WO2012005302A1

WO2012005302A1 - Precious metal recovery device and recovery method

Info

Publication number: WO2012005302A1
Application number: PCT/JP2011/065495
Authority: WO
Inventors: 慶鯖江; 真司阿部; 孝行鷲尾
Original assignee: 田中貴金属工業株式会社
Priority date: 2010-07-07
Filing date: 2011-07-06
Publication date: 2012-01-12
Also published as: EP2592177A1; EP2592177B1; KR101307713B1; JP4666418B1; EP2592177A4; CN102959134A; TW201211318A; JP2012017491A; KR20130016378A; CN102959134B; TWI400360B

Abstract

Provided is a recovery device and recovery method for recovering precious metals from waste liquid that contains precious metals using an electrolytic method. The disclosed recovery device and recovery method curbs the dispersion of precipitated particles and the amount of precipitate due to current anomalies, curbs short circuit failures due to anomalous deposition of precious metals resulting from electric-current constriction, and has even and stable deposition of precious metals. The precious metal recovery device is provided with a cylindrical expander cathode that is arranged along the inner circumference of a cylindrical metal container that forms an electrolytic cell and a cylindrical expander anode that is arranged along the exterior circumference of a pipe shaped anode. The upper part of the expander cathode is fixed to the upper shoulder of the metal container with a reverse L-shaped cross-section, the lower part of the expander cathode is fixed to the bottom of the metal container and both ends of the expander anode are fixed to the pipe shaped cathode with a C-shaped cross section.

Description

Precious metal recovery device and recovery method

The present invention relates to a recovery apparatus and a recovery method for recovering noble metal from a waste liquid containing noble metal by an electrolytic method.

For example, an electrolytic (reduction) method is generally used as a means for recovering noble metal remaining in various waste liquids such as a noble metal plating solution. In this noble metal recovery apparatus using an electrolysis method, a waste liquid is introduced into an electrolytic cell, and an insoluble anode and a cathode are immersed in the waste liquid and energized to reduce and precipitate metal ions in the liquid.

As one aspect of the noble metal recovery apparatus, there is a noble metal recovery apparatus 2 using a cylindrical container 217 (electrolyzer) shown in FIG. 3 (see Patent Document 1). The recovery device 2 includes a cylindrical container 217, an anode 211 provided at the center thereof, and a cylindrical cathode 216 disposed along the inner periphery of the container. When recovering the precious metal, the waste liquid is introduced from the inlet at the bottom of the container, and is electrolyzed by the anode 211 and the cylindrical cathode 216 while being discharged from the opening of the anode through the outlet. . By this process, the noble metal to be collected is electrolytically reduced and deposited on the surface of the cathode 216, and it can be collected.

Such a cylindrical recovery device can be used by continuously circulating the waste liquid. Therefore, in addition to being excellent in work efficiency, for example, an advantage that it is relatively compact compared to a conventional type recovery device (Japanese Patent Laid-Open No. 7-300692, etc.) that continuously laminates a plate-like anode and cathode. There is.

However, there is also a problem with the recovery device described in Patent Document 1 to which the previous cylindrical container is applied. That is, the deposited noble metal may be peeled off from the cathode, and the anode and the cathode may be short-circuited by the peeled noble metal, and the consumption of the anode may be promoted or electrolysis may not be continued. This short circuit is likely to occur particularly when the deposited noble metal has a plate shape or a foil shape.

