KR101134054B1 - Indium adsorbent and indium fractioning method - Google Patents

Abstract

According to the present invention, there is provided an indium adsorbent capable of adsorbing indium and a simple and inexpensive fractionation method of indium for separating and recovering high purity indium from a hydrochloric acid solution containing indium as the main component. The present invention includes a crosslinked structure by copolymerization of styrene or acrylamide and divinylbenzene, and at least one of a quaternary ammonium group and a tertiary ammonium group, and has an anion exchange resin having an acid adsorption performance as a main component. The indium is adsorbed on the anion exchange resin by bringing the acid solution containing hydrochloric acid containing indium into contact with the anion exchange resin.

Indium, hydrochloric acid, adsorption, fractionation, ITO, IZO

Description

INDIUM ADSORBENT AND INDIUM FRACTIONING METHOD}

The present invention relates to an indium adsorbent for adsorbing indium, and an indium fractionation method for separating indium from an acid solution containing hydrochloric acid containing indium as a main component.

Recently, in Japan, most of indium is used for transparent conductive films as indium tin oxide (hereinafter referred to as ITO) or indium zinc oxide (hereinafter referred to as IZO). It accounts for about 70% of the entire indium market (nearly 80% including regenerated materials).

On the other hand, in the flat display device (hereinafter referred to as FPD) industry in which a transparent conductive film is used, the demand for not only liquid crystal display devices of personal computers but also thin and large televisions is greatly increased. Furthermore, in the future, as the EU tightens lead regulations, the demand for lead-free solders made of low-melting alloys containing indium is expected to increase, and the demand will increase.

According to such a market trend, the price of indium is increasing, and at the same time, it is expected that even a "competitive war" will take place to secure raw materials.

Due to this background, the atmosphere for regenerating indium is spreading, and regeneration of indium should be regarded as a "material recovery" technique having important economic feasibility, not just an environmental technique.

As a technique for regenerating indium, conventionally, after eluting an ITO target or the like into an acid, a sulfide method (for example, see Patent Document 1), or a hydroxide method (for example, see Patent Document 2) or a chelate resin ( For example, a method of separating and recovering indium is known by removing impurity metal ions by reference to Patent Document 3) or by solvent extraction (see Patent Document 4, for example).

The indium separated and recovered by the above method is further purified by an electric field refining method (see Patent Document 5, for example).

Patent Document 1: Japanese Patent Application Laid-Open No. 2000-169991

Patent Document 2: Japanese Patent Application Laid-Open No. 2002-69684

Patent document 3: Unexamined-Japanese-Patent No. 2002-308622

Patent Document 4: Japanese Patent Application Laid-Open No. 2000-212658

Patent document 5: Unexamined-Japanese-Patent No. 6-248370

However, in the above conventional method, many alkaline agents are necessary to adjust the pH when separating and recovering indium. In addition, in order to regenerate the separated and recovered indium as described above, it is necessary to purify separately.

In addition, the conventional method is mainly a technique for recovering unused powder such as an ITO target or powder with a sputtering device, and recovering from a glass substrate such as a defective product in a product or a manufacturing process after use is hardly achieved. In particular, in the powder adhering sputtering apparatus, since the deposit is recovered from the sputtering apparatus or the chamber through friction, there is also a problem that impurities are mixed at this time.

On the other hand, separation, recovery, and regeneration of the FPD panel and the conductive film from the etching waste liquid have almost never been performed, and high purity indium is required in order to regenerate with high commodity value.

The present invention has been proposed in view of the above problems, and an object of the present invention is to easily and inexpensively separate and purify high purity indium from an acid solution containing indium adsorbent capable of adsorbing indium and hydrochloric acid containing indium. It is to provide a method for fractionating indium that can be recovered.

[Means for solving the problem]

Characteristic configuration of the indium adsorbent according to the present invention for achieving the above object, crosslinked structure by copolymerization of styrene or acrylamide and divinylbenzene, and at least one of the quaternary ammonium group and tertiary ammonium group, acid adsorption It is based on an anion exchange resin having performance.

That is, according to the said structure, indium can be selectively adsorbed and fractionated by contacting the acid solution which has hydrochloric acid containing indium as a main component.

