsorbed onto a chelate resin, but the process for continuous separation is complicated; It is insufficiently efficient for industrial implementation.

(Problems to be Solved by the Invention) The present invention solves the above-mentioned conventional drawbacks, and its purpose is to
In(nl) can be efficiently selectively extracted from a gold scrap salt aqueous solution containing , or other gold scrap ions, and In(III) can be efficiently back-extracted using a low concentration inorganic acid, especially sulfuric acid. An object of the present invention is to provide a method for separating In. Furthermore, another object of the present invention is to extract Ga(I
Ga(III) is selectively extracted using an inorganic acid.
) to provide a method for efficiently separating and recovering Ga.

(Means for Solving the Problems) The present invention involves separating indium from a gold scrap salt aqueous solution containing in(m) and Ga ([[) or at least one other metal ion by a solvent extraction method. A method,
A step of selectively extracting In(III) by bringing an extraction solvent containing dialkyl phosphoric acid represented by the following general formula (I) as an extractant into contact with the metal salt aqueous solution; The extraction solvent supporting In(
step 1 of back-extracting III) into the aqueous solution,
Thereby, the above object is achieved: Furthermore, the present invention provides at least In(
A method for separating indium and gallium in an aqueous solution of a metal salt containing Ga(III) and Ga(III), the method according to claim 1, wherein In(
Step of separating Ga(III); The metal salt aqueous solution from which In(III) has been removed is mixed and contacted with an extraction solvent containing a substituted quinolinol represented by the following general formula (m) as an extractant, and Ga(III) is separated from Ga(III). a second extraction step of selectively extracting Ga(III); and a second extraction step of selectively extracting Ga(III) from the aqueous solution by mixing and contacting the extraction solvent supporting Ga(III) with an aqueous solution containing an inorganic acid as a back-extracting agent. a second back-extraction step of back-extracting into .

Ql- (where R is an alkyl or alkenyl group having 5 to 15 carbon atoms.

The extractant used in the present invention and represented by the above formula (I) (
Extractant A) is obtained by reacting a higher alcohol with phosphorus oxychloride and hydrolyzing the resulting dialkylphosphoromonochloride. Examples of higher alcohols include 2-hebutylundecanol, 7,7-dimethyl-5-methyl-2-(3,3-dimethyl-1-methylbutyl)octatool, 2-(3-methylbutyl)nonanol, 2-( I-methylbutyl) nonanol and the like are preferably used. The above extractants may be used alone or as a mixture of two or more.

The reaction product usually contains the desired dialkyl phosphoric acid (diester), as well as monoalkyl phosphoric acid (monoester), trialkyl phosphoric acid (triester) and unreacted alcohol. In particular, monoalkyl phosphoric acid is In
In order to form a stable complex with (m), the separation performance of the extraction solvent between In(II[) and other metal ions in the extraction process is reduced. In addition, it becomes difficult to back-extract In(III) from the extraction solvent in the back-extraction process,
have an undesirable effect on the method of the invention. Therefore, the content of monoalkyl phosphoric acid is usually 10 mol% or less, preferably 5 mol% or less, based on the total amount of dialkyl phosphoric acid and monoalkyl phosphoric acid.

The substituted quinolinol represented by the above general formula (III) (referred to as extractant B) used as an extractant for Ga(III) is: -(4-ethyl-1-methyloctyl)-8-hydroxygynolin and the like. As a commercially available substituted quinolinol, Kele manufactured by Schering Co.
xloo etc. are preferably used.

The above extractants A and B are mixed with a suitable organic solvent (diluent) as needed and diluted to obtain the extraction solvent (
Hereinafter, they will be referred to as extraction solvents A and B). The organic solvent used is not particularly limited as long as it is substantially insoluble in water and does not interfere with the function of the extractant. Such organic solvents include high flash point paraffin hydrocarbons,
These include naphthenic hydrocarbons and aromatic hydrocarbons. The concentration of the extractant in this organic solvent is usually 1 to 8.
It is added in an amount of 0 vol%, preferably 5 to 50 vol%. A phase separation promoter may be added to the extraction solvent in order to promote separation of two phases, an organic phase and an aqueous phase. Examples of phase separation promoters include neutral phosphoric acid esters, higher alcohols, alkylphylphenols, and higher branched carboxylic acids, such as tributyl phosphoric acid, indecanol, nonylphenol, and isododecanoic acid.

