WO2023033157A1

WO2023033157A1 - Electrolytic recovery device

Info

Publication number: WO2023033157A1
Application number: PCT/JP2022/033182
Authority: WO
Inventors: 大介吉井
Original assignee: 松田産業株式会社
Priority date: 2021-09-06
Filing date: 2022-09-02
Publication date: 2023-03-09
Also published as: JP2023037977A; JP6975871B1

Abstract

The purpose of the present invention is to provide a technology capable of measuring a recovery amount of a metal without stopping the operation of an electrolytic recovery device. This electrolytic recovery device comprises: an electrolysis tank into which solution is supplied; a space part provided below the electrolysis tank in the gravity direction; a shaft extending from the inside of the electrolysis tank to the space part; a rotary negative electrode which is fixed to the shaft inside the electrolysis tank and rotates about the rotation axis of the shaft; a positive electrode disposed inside the electrolysis tank; a drive mechanism which rotationally drives the shaft about the rotation axis of the shaft; a bearing which is disposed inside the space part and holds the shaft on a lower end section side of the shaft in the gravity direction; a bearing case which has an insulating property and accommodates the bearing; a load sensor which is disposed inside the space part and measures the load of the rotary negative electrode, the load being received by the bearing case via the shaft; and a vibration reducing part which reduces the vibration of the shaft.

Description

Electrolytic recovery device

The present invention relates to an electrolytic recovery device.

　In the manufacturing process of electronic components and semiconductor devices, a wet plating process is performed to form a metal film. The wet plating process generates solutions containing metals (nickel, cobalt, gold, silver, platinum, palladium). Therefore, an electrolytic recovery apparatus for recovering metals from these solutions is known (Patent Document 1). Patent Literature 1 describes an electrolytic recovery apparatus that recovers metals in a solution by depositing metals on a cathode that rotates about its axis.

Japanese Patent No. 5651332

In the electrolytic recovery device, by depositing metal on the cathode while rotating the cathode, the current efficiency in the electrolytic cell can be increased while improving the condition of electrodeposition on the cathode. On the other hand, it is important for the operation of the electrolytic recovery apparatus to know the amount of metal deposited on the cathode, that is, the amount of metal recovered. In general, the metal recovery amount is measured by removing the cathode from the electrolytic recovery device while the operation of the electrolytic recovery device is stopped and weighing the cathode with an electronic balance or the like. However, in this method, it is necessary to stop the operation of the electrolytic recovery apparatus, which reduces the operating rate of the electrolytic recovery apparatus. There is also concern that the cathode removed from the electrolytic recovery apparatus may be stolen.

The purpose of the present invention is to provide a technique that can measure the amount of metal recovered without stopping the operation of the electrolytic recovery device.

In order to solve the above problems, the present invention provides a configuration for reducing vibration of the shaft to which the rotating cathode is fixed.

Specifically, the present invention relates to an electrolytic recovery apparatus for recovering a metal by electrolyzing a solution containing a metal, comprising: an electrolytic cell into which the solution is introduced; a space provided in the electrolytic cell, a shaft extending from the inside of the electrolytic cell to the space, a rotating cathode fixed to the shaft in the electrolytic cell and rotating around the rotation axis of the shaft, and the electrolysis an anode arranged in a tank; a drive mechanism for rotating the shaft around the rotation axis; a bearing arranged in the space and holding the shaft on the lower end side of the shaft in the gravitational direction; a bearing case having insulating properties and containing the bearing; a load cell disposed in the space and measuring the load of the rotating cathode received by the bearing case through the shaft; and a vibration reduction unit for reducing vibration.

In the electrolytic recovery device described above, the vibration reducing section may have a support for suspending the load cell in the space.

In the above electrolytic recovery device, the vibration reducing section may have a vibration absorbing sheet arranged between the load cell and the bottom surface of the space section.

In the electrolytic recovery apparatus described above, the vibration reducing section may include a support for suspending the load cell in the space, and a vibration absorbing sheet disposed between the load cell and the support. .

According to the present invention, the amount of metal recovered can be measured without stopping the operation of the electrolytic recovery device.

