KR101973658B1 - Method for producing high purity aluminum using aqueous aluminium chloride solution - Google Patents

Abstract

According to the present invention, a manufacturing method of high purity aluminum using aluminum chloride aqueous solution includes: a step (a) of pulverizing aluminum dross; a step (b) of producing aluminum chloride aqueous solution by putting the aluminum metal to hydrochloric acid (HCI); a step (c) of removing impurities from the aluminum chloride aqueous solution; and a step (d) of extracting aluminum by mixing an extractant with the aluminum chloride aqueous solution from which impurities are removed. The manufacturing method of high purity aluminum using aluminum chloride aqueous solution is able to reduce the treatment cost of industrial waste and obtain an environment protection effect due to the minimization of aluminum dross as the wasted aluminum dross is recycled by manufacturing an aluminum chloride aqueous solution with the aluminum dross and thus, manufacturing aluminum. Moreover, the present invention has an advantage of manufacturing high purity aluminum with economically high-added values by manufacturing high purity aluminum which has little impurities.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing high purity aluminum using an aluminum chloride aqueous solution,

The present invention relates to a process for producing high purity aluminum using an aluminum chloride aqueous solution and more particularly to a process for producing an aluminum chloride aqueous solution using aluminum dross and hydrochloric acid, And a method for producing aluminum.

Alumina is one of important ceramic raw materials which is widely used for refractories, fillers, ceramic materials, catalysts, and electronic parts of various industries because of excellent insulating property, heat resistance and abrasion resistance. Alumina is a white crystal powder which is obtained industrially by calcining aluminum hydroxide. When the calcination temperature is raised, it is finally a-alumina through various intermediate alumina such as? -Alumina.? -Alumina is chemically most It has a stable, high melting point and high mechanical strength. In recent years, the demand for high purity alumina of 99.99% or more in the electronic industry has increased rapidly, and the demand for high purity alumina products for blue LED, substrates for surface acoustic wave devices and substrates for semiconductors has been greatly increased.

Conventional commercial alumina is produced by converting aluminum metal into an organic compound such as aluminum alkoxide and then pyrolyzing it. Almost all of the alumina currently produced worldwide is produced using an aluminum alkoxide as an intermediate. Such a process has an advantage that alumina having a relatively high purity can be easily produced by simply thermal decomposition of an aluminum alkoxide without a separate purification process (See Patent Document 1 and Patent Document 2).

However, various impurities including the transition metal contained in the raw aluminum metal still remain in alumina as a final product, and there is a possibility that impurities may be incorporated even during the production of alumina, which is a hindrance to the production of high purity alumina of 99.99% or more have.

On the other hand, since aluminum is a well-oxidized metal, when an aluminum metal or aluminum scrap is dissolved, an oxide layer called a droplet is formed on the surface of the aluminum molten metal.

The amount of dross generated during the dissolution of aluminum depends on the operating temperature, the method of dissolution, and the composition of the dissolving scrap.

The aluminum dross is generated in the flow path of the melting furnace and the molten metal when the molten aluminum is poured into the mold.

The aluminum dross can be classified into a white dross, a black dross, and a salt cake.

In the case of white dross, aluminum oxide is formed on the surface of the molten metal above the melting furnace before the molten aluminum is melted and the molten metal is injected into the flask. The white dross contains a large amount of aluminum metal, which accounts for about 60 to 70% Aluminum can be recovered.

Blackdrop is a dross with a relatively low aluminum content rather than a white dross because it contains flux to prevent oxidation of the surface of the molten metal and to improve the efficiency of separation of impurities in the molten metal. It contains 15 to 20% aluminum metal.

The salt cake is a mixture of Blackdroses (Salt (NaCl + KCl)) and redissolved, and the remaining dross after recovering the aluminum metal. Salt cake contains aluminum of 7 ~ 8% Most of them are landfilled or discarded.

KR 10-1374490 B KR 10-1247558 B

The present invention has been proposed in order to solve the above-mentioned problems, and it is an object of the present invention to provide a method for producing high purity aluminum by using an aqueous aluminum chloride solution for producing an aluminum chloride aqueous solution using aluminum dross and producing high purity aluminum .