Since such a phase separation promoter tends to reduce the ability of the extraction solvent to selectively extract metal ion species, the amount added is usually preferably 0 to 30% by weight based on the extractant.

Using the present invention, In(m), or In(m) and Ga(
Examples of aqueous metal salt solutions that can be separated and recovered from III) include metal salt aqueous solutions produced by metal salt wet treatment, compound semiconductor scraps, metal salt aqueous solutions obtained by treating zinc ore leaching residue, etc. with inorganic acids, etc. , In(,m) with other metal ions, or In(Ill) and G
Any aqueous solution containing a(II[) may be used. In particular, in an aqueous solution containing Fa(II), Al(m), and Zn(II) as metal ions other than In(III) and Ga(m), In(
III) and Ga(III) can be separated.

In order to separate and recover In(■) from a metal salt aqueous solution using the method of the present invention, first, the metal salt aqueous solution is mixed with the above extractant A.
In(III) is extracted from the metal salt aqueous solution by bringing it into liquid-liquid contact with an extraction solvent containing the following.

The method of the present invention for extracting In(III) using extractant A is a method in which gold scrap ions are bound to the extractant using the cation exchange ability of the extractant. Since H0 ions are exchanged with gold scrap ions and liberated into the aqueous phase, the pl+ of the aqueous phase decreases. Figure 1 shows the aqueous phase (raffinate) after the extraction process when a metal salt aqueous solution containing various metal ions was extracted using bis(2-hebutylundene) phosphoric acid as extractant A. It is a graph showing the relationship between the pH of the aqueous phase and the extraction rate of metal ions. As can be seen from FIG. 1, In(I[[) can be extracted by arbitrarily adjusting the pH of the raffinate aqueous phase within the range of usually about 0.5 to 4.0. In order to increase the extraction rate of In(m), it is preferable to adjust the pH to 10 or more. Furthermore, by adjusting the pl( of the raffinate aqueous phase), In(II[)
It is possible to selectively extract. For example, In(
When attempting to separate In(III) from a metal salt aqueous solution containing Ga(m), Ga(m), and AI(III), In(III) is sufficiently extracted and Ga(III
) and AI(III) may be selected. Alternatively, when attempting to separate the above three types of ions, In(III) and Ga
By selecting a pH that sufficiently extracts (I[
By back-extracting Ga(III) from the extraction solvent carrying [
III) is separated into the back-extracted aqueous phase. however,
The efficiency of separating and recovering Ga(II[) from other metals such as AI(III) using extractant A is not necessarily good.

Next, this extraction solvent is brought into contact with an aqueous solution containing an inorganic acid as a back-extracting agent to back-extract In(III). As the inorganic acid, sulfuric acid, hydrochloric acid, a mixture thereof, etc. are used. The type of inorganic salt is determined by the type of In salt recovered in the back-extracted aqueous phase.

For example, when attempting to recover In(III) as a chloride, hydrochloric acid is used, and when attempting to recover In(III) as a sulfate, sulfuric acid is used. When using hydrochloric acid, the concentration of the inorganic acid is 0. It is at least IN, preferably at least 0.25N, and when sulfuric acid is used, it is at least 0.25N, preferably at least IN. In the method of the present invention, back extraction proceeds easily, so it is not necessary to increase the inorganic acid concentration to 5N or higher. In this back extraction step, by bringing the organic phase into contact with an inorganic acid, In(m) in the organic phase is ion-exchanged with protons of the inorganic acid, and the PTT of the aqueous phase increases. In
In order to effectively back-extract (III), it is necessary to adjust the pH after liquid-liquid contact to an appropriate value. For example, the pH after contact is 0.9 or less, preferably 0.4 or less when sulfuric acid is used, and 12 or less, preferably 0.8 or less when hydrochloric acid is used. Adjust the acid concentration in the aqueous solution.