FIG. 1 is a cross-sectional view of the electrolytic recovery device according to the embodiment when cut along the axial direction. FIG. 2 is a cross-sectional view of an electrolytic recovery device according to a comparative example cut along the axial direction. FIG. 3 is a graph showing the output voltage of the load cell by the electrolytic recovery device according to the embodiment. FIG. 4 is a graph showing the output voltage of the load cell by the electrolytic recovery device according to the comparative example. FIG. 5 is a graph showing weight changes of the rotating cathode of the electrolytic recovery apparatus according to the embodiment. FIG. 6 is a cross-sectional view of the electrolytic recovery device according to Modification 1 taken along the axial direction. 7 is a graph showing the output voltage of the load cell by the electrolytic recovery device according to Modification 1. FIG. FIG. 8 is a cross-sectional view of the electrolytic recovery device according to Modification 2 taken along the axial direction. 9 is a graph showing the output voltage of the load cell by the electrolytic recovery device according to Modification 2. FIG.

Embodiments of the present invention will be described below with reference to the drawings. The configurations of the following embodiments are examples, and the present invention is not limited to the configurations of these embodiments.

<Embodiment>
An electrolytic recovery device according to an embodiment will be described. FIG. 1 is a cross-sectional view of the electrolytic recovery device according to the present embodiment, taken along the axial direction. It is an apparatus for depositing metal by electrolyzing a solution containing metal (hereinafter simply referred to as "solution") and recovering the metal. The electrolytic recovery device 10 comprises an electrolytic cell 12 . The electrolytic recovery device 10 has an upper end opening 11A formed at the upper end in the installed state, a bottom portion 11B arranged opposite the upper end opening 11A, and a peripheral wall portion 11C connecting the upper end opening 11A and the bottom portion 11B. Further, the electrolytic recovery device 10 has a tubular inner peripheral wall portion 11D and an inner bottom surface portion 11E connecting the inner peripheral wall portion 11D and the peripheral wall portion 11C. The electrolytic recovery device 10 has an outer wall composed of a bottom surface portion 11B and a peripheral wall portion 11C, and an inner wall composed of an inner peripheral wall portion 11D and an inner bottom surface portion 11E, and accommodates various circuits therein. The electrolytic bath 12 is defined by a peripheral wall portion 11C, an inner peripheral wall portion 11D, and an inner bottom surface portion 11E. The bottom surface portion 11B, the peripheral wall portion 11C, the inner peripheral wall portion 11D, and the inner bottom surface portion 11E are made of resin such as hard vinyl chloride.

An upper end opening 12A is formed at the upper end of the electrolytic bath 12 in the installed state. In FIG. 1, a two-dot chain line Z represents the central axis of the electrolytic cell 12, and hereinafter, the two-dot chain line Z is referred to as the central axis Z (corresponding to the "axis of the electrolytic cell" in the present application). A central axis Z of the electrolytic cell passes through the center of the inner peripheral wall portion 11D. A solution introduction hole and a solution discharge hole (not shown) are formed in the peripheral wall portion 11C, and the solution is introduced through the introduction hole by a pump (not shown) installed outside the electrolytic recovery device 10. Moreover, the solution that is about to overflow from the electrolytic cell 12 is discharged from the discharge hole, and this solution is again introduced into the electrolytic cell 12 from the introduction hole. In this manner, during operation of the electrolytic recovery apparatus 10, the solution circulates inside and outside the electrolytic cell 12 through the introduction hole and the discharge hole.

The electrolytic recovery device 10 also includes a shaft 14 extending from inside the electrolytic cell 12 along the central axis Z of the electrolytic cell 12 . The shaft 14 is made of metal so as to have electrical conductivity, and is rotatable around the central axis Z. As shown in FIG. The electrolytic recovery device 10 also includes a space 13 provided below the electrolytic cell 12 in the direction of gravity. The space portion 13 is a region below the electrolytic bath 12 defined by the peripheral wall portion 11C and the bottom portion 11B. The shaft 14 extends from inside the electrolytic bath 12 to inside a bearing case 21 , which will be described later, arranged in the space 13 . In this manner, the electrolytic recovery apparatus 10 is provided with the electrolytic bath 12 on the upper side and the space 13 below the electrolytic bath 12 in the installed state.