The problem to be solved by the present invention is not limited to the above-mentioned problem (s), and another problem (s) not mentioned can be clearly understood by a person skilled in the art from the following description.

In order to solve the above problems, a method for producing high purity aluminum using an aqueous aluminum chloride solution according to a preferred embodiment of the present invention comprises: (a) pulverizing an aluminum dross; (b) adding the pulverized aluminum dross to hydrochloric acid (HCl) to prepare an aqueous solution of aluminum chloride; (c) removing impurities from the aluminum chloride aqueous solution; And (d) extracting the aluminum by mixing the aluminum chloride aqueous solution from which the impurities have been removed and the extracting agent.

In one embodiment, the step (a) comprises: pulverizing aluminum dross; Pulverizing the pulverized aluminum dross; And air classifying the pulverized aluminum dross. ≪ IMAGE >

In one embodiment, the step (b) is preferably performed at 20 to 30 ° C for 5 to 15 minutes with a shaker.

In one embodiment, the impurity in step (c) is preferably iron (Fe).

In one embodiment, in the step (c), the iron is preferably removed by introducing an ion exchange resin into the aluminum chloride aqueous solution.

In one embodiment, the extractant is preferably Di- (2-ethylhexyl) phosphoric acid having 10 to 50% saponified sodium hydroxide (NaOH).

In one embodiment, the concentration of the extractant is preferably 0.5 to 4 M.

In one embodiment, the extraction rate of the aluminum in step (d) is preferably 55 to 90%.

In one embodiment, it is preferable that the step (d) further includes a step of removing the extracted aluminum.

Using the aluminum chloride aqueous solution according to the present invention, aluminum chloride can be used to produce an aqueous aluminum chloride solution, and aluminum can be produced therefrom. As the aluminum dross to be disposed of is recycled, aluminum It is possible not only to reduce industrial waste disposal cost and environmental protection effect due to minimization of dross, but also to manufacture high purity aluminum containing almost no impurities and to produce high purity aluminum having high value added economically There are advantages to be able to.

1 is a schematic view illustrating a method for producing high purity aluminum using an aluminum chloride aqueous solution according to an embodiment of the present invention.
FIG. 2 shows the extraction rate of metal components according to the concentration of D2EHPA as an extractant.
FIG. 3 shows the extraction rate of the metal component with the concentration of the extractant treated with 10% NaOH in D2EHPA.
FIG. 4 shows the extraction rate of the metal component with the concentration of the extractant treated with 20% NaOH in D2EHPA.
FIG. 5 shows the extraction rate of the metal component with the concentration of the extractant treated with 30% NaOH in D2EHPA.
FIG. 6 shows the extraction rate of metal components according to the concentration change of the extracting agent treated with 40% NaOH in D2EHPA.
Figure 7 compares the extraction rates of aluminum with the concentration of each of the extractants.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving it will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings.

It should be understood, however, that the present invention is not limited to the disclosed embodiments, but may be embodied in many different forms and should not be construed as limited to the exemplary embodiments set forth herein. To fully inform the inventor of the category of invention. Further, the present invention is only defined by the scope of the claims.

Further, in the following description of the present invention, if it is determined that related arts or the like may obscure the gist of the present invention, detailed description thereof will be omitted.

Hereinafter, with reference to FIG. 1, a method for producing high purity aluminum using an aluminum chloride aqueous solution according to the present invention will be described in detail.

1 is a schematic view illustrating a method for producing high purity aluminum using an aluminum chloride aqueous solution according to an embodiment of the present invention.

The method for producing high purity aluminum using an aluminum chloride aqueous solution according to the present invention comprises the steps of: (a) pulverizing an aluminum dross (S100); (b) introducing the pulverized aluminum dross into hydrochloric acid (HCl) to prepare an aluminum chloride aqueous solution (S200); (c) removing impurities from the aluminum chloride aqueous solution (S300); And (d) extracting aluminum by mixing the aluminum chloride aqueous solution from which the impurities have been removed with an extracting agent (S400).

