JPS6161688A - Method for separating cu and/or cd and co and/or ni - Google Patents

Abstract

PURPOSE:To separate Cu and Cd, etc. by bringing an aq. soln. contg. Cu, Cd, Co and Ni into contact with an extraction solvent contg. an acidic monothio phosphoric acid compd. as an extractant. CONSTITUTION:An aq. soln. contg. Cu, Cd, Co and Ni is treated with the extraction solvent contg. an acidic monothiophosphoric acid compd. in the extraction conditions in which approximately all parts of Cu/Cd are extracted and practicably a small quantity of Co/Ni is extracted and an aq. soln. contg. the purified Co and Ni is obtained as the raffinate. Then the metal-laden solvent separated from the aqueous phase is brought into contact with an aq. soln. contg. comparatively low-concn. mineral acid in the selected pH. In this case, Co and Ni are transferred to the aqueous phase from the organic phase and the aq. soln. contg. the obtained Co and Ni is circulated to an extraction process.

Description

Detailed Description of the Invention (Technical Field) The present invention provides at least Cd(n) and/or Cu
(II) and Co(II) and/or N1(If
) by treating an aqueous solution containing Cd (
TI) and/or Cu(If) and Co(II)
and/or N1(If).

(Conventional technology) A mixture containing Cd, Cu, Co, Ni, etc.

It is ordered as by-products in metal smelting, such as precipitates in the liquid purification process of zinc hydrometallurgy, and as industrial waste, such as nickel and cadmium waste batteries. Effective separation and recovery of these metals is being considered from the viewpoint of resource recovery and pollution prevention.

Generally, these wastes are first dissolved in mineral acids.

An aqueous solution containing each metal ion is prepared. This aqueous solution is then subjected to a cementation method, a solvent extraction method, or the like to separate and recover each metal ion. However, these conventional separation methods cannot efficiently separate Cd or Cu from Co or Ni. For example, the cementation method uses Cd(II), Cu(U)
, N1(II), Co(II), etc., and by utilizing the difference in ionization tendency, metal ions other than Cd(II) and total diagonal zinc are converted into Cd. This method separates metals other than those by precipitation.

In this cementation method, Cu from Cd(II) is
Although the separation of (I[) is good, N1(n) and C.

Complete removal of (n) requires a long time, and the resulting Ni and Co precipitates are contaminated by coprecipitation of Cd, which is a fatal drawback. moreover.

Since Zn(II) ions are also mixed into the obtained Cd(II) aqueous solution, a further operation for separating Cd and Zn is required. Furthermore, since this cementation method involves a solid-liquid separation operation, it is inevitable that the operation will be complicated and inefficient.

On the other hand, a solvent extraction method uses di-2-ethylhexyl HM (D2EIII'A) as an extractant. In this method 9 e.g. Cd, Cu, Co and Ni
When an aqueous solution containing C and an organic solvent containing an extractant are brought into contact, cd, Cu, and C are sequentially extracted by selecting one extraction condition (PL+condition at the time of contact).

and Ni are extracted. Therefore, the separation of Cd and/or Cu from CO and/or Ni is carried out under strict p)l selective conditions, extracting the Cd and/or Cu into the organic phase and raffinate the aqueous phase. It is done to leave CO and/or Ni in. However, under extraction conditions that effectively recover Cd and/or Cu, it is inevitable that some Co and/or Ni will also be extracted.
Separation between these metals is insufficient if the extraction operation is performed only once.In order to achieve sufficient separation, a washing process is provided in addition to the extraction process, and multiple liquid-liquid contact devices are used for each. Therefore, it is conceivable to adopt a method of bringing the organic phase and the aqueous phase into countercurrent contact.

This requires a large extraction device T, which requires investment in equipment and running costs. The disadvantage of this conventional solvent extraction method is that one extractant, di-2-ethylhexyl = a
This is due to the insufficient extraction and separation ability of Co and/or Ni from Cd and/or Cu. Therefore, in order to overcome these drawbacks and adopt an efficient solvent extraction method, it is necessary to use Cd and/or Cu.
and Co and/or Ni (N
Therefore, the development of a unique extractant is required.

(Objective of the Invention) The present invention provides an extraction method for extracting Cd and/or Cu with CO and/or Ni. By vehicle extraction method, Cd and/or C
The object of the present invention is to provide a method for separating u from CO and/or Ni.