 Therefore, the indium adsorbent according to the present invention can separate indium easily and at low cost.

Further, a first characteristic means of the fractionation method of indium according to the present invention for achieving the above object is a crosslinked structure by copolymerization of styrene or acrylamide and divinylbenzene, and at least one of quaternary ammonium group and tertiary ammonium group And an acid solution containing hydrochloric acid containing indium as a main component to an anion exchange resin having an acid adsorption performance to adsorb the indium to the anion exchange resin.

That is, according to the said means, since indium can be made to adsorb | suck to the said anion exchange resin, it can be distinguished from what was not adsorbed to the said anion exchange resin by contacting the anion exchange resin with the acid solution containing hydrochloric acid containing indium as a main component. have.

This makes it possible to separate indium from the acid solution containing indium easily and at low cost.

A second characteristic means of the method for fractionating indium according to the present invention is to remove indium from the anion exchange resin by adsorbing indium to the anion exchange resin and then contacting the anion exchange resin with water to obtain an indium recovery solution. To get.

That is, according to the said means, since the said anion exchange resin which adsorbed indium can remove indium from the said anion exchange resin by contacting with water, indium can be obtained as an indium recovery liquid.

Therefore, it becomes possible to fractionate indium from an acid solution containing hydrochloric acid containing indium as a main component at a simple and low cost.

A third characteristic means of the indium fractionation method according to the present invention is to measure the acid concentration of the effluent after contacting the anion exchange resin, and fractionate the acid recovery liquid and the indium recovery liquid according to the concentration change value.

That is, according to the said means, since the indium recovery liquid with a high indium concentration can be fractionated by measuring an acid concentration, indium can be collect | recovered easily. In addition, not only the recovery of indium, but also the acidity acid recovery liquid can be recovered and reused.

A fourth characteristic means of the indium fractionation method according to the present invention is to adjust the pH of the indium recovery liquid and recover it as indium hydroxide.

That is, according to the said means, even if metal other than indium adsorb | sucks to the said anion exchange resin, since it can classify by adjusting pH, high purity indium can be collect | recovered easily.

The fifth characteristic means of the method for fractionating indium according to the present invention is to dry or elute the recovered indium hydroxide to an acid.

That is, according to the said means, indium can be manufactured with high purity and easy handling.

A sixth characteristic means of the method for fractionating indium according to the present invention is that the acid solution is hydrochloric acid containing at least one of a conductive film of a flat panel display, an ITO deposit or IZO deposit generated by sputtering, and a lead-free solder containing indium. It is at least one of the thing eluted to the acid which has a main component as a main component, the etching waste liquid of the said conductive film, and the washing waste liquid of a chamber.

That is, according to the above means, recovery of indium from ITO deposits or IZO deposits, lead-free solders, etching wastes of conductive films, cleaning wastes of chambers, etc., caused by a conductive film or sputtering of a flat panel display device, which has been conventionally difficult due to a large amount of impurities. Has become simple and inexpensive.

A seventh characteristic means of the method for fractionating indium according to the invention is that the acid solution is a mixed acid solution comprising nitric acid.

That is, according to the said means, since the indium concentration in an indium recovery liquid can be raised, the recovery efficiency of indium can be improved more.

An eighth characteristic means of the method for fractionating indium according to the present invention is to elute at least one of a conductive film of the flat display device, an ITO deposit or IZO deposit caused by sputtering, a lead-free solder containing indium, or a chamber In order to wash, the acid recovery liquid is used.

That is, according to the said means, since an acid recovery liquid can be used for fractionation of indium, indium can be fractionated more cheaply.

BEST MODE FOR CARRYING OUT THE INVENTION [

The indium adsorbent according to the present invention has a crosslinked structure by copolymerization of styrene or acrylamide and divinylbenzene, and an anion exchange resin having at least one of a quaternary ammonium group and a tertiary ammonium group and having an acid adsorption performance as a main component. .

