JP2020132981A - Metal recovery method and metal recovery apparatus - Google Patents

Abstract

To provide a metal recovery method that can be applied when recovering various metals regardless of the type of metal to be recovered.SOLUTION: In the metal recovery method, using a metal recovery implement having a storage unit made of a bag-shaped body or a bottomed tubular body formed of a predetermined filter cloth, a metal recovery implementation that contains a substitution material made of a metal that is more base than the metal to be recovered in the storage unit is immersed in a solution to be treated in which the metal to be recovered is present in an ionic state, and the solution to be treated and the substitution material are brought into contact with each other in the storage unit of the metal recovery implement to substitute and precipitate the metal to be recovered.SELECTED DRAWING: Figure 2

Description

The present invention relates to a metal recovery method and a metal recovery device, and more particularly to a method capable of advantageously recovering useful metal resources from various wastes.

Conventionally, various methods for recovering various metals from waste have been proposed in order to reuse useful metal resources.

For example, in Patent Document 1 (Japanese Unexamined Patent Publication No. 2007-56367), there is also a method for recovering indium that can efficiently recover indium by separating it from tin from the blast particles used for cleaning the ITO film or the like. Patent Document 2 (Japanese Unexamined Patent Publication No. 2006-150196) proposes powder concentration methods for separating blast powder from Indium-oxidized scrap powder. On the other hand, in Patent Document 3 (Japanese Unexamined Patent Publication No. 2007-253288), a reusable blast component is recovered from used blast powder containing an indium oxide-based oxide so as to be economical and practical, and produced. A method has been proposed, and in Patent Document 4 (Japanese Unexamined Patent Publication No. 2006-241558), an indium elution device capable of efficiently recovering indium from sandblast waste powder containing indium oxide by continuous elution treatment. In addition, in Patent Document 5 (Japanese Unexamined Patent Publication No. 2006-348340), an indium tin-containing metal using a solution obtained by dissolving the recovered product of ITO scattered during the production of an ITO thin film with an acid is used. A manufacturing method has been proposed.

Although various technologies have been proposed for methods for reusing useful metal resources, including those mentioned above, they are not economically viable and are difficult to commercialize. At present, reuse (recycling) has not been established for a large amount of waste. That is, many of the metal recovery methods proposed so far have been developed for the purpose of treating specific wastes, recovering specific metal resources, etc., and such specific methods have been developed. When designing recycling equipment and processes on the premise of commercialization for waste treatment and metal resource recovery, the initial investment is large, the amount of treatment per treatment is small, and the ratio of labor costs (labor costs) is large. Due to such factors, the economic efficiency has further deteriorated, and therefore the situation has been forced to abandon commercialization.

Japanese Unexamined Patent Publication No. 2007-56367 Japanese Unexamined Patent Publication No. 2006-150196 JP-A-2007-253288 Japanese Unexamined Patent Publication No. 2006-241558 Japanese Unexamined Patent Publication No. 2006-348340

Here, the present invention has been made in the context of such circumstances, and the problem to be solved is when recovering various metals regardless of the type of metal to be recovered. The purpose is to provide a metal recovery method that can be applied. Another object of the present invention is to provide a metal recovery device capable of advantageously implementing such an excellent metal recovery method.

Then, in order to solve such a problem, the present invention uses a method of recovering the metal to be recovered as a solid from the waste containing the metal to be recovered, and uses the waste to recover the metal to be recovered. While the solution to be treated, which is present in an ionic state, is prepared, a metal recovery device having a housing portion made of a bag-shaped body or a bottomed tubular body formed of a filter cloth of 30 to 200 mesh is prepared. The metal recovery device, which contains a replacement material made of a metal lower than the metal to be recovered, is immersed in the solution to be treated, and the metal recovery device is used in the storage section. The gist thereof is a metal recovery method characterized in that the metal to be recovered is substituted and precipitated by contacting the solution to be treated with the replacement material.

In such a metal recovery method according to the present invention, it is a preferable first aspect that the replacement material has a linear or foil shape.

Further, in the metal recovery method according to the present invention, the metal to be recovered is one or more selected from the group consisting of indium, tin, copper, nickel, cobalt, bismuth, gold, silver and palladium. Is a preferred second aspect.

Further, in the recovery method of the present invention, it is a preferable third aspect that the metal to be recovered is indium and the metal baser than the metal to be recovered is aluminum or zinc.