(Structure of the Invention) The separation method of the present invention includes an aqueous solution containing at least a metal salt of copper and/or cadmium and cobalt and/or nickel, using an acidic monothiophosphoric acid compound represented by the following general formula as an extractant. 5. Contact with the extraction solvent containing or the solid impregnated with it.
This achieves the above objective.

(Margin below) Here, one of A and B is an oxygen atom.

and the other is a sulfur atom; R1 and Rt are each a substituted or unsubstituted alkyl or cycloalkyl bonded to the P atom directly or via an oxygen atom.

Aryl, alkylaryl or allylalkyl group:
and R1 and R2 are the same or different.

The sum of the carbon numbers of R8 and Rt is 9 or more. It is said that such extractants can exist as tautomers as described below.

(Left below) (I) (If) R1
and R2 preferably have a total carbon number of 9 or more and 36 or less. When the total carbon number is less than 9, the extractant becomes soluble in water, and when it exceeds 36, the metal loading capacity of the extractant becomes small.

In addition, Rt and R2 are 2-ethylhexyl group, isooctyl group,
Preferably, it is an alkyl group such as a 1-methylheptyl group, an octyl group, or an isodecyl group.

As an extractant that satisfies such conditions, there is a 0,0"-dialkylmonothiophosphoric acid compound. In particular.

(1?0) What is represented by the chemical formula zpsoo can be used. Examples include bis(2-ethylhexyl)monothiophosphoric acid, di-isooctylmonothiophosphoric acid,
Bis(1-methylheptyl)monothiophosphoric acid.

These include di-octyl monothiophosphoric acid, bis(3,5,5-trimethylhexyl) monothiophosphoric acid, and di-isodecyl monothiophosphoric acid. These compounds are.

(RO) zPsc] was prepared by reaction of H sulfide (PSCI) with an alcohol having the corresponding alkyl.

It can be obtained by hydrolyzing this. or,
In the presence of triethylamine or a polar solvent (R
O) It can also be obtained by subjecting zPOIl to an addition reaction with sulfur to prepare an amine salt of the target product, and metathesizing this with an acid.

The method of carrying out the present invention is as follows: 1. It is possible to set up a circuit for extraction, washing, and back extraction in the same way as in the usual solvent extraction method.
No particular use of this invention.

The above general formula used > Extractant represented by PSOH and R: The metal extraction reaction is mainly an ion exchange reaction between the acidic 5H'' of the extractant and the metal ion or complex cation of the gold mud.

Therefore, basic 1! selection of various conditions in the solvent extraction method of the present invention! ! Ideally, di-2-ethylhexyl phosphate or 2-ethylhexylphosphonic acid mono-
It is similar or similar to the conventional solvent extraction method using 2-ethylhexyl ester. In other words, metal extraction, cleaning,
The back extraction reaction is controlled by pH buffering.

The extraction order of the extractant of the present invention for various metal ions is C.
u(■) >Cd(n) >Pb(II) >Fe(I
II) Zn(n) AI(I[[) Ca(If) >
Co(If) Mn(II) Mg(II) Ni(■
).

The extraction order of the metals above indicates that the metal ions classified on the left are more easily extracted than the metal ions classified on the right.When the pH at the time of extraction is low (when the H″ concentration is high), Groups are first extracted, and as the pH increases, cloth groups are extracted one after another.

By a solvent extraction method using the extractant of the invention.

The basic method for separating Cd and Cu from CO and Ni is as follows.

(11Cu(n) and/or Cd(n) and Co(
In the extraction step in which an aqueous solution containing C.

The aqueous solution containing purified CO and/or Ni is raffinated by selecting and processing extraction conditions (mainly the depth of the aqueous phase during extraction) that extracts Ni as little as possible. get as. The metal-loaded solvent separated from the aqueous phase is then separated from the co-extracted Co and/or
Or, if necessary, provide a cleaning step to remove Ni.

An aqueous solution containing a mineral acid at a relatively low depth and a selected pH (H
At this time, Co and/or Ni are transferred from the organic phase to the aqueous phase. The resulting Co and/or Ni-containing aqueous solution can be subjected to an extraction step. The metal-loaded solvent is contacted with a relatively high concentration of mineral acid in a back-extraction step under conditions of <pH (H) concentration based on the back reaction during extraction.
These metals are recovered in the back extraction aqueous phase. The amphoteric extraction solvent is recycled to the extraction process.