In addition, the fractionation method of indium according to the present invention has a crosslinked structure by copolymerization of styrene or acrylamide and divinylbenzene, and an anion exchange resin having at least one of quaternary ammonium group and tertiary ammonium group and having acid adsorption performance. Indium is adsorbed to the anion exchange resin by bringing an acid solution containing hydrochloric acid containing indium as a main component into contact. Then, after indium is adsorbed onto the anion exchange resin, indium is released from the anion exchange resin by bringing the anion exchange resin into contact with water.

Therefore, high purity indium can be separated and recovered from an acid solution containing hydrochloric acid containing indium as a main component.

MEANS TO SOLVE THE PROBLEM The present inventors have acid crosslinking structure by copolymerization of styrene or acrylamide, and divinylbenzene, and an acid solution which has hydrochloric acid containing indium as a main component, and at the same time, it has an acid adsorption performance. It was found that indium can be adsorbed onto the anion exchange resin by contacting with an anion exchange resin having an excitation. As a result of repeated studies, as shown in Fig. 1 (a), indium is an indium chloro complex composed of indium and chlorine having an anion characteristic in an acid solution containing hydrochloric acid as a main component. It was found that the adsorbed specifically to the anion exchange resin.

The indium is released by contacting the indium-adsorbed anion exchange resin with water, but since indium is adsorbed as a chlorine complex as described above, the strong acid hydrochloric acid is first released, and then indium is released. That is, the indium chlorine complex, as shown in Fig. 2, by the removal of hydrochloric acid, the chlorine concentration is lowered, the chlorine ion as a ligand is replaced with a water molecule, and becomes an indium aquo chlorocomplex (Indium aquo chlorocomplex), It is cationized and repulsed with the anion exchange resin (adsorption capacity decreases), thereby leaving. For this reason, the acid concentration of water after contacting the anion exchange resin which adsorbed indium and an acid continuously is measured, and the acid recovery liquid with high acid concentration and the indium recovery liquid with high indium concentration can be distinguished according to the concentration change value.

On the other hand, in FIG. 2, although the indium aqua chlorine complex is cationized and released from the anion exchange resin, the indium aqua chlorine complex does not necessarily need to be cationized. Even in the case of neutral, since the ionic bonding force with the anion exchange resin is lowered, it can be released.

In the case of indium, even in hydrochloric acid solution, when nitric acid is present, as shown in Fig. 1 (b), indium? Aqua? Chlorine complex in which a part of the chlorine ion, which is a ligand, is replaced by a water molecule, as shown in Fig. 1 (b). exist. Therefore, after the hydrochloric acid is released, the substitution of the chlorine ion as a ligand to the water molecule is promoted, and the concentration of indium in the indium recovery solution can be further increased. From this viewpoint, it is preferable that the acid solution containing hydrochloric acid containing indium as a main component is a mixed acid solution containing nitric acid. On the other hand, in the case of the mixed acid solution containing nitric acid, the ratio of hydrochloric acid and nitric acid is preferably 1 to 15 mol of nitric acid relative to 100 mol of hydrochloric acid for ease of adsorption and detachment of indium.

If the indium adsorbent according to the present invention has a crosslinked structure by copolymerization of styrene or acrylamide and divinylbenzene, and an anion exchange resin having at least one of quaternary ammonium group and tertiary ammonium group and having acid adsorption performance, It does not specifically limit, It can select arbitrarily. The crosslinked structure may include other than styrene or acrylamide and divinylbenzene, and may be gel or porous. The quaternary ammonium group and the tertiary ammonium group are functional groups having acid adsorption performance, and if any one is contained, acid adsorption performance can be preferably given to the anion exchange resin. As the quaternary ammonium group, it is preferable to apply a dimethyl ammonium group or the like as the tertiary ammonium group such as trimethylammonium group or dimethylethanol ammonium group. However, the present invention is not limited thereto. Can be. In addition, the ion type of the anion exchange resin is preferably Cl type or OH type.

In consideration of the acid adsorption performance, the average particle diameter of the resin is preferably about 150 to 250 ± 25 μm, the total exchange capacity is preferably 1 meq / mL or more, and more preferably 1.2 meq / mL or more.