Furthermore, according to the present invention, Ga(III) can be separated and recovered from this metal salt aqueous solution from which In(III) has been removed. For this purpose, an aqueous solution of a metal salt excluding In(III) is brought into liquid-liquid contact with an extraction solvent containing the extractant B, and then an aqueous solution of an inorganic salt is added to the aqueous solution of the extractant B.
Back-extract a(III).

A method for separating and recovering Ga(III) using extractant B is a method in which the extractant forms a chelate with a metal ion to extract the metal ion. In this case as well, as the extraction progresses, H3 ions are liberated into the aqueous solution, and the pH of the aqueous solution phase decreases. FIG. 5 is a graph showing the relationship between the PTT of the raffinate aqueous phase and the metal ion extraction rate when a metal salt aqueous solution containing various metal ions is extracted using KelexlOO as the extractant B. As can be seen from FIG. 5, the PTT of the raffinate aqueous phase is usually 1.0 to 4.
By adjusting arbitrarily within the range of 0 degree, Ga(II
I) can be extracted. In order to increase the extraction rate of Ga(m), it is preferable to adjust the pH to 1.5 or higher.

Furthermore, by adjusting the pH of the raffinate aqueous phase, it is possible to selectively extract Ga(■).

For example, Ga(m), Fe(It), and At(
When attempting to separate Ga(III) from an aqueous solution of metal salts containing III), it is possible to select a PTT that sufficiently extracts Ga(III) but does not extract Fe(II) and AI(III). be.

Sulfuric acid, hydrochloric acid, a mixture thereof, or the like is used as the inorganic acid for back-extracting Ga(Ill). For example, G
When a(III) is to be recovered as a chloride, hydrochloric acid is used, and when a(III) is to be recovered as a sulfate, sulfuric acid is used. When using hydrochloric acid, the concentration of the inorganic acid is at least IN, preferably 1.5 to 3N, and when using sulfuric acid, it is at least 2N, preferably at least 3N,
More preferably, it is 4N-1ON.

In order to adjust the pH of the raffinate aqueous phase in the above-mentioned In(III) and Ga(m) extraction process, the acidic groups of the extractant in the extraction solvent are usually converted in advance to an alkali salt (e.g. ammonium salt) in an appropriate ratio. shall be.

Alternatively, an alkali or inorganic acid may be added and mixed into the organic phase or aqueous phase introduced into the apparatus as required. Here, as the alkali, ammonium ions, alkali metal ions, and hydroxides or carbonates of metal ions extracted at a higher pH than the metal ions to be extracted are suitable. Examples include ammonia, sodium hydroxide, sodium carbonate, etc., and these are usually added as an aqueous solution.

The method of extraction by bringing an extraction solvent into contact with an aqueous metal salt solution is as follows:
Any well known procedure used in solvent extraction methods may be used. Not only the continuous multi-stage contact method but also the batch, continuous batch and batch circulating methods are effective. When carrying out countercurrent multi-stage extraction, a column type apparatus such as a packed column, a pulsed column, a disk base, or a mixer-settler is preferably used. Equipment is also available.

During extraction, the volume ratio of the extraction solvent to the metal salt aqueous solution is not particularly limited, but is usually 1:20 to 20:
1. Preferably, the ratio is 1:20 to 5:1. This volume ratio is determined by taking into account the concentration of the extractant in the extraction solvent, the concentration of the metal ions to be extracted in the aqueous metal salt solution, and the method of contacting the organic phase with the aqueous phase (for example, the type of apparatus). Generally, the amount of target ions (In(m) or Ga(m)) remaining in the raffinate aqueous phase is minimized;
The organic phase (extraction solvent) is adjusted so that the target ions are contained in a high concentration.

The temperature at which liquid-liquid contact and phase separation are carried out is preferably higher, from the standpoint of reducing the viscosity of the organic phase and promoting the rate of phase separation, but it is not critical. Its temperature is
Considering the flash point, reaction energy, etc. of the organic solvent used as the extraction solvent, the temperature is usually maintained at 10 to 80°C. liquid-
The time required for liquid contact varies depending on conditions such as the contact method, equipment used, temperature, and metal ions to be extracted.
It is usually preferable to stir and mix for 5 minutes or more.

In(m) or Ga(III) is extracted from the extraction solvent supporting In(III) or Ga(III) using an inorganic acid aqueous solution.
The back extraction step to recover III) can be carried out using any liquid-liquid contacting device according to a similar procedure to the extraction step.