(2) Also, Co and/or Ni in the raw material aqueous solution
When the content of Co and/or Ni is low5 or when metal ions that are more difficult to extract than Co and Ni are present, a method can be adopted in which most of Co and/or Ni is extracted along with Cu and/or Cd in the extraction step. . In this case.

Co and Ni are purified and recovered by controlling the contact p++ in the washing step.

Although the extraction solvent used in the present invention can be used alone, it is generally diluted with an organic diluent to facilitate phase separation between the organic phase and the aqueous phase after liquid-liquid contact operation. It is preferable to use

The organic diluent may be one that dissolves the extractant, is insoluble in water, and does not interfere with the function of the extractant during extraction. These include paraffinic hydrocarbons, naphthenic hydrocarbons, aromatic hydrocarbons, and their halogen-substituted compounds. In particular, petroleum distillates such as kerosene or naphtha,
Toluene and carbon tetrachloride are preferred, but are not limited thereto.

The extractant concentration in the extraction solvent is determined by the aqueous solution to be extracted (
Concentration of the target metal to be extracted in the stock solution) and.

Although it is also determined in relation to the phase ratio of organic phase and aqueous phase.

Generally 1 to 60% by volume of extractant, preferably 1 to 3%
0% by volume is adopted.

Modifiers can also be added to the extraction solvent to prevent it from forming emulsions and promote phase separation, or to increase the solubility of the extracted metal complexes in the organic phase. It is. Examples of modifiers include phosphorus compounds such as tributyl phosphate, dibutyl butylphosphonate, di-2-ethylhexyl phosphoric acid, and trioctylphosphine oxide; higher alcohols such as isodecanol; higher carboxylic acids; higher ethers; There are ketones.

The use of these modifiers has the above-mentioned effect of improving phase separation and the effect of acting as a diluent. At the same time, Cu
For example, it has the favorable effect of increasing the extraction pH range for gold such as Cd, and allowing the use of low-cooperation mineral acids when back-extracting gold.

To facilitate back extraction of Cu and Cd.

The effect of adding compounds such as tributyl phosphate and trioctylphosphine oxide is significant.

Although the amount added can vary over a wide range, it is usually used in an amount of 1 to 3 times the amount of the extractant.

The reaction of bringing the above-mentioned extraction solvent used in the present invention into contact with an aqueous solution containing gold mud ions to extract metal ions is the same as the extraction reaction using conventional extraction solvents, as described above.
It is important to select the pH during extraction because it is controlled by the buffering effect of 1m°H.

Therefore, in order to sufficiently extract Cu and Cd, the concentration of hydrochloric acid during extraction should be 3.5 times the standard or less.

Preferably, it is selected to be 2.5 times or less. and.

As the hydrochloric acid concentration during extraction is decreased (pH is increased), subsequent extraction of Cu and Cd is followed by subsequent extraction of metal ions such as CO and Ni.

The upper limit of pH is limited by the formation of precipitates and deterioration of phase separation, and is usually 0, p)! 6.5 or less is appropriate.
On the other hand, in the case of extraction from an aqueous sulfuric acid solution, the sulfuric acid concentration is 6N.
Not only in the following, but also in 6N and above, Cu and Cd
Extract sufficiently. When performing multi-stage countercurrent extraction, the H"9i degree of the contacting aqueous phase in the four major stages of the aqueous phase (raw material aqueous solution) should be controlled to be greater than the H" concentration of the contacting aqueous phase in the organic phase introduction stage. Accordingly, Cu and Cd can be maximally extracted from the aqueous phase in the phase conductor stage, and at the same time, Co and Ni can be transferred from the organic phase to the aqueous phase in the aqueous phase introduction stage. By doing this, Cu and C
The separation effect and recovery rate of d from Co and Ni can be improved.

The optimum pi (or optimum W, acid concentration) at this time can be easily determined depending on the ratio and concentration of Cu and Cd to Co and Ni in the raw material water.

The pH or mineral acid concentration during extraction can be controlled by
Organic phase (extraction solvent) or aqueous phase (raw material aqueous solution)
This can be carried out by adding and mixing an alkali or mineral acid as appropriate. Furthermore, if necessary, an alkali or mineral acid may be added during the contact between the organic phase and the aqueous phase. As an alkali.