In order to solve this problem, as another embodiment, a cylindrical container 310 constituting the electrolytic cell shown in FIG. 4 and a bottom part arranged at the center of the container so that the waste liquid flows from the container upper part to the container bottom part. A noble metal recovery device 3 including a pipe-shaped anode 311 having an opening in the tube and a cylindrical cathode 312 disposed along the inner periphery of the container, There is a noble metal recovery device 3 in which a net-like first cylindrical body connected to is disposed (see Patent Document 2). In this recovery device 3, first, a cylindrical body formed by winding a titanium punching metal along the inner periphery of the cathode is used as a first cylindrical body. Since the first cylinder acts as a cathode, the deposited noble metal also adheres to the cylinder, but the deposited noble metal has a powdery and granular shape and adheres to the surface of the cylinder and the inner wall of the hole. This deposited noble metal is held in the cylinder with good adhesion, and short-circuiting with the anode due to peeling is less likely to occur. Further, the noble metal deposited on the smooth cylindrical cathode is held in the gap between the cylindrical body and the cathode even if it is peeled off, so that a short circuit with the anode does not occur. Further, the waste liquid is supplied by the anode, and the pipe-shaped anode bottom is opened, so that the waste liquid flows from the top to the bottom of the anode. In the technique described in Patent Document 2, when the powdered precious metal is peeled off from the first cylindrical body and deposited on the bottom of the container, the container bottom and the anode may be short-circuited. Therefore, by supplying the waste liquid from the bottom of the anode and continuously passing the liquid, the deposited noble metal powder deposited on the bottom of the container can be pushed to the outer periphery of the bottom of the container by a water flow, and this short circuit can be prevented.

Japanese Unexamined Patent Publication No. 2000-45089 Japanese Laid-Open Patent Publication No. 2006-28555 (Japanese Patent No. 41151904)

However, even in the technique described in Patent Document 2, the precipitation amount varies due to the current abnormality due to the fluctuation of the first cylinder acting as the cathode, and the abnormal precipitation of the noble metal resulting from the current concentration at the end of the cylinder. It was not possible to completely suppress the short circuit failure caused by falling as metal powder.

Therefore, the present invention is advantageous for dissolution during purification of recovered materials by suppressing the amount of precipitation or precipitation particles due to current abnormality as described above and short-circuit failure due to abnormal precipitation of noble metals due to current concentration. It is an object of the present invention to provide a noble metal recovery apparatus and a noble metal recovery method capable of stably depositing a uniform noble metal with good quality. Furthermore, an object of the present invention is to provide a noble metal recovery apparatus and a noble metal recovery method capable of depositing noble metal uniformly and stably and recovering the noble metal efficiently.

The present inventors have intensively studied and made a plurality of improvements in the collection apparatus and the collection method to which the cylindrical container is applied, and found a collection apparatus and a collection method that can solve the above problems.

The aspect of the present invention will be described in detail as follows.
The noble metal recovery device includes a cylindrical metal container constituting an electrolytic cell, an insulating lid having a waste liquid outlet that can be hermetically sealed and removed, and a center of the insulating lid. A pipe-shaped anode for circulating the waste liquid from the top to the bottom; a cylindrical expander cathode disposed along the inner periphery of the metal container; and a tubular shape disposed along the outer periphery of the pipe-shaped anode An expander anode, wherein the upper part of the expander cathode is connected and fixed to the upper shoulder of the metal container in an inverted L-shaped cross section, and the lower part of the expander cathode is the It is connected and fixed to the bottom of a metal container, and both ends of the expander anode are connected and fixed to the pipe-shaped anode in a U-shaped cross section.
Here, the length of the expander anode is preferably a length obtained by multiplying the length of the expander cathode by 0.5 to 0.95.
The metallic container and the expander cathode are preferably made of one or more metals or alloys of titanium, tantalum, niobium, zirconium and hafnium.
Moreover, it is preferable that the center part of the expander cathode has a shape that bulges toward the expander anode.
Moreover, it is preferable that at least the surface of the pipe-shaped anode and the expander anode is made of a platinum group metal, alloy or oxide.
On the other hand, the noble metal recovery method according to the embodiment of the present invention includes a pipe-shaped anode penetrating the center of a sealed and removable insulating cover provided on a cylindrical metal container constituting an electrolytic cell, and a metal Prepare a container and an expander cathode disposed along the inner periphery of the container and a cylindrical expander anode disposed along the outer periphery of the pipe-shaped anode, and collect the waste liquid from the recovery waste liquid tank containing the waste liquid containing the noble metal. And the step of circulating the waste liquid sent from the top to the bottom of the pipe-shaped anode, and the distributed waste liquid from the bottom between the expander cathode and the pipe-shaped anode. In the precious metal recovery method, comprising the step of electrolyzing while flowing back to the upper part, and the step of discharging the waste liquid from the waste liquid outlet from the waste liquid outlet and circulating it back to the recovered waste liquid tank through the filter. The upper part of the expander cathode is connected and fixed to the upper shoulder of the metal container in an inverted L-shaped cross section, and the lower part of the expander cathode is connected and fixed to the bottom of the metal container. Both ends are connected and fixed to the pipe-shaped anode in a U-shaped cross section.
Here, the length of the expander anode is preferably a length obtained by multiplying the length of the expander cathode by 0.5 to 0.95.
The metallic container and the expander cathode are preferably made of one or more metals or alloys of titanium, tantalum, niobium, zirconium and hafnium.
Moreover, it is preferable that the center part of the expander cathode has a shape that bulges toward the expander anode.
Further, it is preferable that at least the surfaces of the pipe-shaped anode and the expander anode are made of a platinum group metal, alloy or oxide.