The water which is brought into contact with the anion exchange resin in order to remove the indium is not particularly limited, and neutral water such as purified water, pure water, ion exchange water, alkaline water, and the like are also possible. That is, it does not matter at all as long as it can remove indium when it contacts with anion exchange resin.

As an embodiment of the method for fractionating indium using the indium adsorbent according to the present invention, a method of separating and recovering indium from an ITO conductive film of an FPD panel will be described with reference to the drawings.

The recovery of indium from the FPD panel consists of an indium adsorption step and an indium recovery step as shown in FIG. 3. Hereinafter, each process is demonstrated.

(Indium adsorption process)

An indium adsorption process is a process of making indium in an FPD panel adsorb | suck to an indium adsorbent.

First, the FPD panel is cut or pulverized to a size of 10 mm or less, preferably 1 mm or less (S1), and the ITO conductive film in the FPD panel is eluted with an acid containing hydrochloric acid as a main component (S2). Next, insoluble matters, such as glass and a film in a solution, are removed by filtration etc. (S3).

The cutting or pulverization of the FPD panel performed at this time is for easily eluting the ITO conductive film to an acid, and as long as the conductive film can be eluted to an acid, the size of the FPD panel to be cut or pulverized is not limited. Moreover, it can cut and grind by a conventionally well-known method.

The acid containing hydrochloric acid eluting the FPD panel as long as it elutes ITO is not particularly limited and may be hydrochloric acid alone or mixed acid with nitric acid, sulfuric acid, perchloric acid, phosphoric acid, hydrofluoric acid, organic acid and the like. And as mentioned above, in order to remove indium efficiently, the mixed acid containing nitric acid is preferable.

The acid concentration can also be arbitrarily selected. For example, when eluting the FPD panel, it is preferable to use a solution having an acid concentration of about 10 to 25% in consideration of safety. The higher the temperature of the acid is, the easier it is to elute, but in consideration of safety, ease of handling and the like, it is preferable to elute at about 30 to 90 ° C, more preferably about 40 to 80 ° C. On the other hand, when using a mixed acid containing nitric acid, there is a possibility that a passivation may be formed in the high temperature region, and particularly preferably about 40 to 60 ° C.

The acid solution containing ITO and impurity metal which constituted the FPD panel thus obtained is passed through a column packed with the indium adsorbent of the present invention. Indium is adsorbed together with the acid and tin in the indium adsorbent of the present invention, and impurity metals such as aluminum pass through the column as metal salts. In this way, indium and tin and impurity metals can be separated.

And the solution containing the impurity metal which passed the column can be precipitated as sludge, such as hydroxide, by adding alkali, such as sodium hydroxide, and adjusting pH to about 8 (S4). In addition, the solution from which sludge has been removed by solid-liquid separation (S5) may be discharged as it is or used in a subsequent indium recovery process (S6).

(Indium recovery step)

The indium recovery step is a step of removing indium from the indium adsorbent and recovering it.

Water is passed through the column packed with the indium adsorbent treated in the indium adsorption step in the same direction as the solution passed in the indium adsorption step. In this way, the acid adsorbed on the indium adsorbent can be eluted. First, the column is connected to an acid recovery line, and the acid concentration of the recovery liquid having passed through the column is continuously measured by an electrical conductivity meter (S7), and the acid recovery liquid having a high acid concentration is recovered. The recovered acid recovery liquid can be reused as an acid for eluting the FPD panel or the like (S8). When the change value of the acid concentration is larger than a constant value (S7), the indium recovery liquid is recovered by changing the connection of the column from the acid recovery line to the indium recovery line. Afterwards, the connection of the lines can be changed again to separately recover the weak acid recovery liquid having a low concentration of indium. In this case, the weak acid recovery liquid can be reused as water for passing through the column in this step.

On the other hand, the acid recovery liquid does not necessarily need to be fractionated, and the acid recovery liquid may be recovered as an indium recovery liquid for recovering indium from the beginning.

Since the indium recovery solution contains indium and tin, first, an alkali such as sodium hydroxide is added to the indium recovery solution to adjust the pH to about 1.5 to 2.5 (S9). In this way, the tin can be precipitated with tin sludge of tin hydroxide, and solid-liquid separation can be performed (S10).