There is no need to be specific, and examples include those containing ammonium ions, alkaline earth metal ions, etc., their hydroxides, oxides, carbonates, and aqueous solutions thereof. Specifically, ammonia, caustic soda; soda carbonate, calcium hydroxide, etc. Hydroxides, oxides, and carbonates having metal ions at a later extraction rank than the metal to be extracted may also be used.

To control the pH, the acidity of the extractant in the extraction solvent
It is also possible to use (H") in advance in a suitable proportion as an alkali or as a salt of a metal ion that is in a later extraction order than the metal to be extracted.

The volume ratio (0/A) of the extraction solvent (organic phase) and raw material aqueous solution (aqueous phase) that come into contact in the extraction step can vary over a wide range. The most effective volume ratio is related to the concentration of the extractant in the extraction solvent, the concentration of the target metal to be extracted in the raw material aqueous solution, as well as the operation and mounting style, and is not particularly limited, but is preferably is 20/1~1/20
．． In particular, it is 5/1 to 115. This ratio is generally set to achieve total incorporation of the extractive metal into the organic phase used.

In order to remove and recover Co and Ni in the organic phase obtained in the extraction step, it is possible to provide a washing step between the extraction step and the back extraction step. In the washing step, it is preferable to use an aqueous solution containing mineral acid and/or an extraction metal such as Cd as a washing liquid through the same ion exchange reaction and procedure as in the extraction step. If the concentration of mineral acid is selected within an appropriate range, C
It is possible to remove Go and Ni even if they contain metal ions after the extraction target metals such as O and Ni. An aqueous raw material solution (before treatment) can also be used as a cleaning liquid. In the cleaning process, the organic phase and the aqueous phase are brought into multi-stage countercurrent contact to increase the effectiveness and efficiency of removing Co and Ni, and to reduce the loss of Cu and Cd to the cleaning solution. can increase the purity of Contact between organic and aqueous phases during the washing process (when the aqueous phase)
The pH (H'' concentration is usually selected in the range of 6N to pH 4. However, when using a cleaning solution containing hydrochloric acid, the concentration should be 4N or less to prevent loss of Cd to the cleaning aqueous phase. When a wash solution containing sulfuric acid is used, the loss of Cd to the wash water phase is reduced, and the recovery efficiency of Co and Ni is also increased compared to when a wash solution containing hydrochloric acid is used.

Also, in the cleaning process. Contact ratio between organic phase and aqueous phase (0/
A) can be set over a wide range, but in an industrial setting it is set within a small range 1, for example 0.5.
The range of 5 to 5 is preferable.

The organic phase containing at least one of Cd and Cu obtained through the above extraction step or washing step is subjected to back extraction treatment to recover these metals. Back extraction is generally performed with an aqueous solution containing a mineral acid such as hydrochloric acid or sulfuric acid, and the metal ions in the organic phase are ion-exchanged with H of the mineral acid, and the salt of the mineral acid used in the back extraction solution is removed. It is recovered either as a precipitate or as an aqueous solution. Furthermore, alkali and/or
Alternatively, the metal can be removed and recovered from the organic phase by using antimony hydrogen fluoride or the like.

When performing back extraction using mineral acids, the organic and aqueous phases (
Optimal H'' lacquer degree of the aqueous phase when in contact with mineral acids).

For example, it varies depending on the type of mineral acid, the concentration of the extractant in the extraction solvent, the presence or absence of a modifier in the extraction solvent, etc.

Back extraction is possible using hydrochloric acid at a lower normal concentration than when using sulfuric acid. Hydrochloric acid is therefore preferred over sulfuric acid. Hydrochloric acid can also be advantageously used in the back-extraction step if contact with aqueous sulfate solutions takes place in the extraction and washing steps. When hydrochloric acid is used and no modifier is added to the extraction solvent, the concentration of hydrochloric acid in the aqueous phase at the time of contact required for back extraction is usually 9.
For back extraction of Cd, 3.5 normal or higher is selected, and for Cu, 6 normal or higher is selected. Furthermore, when a modifier is added to the extraction solvent, back extraction is possible even at lower hydrochloric acid concentrations. When sulfuric acid is used and no modifier is added to the extraction solvent, Cu and Cd present in an amount of 2 equivalents or more relative to the extractant in the organic phase will be removed by sulfuric acid at a low concentration. However, it is difficult to sufficiently back-extract Cu and Cd of less than 2 equivalents.