In the method for producing high purity aluminum using an aluminum chloride aqueous solution according to an embodiment of the present invention, step (a) (S100) is a step of pulverizing aluminum dross.

The step (a) (S100) may include: pulverizing the aluminum dross; Pulverizing the pulverized aluminum dross; And air classification of the crushed aluminum dross.

In the step of pulverizing the aluminum dross, the aluminum dross may be pulverized by a jaw crusher and a roll crusher, and the pulverizing time is not limited.

The reason for crushing the aluminum dross is to minimize the incorporation of impurities, and the particle size of the crushed aluminum dross is preferably 5 to 50 mesh.

When the particle size of the pulverized aluminum dross is out of the above-mentioned range, a large amount of impurities may be contained, which may cause a problem that the recovery rate of aluminum is deteriorated.

The method of crushing the aluminum dross using the coarse crusher and the roll crusher is well known in the art, and thus a description thereof will be omitted.

The pulverization of the milled aluminum dross may be carried out for 20 to 100 minutes using a ball mill, specifically, for 60 minutes.

The step of air classification of the pulverized aluminum dross may be classified using an air classifier.

The air classification can be performed at a speed of 1,000 rpm to 11,000 rpm using a classifier wheel having a diameter of 50 mm, specifically, at a speed of 3,000 rpm.

By the pulverization and air classification, an aluminum chloride aqueous solution having a high aluminum recovery rate can be produced from aluminum dross.

In step (b) of step (S200), the aluminum metal is poured into hydrochloric acid (HCl) to prepare an aluminum chloride aqueous solution .

The step (b) (S200) may be performed at 20 to 30 ° C for 5 to 15 minutes with a shaker, specifically, at 25 ° C for 10 minutes with a vibrator.

In the method for producing high purity aluminum using an aluminum chloride aqueous solution according to an embodiment of the present invention, the step (c) (S300) is a step of removing impurities from the aluminum chloride aqueous solution.

The impurity in step (c) S300 may be iron (Fe).

In step (c) (S300), iron may be removed by introducing an ion exchange resin into the aluminum chloride aqueous solution.

The ion exchange resin may be TP207 and has the following structural formula.

[constitutional formula]

The reason why the iron (Fe) is removed first by introducing the ion exchange resin into an aqueous solution of aluminum chloride is to increase the purity of aluminum.

If the above step is not carried out, there is a problem that the purity of aluminum may be lowered because iron is extracted together with aluminum at the time of finally extracting aluminum.

In the step (c) (S300), the cation exchanged with the CH ₂ COO- group of the structural formula and the metal ion in the solution are substituted during the ion exchange. At this time, Orbitals of the dendrites. Accordingly, only the metal ion species having an empty d-orbital can be ion-exchanged. In step (c) (S300), the free electrons existing in the nitrogen of the ion-exchange resin react with the iron having the d- Exchange is made.

The contents of the above reaction can be summarized as follows.

[Reaction Scheme]

The method may further include removing the aluminum chloride aqueous solution from which the impurities have been removed after the step (c) (S300). However, the present invention is not limited to the method of removing the iron ion-exchanged ion exchange resin.

In the method of manufacturing high purity aluminum using an aluminum chloride aqueous solution according to an embodiment of the present invention, the step (d) (S400) comprises a step of mixing aluminum chloride aqueous solution from which the impurities have been removed and an extracting agent to extract aluminum to be.

The extracting agent may be a di- (2-ethylhexyl) phosphoric acid having 10 to 50% saponified sodium hydroxide (NaOH); D2EHPA), and specifically sodium hydroxide (NaOH) may be 40% saponified di-2-ethylhexyl phosphate (40% D2EHPA).

The concentration of the extractant may be from 0.5 to 4 M, and more specifically from 1 to 3 M. When the concentration of the extracting agent is out of the above-mentioned range, there is a problem that the extraction rate and purity of aluminum are lowered.