According to the noble metal recovery apparatus and the noble metal recovery method in the aspect of the present invention, it is possible to purify the recovered material by suppressing the amount of precipitation due to current abnormality and the variation in precipitated particles and short-circuit failure due to abnormal precipitation of noble metal resulting from current concentration. It is possible to stably deposit a uniform noble metal that is convenient for dissolution during the process. Furthermore, according to the noble metal recovery apparatus and the noble metal recovery method of the present invention, it is possible to deposit the noble metal uniformly and stably, and the noble metal can be efficiently recovered.

FIG. 1 is a schematic cross-sectional view showing an embodiment of the noble metal recovery apparatus of the present invention. FIG. 2 is a schematic view showing an embodiment according to the noble metal recovery method of the present invention. FIG. 3 is a diagram showing a cross-sectional structure of a conventional noble metal recovery device (Patent Document 1). FIG. 4 is a diagram showing a cross-sectional structure of a conventional noble metal recovery device (Patent Document 2).

Hereinafter, an embodiment of the present invention will be described together with a cross-sectional view (FIG. 1) of a noble metal recovery apparatus for recovering noble metal by electrolysis from a waste liquid containing noble metal. The noble metal recovery apparatus 1 in the present embodiment connects and fixes the upper part of the expander cathode 12 to the upper shoulder of the metal container 10 in an inverted L-shaped cross section, and connects and fixes the lower part to the bottom of the metal container 10. In addition, it is possible to suppress short-circuiting with the anode due to wobbling of the cathode, abnormal precipitation due to current abnormality, and short-circuiting due to falling of the precipitate. Further, although current is concentrated at both ends of the expander cathode 12 as it is, since both ends are electrically connected to the metal container 10, current concentration at both ends of the cathode can be suppressed, and the noble metal derived therefrom can be suppressed. Short circuit due to abnormal precipitation can be suppressed. The connection and fixation may be all or part of the circumference between the upper and lower portions of the expander cathode 12 and the metal container 10. The fixing of the connection may be either by welding the expander cathode 12 directly or by welding via a spacer. When connecting and fixing the entire circumference through a spacer, a shape having holes in the spacer is preferable in consideration of the flow of waste liquid. In the case of partial connection fixation, it is preferable to fix two or more at the upper and lower portions in consideration of the suppression of wobbling. The connection mode can be performed by ordinary spot welding or pressure welding, but is not limited to the above mode as long as electrical connection is possible. The expander cathode 12 in this embodiment may be a single layer or a multilayer. However, considering the recovery efficiency, the expander cathode 12 is preferably a multilayer. Further, considering the manufacturing cost and operating cost of the apparatus, the expander cathode 12 preferably has 2 to 5 layers.