The electrolytic recovery device 10 also includes a rotating cathode 15 that is fixed to a shaft 14 in the electrolytic cell 12 and rotates around the rotation axis of the shaft 14 , and an anode 17 that is arranged in the electrolytic cell 12 . The electrolytic recovery apparatus 10 electrolyzes the solution by applying a voltage between the rotating cathode 15 and the anode 17, thereby depositing (electrodepositing) the metal contained in the solution on the surface of the rotating cathode 15. Let Thus, the electrolytic recovery device 10 can recover the metal. The rotating cathode 15 has a cylindrical shape and is arranged in the electrolytic cell 12 from the upper end opening 12A. A screw groove is formed in the upper end of the shaft 14 , and the rotating cathode 15 is attached to the shaft 14 by fixing a bolt 16 to the screw groove while the rotating cathode 15 is inserted through the shaft 14 . . Further, the rotating cathode 15 can be removed from the shaft 14 by removing the bolt 16 from the shaft 14 . The electrolytic recovery device 10 also includes a carbon brush 19 electrically connected to the shaft 14 . The carbon brush 19 is electrically connected to the shaft 14 in the space 13 and supplies direct current to the rotating cathode 15 via the shaft 14 . It should be noted that current supply to the rotating cathode 15 may be performed through the shaft 14 and is not limited to using the carbon brush 19 .

The electrolytic recovery device 10 also includes a drive mechanism 18 that rotates the shaft 14 around the rotation axis. In this embodiment, the drive mechanism 18 is connected to the shaft 14 within the space 13 and transmits rotary motion to the shaft 14 . The drive mechanism 18 includes a motor 18A, a motor pulley 18B fixed to the rotating shaft of the motor 18A, a pulley 18D through which the shaft 14 is inserted and fixed to the shaft 14, and a timing for transmitting the rotational motion of the motor pulley 18B to the pulley 18D. It has a belt 18C. The motor 18A is a drive source operated by a drive circuit (not shown) housed in the electrolytic recovery device 10. As shown in FIG. The timing belt 18C is made of rubber, for example, and mechanically connects the motor pulley 18B and the pulley 18D. The timing belt 18C can be bent even if metal is deposited on the rotating cathode 15 and the load applied to the shaft 14 increases.

The electrolytic recovery device 10 also includes a bearing 20 that is arranged in the space 13 and holds the shaft 14 on the lower end side of the shaft 14 in the direction of gravity, and a bearing case 21 that houses the bearing 20 . The bearing case 21 has a box shape (cup shape) with an open upper end, and the outer peripheral surface of the bearing 20 is fixed to the inner peripheral surface of the bearing case 21 . As a result, the rotational motion of the shaft 14 is not transmitted to the bearing case 21 . The bearing case 21 is installed so as not to rotate with the shaft 14 . Moreover, the bearing case 21 is made of an insulating resin material such as vinyl chloride, and has insulating properties.

The electrolytic recovery device 10 also includes a load cell 22 which is arranged in the space 13 and measures the load of the rotating cathode 15 received by the bearing case 21 via the shaft 14 . The load cell 22 has the bearing case 21 mounted thereon so that the load of the bearing case 21 can be measured. The load cell 22 detects the load of the rotating cathode 15 as the radial load of the shaft 14, converts the detected load into an electrical signal, and outputs the electrical signal. A manager of the electrolytic recovery apparatus 10 can obtain information on the amount of metal deposited on the rotating cathode 15 by monitoring the output signal value of the load cell 22 .