Then, after removing the tin sludge, the pH of the indium recovery liquid is adjusted to about 4.5 to 5.5 (S11). In this way, indium sludge of high purity indium hydroxide can be obtained. The obtained indium sludge is solid-liquid separated (S12), and then washed and dehydrated with washing water, then dried or eluted again with acid to recover as an indium solution of about 5%. The solution after removing indium sludge can be discharged as it is or used for indium recovery (S13).

The above method relates to a method of fractionating indium from the ITO conductive film of the FPD panel, but is not limited thereto. For example, the acid solution is an ITO deposit formed by an IZO conductive film or sputtering instead of the ITO conductive film of the FPD panel. Or an eluted lead-free solder containing IZO deposit or indium in an acid, an etching waste liquid for a conductive film, a cleaning waste liquid for a chamber, or the like can be used. In particular, the indium adsorbent according to the present invention, even when the indium is separated from the ITO deposit or the like, because the ITO deposit or the IZO deposit attached to the device or the glass during sputtering causes impurities such as other metals or glass to mix. And the method of fractionating indium. On the other hand, when the ITO deposits and the like are eluted under the same conditions as in the case of the ITO conductive film, the particles are larger, and therefore, it takes longer.

When indium is fractionated from an acid solution containing zinc such as an IZ0 conductive film or an IZO deposit, the indium recovery liquid recovered in S7 also contains zinc. Thus, after recovering indium from the indium recovery liquid or before recovering, By adjusting to the extent, zinc can be precipitated as zinc sludge of zinc hydroxide, and solid-liquid separation can be carried out.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure explaining the adsorption mechanism of indium.

2 is a view for explaining the release mechanism of indium.

3 is a view for explaining an embodiment of the indium recovery method.

4 is a graph showing the behavior of indium in a hydrochloric acid solution.

5 is a graph showing the behavior of indium in a sulfuric acid solution.

6 is a graph showing the behavior of indium in nitric acid solution.

7 is a graph showing the behavior of silicic acid in a hydrochloric acid solution.

8 is a graph showing the behavior of iron in a hydrochloric acid solution.

9 is a graph showing the relationship between temperature and recovery rate.

10 is a graph showing the relationship between acid concentration and indium ion concentration.

11 is a graph showing the behavior of indium in concentrated hydrochloric acid.

12 is a graph showing the relationship between pH and indium ion concentration.

13 is a graph showing the behavior of indium in a mixed acid solution.

14 is a graph showing the behavior of indium in a mixed acid solution.

15 is a graph showing the relationship between pH, indium ion concentration, and zinc ion concentration.

Hereinafter, the Example of the indium fractionation method which concerns on this invention is described.

(Example 1, Comparative Examples 1-4)

(Sorption Mechanism Analysis)

1000 g of cullets obtained by cutting and crushing the liquid crystal panel into a size of about 5 mm were put in 500 mL of hydrochloric acid (3.5% HCl), 500 mL of sulfuric acid (9.8% H ₂ SO ₄ ), and 500 mL of nitric acid (6% HNO ₃ ), respectively, at 80 ° C. After stirring for 60 minutes at, the insolubles were filtered to obtain an acidic solution eluted with ITO. LV = 1.5 m / h in the column (φ20 mm × 250 mmH) in which the acidic solution and the etching waste solution of the ITO conductive film were filled with 60 g of a gel-type anion exchange resin having a crosslinked structure and a trimethylammonium group by copolymerization of styrene and divinylbenzene, respectively. After passing at a rate of, pure water was passed from the same direction as the solution was added to the column. And the ion concentration after making solution and water pass through was measured, and each was shown to FIGS. 4-8.

4 to 6 show the behavior of indium and acid when the hydrochloric acid solution, sulfuric acid solution and nitric acid solution of ITO are brought into contact with an ion exchange resin, respectively. Fig. 7 shows the behavior of silicic acid and acid when the hydrochloric acid solution of ITO is brought into contact with an anion exchange resin. Fig. 8 shows the behavior of iron and acid when the etching waste liquid is brought into contact with an anion exchange resin.