The expander anode 13 in the present embodiment can avoid current anomalies due to anode wobbling by connecting and fixing both ends of the expander anode 13 to the pipe-shaped anode 11 in a U-shaped cross section. The connection fixing may be all or part of the circumference between the both ends of the expander anode 13 and the pipe-shaped anode 11. The fixing of the connection may be either by welding the expander anode 13 directly or by welding via a spacer. In the case of connection fixation on the entire circumference, a shape having a hole between the upper and lower pipe-like anodes 11 is preferable in consideration of the flow of the waste liquid. In the case of partial connection fixation, it is preferable to fix two or more at both ends in consideration of suppression of wobbling. The lower part of the expander anode 13 and the lower part of the pipe-like anode 11 are preferably equidistant from the bottom of the electrolytic layer.

The length of the expander anode 13 in this embodiment is preferably a length obtained by multiplying the length of the expander cathode 12 by 0.5 to 0.95. When the length of the expander anode 13 exceeds the length obtained by multiplying the length of the expander cathode 12 by 0.95, the deposited powdery noble metal accumulates on the bottom of the metal container 10 and is likely to cause a short circuit. Or, abnormal deposition occurs at the bottom of the expander cathode 12. When the length of the expander anode 13 is less than the length of the expander cathode 12 multiplied by 0.5, the current distribution on the cathode can be greatly biased, and the amount of precipitation and the shape of the deposited metal are non-uniformly purified. This causes a reduction in the recovery efficiency such as a long dissolution time for the liquid. Further, in consideration of suppression of a reduction in recovery efficiency, the length of the expander anode 13 is more preferably a length obtained by multiplying the length of the expander cathode 12 by 0.7 to 0.95.

The metallic container 10 and the expander cathode 12 in this embodiment are preferably made of one or more metals or alloys of titanium, tantalum, niobium, zirconium and hafnium. When a metal or alloy other than the above metal is used, it is often used when a noble metal (gold, platinum, etc.) electrolytically deposited on the metallic container 10 and the expander cathode 12 is dissolved and recovered from the electrode for purification after recovery. If aqua regia is used, the metallic container 10 and the expander cathode 12 may be dissolved. Alternatively, even when an insoluble metal such as stainless steel is used, a trace amount of lead component that is difficult to separate from the recovered component is eluted, which causes a problem in subsequent purification. Furthermore, it is more preferable to use titanium metal or an alloy thereof in consideration of low cost, high workability and insolubility in aqua regia.

The expander cathode 12 in the present embodiment has a shape in which the central portion swells, thereby enabling more uniform deposition, suppressing current abnormality and depositing noble metal with high recovery efficiency. The bulging shape is a shape in which the cut surface draws an arc so that the central portion of the expander cathode 12 is closest to the anode. The reason for adopting this shape is that the current deviation at the cathode end is further suppressed, and more uniform electrolysis is possible.

The pipe-shaped anode 11 and the expander anode 13 in the present embodiment are preferably insoluble materials, and at least the surface is preferably made of a platinum group metal, alloy or oxide. Further, a valve metal such as titanium plated with platinum or a platinum alloy or coated with iridium oxide or ruthenium oxide is more preferable in terms of cost and durability.

It is preferable that the major axis and the minor axis length of the rhomboids of the expander cathode 12 and the expander anode 13 are 4 × 2 to 16 × 8 mm, respectively. This is because if the length is less than 4 × 2 mm, clogging of the holes due to electrodeposition occurs early, and if the length exceeds 16 × 8 mm, the surface area becomes smaller and the recovery efficiency decreases.

Next, a noble metal recovery method using the noble metal recovery apparatus 1 configured as described above will be described with reference to FIGS. In the noble metal recovery method of the present embodiment, the waste liquid is sent from the recovery waste liquid tank 20 containing the waste liquid containing the noble metal by the pump 21 or the like, and the sent waste liquid flows through the pipe-shaped anode 11 from the top to the bottom. The circulated waste liquid is electrolyzed while flowing back from the bottom to the top between the expander cathode 12 and the pipe-shaped anode 11, the waste liquid is discharged from the waste liquid outlet 15, and returned to the recovered waste liquid tank 20 through the filter 22. The returned waste liquid is circulated. At this time, the upper part of the expander cathode 12 is connected and fixed to the upper shoulder of the metal container 10 in an inverted L-shaped cross section, and the lower part of the expander cathode 12 is connected and fixed to the bottom of the metal container 10. Short-circuiting with the anode due to wobbling of the cathode, abnormal precipitation due to current abnormality, and short-circuiting due to dropping of the precipitate can be suppressed. Further, although current is concentrated at both ends of the expander cathode 12 as it is, current concentration at both ends of the cathode can be suppressed by connecting and fixing to the metal container 10, and short circuit due to abnormal deposition of noble metal derived therefrom. Can be suppressed. Since both ends of the expander anode 13 are connected and fixed to the pipe-shaped anode 11 in a U-shaped cross section, a short circuit with the cathode can be suppressed. The metal powder that has flowed out together with the waste liquid from the waste liquid outlet 15 is trapped by the filter 22 provided in the next step, and further, a short circuit between the electrodes can be suppressed.