In the electrolytic recovery device 10 according to this embodiment, the rotating cathode 15 is attached to the shaft 14 and driven to rotate together with the shaft 14 by the drive mechanism 18 . If the load of the shaft 14 were directly received by the load cell 22 , the rotation of the shaft 14 would cause friction, which could wear the contact surface of the load cell 22 with the shaft 14 . Further, in order to electrolyze the solution in the electrolytic cell 12, it is necessary to supply a direct current to the rotating cathode 15, and this current supply is performed through the shaft 14. Therefore, if the shaft 14 and the load cell 22 are in direct contact with each other, a voltage will be applied to the load cell 22 . Application of a voltage to the load cell 22 is not preferable because it causes failure of the load cell 22 .

Therefore, in the electrolytic recovery device 10 according to this embodiment, the bearing case 21 is arranged between the shaft 14 and the load cell 22 . Since the bearing case 21 does not rotate together with the shaft 14 due to the bearings 20, it is possible to prevent the load cell 22 from wearing even if it comes into direct contact with the load cell 22.例文帳に追加Moreover, the bearing case 21 has insulation. Therefore, the bearing case 21 can prevent the DC current supplied to the shaft 14 from flowing through the load cell 22 and applying a voltage to the load cell 22 .

The electrolytic recovery device 10 also includes a vibration reduction section 23 that is arranged below the load cell 22 in the direction of gravity and that reduces vibration of the shaft 14 . The shaft 14 is rotationally driven by a driving mechanism 18 and generates vibrations during driving. When the load cell 22 detects this vibration, the detected value of the radial load of the shaft 14 contains noise. This makes it impossible for the load cell 22 to accurately detect the radial load on the shaft 14 . Therefore, the electrolytic recovery device 10 according to this embodiment includes the vibration reducing section 23 . The vibration reduction unit 23 reduces the vibration of the shaft 14 to prevent noise from being mixed in the detected value of the radial load of the shaft 14 . Thereby, the electrolytic recovery device 10 can accurately measure the radial load of the shaft 14 , that is, the amount of metal deposited on the rotating cathode 15 .

In this embodiment, the vibration reduction section 23 has a support 23A and a vibration absorption sheet 23B. The support 23</b>A reduces vibration of the shaft 14 by suspending the load cell 22 within the space 13 . The support 23A suspends the load cell 22 within the space 13 in order to prevent the load cell 22 from contacting the bottom surface portion 11B. The support 23A is made of, for example, a resin material such as vinyl chloride, and is fixed inside the peripheral wall 11C with bolts (not shown). By suspending the load cell 22, the support 23A damps the vibration of the shaft 14, thereby reducing the vibration of the shaft 14. As shown in FIG.

The vibration absorbing sheet 23B has a sheet shape made of a material having viscoelasticity. In this embodiment, the vibration absorbing sheet 23B is formed of gel in a sheet shape with a thickness of about 5 mm. The vibration absorbing sheet 23B can reduce vibration of the shaft 14 by viscoelasticity. The vibration absorbing sheet 23B may be made of other viscoelastic materials such as rubber and sponge.

Next, the output voltage of the load cell 22 by the electrolytic recovery device 10 according to this embodiment and the output voltage of the load cell 22 by the electrolytic recovery device 100 according to the comparative example will be compared. FIG. 2 is a cross-sectional view of an electrolytic recovery device according to a comparative example cut along the axial direction. As shown in FIG. 2, the electrolysis recovery apparatus 100 according to the comparative example is not provided with the vibration reducing section 23, and the load cell 22 is mounted on the pedestal 24 installed on the bottom surface section 11B. In this manner, the electrolytic recovery device 100 is configured without the vibration reducing section 23 .

FIG. 3 is a graph showing the output voltage of the load cell 22 by the electrolytic recovery device 10 according to this embodiment. FIG. 4 is a graph showing the output voltage of the load cell 22 by the electrolytic recovery device 100 according to the comparative example. In the graphs of FIGS. 3 and 4, the vertical axis represents the output voltage (V) of the load cell 22, and the horizontal axis represents the operating time (seconds) of each electrolytic recovery device. In order to compare the noise of the output voltage of the load cell 22, the data of FIGS. 3 and 4 were obtained without introducing the solution into the electrolytic cell 12. FIG. Note that the output voltage of the load cell 22 is obtained by being amplified by an amplifier.