On the other hand, the present invention is a metal recovery device provided with a melting tank for substituting and precipitating the metal to be recovered from a solution in which the metal to be recovered is present in an ionic state, and the inside of the melting tank. It is characterized in that a metal recovery device having a housing portion made of a bag-shaped body or a bottomed tubular body formed of a filter cloth of 30 to 200 mesh is attached in a detachable state. The metal recovery device is also the gist.

As described above, in the metal recovery method according to the present invention, a metal recovery device having a housing portion made of a bag-shaped body or a bottomed tubular body formed of a predetermined filter cloth is used. A state in which a replacement material made of a metal lower than the metal to be recovered is housed inside a storage portion (a bag-shaped body or a bottomed tubular body made of a predetermined filter cloth) in the metal recovery device, and the replacement material is collected. The metal recovery device is immersed in a solution to be treated in which the metal to be recovered is present in an ionic state. Then, the solution to be treated in which the metal to be recovered exists in an ionic state penetrates into the accommodating portion of the metal recovery instrument and is brought into contact with a replacement material made of a metal lower than the metal to be recovered and replaced. The metal substitution reaction effectively proceeds between the metal constituting the material and the metal ion in the solution to be treated, and thus the metal to be recovered is substituted and precipitated.

In the present invention, as the metal constituting the substitution material, a metal that is more base than the metal existing in the ionic state in the solution to be treated is selected and used. That is, the type of metal contained in the solution to be treated in the ionic state is not particularly limited, and the metal recovery method according to the present invention can be applied when recovering various metals.

Further, in the present invention, the metal to be recovered is substituted and precipitated inside the accommodating portion (bag-shaped body or bottomed tubular body made of a predetermined filter cloth) in the metal recovery instrument, and thus the metal substitution reaction is terminated. It also has the advantage that the metal to be recovered can be obtained by a simple operation of taking it out from the accommodating portion of the metal recovery device later.

Then, in the metal recovery device according to the present invention, it is possible to more advantageously enjoy the effects of the metal recovery method described above.

It is a top view which shows an example of the melting tank in the metal recovery apparatus according to this invention. It is sectional drawing on the AA plane of FIG. It is a front view which shows an example of the metal recovery instrument. It is a right side view of the metal recovery instrument shown in FIG. It is sectional drawing on the BB plane of FIG. It is sectional drawing on the CC plane of FIG.

Hereinafter, the present invention will be described in detail with reference to the drawings as appropriate.

First, as the waste containing the metal to be recovered used in the present invention, any conventionally known waste can be used without particular limitation. For example, waste such as slag and sludge containing one or more metals selected from the group consisting of indium, tin, copper, nickel, cobalt, bismuth, gold, silver and palladium, or alloys thereof. It can be used in the present invention. More specifically, ITO (indium tin oxide) -containing blast powder, palladium-containing waste acid, tin oxide-containing sludge, aluminum powder-containing indium scrap, powdery or granular rare earth magnets, sulfide-containing reduced slag, and the like are exemplified. Can be done.

Among such wastes, those which are in a non-liquid state such as a solid state and the metal to be recovered does not exist in an ionic state are slurried by adding water, and then an acid or an alkali is added. A solution (solution to be treated) in which the metal to be recovered exists in an ionic state is prepared.

Here, in the present invention, a solution in which the metal to be recovered exists in an ionic state (solution to be treated) is a 200-mesh filter at room temperature so that it can be effectively permeated into the accommodating portion of the metal recovery instrument described later. It is preferable that the fluidity is such that it easily permeates the cloth. Water is added to form a slurry so as to exhibit such fluidity. Further, examples of the acid or alkali that dissolves and ionizes the metal to be recovered include hydrochloric acid, sulfuric acid, and an aqueous sodium hydroxide solution.

Further, if the nitrate ion concentration in the solution to be treated is too high, the progress of the metal substitution reaction may be hindered, or the solid metal to be recovered generated by the metal substitution reaction may be dissolved in the solution again. Therefore, it is preferable that the solution to be treated containing nitrate ions is subjected to the recovery method of the present invention after the nitrate ion concentration is set to 1000 ppm or less according to a conventionally known method.

Even if the metal to be recovered is a liquid waste existing in an ionic state, it can be prepared by appropriately adding water and / or an acid (alkali) as needed. It is also possible to use the prepared one as the solution to be treated of the present invention.