The extraction rate of the aluminum may be 55-90%.

The step (d) may further include a step of removing the extracted aluminum.

The step of removing the extracted aluminum may be carried out in 1 M hydrochloric acid at 20 to 30 ° C.

The aluminum produced as described above may have a purity of 99% or more.

Hereinafter, the present invention will be described in detail with reference to specific examples.

Example 1 Preparation of Aluminum Chloride Aqueous Solution

15 g of aluminum dross was prepared by pulverizing with a jaw crusher and a roll crusher for 20 minutes.

The pulverized aluminum dross was ground using a ball mill for 30 minutes.

The air-classified aluminum dross was recovered at a speed of 3,000 rpm using an air classifier having a classifying wheel of 50 mm in crushed aluminum dross.

15 g of air-classified aluminum dross was added to 100 ml of 35% hydrochloric acid aqueous solution and mixed for 2 hours. The solution in which the air-classified aluminum dross was dissolved was filtered with a filter having a size of 1 mu m and separated into a solution and a remnant.

The solution was again filtered through a 0.45 μm cellulose filter and then diluted to 500 ml to prepare an aqueous aluminum chloride solution.

Example 2: Preparation of high purity aluminum

The iron was removed by adding an ion exchange resin (TP207) at a concentration of 100 g / ml to 10 ml of the aqueous aluminum chloride solution prepared according to Example 1.

Aluminum and other metal components were separated and recovered by adding 1M of D2EHPA in which 40% saponified sodium hydroxide was added to the aqueous aluminum chloride solution from which iron had been removed.

Example 3

High purity aluminum was prepared in the same manner as in Example 2 except that the extractant 2 M was used.

Example 4

High purity aluminum was prepared in the same manner as in Example 2 except that Extractant 3 M was used.

Experimental Examples 1 to 5

D2EHPA (Experimental Example 1) and 10% Na-D2EHPA (Experimental Example 2), 20% Na-D2EHPA (Experimental Example 3), 30% Na-D2EHPA % Na-D2EHPA (Experimental Example 5) were each mixed.

After reacting for 10 minutes using a shaker, the concentration of metal ions in the aluminum chloride aqueous solution was analyzed by ICP. At this time, the reaction temperature is 25 占 폚. The extraction rate was calculated using the following equation

% E = De x 100 / (De + Vaq / Vorg)

Vaq: water volume, Vorg: organic phase volume, De: [metal ion] org / [metal ion] aq

The removal of aluminum extracted with the extractant was carried out in 1 M hydrochloric acid solution. The temperature was controlled at 25 ℃ and the ratio of organic phase / water phase was maintained at 1: 1.

Here, the metal ion refers to a metal contained in an aqueous aluminum chloride solution such as iron, manganese, and magnesium.

FIG. 2 shows the extraction rate of metal components according to the concentration of D2EHPA as an extractant.

As the concentration of D2EHPA increases, the extraction rate of aluminum is relatively low between 4 and 10%. In addition, the extraction rate of Fe increased with the increase of the extractant concentration, indicating that it is between 20.7 and 68.1%.

FIG. 3 shows the extraction rate of the metal component with the concentration of the extractant treated with 10% NaOH in D2EHPA.

NaOH treatment showed complete inhibition of the extraction of Mg and Mn contained in the aluminum chloride aqueous solution as impurities except iron. The extraction rate of iron was 13 ~ 37% as the extractant concentration varied from 0.1 to 1 M As shown in Fig.

However, the extraction rate of aluminum appears to be a low value between 8 and 17% as the extractant concentration varies between 0.1 and 1 M.

Figs. 4 to 6 show the extraction rates of the metal components with the concentration of the extracting agent treated with 20% NaOH, 30% NaOH and 40% NaOH in D2EHPA, and Fig. The comparison of extraction rates.

When the 20% Na-D2EHPA extractant was used, the extraction rate of iron decreased as the concentration of extractant increased. As a result, the extraction rate of iron at the concentration of 1 M of extractant was 14.7%, while that of aluminum was increased to 22.6%.