In the noble metal recovery method of the present embodiment, the length of the expander anode 13 is preferably a length obtained by multiplying the length of the expander cathode 12 by 0.5 to 0.95. When the length of the expander anode 13 exceeds the length obtained by multiplying the length of the expander cathode 12 by 0.95, the deposited powdery noble metal is deposited on the bottom of the metal container 10 and is likely to cause a short circuit. Or, abnormal deposition occurs at the bottom of the expander cathode 12. When the length of the expander anode 13 is less than the length of the expander cathode 12 multiplied by 0.5, the current distribution on the cathode can be greatly biased, and the amount of precipitation and the shape of the deposited metal are non-uniformly purified. This causes a reduction in the recovery efficiency such as a long dissolution time for the liquid. Further, in consideration of suppression of a reduction in recovery efficiency, the length of the expander anode 13 is more preferably a length obtained by multiplying the length of the expander cathode 12 by 0.7 to 0.95.

The metallic container 10 and the expander cathode 12 are preferably made of one or more metals or alloys of titanium, tantalum, niobium, zirconium and hafnium. When a metal or alloy other than the above metal is used, it is often used when a noble metal (gold, platinum, etc.) electrolytically deposited on the metallic container 10 and the expander cathode 12 is dissolved and recovered from the electrode for purification after recovery. If aqua regia is used, the metallic container 10 and the expander cathode 12 may be dissolved. Alternatively, even when a poorly soluble metal such as stainless steel is used, a trace amount of lead component that is difficult to separate from the recovered component is eluted, which causes a problem in subsequent purification. Furthermore, it is more preferable to use titanium metal or an alloy thereof in consideration of low cost, high workability and insolubility in aqua regia.

The expander cathode 12 preferably has a shape in which the central portion bulges. As a result, uniform precipitation is possible, current anomalies are suppressed, and noble metals can be deposited with high recovery efficiency. The bulging shape is a shape in which the cut surface draws an arc so that the central portion of the expander cathode 12 is closest to the anode. The reason for adopting this shape is that the current deviation at the cathode end is further suppressed, and more uniform electrolysis is possible.

The pipe-shaped anode 11 and the expander anode 13 are preferably made of at least a platinum group metal, alloy or oxide. Further, a valve metal such as titanium plated with platinum or a platinum alloy, or coated with iridium oxide or ruthenium oxide is more preferable in terms of cost and durability.

In the precious metal recovery apparatus of the present embodiment, the liquid feed rate of the recovered waste liquid in the precious metal recovery apparatus varies depending on the metal ion species in the target waste liquid, electrolysis conditions, etc., but is preferably 5 to 30 L / min. When the liquid feed rate is less than 5 L / min, the concentration of noble metals in the electrolytic chamber is biased and non-uniform precipitation is likely to occur, and when it exceeds 30 L / min, the electrolytic recovery efficiency is reduced and recovery takes a long time. This is inappropriate. The current density of the metallic container and the expander cathode is preferably 0.05 to 0.30 A / dm2. When the current density of the metallic container and the expander cathode is less than 0.05 A / dm 2, the recovery takes a long time, and when it exceeds 0.30 A / dm 2, the recovery efficiency is not improved and the cost increases.