However, if the modifier is added in an equivalent molar amount or more to the extractant, back extraction becomes possible.

Furthermore, when nitric acid is used for back extraction, it can be carried out at a lower specified concentration than hydrochloric acid. However, there is a limit to the repeated use of the extraction solvent because it involves deterioration of the extractant.

In addition, when a mixture of Pb, Cd, Cu, etc. is present in the organic phase, the back extraction process is divided into several stages.

It is also possible to separate and recover each metal by adjusting the mineral acid concentration of the contact aqueous phase in each back extraction step or by changing the back extraction means such as the type of mineral acid.

In the extraction, washing, and back-extraction steps of the present invention, the temperature at which liquid-liquid contact and phase separation are performed is not critical. On the other hand, lower temperatures are better in relation to the flash point of the diluent (organic solvent) and the stability of the extractant. Generally, the temperature is maintained at 20 to 70°C.

In addition, the operations and methods of each stage of (metal) extraction, washing, and back-extraction in the present invention can be carried out by any well-known procedure using any apparatus used in liquid-liquid extraction. For example, it is common to use a multi-stage extractor with countercurrent i! I! Sequential contact methods are preferred, but co-current, batch, or circulation methods are also acceptable.

Furthermore, the present invention utilizes an emulsion-type liquid fat extraction method in which a W10/W type emulsion is formed between an aqueous raw material solution, an extraction solvent, and a back extraction solution (mineral acid), and extraction and back extraction are performed simultaneously, or a continuous porous plate (perforated A fixed membrane type liquid membrane extraction method in which an organic or inorganic porous plate (with an organic or inorganic porous plate) is impregnated with an extraction solvent, and the raw material aqueous solution and back-extracted mineral acid are brought into contact with each other on both sides, or an extraction solvent is applied to an inert porous body. It goes without saying that this can also be carried out by impregnating and supporting the material and alternately flowing the acid into the raw material aqueous solution and back extraction.

(Margin below) (Example) The present invention will be described below with reference to Examples.

Cu(II), Cd(II) of the extractant of the present invention
, Pb(If).

Zn(II), Fe(TI[), Co(II)
) and N1(II), the following extraction experiment was conducted to clarify the extraction separation ability regarding N1(II).

Extractant: (RO) Paraffinic hydrocarbon (trade name Shell Zoll 71
(manufactured by Nigel Chemical Co., Ltd.), and extraction was performed by contacting this with an aqueous solution containing chlorides of each metal.

Extraction pH 2. Adjustment of pH or hydrochloric acid concentration during extraction.

This was carried out by adding aqueous ammonia to the organic phase to convert the acidic groups of the extractant into ammonium salts in advance at a fixed ratio, or by pre-existing a fixed concentration of hydrochloric acid in the synthetic salt aqueous solution.

Ratio of organic phase to aqueous phase: The ratio of organic phase to aqueous phase (0/A) is l:
1 was adopted.

Metal ion concentration The initial concentration of dimetal ions is Cu.

Cd, Zn, Fe, Co and Ni each 1 g/l; pb
is 0.5g/l: And the initial total concentration of metal ions is 6.5g#! The organic phase and the aqueous phase were brought into contact so that

Extraction procedure: Contacting was carried out by shaking for 20 minutes in an Ehrlenmeyer flask at 25°C.

The relationship between the pH or hydrochloric acid concentration of the aqueous phase at extraction equilibrium and the extraction percentage of each metal is shown in Figure 1 (A) and (B).
Figure (A) shows the hydrochloric acid concentration in the raffinate aqueous phase and the extraction rate of each metal, and Figure 1 (B) shows the region of low hydrochloric acid concentration in the raffinate aqueous phase in Figure 1 (A) relative to the pH of the raffinate aqueous phase. Figure 1 (A) and (B) show the extraction rate of each metal as the concentration of hydrochloric acid in the aqueous phase at the time of contact decreases.

It is shown that Cu, Cd, Pb, Fe, Zn, Co and Ni are extracted in sequence. For example, in the case of raffinate hydrochloric acid concentration IN, Cu.