In FIG. 3, the area surrounded by a rectangle S1 indicates the period during which the drive mechanism 18 was driven, and in FIG. 4, the area surrounded by the rectangle S2 indicates the period during which the drive mechanism 18 was driven. As can be seen from the comparison between FIGS. 3 and 4, the electrolytic recovery device 10 according to the present embodiment can significantly reduce noise in the output voltage of the load cell 22 more than the electrolytic recovery device 100 according to the comparative example.

Therefore, the electrolytic recovery device 10 according to the present embodiment can measure the radical load of the shaft 14, that is, the amount of metal deposited on the rotating cathode 15 by the output voltage of the load cell 22. Therefore, the administrator can continuously measure the metal recovery amount without stopping the operation of the electrolytic recovery apparatus 10 . Therefore, the electrolytic recovery apparatus 10 does not lower the operation rate, and the rotating cathode 15 does not need to be removed until the replacement timing of the rotating cathode 15, so that theft of the rotating cathode 15 can be suppressed.

Next, the change in weight of the rotating cathode 15 obtained from the output voltage of the load cell 22 when the electrolytic recovery device 10 according to this embodiment is actually operated will be described. FIG. 5 is a graph showing weight changes of the rotating cathode 15. As shown in FIG. In the graph of FIG. 5, the vertical axis represents the weight (g) of the rotating cathode 15, and the horizontal axis represents the operating time of the electrolytic recovery device 10. As shown in FIG. As shown in the graph of FIG. 5, the noise of the load cell 22 is suppressed, and the change in weight of the rotating cathode 15, that is, the amount of metal recovered can be accurately grasped.

For example, there are cases where the recovery company that recovers metals and the manufacturer of semiconductor devices that use electrolytic recovery equipment are different. In this case, generally, the collector installs the electrolytic recovery apparatus at the manufacturer's manufacturing site, and the manager of the collector resides at a remote location from the electrolytic recovery apparatus. According to the electrolytic recovery device 10 according to the present embodiment, the administrator can receive the weight information of the rotating cathode 15 transmitted via the network from the information terminal device connected to the electrolytic recovery device 10, the terminal device carried by him/herself, or the administrator. It can be obtained from a terminal device installed at the place of residence. Therefore, the electrolytic recovery device 10 according to this embodiment can be monitored from a remote location.

Also, the replacement timing of the rotating cathode 15 is, for example, when the output voltage value of the load cell 22 reaches approximately 1.4 V and when the weight of the rotating cathode 15 reaches approximately 2.0 kg. Thus, the administrator can determine the replacement timing of the rotating cathode 15 by monitoring the weight of the rotating cathode 15 . It should be noted that the output voltage value of the load cell 22 at the replacement timing of the rotating cathode 15 changes depending on the specification of the load cell 22 and the setting of the amplification factor of the amplifier. The administrator can appropriately determine the replacement timing of the rotating cathode 15 by grasping the specifications of the load cell 22, the amplification factor of the amplifier, the output voltage value of the load cell 22, and the weight of the rotating cathode 15. be able to.

<Modification 1>
Next, an electrolytic recovery device according to Modification 1 of the embodiment will be described. FIG. 6 is a cross-sectional view of the electrolytic recovery device according to Modification 1 taken along the axial direction. In the electrolytic recovery device 10 according to this modification, the vibration reducing section 23 has the support 23A and does not have the vibration absorbing sheet 23B. That is, the electrolysis recovery device 10 according to this modification has a configuration in which the vibration absorbing sheet 23B is omitted from the electrolysis recovery device 10 according to the above-described embodiment.

FIG. 7 is a graph showing the output voltage of the load cell 22 by the electrolytic recovery device 10 according to this modified example. In the graph of FIG. 7, the vertical axis represents the output voltage (V) of the load cell 22, and the horizontal axis represents the operating time (seconds) of the electrolytic recovery apparatus. In order to compare the noise of the output voltage of the load cell 22 of the electrolysis recovery apparatus 10 according to this modified example and the output voltage of the load cell 22 of the electrolysis recovery apparatus 100 according to the comparative example shown in FIG. The data in FIG. 7 were obtained without introducing Note that the output voltage of the load cell 22 is obtained by being amplified by an amplifier.