In the noble metal recovery method of the present embodiment, abnormal precipitation or the like is suppressed for the noble metal attached to the metallic container 10 or the expander cathode 12, the noble metal deposited on the bottom of the metal container 10 and the noble metal trapped on the filter 22. Therefore, it is possible to easily perform separation and dissolution with aqua regia or KCN solution, which is a stripping solution, and perform purification to increase the purity of the noble metal to about one digit. As the stripping solution, it is preferable to use aqua regia that can simultaneously dissolve various precious metals.

Hereinafter, an aspect of the embodiment of the noble metal recovery apparatus of the present invention will be described with reference to FIGS. 1 and 2. A cylindrical metal container 10 (dimensions: inner diameter 150 mm, height 700 mm) serving as an electrolytic cell, and a first cylindrical expander cathode 12 (dimension: diameter 140 mm, plate) along the inner periphery of the metal container 10 Thickness 1 mm, length 685 mm, diagonal length 6 (major axis) × 3 (minor axis) mm), and a cylindrical expander cathode 12 in the second layer along the inner circumference of the metal container 10. (Dimensions: diameter 130 mm, plate pressure 1 mm, length 685 mm, diagonal length 6 (major axis) × 3 (minor axis) mm of the rhombic hole) are arranged. On the other hand, a pipe-shaped anode 11 (dimensions: outer diameter 22 mm, length 690 mm, plate thickness 2 mm) is inserted in the center of the metal container 10, and a cylindrical expander is formed along the outer periphery of the pipe-shaped anode 11. The anode 13 (dimensions: outer diameter 38 mm, plate thickness 1 mm, length 590 mm, diagonal length 8 (major axis) × 4 (minor axis) mm) of the rhomboid holes is arranged. The bottom of the pipe-shaped anode 11 is opened, and is spaced a certain distance (95 mm) from the bottom surface of the metal container 10. The length of the expander anode 13 in this case is a length obtained by multiplying the length of the expander cathode 12 by 0.86.

The upper part of the expander cathode 12 is integrally connected and fixed by welding with the upper shoulder of the metal container 10 and four connected metal plates (dimensions: 8 mm × 12 mm, plate thickness 1 mm), and has an inverted L-shaped cross section as a whole. It is formed. The lower part of the expander cathode 12 is connected and fixed to the bottom part of the metal container 10 in the same manner as the upper part. Both ends of the expander anode 13 are integrally connected and fixed by welding to the pipe-shaped anode 11 and a ring-shaped connecting metal plate (dimensions: outer diameter 38 mm, inner diameter 18 mm, plate pressure 1 mm). It is formed.

The metallic container 10, the expander cathode 12 and the connecting metal plate of the cathode are made of titanium, and the pipe-shaped anode 11, the expander anode 13 and the connecting metal plate of the anode are made of iridium-plated titanium as a base material. .

As one aspect of the noble metal recovery method according to the present embodiment, the waste liquid is sent from the recovery waste liquid tank 20 containing the gold-containing waste liquid by the pump 21, and the sent waste liquid is transferred from the top of the pipe-shaped anode 11 to the bottom. The liquid is circulated and passed through the bottom of the metal container 10. The discharged waste liquid is electrolyzed while flowing back from the bottom to the top between the cathode and the anode. The electrolyzed waste liquid is discharged from a waste liquid outlet 15 formed in the insulating lid 14 on the upper side of the metal container 10, and returned to the recovered waste liquid tank through the bobbin filter 22. The circulation liquid feeding speed varies depending on the metal ion species and electrolysis conditions in the target waste liquid, but in the electrolytic recovery of gold from the plating solution 500 L (gold concentration 1.5 g / L) containing gold, the liquid feeding is performed. It is carried out at a speed of 10 to 20 L / min. The electrolytic conditions during the recovery operation were performed at a current density of 0.1 to 0.2 A / dm2. The time required for one collection operation is 12 to 18 hours under the above-described liquid feeding speed and electrolysis conditions.