For example, the target ions can be removed from the extraction solvent by using one to several stages of mixers. In(III) or Ga(m) may be contained in the back-extracted aqueous phase. For example, by recycling the back-extracted aqueous phase from which In(I[[) or Ga(III) has been extracted once again to the back-extracted aqueous phase, In(m) or
a(III) can be concentrated and recovered to a high concentration.

The volume ratio of the organic phase to the inorganic acid aqueous solution in the back extraction step is related to the concentration of In(III) or Ga(m) in the organic phase and the concentration of the inorganic acid aqueous solution, and can be set within a fairly wide range. The ratio is usually selected between 20:1 and 1:10.

The temperature during back extraction is usually 1O2 from the same point of view as during extraction.
Performed at ˜80° C., but not critical. The required time for liquid-liquid contact in the back-extraction step should also be determined in consideration of the same conditions as in the extraction step. Usually, it is preferable to stir and mix for 5 minutes or more.

The extraction solvent regenerated after the back-extraction step can be recycled to a new extraction step.

Furthermore, if other metal ions are present in the extraction solvent along with the metal ions to be extracted in the extraction process, impurity gold ions can be separated by providing a washing process between the extraction process and the back extraction process. Only the target ions can be recovered.

For example, extraction solvent A includes In(III) and Ga.
(■), Zn(II), AI(m), Fe(I[), etc. are easily extracted. Extraction solvent B contains Ga(I
ll), along with Fe(II), Zn(II), AI(I
[[) etc. often coexist. In the washing step, the extraction solvent is brought into contact with an aqueous solution containing an inorganic acid using a well-known liquid-liquid contacting device and applying the liquid-liquid contacting procedure described above. At this time, the pH after contact is adjusted depending on the concentration of the inorganic acid aqueous solution so that impurity metal ions are sufficiently transferred to the aqueous phase and metal ions to be extracted are not transferred to the aqueous phase. The optimum pH value after contact is appropriately set depending on the target metal ion species, but is usually in the range of 1.0 to 5.0.

Although the volume ratio of the extraction solvent to the aqueous phase can be set within a wide range, a range of 1:5 to 10:1 is usually used industrially. The temperature of the washing step, as well as the extraction or back-extraction step, is usually kept between 10 and 80°C. Note that in the cleaning step, the metal ion species to be cleaned; for example, Ga(III), Zn(I
In order to improve the purity of I), Al(III), Fe(U), etc., the process can be divided into two or more steps. The aqueous phase containing the metal salts after washing is recycled to the extraction step or recovered separately.

According to the method of the present invention, using extraction solvent A, In(m
), Ga (m), Fe (II), AI (m), Z
In(III) from a metal salt aqueous solution containing n(■) etc.
) can be efficiently extracted. Furthermore, In
From extraction solvent A carrying (III), In(III)
It is also easy to reverse extract. For example, 0. Back extraction can be effectively performed with hydrochloric acid at a low concentration of IN or higher or sulfuric acid at a concentration of 0.25N or higher.

Furthermore, according to the method of the present invention, In(III)
Using extraction solvent B, Ga(III) can be efficiently separated and extracted from the metal salt aqueous solution after separation. Then, Ga(m) supported on extraction solvent B is 4N
It is possible to back-extract with -10N sulfuric acid or 1.5-3N hydrochloric acid.

(Example) The invention is illustrated by the following examples.

Using bis(2-hebutylundecyl) phosphoric acid (hereinafter referred to as B2HUPA) having the following structure as an extractant, the extraction ability for several metal ions including In(III) was improved. evaluated.

ROO \/ /\ROOH Here, R is (CH3)3CCH2CH(CHx)
CH2CH2CHCH2-(CH3)3CC112CH
(CH3).

B2HUPA was dissolved in kerosene (aliphatic hydrocarbon diluent) and used as an extraction solvent. What is the purity of B211UPA used? 2. Ovt% and monoester 1.7v
It contained t%. The extractant concentration in the extraction solvent is B2H
The total concentration of UPA and monoester is 0.5 mol/
IQ (Hereinafter, the concentration of the extractant in the extraction solvent is indicated by the total concentration of diester and monoester) (approximately 45vol%).