As described above, while the solution to be treated in which the metal to be recovered exists in an ionic state is prepared, a replacement material made of a metal baser than the metal to be recovered is prepared.

Here, the metal that is more base than the metal to be recovered means a metal having a higher ionization tendency than the metal to be recovered. In the present invention, the metal constituting the substitution material can be used without particular limitation as long as it is lower than the metal to be recovered (has a high ionization tendency). Specifically, when the metal to be recovered is indium, a substitute material made of aluminum, zinc or iron, preferably a substitute material made of aluminum or zinc is used.

Further, in the present invention, the shape of the replacement material is not particularly limited, but the replacement material is preferably linear (linear body) or foil-like (foil-like body). .. More preferably, a linear body having a diameter (wire diameter) of about 0.5 to 1.5 mm is used. Further, as the foil-like body, one obtained by press-molding a plurality of metal foils at a press pressure of about 2 to 10 MPa is more advantageously used. By using a substitution material having such a predetermined shape, the metal substitution reaction proceeds more advantageously, and the target metal can be recovered more effectively.

Then, in the present invention, the above-mentioned replacement material is accommodated in the accommodating portion of the metal recovery device provided with the accommodating portion made of a bag-shaped body or a bottomed tubular body formed of a filter cloth of 30 to 200 mesh. In this state, the metal to be recovered is immersed in the solution to be treated, which exists in an ionic state.

That is, by such immersion, the replacement material and the solution to be treated are brought into contact with each other in the accommodating portion of the metal recovery device, and the metal substitution reaction proceeds between the metal constituting the replacement material and the metal ions in the solution to be treated. By doing so, the metal to be recovered is subjected to substitution precipitation and is produced as a solid substance. Further, since the filter cloth constituting the accommodating portion has a mesh number within a predetermined range, the produced solid matter is advantageously stopped in the accommodating portion and is taken out from the accommodating portion after the completion of the metal substitution reaction. It is possible to recover the target metal by such a simple operation.

The metal recovery device used in the present invention is provided with an accommodating portion made of a bag-shaped body or a bottomed tubular body formed of a filter cloth, and the number of meshes of the filter cloth constituting the accommodating portion is large. If it is too large, the permeation (penetration) of the solution to be treated may be hindered and the metal substitution reaction may not proceed effectively. On the other hand, if the number of meshes of the filter cloth constituting the accommodating portion is too small, the generated solid material made of the metal to be collected may fall off from the accommodating portion. Therefore, in the present invention, for metal recovery having a storage portion made of a bag-shaped body or a bottomed tubular body formed of a filter cloth of 30 to 200 mesh, preferably a filter cloth of 80 to 150 mesh. The instrument will be used. As the filter cloth, a filter cloth made of a synthetic resin having excellent acid resistance (alkali resistance) is generally used.

In addition, various conditions such as the immersion time of the metal recovery device containing the replacement material in the solution to be treated and the pH and temperature of the solution to be treated during immersion are the same as the metal to be recovered and the metal constituting the replacement material. It will be appropriately determined by comprehensively considering the combination, the amount of the solution to be treated, the amount of metal ions to be recovered contained in the solution to be treated, and the like. Further, in order to allow the metal substitution reaction to proceed efficiently, it is preferable that the metal recovery instrument containing the substitution material is immersed in the solution to be treated, which has been subjected to the stirring treatment.

By the way, the metal recovery method according to the present invention can be advantageously carried out, for example, by using a metal recovery device provided with a melting tank shown in FIGS. 1 and 2. FIG. 1 is a plan view schematically showing a melting tank of a metal recovery device capable of carrying out the present invention, and FIG. 2 is a cross-sectional view taken along the plane AA of FIG. It should be noted that in FIG. 2, it is understood that the parts other than the tank main body (12), the jacket (16) and the lid (18) are not hatched in order to make the drawing clear. It should be.

As is clear from FIGS. 1 and 2, first, the dissolution tank 10 has a tank main body 12 for accommodating the solution, and a gap 14 is separated from the outer side of the tank main body 12. The jacket portion 16 is arranged so as to cover the outer periphery of the tank main body portion 12. A liquid heat medium (not shown) is sealed in the gap 14, and the heat medium is heated or cooled by a heating / cooling mechanism (not shown) to be accommodated in the tank main body 12 and the space 14 thereof. It is possible to control the temperature of the solution.