As a result, as shown in Fig. 4, it was found that indium eluted with hydrochloric acid was adsorbed to an anion exchange resin by passing through a hydrochloric acid solution, and then released well after passing water through. In addition, this behavior in which indium is released after hydrochloric acid is removed is similar to that of silicic acid shown in FIG. It is similar to the behavior of hydrochloric acid and iron shown in FIG. In addition, eluted to nitric acid is not adsorbed to the anion exchange resin as shown in Fig. 6, similar to the behavior of a general metal salt.

That is, indium is considered to form sulfuric acid and sulfate (In ₂ (SO ₄ ) ₃ ) in sulfuric acid solution, similarly to the behavior of iron in hydrochloric acid solutions generally known. In addition, in a nitric acid solution, metal is generally known to form a sorbate, and in an indium nitric acid solution, an aqua complex ([In (H ₂ O) _n ] ³⁺ , 1 ≦ _n ≦ 6, In which n is an integer), and it is assumed that In is not adsorbed. On the other hand, in the hydrochloric acid solution, indium exhibits the same behavior as that of silicic acid, so that it is anionized and the chlorine complex of indium ([In (Cl) _n ] ^3-n , 1 ≦ ⁿ ≦ 6, It can be assumed that n is an integer here, and in hydrochloric acid solution, such a shape is obtained. Therefore, it is specific to an anion exchange resin having an acid adsorption performance only when indium is eluted in an acid solution containing hydrochloric acid as a main component. It is thought that it can adsorb | suck quickly.

(Example 2)

When 100 g of cullets cut and pulverized the liquid crystal panel into a size of about 5 mm were put in 500 mL of hydrochloric acid (3.5% HCl), and the temperature was set to 30, 40, 50, 60, 70, 80, 90 ° C., and stirred for 90 minutes. The indium content of the hydrochloric acid solution of was investigated.

As a result, as shown in FIG. 9, the recovery rate recovered in a hydrochloric acid solution became 35% or more when stirred at 30 degreeC or more, and 50% or more when stirred at 60 degreeC or more. In addition, hydrogen chloride gas was generated at 90 ° C. Therefore, in order to make a recovery rate 50% or more, it turned out that it is especially preferable to elute at 60-80 degreeC.

(Example 3)

100 g of the crushed and pulverized liquid crystal panel was cut into 500 mL of hydrochloric acid (3.5% HCl), stirred at 80 ° C. for 90 minutes, and the insolubles were filtered to obtain a hydrochloric acid solution containing ITO. The hydrochloric acid solution was passed through a column (φ20 mm × 250 mmH) filled with 60 g of a gel-type anion exchange resin having a crosslinked structure by copolymerization of styrene and divinylbenzene and trimethyl ammonium group at a rate of LV = 1.5 m / h. Subsequently, pure water was passed through the column in the same direction as the hydrochloric acid solution was added, and the solution passed through the column was sampled every 5 mL, and the chlorine ion concentration and the indium ion concentration representing the acid concentration were measured. As a result, as shown in FIG. 10, it turned out that when the acid concentration starts to fall largely, the concentration of indium increases. That is, by measuring the acid concentration, it was found that the solution passed through the column can be classified into an acid recovery solution and an indium recovery solution.

(Example 4)

The liquid crystal panel was cut into a size of about 5 mm, 200 g of cullet was added to 500 mL of concentrated hydrochloric acid (35% HCl), stirred at 80 ° C. for 60 minutes, and the insolubles were filtered to obtain a hydrochloric acid solution containing ITO. Using this hydrochloric acid solution, the ion concentration after flowing the hydrochloric acid solution and water was measured in the same procedure as in Example 1. As a result, as shown in FIG. 11, it was found that even indium in a concentrated hydrochloric acid solution can be satisfactorily classified.

However, in the case of the concentrated hydrochloric acid solution, some aluminum is also adsorbed, so it is more preferable to use a dilute hydrochloric acid solution.