To adjust the pH of the raffinate aqueous phase, the extraction solvent was contacted with a sodium hydroxide solution to make the appropriate proportion of the extractant the sodium salt.

In(nI), (ia(III),
An aqueous solution containing Fe(■), AI(I[[) and Zn(II) nosulfate was prepared. The concentration of metal ions is
Considering that the sodium hydroxide solution added to the extraction solvent would transfer to the aqueous phase upon contact, the initial concentration was adjusted as follows with respect to the total volume of the aqueous phase.

That is, In(m) is 0.50g/jZ, Ga
(II[) is 0.46g/4, Fe(n) is 1.54g
/4, AI (III) is 1.41g/42. Moshite a
n(II) is 3.1'8g/42. Met. Also in the Examples described below, the initial concentration of the metal salt is adjusted in consideration of the amounts of acid and alkali.

The above extraction solvent and metal salt aqueous solution were mixed in a volume ratio of 1:l.
Mix in an Ersin Mayer flask and add 2
The system was heated for 2 hours at 5°C to allow contact. The mixture was then allowed to stand and the aqueous and organic phases were separated. FIG. 1 shows the relationship between the pH of the aqueous phase (raffinate aqueous phase) after two-phase separation and the ratio (extraction rate) of each metal ion extracted from the aqueous solution to the organic phase.

As is clear from FIG. 1, according to the method of the present invention, as the pt+ of the raffinate aqueous phase increases, In(m
), Zn (II), Ga (III), AI (m),
Metal ions are extracted in the order of Fe (■). In(I
In order to sufficiently extract II), the p of the raffinate aqueous phase is
H is adjusted to about 0.5 or more, preferably 1.0 or more.

In by selecting pl+ of the raffinate aqueous phase
It is possible to separate (III) from other metal ions. For example, the pl+ of the raffinate aqueous phase is approximately lO
By adjusting to
It can be seen that I(m) and Fe(II) remain in the aqueous phase.

Saketsu 1 In(m), Ga(m), Fe(
Metal ions were extracted in the same manner as in Example 1 except that an aqueous solution containing sulfates of Al(III), Al(III), and Zn(II) was used. The initial concentration of metal ions is
In(m) is 0.50g/II, Ga(m) is 0°51
g/42. Fe(I[1) is 1.67g/4, AI(
m) is 1°59g/42, and Zn(II) is 3.2
It was 3g/4.

FIG. 2 shows the relationship between the pH of the raffinate aqueous phase and the extraction rate of each metal ion. As is clear from FIG. 2, according to the method of the present invention, In(III) can be converted to Zn(ff), Ga(
III) and AI(III). However, Fe(m) is In(II
In(III) is extracted at approximately the same pH as In(III)
It was impossible to separate them.

In (In), Ga (m), Fe as aqueous solutions of metal salts
Using an aqueous solution containing sulfates of (II), AI(III), and Zn(II), the initial concentration of metal ions was adjusted to
n(III) is 0.31g/4. Ga(III) is 0
．． 29g/42. Fe(I[) is 15.7 g/u, A
I (I[[) is 15.7 g/U, and Zr+(
IT) is 320g/I2. Metal ions were extracted in the same manner as in Example 1 except that the film was closed.

FIG. 3 shows the relationship between the pH of the raffinate aqueous phase and the extraction rate of each metal ion. In Example 1, In in the metal salt aqueous solution
The initial concentration of (II[) is Fe(I[) and ^1(II
The initial concentration was 1/3 of Fe(I) and 1/6 of Zn(II), but in this example, Fe(I[and 11 of AI(m)
50, 1/loo of Zn (I[). As is clear from FIG. 3, according to the present invention, In(nl
) can be separated and extracted.

Using bis(2-pentylnonyl) phosphoric acid (hereinafter referred to as B2PNPA) having the following structure as an extractant,
The extraction ability for several metal ions including In(nl) was evaluated: where R is .CH2Cl (Ch)CIhCHa-
1 or CH3C82C82C)I(C1+3)-.

B2PNPA was dissolved in kerosene and used as an extraction solvent.