Further, on the opening side of the tank body 12, a lid 18 that can make the inside of the tank body 12 a closed space is arranged. A liquid supply pipe 20 is arranged on the lid portion 18 via a mounting portion 22, and a pH meter 24 is assembled via the mounting portion 26 so as to be located on the tank body portion 12 side. The pH of the solution to be treated during the metal substitution reaction is sequentially measured by a pH meter 24, and the required amount of acid, alkali or water is appropriately added to the tank body 12 from the liquid supply pipe 20 according to the measured value. It is supposed to be supplied inside.

Further, the lid portion 18 is provided with an exhaust pipe 28 via a mounting portion 30 (see FIG. 1) so that the gas generated during the metal substitution reaction is appropriately discharged. Further, the stirrer 32 is assembled to the lid 18 so that the stirring blade 34 is located on the tank body 12 side, so that the solution to be treated contained in the tank body 12 can be stirred. ..

In addition, the lid 18 of the melting tank 10 of the present invention is provided with an opening 38 for inserting and holding the metal recovery instrument 36, and the metal recovery instrument 36 is inserted into the opening 38. By arranging the lid member 40 above in this state, the metal recovery instrument 36 is configured to be fixed.

The metal recovery device 36 will be described in more detail. 3 to 4 are explanatory views showing the metal recovery device 36, FIG. 3 is a front view, FIG. 4 is a right side view, and FIG. 5 is a sectional view taken along the line BB of FIG. FIG. 6 is a cross-sectional view taken along the line CC of FIG. As shown in FIGS. 3 to 6, the metal recovery device 36 is composed of a support 42 and a bottomed tubular body 44. In addition, in FIG. 5 and FIG. 6, the cross section of the bottomed tubular body 44 is represented by a thick dotted line.

The support 42 is composed of a support portion 46a in which a plurality of rod-shaped members made of vinyl chloride resin are assembled to form a rectangular parallelepiped as a whole, and a flange portion 46b assembled above the support portion 46a. A bottomed tubular body 44 is attached to and fixed to the support portion 46a. By locking the flange portion 46b with the opening 38 of the lid portion 18, the metal recovery instrument 36 is prevented from falling into the tank body portion 12. The bottomed tubular body 44 is formed of a 30-200 mesh filter cloth. The metal recovery instrument 36 composed of such a support 42 and a bottomed tubular body 44 has an opening above the support, and a replacement material can be inserted (inserted) from such an opening.

Then, when recovering the metal according to the present invention using the metal recovery device provided with the melting tank 10 having such a configuration, first, the lid portion 18 is moved upward and into the tank main body portion 12. Slurry waste is put in. Next, the lid portion 18 is moved downward to make the inside of the tank main body 12 a closed space, and then an acid or alkaline aqueous solution is added to the slurry-like waste in the tank main body 12 through the liquid supply pipe 20. As a result, a solution (solution to be treated) in which the metal to be recovered exists in an ionic state is prepared. After that, the metal recovery device 36 containing the predetermined replacement material is inserted into the tank body 12 from the lid 18 and immersed in the solution to be treated, and the metal recovery device 36 in the metal recovery device 36 is to be treated. When the solution is brought into contact with the solution for a predetermined time, the metal substitution reaction proceeds, so that the target metal is substituted and precipitated. In the present invention, the metal recovery instrument 36 is removed from the lid 18 after the metal substitution reaction is completed, and the metal recovery instrument 36 is removed from the inside of the metal recovery instrument 36 from the place where the replaced and precipitated metal solid matter effectively stops in the metal recovery instrument 36. There is an advantage that the solid metal to be recovered can be obtained by a simple operation of taking out the solid metal. The solution in the tank body 12 after the completion of the metal substitution reaction is subjected to treatments such as neutralization and filtration according to the same method as in the past.

Although the typical embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various aspects are based on the knowledge of those skilled in the art as long as the gist of the present invention is not deviated. It should be understood that changes, corrections, improvements, etc. can be made.

By the way, in order to confirm the effect of the metal recovery method according to the present invention, the following metal recovery test was carried out.

− Example 1-
50 g of indium-containing waste (indium content: 20% by mass), 150 mL of tap water, and 50 mL of 35% hydrochloric acid are added to a 300 mL beaker and stirred to allow indium to be present in an ionic state. A solution was prepared. On the other hand, as a metal recovery instrument, a cylindrical bottomed tubular body having a diameter of 50 mm and a height of 60 mm, which is formed of an 80-mesh filter cloth (however, one has a bottom). (Only at the end) was prepared, and an aluminum wire (diameter: 1.0 mm, length: 30 mm) was prepared as a replacement material.