(Example 5)

The change of the indium ion concentration and tin ion concentration in the indium recovery liquid at the time of changing the pH of the indium recovery liquid obtained in Example 3 to 1-10 was measured. As a result, as shown in Fig. 12, it was found that when the pH is greater than 2, tin precipitates with tin hydroxide, and when the pH is higher than 4, indium begins to precipitate with indium hydroxide. It was found that indium and tin can be separated by adjusting the pH.

(Example 6)

100 g of cullets obtained by cutting and crushing the liquid crystal panel into a size of about 5 mm were placed in hydrochloric acid (3.5% HCD 50OmL), stirred at a rotary evaporator at 80 ° C. for 60 minutes, and the insolubles were filtered to obtain a hydrochloric acid solution containing ITO. To the hydrochloric acid solution were further added 100 g of the cullet and the same operation was repeated nine times.The composition of the hydrochloric acid solution thus obtained is shown in Table 1.

[Table 1]

Composition of Acid Solution (mg / L) In Al Sn Cl 516 130 42.6 34475

This hydrochloric acid solution was treated in the same manner as in Example 3 to obtain an indium recovery solution. The result of having measured the composition of this indium recovery liquid is shown in Table 2.

TABLE 2

Composition of Indium Recovery Solution (mg / L) In Al Sn Cl 1324.5 5.2 6.3 8400

Sodium hydroxide was added to this indium recovery liquid, pH was adjusted to 2, and it stirred for 30 minutes. Subsequently, a polymer flocculant was added and the obtained precipitate was removed by filtration. Sodium hydroxide was further added to the solution, pH was adjusted to 5 and stirred for 30 minutes. The obtained precipitate was collected by filtration and dried, and then its composition was examined. The result was as having shown in Table 3, and it turned out that high purity indium is obtained.

[Table 3]

Composition of Indium Sludge (mg) In Al Other (decision water, etc.) 382.1 0.4 67.4

(Example 7)

200 g of the crushed crushed liquid crystal panel was cut into 500 mL of mixed acid (5 mol / L HCl + 0.25 mol / L HNO ₃ ), and stirred at 80 ° C. for 60 minutes using a rotary evaporator. A mixed acid solution containing ITO was obtained. 200g of said cullets was further added to this mixed acid solution, and the same operation was repeated 5 times. The composition of the mixed acid solution thus obtained is shown in Table 4.

[Table 4]

Composition of Mixed Acid Solution (mg / L) In Al Sn Si 537 382 63.5 50.8

Using this mixed acid solution, the ion concentration after flowing the mixed acid solution and water was measured in the same procedure as in Example 1. As a result, as shown in FIG. 13, in the case of using a mixed acid solution, indium is not released at the time of water passing through the solution or at the beginning of water passing through, and the indium can be separated well compared to FIG. 3 using the hydrochloric acid solution. I could see that.

The indium adsorption and release rate are shown in Table 5 when compared with Example 1. In other words, in the mixed acid, the separation performance of indium was good, and in acid recovery, most of indium was not contained, and the content rate of Al as an impurity was also low.

And it is estimated that it is because of an experimental error that total leaving rate exceeds 100%.

TABLE 5

Elution Adsorption rate Bounce Rate (Bounce Rate / Sorption Amount) Al impurities Acid recovery Breakaway Total exit Content Hydrochloric acid 100% 30.6% 70.7% 101.3% 1.27% Mixed acid 100% 0.2% 100.7% 100.9% 0.31%

(Example 8)

200 mg of IZO was put in 200 mL of mixed acid (5 mol / L HCl + 0.25 mol / L HNO ₃ ), and a mixed acid solution was obtained in the same manner as in Example 7. Using this mixed acid solution, the ion concentration after flowing the mixed acid solution and water was measured in the same procedure as in Example 1. As a result, as shown in Fig. 14, zinc also exhibited the same curve as indium, and it was found that adsorption and desorption was carried out as a chlorine complex in the same manner as indium.

(Example 9)

200 mg of IZO was put in 200 mL of mixed acid (5 mol / L HCl + 0.25 mol / L HNO ₃ ), and a mixed acid solution was obtained in the same manner as in Example 7. When the pH of this mixed acid solution was changed to 3-9, the change of the indium ion concentration and zinc ion concentration in the IZO mixed acid solution was measured.