Cd and pb were each extracted 100%, and F
60% of e and 30% of Zn are extracted. On the other hand, C.

and Ni are hardly extracted, although the hydrochloric acid concentration in the raffinate aqueous phase has increased from the initial concentration by approximately the same amount as the ffi concentration of the extracted metals.

This is the H or N of the extracted metal cation and extractant.
i1. ” indicates that an ion exchange reaction occurred.

Toma A4 student L Cu(n) using the same extractant as in Example 1.

Zn(II), Co(II) and N1(I
Extraction tests of these metals from aqueous sulfate solutions containing I) were carried out.

0.5 mol of di-2-ethylhexyl monothiophosphoric acid
/7! (approximately 18% by volume) in a naphthenic hydrocarbon solvent (trade name: Dispersol; Shell Chemical Co., Ltd.), and mixed this with an aqueous solution containing the sulfate of each metal.
Shaking contact was carried out for 20 minutes at 0°C.

The ratio of organic phase to aqueous solution (0/A) is 1:1; and the initial concentration of metal ions is 2.5 g/6, respectively (total concentration L
og/j2). The pt+ or sulfuric acid concentration during extraction was adjusted in the same manner as in Example 1 by adding aqueous ammonia and sulfuric acid.

Table 1 shows the relationship between the sulfuric acid concentration or pH of the aqueous phase at extraction equilibrium and the extraction rate of each metal.
Table 1 shows a comparative example in which di-2-ethylhexyl phosphoric acid (02EHPA) was used in place of -ethylhexyl monothiophosphoric acid.

Table 1 As is clear from Table 1, the extractants of the present invention are:

Compared to conventional extractants, the separation performance of Cd, Co, and Ni is significantly superior. Also, separately.

When an attempt was made to extract from an aqueous solution containing the same amount of Cu(II) instead of Cd(II), almost the same extraction results as for Cd in Table 1 were obtained.

The metal extraction characteristics when using the extractants of the present invention with various R of zPsOFI were investigated.

R is an n-octyl group, a l-methylheptyl group,
The same extraction conditions as in Example 2 were employed except that the extractants, 3,5,5-trimethyl group and isodecyl group, were each dissolved in dispersol to form a 0.5M solution. The result is.

No matter which extraction agent was used, the same tendency as in Example 2 when di-2-ethylhexylmonothiophosphoric acid was used was obtained. That is, Zn(II).

Cd(II) was preferentially extracted from Co(n) and N1(II). There was also no significant difference in the relationship between the sulfuric acid concentration or pH of the aqueous phase during extraction and the extraction rate of each metal. As an example, the extraction results when R is an isodecyl group are shown in Table 2.

Table 2 Extracting agent R of the present invention, metal extraction characteristics were investigated when R of PSO) I was directly bonded to the phosphorus CP) atom without intervening oxygen.

As an extractant, di-octylmonothiophosphinic acid, in which R is an octyl group, was dissolved in a paraffin hydrocarbon solvent to a concentration of 0.5 rsol/12.

This is converted into Cd(n), Co(II) and N1(I
It was brought into contact with an aqueous solution containing the sulfate of I) at 25° C. for 20 minutes with shaking. The initial concentration of metal ions is 10 g/j of Cd.
! ,C.

and Ni were each 5 g/f. Other extraction conditions and original procedures were the same as in Example 2. The sulfuric acid concentration or pH of the aqueous phase at extraction equilibrium and the extraction rate of each metal are
Shown in the table.

Table 3 From Table 3 1 The extractant of this example, di-octyl monothiophosphinic acid, as well as di-2-ethylhexyl monothiophosphoric acid, has a remarkable ability to extract and separate Cd from Co and Ni. I understand that. Similar results were obtained in another extraction experiment using an aqueous sulfate solution containing the same amount of Cu(U) instead of Cd(ff).

A cleaning study was conducted to remove Co and Ni from the organic phase containing Co(■) and N1(II) extracted simultaneously with 11 IL Cu(II) and Cd(TI).

Di-2-ethylhexylmonothiophosphoric acid 0.5 mol/
Paraffinic hydrocarbon (Schelsol 71) solution of E and Cd(II), Co(II) and N1(I)
I) with an aqueous sulfate solution of Cd 20.9
g/j! , Co 2.62J! /l and NiO
, 484get was extracted to prepare the organic phase containing it.