The purity of B2PNPA used was 67.8 vt%, and it contained 0.2 vt% of monoester. The extractant concentration in the extraction solvent was adjusted so that the total concentration of 82PNPA and monoester was 0.5 mol/λ (approximately 40
vo1%).

As the metal salt aqueous solution, the same metal salt aqueous solution as in Example 3 was used.

Metal ions were extracted in the same manner as in Example 1 using the above extraction solvent and metal salt aqueous solution. FIG. 4 shows the relationship between pl+ of the raffinate aqueous phase and the extraction rate of each metal ion. As is clear from Figure 4, B2PNPA is B21
It has the same extraction capacity as 1UPA. Then, by selecting the pH of the raffinate aqueous phase, In(III)
can be separated from other metal ions.

Ke, a typical substituted quinolinol, is used as an extractant.
Extractability for several types of metal ions including Ga(III) was evaluated using lexlOO.

First, Kelexloo was dissolved in kerosene and used as an extraction solvent. The concentration of extractant in the extraction solvent is 25vol%
It was adjusted so that

Ga(III), Fe(II) as metal salt aqueous solution
An aqueous solution containing sulfates of , AI(■) and Zn(II) was prepared. The concentration of metal ions is Ga(m)
is 0.31g/j2. , Fe(I[) is 15.6g/4
．． At (m) was 16°0 g/42, and Zn (ff) was 3L, 3 g/12.

To adjust the pH of the raffinate aqueous phase, sulfuric acid or sodium hydroxide solution was added to the metal salt aqueous solution.

Metal ions were extracted in the same manner as in Example 1 using the above extraction solvent and metal salt aqueous solution. FIG. 5 shows the relationship between the pH of the raffinate aqueous phase and the extraction rate of each metal ion. As is clear from FIG. 5, according to the method of the present invention,
As the pH of the raffinate aqueous phase increases, Ga(I
II), Fe (II), AI (III) = Zn (
Metal ions are extracted in the order II). Ga(III
), the pu of the raffinate aqueous phase is adjusted to about 1.0 or more, preferably 1.5 or more. Ga(II) by selecting the pH of the raffinate aqueous phase.
I) can be separated from other scrap gold ions. For example, the pH of the raffinate aqueous phase is 1.6-2.0.
By adjusting to
It can be seen that Zn(II) and Zn(II) remain in the aqueous phase.

The same B2HUPA as in Example 1 was used as the extractant,
B2HUPA was dissolved in kerosene so that the concentration was 0.3 mol #Z and used as an extraction solvent (approximately 27 vol 1%)
. This extraction solvent was brought into contact with an aqueous solution of indium sulfate to obtain an organic phase carrying 1.0 g/Q of In(III). This organic phase was mixed with an equal volume of aqueous sulfuric or hydrochloric acid and brought into contact with shaking at 25°C for 2 hours. Initial concentration of inorganic acid aqueous solution and In (■) back extracted from the organic phase
The relationship with the ratio (reverse extraction rate) is shown in Table 1 together with the results of Comparative Example 1, which will be described later, and is shown graphically in FIG.

Di(2-ethylhexyl)phosphoric acid (D2
In the same manner as in Example 6 except that EHPA) was used,
Back extraction of In(m) was performed. Table 1 shows the relationship between the initial concentration of the inorganic acid aqueous solution and the ratio of In(III) back extracted from the organic phase (reverse extraction rate).

(The following is a blank space) As is clear from Table 1, in the method of the present invention, 0.5N
It is possible to back-extract more than 99% of In(III) even with hydrochloric acid. Furthermore, when using sulfuric acid, in Comparative Example 1 using a conventional extractant, even with 8N sulfuric acid, 50%
In(III)L below was not back extracted, whereas in Example 6 using the method of the present invention, even with 2N sulfuric acid, 98
It is possible to back-extract more than % of In(III).

Actual resistance 1- Back extraction was performed in the same manner as in Example 6, except that 01-2N sulfuric acid or hydrochloric acid aqueous solution was used as the inorganic acid aqueous solution for back extraction. Table 2 shows the relationship between the initial concentration of the inorganic acid used, the pH of the aqueous phase after contact, and the back extraction rate of In(m).
Shown below.

