JP3479677B2 - Method for selectively recovering copper ions from alkaline solution - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for selectively recovering copper ions from a solution having a pH of more than 2.5.

[0002]

2. Description of the Related Art Currently, LIX65N is used for industrial wet refining of copper.
Alkyl derivatives of hydroxy oxime such as LIX860 and Acorga P series are used, but these extractants separate each metal ion by the difference of adsorption pH by the metal.

However, at high pH, all the metals are extracted, so that it becomes impossible to express the selectivity for copper. Especially in the extraction of copper from an aqueous ammoniacal solution, the selectivity for copper is reduced. For example, in the wet refining of copper ore, copper must be recovered from the ammonia leaching solution, but in this case, the conventional extractant has a low selectivity for copper and cannot be effectively wet-refined in copper. I have a problem.

[0004]

The present invention has been made to overcome such drawbacks existing in the prior art, and is a solution having a pH of more than 2.5, preferably an alkaline solution, more preferably an aqueous ammonia solution. It is an object of the present invention to provide a method for selectively recovering copper ions from water.

[0005]

[0006]

In order to solve the above problems, the present invention has the following structure:

[Chemical 2] (Wherein R ₁ is a C _{1 to} C ₁₂ linear or branched alkyl group, R ₂ is a C _{1 to} C ₁₂ linear or branched alkyl group or a phenyl group), pH 2. A method for selectively recovering copper ions from a solution of more than 5, (1) the solution containing copper ions, the step of adding the compound to form a chelate compound of copper, (2) the above There is provided a method comprising the steps of recovering the copper chelate compound from a solution, and (3) releasing copper ions from the recovered copper chelate compound.

(Wherein R ₁ is a C _{1 to} C ₁₂ linear or branched alkyl group, and R ₂ is a C _{1 to} C ₁₂ linear or branched alkyl group or a phenyl group). Provide a copper chelating agent.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below.

Example 1 In this example, the following structure:

[Chemical 3]

(Where R ₁ = octyl group, R ₂ = phenyl group)
A method for selectively recovering copper using a compound having 2- (4-hydroxy-4-n-octyloxybenzophenone oxime) is described.

In this example, all extraction experiments were carried out by the batch method.

The aqueous phase is a 1 mol / dm ³ ammonium nitrate solution and contains each metal ion in a concentration of 1 mmol / dm ³ . The pH of the aqueous phase was adjusted with nitric acid and ammonia.

The organic phase is 0.01 mol / dm ³ of 2-hydroxy-4-
It is a toluene solution of n-octyloxybenzophenone oxime.

Equivalent amounts of each phase were placed in an Erlenmeyer flask and kept at 30 ° C.
It was shaken for 24 hours. After shaking, the aqueous phase was separated, the concentration of each metal remaining in the aqueous phase was measured by an atomic absorption spectrophotometer, and the extraction rate was calculated using the following formula.

E = (C ₀ −C _e ) × 100 / C ₀ [%] (where C ₀ is the initial concentration of metal ion and C _e is the concentration after equilibration). Shown in 1.

As is clear from FIG. 1, in the pH range of 2 or more, the extraction rate of Cu ²⁺ reached almost 100%, but Ag ⁺ , P
The extraction rates of d ²⁺ , Ni ²⁺ , Fe ³⁺ , Cd ²⁺ and Cr ³⁺ were almost 0%.

From this example, the compound of this example was adjusted to pH 2
It has been demonstrated that copper ions can be extracted in a very specific range over a wide range of ~ 10.

Example 2 In this example, the effect of ammonia concentration on the extraction rate of copper was investigated.

2-hydroxy-4-n-octyloxybenzophenone oxime 0.01 mol / dm ³ in toluene, 1 mmol
/ dm ³ of an aqueous ammonia 0.05 to 1 mol / dm ³ containing each metal ion concentration taken in equal amounts, and shaken for 24 hours in a thermostat at 30 ° C..

The results of extraction of each metal are shown in FIG. As is clear from FIG. 2, in the low ammonia concentration range up to 0.5 mol / dm ³ , only 100% of copper can be extracted and other metals are hardly extracted.

From this example, it was revealed that the copper chelating agent of this example can be used as an extractant capable of selectively extracting copper ions from an ammonia solution in wet scouring of copper.

In this example, a back-extraction experiment was carried out using a toluene solution of 2-hydroxy-4-n-octyloxybenzophenone oxime (0.01 mol / dm ³ ) containing 98 ppm, 54 ppm and 5 ppm of copper, respectively. went. As a back extractor,
2 mol / dm ³ sulfuric acid was used.

The results are shown in the table below.

[Table 1]

As is apparent from the table, 2-hydroxy-4-n
-Octyloxybenzophenone oxime can be almost 100% back-extracted by using dilute acid, despite having very good selectivity for copper. Such properties are extremely useful for copper recovery.

[0025]

Industrial Applicability According to the method of the present invention, copper ions can be extremely selectively recovered from a solution having a pH of more than 2.5, especially an alkaline solution.

Therefore, the method of the present invention can be used to selectively extract copper ions from an ammonia solution, and can be applied to wet scouring of copper.

Further, the copper chelate compound used in the method of the present invention can release copper ions into an aqueous solution by back extraction although it has high copper selectivity.

[Brief description of drawings]

FIG. 1 shows the copper selectivity of the method of the present invention.

FIG. 2 is a graph showing the relationship between the extraction rate of copper by the copper chelate compound used in the method of the present invention and the ammonia concentration.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-49-132025 (JP, A) Kompleksn. Ispol 'z. Miner. Syr'ya, 1984, 7, p. 76-81 (58) Fields investigated (Int.Cl. ⁷ , DB name) C07K 3/00 C02F 1/62 CA (STN) REGISTRY (STN)

Claims (7)

(57) [Claims] 1. The following structure: embedded image (Here, R ₁ is a C ₁ -C ₁₂ straight-chain or branched alkyl group,
R ₂ is a phenyl group) -containing compound having a pH of 2.5, and is a method of selectively recovering copper ions, wherein (1) the solution containing copper ions is added with the compound. To form a copper chelate compound, (2) recovering the copper chelate compound from the solution, and (3) releasing copper ions from the recovered copper chelate compound. 2. The method according to claim 1, wherein R ¹ is an octyl group. 3. The method according to claim 1, wherein the pH of the solution is 10 or less. 4. The method according to claim 1, wherein the solution is an aqueous ammonia solution. 5. The method according to claim 1, wherein the recovery in step (2) is performed by extraction with an organic solvent. 6. The method according to claim 1, wherein the release of copper ions from the copper ion compound in step (3) is performed by back extraction with a dilute aqueous acid solution. how to. 7. The method of claim 6, wherein the dilute acid is selected from at least one of the group consisting of sulfuric acid, perchloric acid, and nitric acid.