A metal recovery instrument (bottomed tubular body made of filter cloth) containing a replacement material inside was immersed in the solution to be treated by hanging it from above the beaker, and the replacement material and filter cloth in the device were permeated. It was brought into contact with the solution to be treated. During immersion of the metal recovery device, hydrochloric acid is appropriately added to the beaker so that the pH of the solution to be treated in the beaker is maintained at 1.5 to 2.5, and the inside of the beaker is used using a water bath. The temperature of the solution to be treated was maintained at 50 to 60 ° C., and maintained in such a state for 3 hours. After soaking for 3 hours, the metal recovery device was taken out from the beaker and the inside thereof was checked. As a result, the formation of a solid substance was observed. Although this solid product contains a trace amount of aluminum, it was confirmed by component analysis that it was mainly composed of indium. The amount of indium contained in the obtained solid (recovered metal amount) was measured, and the indium recovery rate was calculated from the following formula (1). The results are shown in Table 1 below.
Recovery rate (%) = {Amount of recovered metal (g)} / {Amount of metal to be recovered in the solution to be treated (g)}
× 100 ・ ・ ・ (1)

− Example 2 to Example 4-
A metal recovery test was carried out according to the same method as in Example 1 except that a metal recovery device (bottomed tubular body) formed of a filter cloth having the number of meshes shown in Table 1 below was used. Carried out. The recovery rate of indium in each example is shown in Table 1 below.

-Example 5 to Example 8-
A metal recovery test was carried out according to the same method as in Example 1 except that an aluminum wire having a diameter (wire diameter) shown in Table 2 below was used as a replacement material. The recovery rate of indium in each example is shown in Table 2 below.

− Example 9−
50 g of nickel / cobalt-containing waste having a nickel content of 10% by mass and a cobalt content of 10% by mass, 150 mL of tap water, and 50 mL of 35% hydrochloric acid were added to a 300 mL beaker. By stirring, a solution to be treated in which nickel and cobalt were present in an ionic state was prepared. Further, as a metal recovery instrument, a cylindrical bottomed tubular body having a diameter of 50 mm and a height of 60 mm, which is formed of an 80-mesh filter cloth (however, one has a bottom). Only at the end.) Was prepared. Further, a foil-like body obtained by pressing five aluminum foils stacked at a pressing pressure of 2 MPa was prepared as a replacement material.

A metal recovery instrument (bottomed tubular body made of filter cloth) containing a replacement material inside was immersed in the solution to be treated by hanging it from above the beaker, and the replacement material and filter cloth in the device were permeated. It was brought into contact with the solution to be treated. During immersion of the metal recovery device, hydrochloric acid is appropriately added to the beaker so that the pH of the solution to be treated in the beaker is maintained at 1.0 to 1.5, and the inside of the beaker is used using a water bath. The temperature of the solution to be treated was maintained at 30 ° C., and maintained in such a state for 3 hours. After soaking for 3 hours, the metal recovery device was taken out from the beaker and the inside was checked. As a result, the formation of a solid substance was observed. Although this solid product contained a trace amount of aluminum, it was confirmed by component analysis that it was mainly composed of nickel and cobalt. The respective amounts (recovered metal amount) of nickel and cobalt contained in the obtained solid material were measured, and the recovery rate of nickel and cobalt was calculated from the above formula (1). The results are shown in Table 3 below.

− Examples 10 to 13−
A metal obtained by pressing five aluminum foils stacked at the pressing pressure shown in Table 3 below, except that a foil-like body obtained by pressing the foil-like body was used as a replacement material according to the same method as in Example 9. A recovery test was conducted. The recovery rates of nickel and cobalt in each example are shown in Table 3 below.

− Example 14−
A metal recovery test was carried out according to the same method as in Example 9 except that indium-containing waste was used instead of nickel / cobalt-containing waste. As a result, a solid product containing indium as a main component was obtained, and indium was obtained. Was confirmed to be recoverable.

− Example 15−
When a metal recovery test was carried out according to the same method as in Example 9 except that tin-containing waste was used instead of nickel / cobalt-containing waste, a solid product containing tin as a main component was obtained, and tin was obtained. Was confirmed to be recoverable.