This organic phase was brought into mixed contact with sulfuric acid or hydrochloric acid having various Mi concentrations, and the effect of removing CO and Ni in the organic phase was investigated.

The volume ratio of organic phase to aqueous phase (0/A> during washing was 1:1. The time of mixing contact was 20 minutes, and the temperature was 25°C.

Table 4 shows the test results when cleaning with sulfuric acid, and Table 5 shows the test results when cleaning with hydrochloric acid. However, the cleaning rate was calculated using the following formula.

Here, C+ is gold J7E 78 degrees in the aqueous phase after washing.

5C2 is the metal concentration in the organic phase after washing.

(The following is a blank space) As is clear from Tables 4 and 5, Co and Ni can be effectively removed from the organic phase by appropriately adjusting the mineral acid concentration during washing. For example, 0.15N
Using (regular) sulfuric or hydrochloric acid, most of the Co and Ni are removed from the organic phase at a pH of about 2.5, and only 6-8% of the Cd is lost as it elutes into the wash aqueous phase. Ta.

In addition, another cleaning test revealed that even when Cu was contained in the organic phase instead of Cd, Co and Ni were removed by cleaning at a rate that was almost the same as the above-mentioned removal rate. In this case, the elution (loss) of Cu into the wash water phase is C
It was less than in case d.

1. A back extraction test of Cd was conducted from the cultivation phase a from which Cd (ff) was extracted.

Di-2-ethylhexylmonothiophosphoric acid 0.5 mol/
Cd (
(2) Back extraction of Cd was carried out by shaking and contacting 12.7 g of the extracted organic phase with hydrochloric acid. 0
/A is 1. The contact time was 5 minutes and the temperature was 25°C. Back extraction was carried out by repeated contact with 4.5N or 6N hydrochloric acid each time using fresh water. The result is the 6th
The back extraction rate shown in the table is calculated using the following formula.

to 1 Here, CI is the initial concentration of Cd in the organic phase.

C2 is the Cd concentration in the organic phase.

(Left below) Table 6 From Table 6, when using hydrochloric acid of 4.5N or more, Cd (■)
can be back-extracted from the organic phase.

5.51 A test for back extraction of Cu was conducted from the organic phase from which Cu(II) was extracted.

Di-2-ethylhexylmonothiophosphoric acid 0.5 mol/
l of n-dodecane? 9.9 g of Cu(II) in the skin
The back extraction of Cu was carried out by shaking and contacting the organic phase with 6N hydrochloric acid after extracting the EL. 0/
A is 1. The shaking contact time was 1 hour and the temperature was 25°C.
Met. Table 7 shows the back-extraction results for repeated contact using fresh hydrochloric acid each time.

In this way, by repeating the back extraction several times using 6N hydrochloric acid, Cu(■) can be recovered from the organic phase.

Table 7 Cu when a modifier is added to the extractant of the present invention,
In order to clarify the extraction separation ability of Cd, Zn, Co and Ni, the following extraction experiment was conducted.

Di-2-ethylhexylmonothiophosphoric acid as an extractant and tributyl phosphate (TBP) as a modifier were each diluted and dissolved in Dipersol to a concentration of Q, 5 mol/(!). ,
It was brought into contact with an aqueous solution containing sulfates of Cd(II), Zn(II), Co(n) and Ni(■) at 50° C. for 20 minutes with shaking. The ratio of the observed phase to the aqueous phase (0/A)
is 1. The initial concentration of metal ions is 2g/I, respectively.
The pH or sulfuric acid concentration during extraction was adjusted as in Example 2, with a total concentration of 10 g/E.

Table 8 shows the relationship between the sulfuric acid concentration or pH of the aqueous phase at extraction equilibrium and the extraction rate of each metal.

In this way, even if a modifier is added, Cu and Cd
It can be seen that the extraction separation ability between Cu and Ni is sufficiently large.For example, at pH 2.1, Cu is 1
00% of Cd was extracted, and 99.9% of Cd was extracted, whereas only 0.1% of Co and 0.0% of Ni were extracted.

(The following is a margin) 5 m When a modifier is added to the extractant of the present invention, Cu (
A test was conducted to back-extract Cu from the organic phase from which U ) was extracted.