In addition, when 30% Na-D2EHPA extractant is used, it can be confirmed that the extraction rate of iron is almost suppressed at 0.5 ~ 0.7 M of extractant concentration.

When the 40% Na-D2EHPA extractant is used, the extraction rate of iron is slightly improved, and the extraction rate of aluminum is improved to 45%.

analysis

Table 1 shows the results of iron removal experiments by adding an ion exchange resin (TP207) to the aqueous aluminum chloride solution prepared according to Example 2. The extraction ratios of aluminum produced according to Examples 2 to 4 and The purity was measured and is shown in Table 2 below.

Ion exchange resin
Concentration (g / ml) 30 70 100 Concentration of filtrate (ppm) 4.3 1.9 0.02 Iron removal rate (%) 96.9 98.6 99.9

When the concentration of the ion exchange resin was 100 g / ml, the concentration of c iron in the filtrate after the ion exchange reaction was found to be 0.02 ppm.

40% Na-D2EHPA concentration 1 M 2 M 3 M Al extraction rate (%) 58 78 85 Other metal extraction (ppm) 0.3 0.4 0.3 water 99.994 99.995 99.997

When extracting the solvent with 40% Na-D2EHPA extractant 1M in an aqueous solution of aluminum chloride which had been iron-removed according to Examples 2 to 4, the extraction rate of aluminum increased and the aluminum extraction rate increased with increasing concentration of 40% Na-D2EHPA .

In addition, as a result of analyzing the components by removing the metal components, the amount of other metal extracts showed an extremely small value of 0.3 ppm or less. From these results, it can be confirmed that the purity of aluminum produced according to one embodiment of the present invention is a value of 99.99% or more.

Although a specific example of the method for producing high purity aluminum using an aluminum chloride aqueous solution according to an embodiment of the present invention has been described above, it is apparent that various modifications can be made within the scope of the present invention.

Therefore, the scope of the present invention should not be limited by the illustrated embodiments, but should be defined by the scope of the appended claims, as well as the appended claims.

It is to be understood that the above-described embodiments are illustrative and non-restrictive in all aspects, and that the scope of the present invention is indicated by the appended claims rather than the foregoing description, and the meaning and scope of the claims and their equivalents All changes or modifications that come within the scope of the present invention should be construed as being included within the scope of the present invention.

S100: Step of crushing aluminum dross
S200: Step of producing an aluminum chloride aqueous solution
S300: Step of removing impurities
S400: Step of extracting aluminum

Claims (9)

(a) pulverizing an aluminum dross;
(b) adding the pulverized aluminum dross to hydrochloric acid (HCl) to prepare an aqueous solution of aluminum chloride;
(c) removing impurities from the aluminum chloride aqueous solution; And
(d) extracting aluminum by mixing the impurity-removed aluminum chloride aqueous solution with an extracting agent,
Wherein the extracting agent is di- (2-ethylhexyl) phosphoric acid having 10 to 50% saponified sodium hydroxide (NaOH), and the concentration of the extracting agent is 0.5 to 4 M A process for producing high purity aluminum using an aluminum chloride aqueous solution.
The method according to claim 1,
The step (a)
Crushing the aluminum dross;
Pulverizing the pulverized aluminum dross; And
And air classifying the pulverized aluminum dross. The method for producing high purity aluminum according to claim 1,
The method according to claim 1,
The step (b)
And then performing the reaction with a shaker at 20 to 30 ° C for 5 to 15 minutes.
The method according to claim 1,
Wherein the impurity in step (c) is iron (Fe).
The method according to claim 1,
The step (c)
A process for producing high purity aluminum using an aluminum chloride aqueous solution, characterized in that iron is removed by introducing an ion exchange resin into an aluminum chloride aqueous solution.
delete delete The method according to claim 1,
Wherein the extraction rate of the aluminum in step (d) is 55 to 90%.
The method according to claim 1,
The step (d)
Further comprising the step of removing the extracted aluminum. ≪ RTI ID = 0.0 > 11. < / RTI >

Images