− Example 16−
When a metal recovery test was carried out according to the same method as in Example 9 except that a cobalt sulfate reagent was used instead of the nickel / cobalt-containing waste, a solid product containing cobalt as a main component was obtained, and cobalt was obtained. It was confirmed that it could be recovered.

-Example 17, Example 18-
A metal recovery test was carried out in the same manner as in Example 16 except that the temperature of the solution to be treated was set to the temperature shown in Table 4 below while the metal recovery device was immersed, and cobalt was recovered. did. The cobalt recovery rate in each of Examples 17 and 18 was calculated with the amount of cobalt recovered in Example 16 as the recovery rate of 100%. The results are shown in Table 4 below.

− Example 19−
A metal recovery test was carried out according to the same method as in Example 1 except that a zinc wire (diameter: 1.0 mm, length: 30 mm) was used as a substitute material instead of the aluminum wire. When the recovery rate of indium was calculated according to the above formula (1), it was 97%.

− Example 20−
50 g of copper-containing waste (copper content: 20% by mass), 150 mL of tap water, and 50 mL of 35% hydrochloric acid are put into a 300 mL beaker and stirred to treat copper in an ionic state. A solution was prepared. On the other hand, as a metal recovery instrument, a cylindrical bottomed tubular body having a diameter of 50 mm and a height of 60 mm, which is formed of an 80-mesh filter cloth (however, one has a bottom). (Only at the end) was prepared, and an iron wire (diameter: 1.0 mm, length: 30 mm) was prepared as a replacement material.

A metal recovery instrument (bottomed tubular body made of filter cloth) containing a replacement material inside was immersed in the solution to be treated by hanging it from above the beaker, and the replacement material and filter cloth in the device were permeated. It was brought into contact with the solution to be treated. During immersion of the metal recovery device, hydrochloric acid is appropriately added to the beaker so that the pH of the solution to be treated in the beaker is maintained at 1.0 to 2.0, and the inside of the beaker is used by using a water bath. The temperature of the solution to be treated was maintained at 10 to 40 ° C., and maintained in such a state for 3 hours. After soaking for 3 hours, the metal recovery device was taken out from the beaker and the inside thereof was checked. As a result, the formation of a solid substance was observed. Although this solid product contains a trace amount of iron, it was confirmed by component analysis that it was mainly composed of copper. The amount of copper contained in the obtained solid (recovered metal amount) was measured, and the copper recovery rate was calculated from the above formula (1) and found to be 91%.

As is clear from the above-mentioned examples, in the recovery method according to the present invention, the target metal is advantageously recovered by appropriately selecting a metal constituting the replacement material according to the metal to be recovered. It is acknowledged that it is obtained, and it is confirmed that the recovery method of the present invention is suitable for recovery of various metals.

10 Melting tank 12 Tank body 18 Lid 36 Metal recovery equipment 44 Bottomed tubular body

Claims (5)

A method of recovering the metal to be recovered as a solid from waste containing the metal to be recovered is used.
The waste is used to prepare a solution to be treated in which the metal to be recovered is present in an ionic state, while the waste is composed of a bag-shaped body or a bottomed tubular body formed of a filter cloth of 30 to 200 mesh. A metal recovery device with a containment is prepared,
The metal recovery device, which contains a replacement material made of a metal lower than the metal to be recovered, is immersed in the solution to be treated, and the metal recovery device is used in the storage section. By bringing the solution to be treated into contact with the replacement material, the metal to be recovered is replaced and precipitated.
A method for recovering a metal, which is characterized in that. The method for recovering a metal according to claim 1, wherein the replacement material has a linear or foil shape. The metal according to claim 1 or 2, wherein the metal to be recovered is one or more selected from the group consisting of indium, tin, copper, nickel, cobalt, bismuth, gold, silver and palladium. How to collect. The method for recovering a metal according to claim 1 or 2, wherein the metal to be recovered is indium and the metal to be recovered is aluminum or zinc, which is more base than the metal to be recovered. A metal recovery device provided with a dissolution tank for substituting and precipitating the metal to be recovered from a solution in which the metal to be recovered is present in an ionic state.
A metal recovery device having a storage portion made of a bag-shaped body or a bottomed tubular body formed of a filter cloth of 30 to 200 mesh is attached to the melting tank in a detachable state. A metal recovery device characterized by.

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