As a result, as shown in Fig. 15, when the pH was higher than 4.5, indium precipitated as indium hydroxide, and all precipitated as soon as the pH reached 5.5. When the pH was higher than 8.5, zinc began to precipitate with zinc hydroxide, and when the pH reached 9.5, all precipitated.

As described above, it was found that by adjusting the pH of the solution, indium and zinc can be separated as in the case of ITO, and indium can be recovered with high purity.

In the present invention, indium can be recovered from an acid solution containing hydrochloric acid as a main component. Particularly, indium can be recovered from an acid solution such as an ITO deposit, an IZO deposit formed by sputtering, a lead-free solder containing indium, an etching waste liquid of a conductive film, and a chamber cleaning waste liquid used in an FPD panel. It can also be used for acid recovery.

Claims (17)

delete An acid solution containing indium-containing hydrochloric acid as a main component in an anion exchange resin having an acid adsorption performance, comprising a crosslinked structure by copolymerization of styrene or acrylamide and divinylbenzene, and at least one of a quaternary ammonium group and a tertiary ammonium group Contacting the adsorbed indium to the anion exchange resin; And Adsorbing the indium to the anion exchange resin, and then contacting the anion exchange resin with water to remove the indium from the anion exchange resin to obtain an indium recovery solution. Indium fractionation method comprising a. delete 3. The method of claim 2, The acid concentration of the effluent contacted with the anion exchange resin is measured, and the acid recovery liquid and the indium recovery liquid are classified according to the concentration change value. 3. The method of claim 2, PH of the said indium recovery liquid is adjusted, and it collects as indium hydroxide, The classification method of the indium characterized by the above-mentioned. 5. The method of claim 4, PH of the said indium recovery liquid is adjusted, and it collects as indium hydroxide, The classification method of the indium characterized by the above-mentioned. The method of claim 5, A method for fractionating indium, wherein the recovered indium hydroxide is dried or eluted with an acid. The method of claim 6, A method for fractionating indium, wherein the recovered indium hydroxide is dried or eluted with an acid. 3. The method of claim 2, The acid solution is obtained by eluting at least one of a conductive film of a flat panel display, an ITO deposit or an IZO deposit caused by sputtering, and a lead-free solder containing indium to an acid containing hydrochloric acid as a main component. And at least one of the cleaning waste liquid of the chamber. delete 5. The method of claim 4, The acid solution is obtained by eluting at least one of a conductive film of a flat panel display, an ITO deposit or an IZO deposit caused by sputtering, and a lead-free solder containing indium to an acid containing hydrochloric acid as a main component. And at least one of the cleaning waste liquid of the chamber. The method of claim 5, The acid solution is obtained by eluting at least one of a conductive film of a flat panel display, an ITO deposit or an IZO deposit caused by sputtering, and a lead-free solder containing indium to an acid containing hydrochloric acid as a main component. And at least one of the cleaning waste liquid of the chamber. The method of claim 6, The acid solution is obtained by eluting at least one of a conductive film of a flat panel display, an ITO deposit or an IZO deposit caused by sputtering, and a lead-free solder containing indium to an acid containing hydrochloric acid as a main component. And at least one of the cleaning waste liquid of the chamber. The method of claim 7, wherein The acid solution is obtained by eluting at least one of a conductive film of a flat panel display, an ITO deposit or an IZO deposit caused by sputtering, and a lead-free solder containing indium to an acid containing hydrochloric acid as a main component. And at least one of the cleaning waste liquid of the chamber. The method of claim 8, The acid solution is obtained by eluting at least one of a conductive film of a flat panel display, an ITO deposit or an IZO deposit caused by sputtering, and a lead-free solder containing indium to an acid containing hydrochloric acid as a main component. And at least one of the cleaning waste liquid of the chamber. The method according to any one of claims 2, 4 to 9, and 11 to 15, The acid solution is a mixed acid solution containing nitric acid. 5. The method of claim 4, Wherein the acid recovery liquid is used to elute at least one of a conductive film of a flat panel display, an ITO deposit or IZO deposit caused by sputtering, and a lead-free solder containing indium, or to clean the chamber. Fractionation method of indium.

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