In the recovery of gold from the plating waste solution containing gold, the precious metal recovery device 1 after electrolysis is removed together with the metal container 10 including the expander cathode 12 on which gold is deposited, and the filter 22 to which gold powder is attached in some cases. The precipitated gold is used as aqua regia as a solution for purification. Titanium does not dissolve in aqua regia. The solution can be poured into the metal container 10 and gold can be dissolved by stirring in the recovery device. Alternatively, the metal container 10 including the expander cathode 12 on which gold is deposited can be put into a solution bath to dissolve the gold. The deposited gold is easily dissolved in aqua regia etc.

Satisfactory results were obtained in the gold recovery from the plating waste solution containing gold using the noble metal recovery apparatus of the present invention. Specifically, no short circuit occurred due to abnormal gold deposition resulting from current concentration at both ends of the cathode. Further, the deposited metal was uniformly deposited with a thickness of 0.5 to 3.0 mm, and it was possible to easily perform aqua regia dissolution when purifying the recovered material. The yield of recovered gold from the recovered waste liquid was 99.9%.

Claims

Cylindrical metal container constituting the electrolytic cell, an insulating lid body having a waste liquid outlet capable of sealing and removing the metal container, penetrating through the center of the insulating lid body, the waste liquid from above A pipe-shaped anode that circulates to the bottom, a cylindrical expander cathode that is disposed along the inner periphery of the metal container, and a tubular expander anode that is disposed along the outer periphery of the pipe-shaped anode. A noble metal recovery device comprising:
The upper part of the expander cathode is connected and fixed to the upper shoulder of the metal container in an inverted L-shaped cross section, and the lower part of the expander cathode is connected and fixed to the bottom of the metal container. A noble metal recovery apparatus, wherein both ends of the anode are connected and fixed to the pipe-like anode in a U-shaped cross section.
The noble metal recovery device according to claim 1,
The expander anode has a length obtained by multiplying the length of the expander cathode by 0.5 to 0.95.
The noble metal recovery device according to claim 1,
The metallic container and the expander cathode are precious metal recovery devices made of one or more metals or alloys of titanium, tantalum, niobium, zirconium and hafnium.
The noble metal recovery device according to claim 1,
A noble metal recovery apparatus in which a central portion of the expander cathode has a shape bulging toward the expander anode.
The noble metal recovery device according to claim 1,
The pipe-shaped anode and the expander anode are noble metal recovery devices in which at least the surface thereof is made of a platinum group metal, alloy or oxide.
In the precious metal recovery method,
A pipe-shaped anode penetrating through the center of a hermetically sealed and removable insulating cover provided on a cylindrical metal container constituting the electrolytic cell;
An expander cathode disposed along the inner circumference of the metal container, and
A cylindrical expander anode arranged along the outer periphery of the pipe-shaped anode, and
A step of sending the waste liquid from the recovery waste liquid tank containing the waste liquid containing the noble metal;
A step in which the sent waste liquid circulates in the pipe-shaped anode from the top to the bottom;
A step of electrolyzing the circulated waste liquid while flowing back from the bottom to the top between the expander cathode and the pipe-shaped anode;
Discharging the waste liquid from the waste liquid outlet, returning it to the recovered waste tank through a filter, and circulating the electrolyzed waste liquid;
In the precious metal recovery method including
The upper part of the expander cathode is connected and fixed to the upper shoulder of the metal container in an inverted L-shaped cross section, and the lower part of the expander cathode is connected and fixed to the bottom of the metal container. A noble metal recovery method, wherein both ends of the anode are connected and fixed to the pipe-like anode in a U-shaped cross section.
The noble metal recovery method according to claim 6,
The length of the expander anode is a noble metal recovery method in which the length of the expander cathode is multiplied by 0.5 to 0.95.
The noble metal recovery method according to claim 6,
The metallic container and the expander cathode are precious metal recovery methods comprising one or more metals or alloys of titanium, tantalum, niobium, zirconium and hafnium.
The noble metal recovery method according to claim 6,
A noble metal recovery method, wherein a central portion of the expander cathode has a shape bulging toward the expander anode.
The noble metal recovery method according to claim 6,
The pipe-shaped anode and the expander anode are noble metal recovery methods in which at least the surface thereof is made of a platinum group metal, alloy or oxide.