Di-2-ethylhexyl monothiophosphoric acid 0.5n+ol
/l and tributyl phosphate) 0.5a+ol/
j! Cu(n) in a paraffinic hydrocarbon solution containing
The sample containing 1.04 g/l was brought into contact with an equal volume of hydrochloric acid for back extraction. Contact time was 30 minutes and temperature was 25°C. Back extraction was carried out by repeated contact with 3N or 6N hydrochloric acid, each freshly brewed each time.

The results are shown in Table 9.

Table 9 As shown, almost all of the Cu was back-extracted by just 2 to 3 times of contact with 6N hydrochloric acid.

Comparing this result with the results of Example 7 (Table 7), we find that
It is clear that the addition of modifiers renders the back extraction acceptable.

Cd (
A back extraction test of Cd with sulfuric acid was performed from the extracted [5 phases].

Di-2-ethylhexylmonothiophosphoric acid 0.5 mol/
E and tributyl phosphate 0.75RI01/
Cd(If) in a paraffinic hydrocarbon solution containing l
2.02g/l.

Fe(n[) 2.33g/l and Pb(n)
2.8mg/ji! Extract and sonicate: f Mechanism Back extraction was performed by contacting with an equal volume of sulfuric acid aqueous solution. The contact time was 1 hour and the temperature was 25°C. The results obtained when the observation phase was brought into contact once with sulfuric acid aqueous solutions of various concentrations are shown in the 10th table.
Shown in the table.

Table 10 As is clear from Table 10, by adding a modifier, Cd can be back-extracted from the organic phase even with sulfuric acid at a low concentration of 5N or less.

In order to clarify the extraction and separation ability of various metal ions when a larger amount of modifier is added to the extractant of the present invention,
The following extraction experiment was conducted.

Di-2-ethylhexylmonothiophosphoric acid 0 as extractant
．． 5a+of/jl! and tributyl phosphate as a modifier were diluted and dissolved in paraffin hydrocarbon to a concentration of 1.0 mol/1, and this was added to Cd(U).
), Zn(I[), Co(n) and N1(II) sulfates were brought into contact with an aqueous solution containing sulfates at 25° C. for 20 minutes with shaking. The ratio of organic phase to aqueous phase (0/A) is 1. The initial concentration of metal ions is 2g/l<total concentration 8g/jl, respectively.
It was ri. The pH or sulfuric acid concentration during extraction was adjusted in the same manner as in Example 2. Table 11 shows the relationship between the sulfuric acid concentration or pH of the aqueous phase at extraction equilibrium and the extraction rate of each metal.

As is clear from Table 11, even when the modifier is used at twice the molar concentration of the extractant, the ability to extract and separate Cd from Co and Ni is sufficiently excellent.

Table 11 (Effects of the Invention) According to the method of the present invention, as described above, by using an acidic monothiophosphoric acid compound as an extractant.

Efficiently extracts and removes Cd and/or Cu and CO and/or Ni from an aqueous solution containing at least a metal salt of Cd and/or Cu and CO and/or Ni, and also extracts these metals and removes the loaded metals. The extractant of the present invention can efficiently separate Cd and/or Cu from Co and/or Ni by back extraction from the phase observation. There is also the advantage that back extraction efficiency is improved.

4. 7. of the drawing. Figures 1 (A) and CB) show the relationship between the hydrochloric acid concentration in the aqueous phase and the pH of the aqueous phase at extraction equilibrium, respectively, and the extraction percentage of each metal.

that's all

Claims (1)

[Scope of Claims] 1. An aqueous solution containing at least a metal salt of copper and/or cadmium and cobalt and/or nickel using an extraction solvent containing an acidic monothiophosphoric acid compound represented by the following general formula as an extractant or A method for separating copper and/or cadmium from cobalt and/or nickel comprising contacting the same with an impregnated solid. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ Here, one of A and B is an oxygen atom and the other is a sulfur atom; R_1 and R_2 are each a substituted or Unsubstituted alkyl, cycloalkyl, aryl, alkylaryl or arylalkyl group: and R_1
and R_2 are the same or different, R_1 and R_2
The sum of the carbon numbers is 9 or more. 2. Claim 1, wherein the aqueous solution containing at least a metal salt of copper and/or cadmium and cobalt and/or nickel is brought into contact with the extraction solvent to extract copper and/or cadmium from the aqueous solution. Method described. 3. The method according to claim 1 or 2, wherein the extractant is O,O'-dialkylmonothiophosphoric acid.