(Left below) From Table 2, it can be seen that when the organic phase and the inorganic acid aqueous solution come into contact, H3 ions in the aqueous phase after contact occur due to an ion exchange reaction between In(m) in the organic phase and H9 ions in the inorganic acid aqueous solution. It can be seen that the concentration is decreasing (pH is increasing).

FIG. 7 shows the relationship between the pH of the aqueous phase after contact and the back extraction rate.

As is clear from FIG. 7, in the back extraction of In(III), the p)I of the aqueous phase after contact is 0.8 or less, preferably 0.6 or less when sulfuric acid is used, When hydrochloric acid is used, it is sufficient that it is 1.1 or less, preferably 1.0 or less.

As an extractant, B2PNPA was used, and an extraction solvent was prepared by dissolving it in kerosene so that the concentration of B2PNPA was 03o1/λ (approximately 25vol%). In the same manner as in Example 6, 1. Og/ffi In(III)
was carried. Next, in the same manner as in Example 6, this organic phase was brought into contact with an equal volume of hydrochloric acid to perform back extraction of In(m). Table 3 shows the relationship between the initial concentration of hydrochloric acid and the back extraction rate.

Table 3 0.24 0.49 0.97 1.94
Back extraction rate (% > 40.8 91.6 99.6 1
00 Table 3, even when using 82PNPA, the method of the present invention can remove 90% or more of In(m) with 0.5N hydrochloric acid.
) was back-extracted, and it is clear that back-extraction is possible with low-concentration hydrochloric acid.

Using Kelexloo as the extractant, Kelexlo
It was dissolved in Keronne so that the concentration of O was 25vol% and used as an extraction solvent. This extraction solvent was brought into contact with an aqueous gallium sulfate solution, and 3.1 g/4 of Ga(II) was added to the organic phase.
I) was supported. This organic phase was mixed with an equal volume of an aqueous inorganic acid solution and contacted by threading at 25°C for 2 hours to perform back extraction. Table 4 shows the relationship between the initial concentration of inorganic acid and the back extraction rate of Ga(m).

From Table 4, when sulfuric acid is used in the back extraction of Ga(I[[) from the extraction solvent using KelexlOO as the extractant, approximately 4N sulfuric acid is sufficient to extract Ga(III).
It can be seen that when hydrochloric acid is used, the back extraction rate shows the highest value when about 2N hydrochloric acid is used.

(Effects of the Invention) According to the method of the present invention, it is possible to efficiently selectively extract In ions from a metal salt aqueous solution containing In, Gas, or other metal ions. It is possible to back-extract In(III) using an aqueous acid solution. For example, it is possible to back-extract almost 100% of In(II[) using hydrochloric acid or sulfuric acid at a concentration of 2N or less. Therefore, there are fewer problems such as corrosion of the device by the inorganic acid aqueous solution.

Further, according to the method of the present invention, Ga ions can be efficiently and selectively extracted from the metal salt aqueous solution from which the In ions have been extracted. The extracted Ga ions can then be easily back-extracted.

Since all of the above back-extraction steps are performed with high yields, it is possible to use the extraction solvent repeatedly.

Thus, the method of the present invention can be applied to In(m) and Ga(I
To provide a method for easily and inexpensively separating II).

4. Figure 1 shows the daily explanation of In (m), G using B2HUPA.
Graph showing the relationship between the pH of the raffinate aqueous phase and the extraction rate when metal ions are extracted from an aqueous solution containing a(m), Fe(II), Al(III), and 2n(II) sulfates. It is.

Figure 2 shows In (m) using B2+1UPA,
Ga (IIJ), Fe (m), AI (III)
, and p+ of the raffinate aqueous phase when metal ions are extracted from an aqueous solution containing sulfate of Zn(II).
It is a graph showing the relationship between + and extraction rate.

Figure 3 shows In(LH) using B2HIIPA.
, Ga (III), and high concentrations of Fe (II)
, AI(III), and Zn(IJ) sulfates are extracted from an aqueous solution containing sulfates of Zn(IJ). FIG.

Figure 4 shows In(III) using B2PNPA.
, Ga (m), Fe (U), AI (III)
, and the pH of the raffinate aqueous phase when gold scrap ions are extracted from an aqueous solution containing sulfate of Zn(I[)
It is a graph showing the relationship between and extraction rate.

Figure 5 shows Ga(m), F using kelexlOO.
e(I1), AI(m), and Zn(I[)
It is a graph showing the relationship between the pH of the raffinate aqueous phase and the extraction rate when gold scrap ions are extracted from an aqueous solution containing a sulfate.

FIG. 6 is a graph showing the relationship between the initial concentration of inorganic acid and the back extraction rate when In(III) is back extracted from B2HUPA carrying In(III) using sulfuric acid and an aqueous hydrochloric acid solution.

FIG. 7 is a graph showing the relationship between the pH of the aqueous phase after contact and the back extraction rate when In(IIIr) is back extracted from B2HIIPA carrying In(III) using sulfuric acid and an aqueous hydrochloric acid solution. It is.

Figure 3 Figure 4 that's all Roughine-1-71 (Omega) pH (25°C) Figure 5 Raffinate wood grain pH Figure 6 100 ",.

Acid Neel Watari (N) Figure 7 Mizubume H

Claims (1)

[Claims] 1. A method for separating indium from a metal salt aqueous solution containing In(III) and Ga(III) or at least one other metal ion by a solvent extraction method, comprising: A step of selectively extracting In(III) by bringing an extraction solvent containing dialkyl phosphoric acid represented by general formula (I) as an extractant into contact with the metal salt aqueous solution; and The extraction solvent supporting In(III
) is back-extracted into the aqueous solution. ,
It has the structure ▲There are mathematical formulas, chemical formulas, tables, etc.▼, where m is an integer of 4 or more, and m+n is an integer of 8 to 20. 2. The monoalkyl phosphate represented by the following general formula (II) mixed in the extractant is 10 mol based on the total amount of the dialkyl phosphate represented by the general formula (I) and the monoalkyl phosphate. % or less: ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (II) where R^3 is R^1 or R^2 shown in the formula (I). It is similar to 3. The extraction solvent contains a monoalkyl phosphate represented by the general formula (II) at a concentration of 5 mol% or less based on the total amount of the dialkyl phosphate and the monoalkyl phosphate. The method described in 2. 4. The method of claim 1, wherein the back extractant is selected from the group consisting of hydrochloric acid, sulfuric acid, and mixtures thereof. 5. The method according to claim 1, wherein the back extractant is sulfuric acid, and the pH of the aqueous solution of the back extractant after back extraction is 0.9 or less. 6. The method according to claim 1, wherein the back extractant is hydrochloric acid, and the initial concentration of the back extractant aqueous solution is 6N or less. 7. The method according to claim 1, wherein the back extractant is hydrochloric acid, and the pH of the back extractant aqueous solution after back extraction is 1.2 or less. 8. Metal ions other than In(III) and Ga(III) contained in the metal salt aqueous solution are Fe(II), Al(
III), Zn(II). 9. At least In(III) and Ga are extracted by solvent extraction method.
(III) A method for separating indium and gallium in a metal salt aqueous solution containing
Step of separating Ga(III); The metal salt aqueous solution from which In(III) has been removed is brought into contact with an extraction solvent containing a substituted quinolinol represented by the following general formula (III) as an extractant, and Ga(III) is separated. ); and a second extraction step of selectively extracting Ga(III); and a second extraction step of selectively extracting Ga(III) by mixing and contacting the extraction solvent supporting Ga(III) with an aqueous solution containing an inorganic acid as a back-extracting agent. Separation method for indium and gallium, including a second back extraction step of back extraction into an aqueous solution: ▲Mathematical formulas, chemical formulas, tables, etc.▼(III) Here, R is 5 to 15 carbon atoms is an alkyl group or alkenyl group having 10. The method of claim 9, wherein the back extraction agent used in the second back extraction step is selected from the group consisting of hydrochloric acid, sulfuric acid, and mixtures thereof. 11. The method according to claim 9, wherein the back extractant used in the second back extraction step is sulfuric acid with a concentration of 10N or less. 12. The method according to claim 9, wherein the back-extraction agent used in the second back-extraction step is hydrochloric acid with a concentration of 1.5-3N.