In FIG. 7, the area surrounded by a rectangle S3 indicates the period during which the driving mechanism 18 was driven. As can be seen from the comparison between FIG. 4 and FIG. 7, the electrolytic recovery device 10 according to this modified example can reduce noise in the output voltage of the load cell 22 more than the electrolytic recovery device 100 according to the comparative example. Therefore, the electrolytic recovery apparatus 10 according to this modified example can continuously measure the amount of recovered metal without stopping the operation.

<Modification 2>
Next, an electrolytic recovery device according to Modification 2 of the embodiment will be described. FIG. 8 is a cross-sectional view of the electrolytic recovery device according to Modification 2 taken along the axial direction. In the electrolytic recovery device 10 according to this modification, the vibration reducing section 23 has the vibration absorbing sheet 23B and does not have the support 23A. In this modified example, a vibration absorbing sheet 23B is arranged on a pedestal 24 installed on the bottom surface portion 11B, and a load cell 22 is placed on the vibration absorbing sheet 23B. In this modification, the vibration absorbing sheet 23B is arranged between the load cell 22 and the bottom surface portion 11B of the space portion 13. As shown in FIG. Alternatively, the vibration absorbing sheet 23B may be arranged on the bottom surface portion 11B without providing the pedestal 24, and the load cell 22 may be placed on the vibration absorbing sheet 23B. That is, the electrolysis recovery device 10 according to this modification has a configuration in which the support 23A is omitted from the electrolysis recovery device 10 according to the above-described embodiment.

FIG. 9 is a graph showing the output voltage of the load cell 22 by the electrolytic recovery device 10 according to this modified example. In the graph of FIG. 9, the vertical axis represents the output voltage (V) of the load cell 22, and the horizontal axis represents the operating time (seconds) of the electrolytic recovery apparatus. In order to compare the noise of the output voltage of the load cell 22 of the electrolysis recovery apparatus 10 according to this modified example and the output voltage of the load cell 22 of the electrolysis recovery apparatus 100 according to the comparative example shown in FIG. The data in FIG. 9 were obtained without introducing Note that the output voltage of the load cell 22 is obtained by being amplified by an amplifier.

In FIG. 9, the area surrounded by a rectangle S4 indicates the period during which the drive mechanism 18 was driven. As can be seen from the comparison between FIG. 4 and FIG. 9, the electrolytic recovery device 10 according to this modified example can reduce the noise of the output voltage of the load cell 22 more than the electrolytic recovery device 100 according to the comparative example. Therefore, the electrolytic recovery apparatus 10 according to this modified example can continuously measure the amount of recovered metal without stopping the operation.

Although the embodiments of the present invention have been described above, the various embodiments described above can be combined as much as possible.

10...Electrolytic recovery device 11A...Upper end opening 11B...Bottom part 11C...Surrounding wall part 11D...Inner peripheral wall part 11E...Inner bottom part 12...Electrolytic bath 12A...Upper end opening 13...Space part 14. Shaft 15 Rotating cathode 16 Bolt 17 Anode 18 Drive mechanism 18A Motor

18B Motor pulley

18C Timing belt 18D Pulley 19 Carbon brush 20 Bearing 21 Bearing Case 22 Load cell 23 Vibration reducing portion 23A Support 23B Vibration absorbing sheet 24 Base 100 Electrolytic recovery device

Claims

An electrolytic recovery device for recovering the metal by electrolyzing a solution containing the metal,
an electrolytic cell into which the solution is introduced;
a space provided below the electrolytic cell in the direction of gravity;
a shaft extending from inside the electrolytic cell to the space;
a rotating cathode fixed to the shaft in the electrolytic cell and rotating about the axis of rotation of the shaft;
an anode disposed within the electrolytic cell;
a drive mechanism that rotates the shaft about the rotation axis;
a bearing that is arranged in the space and holds the shaft on the lower end side of the shaft in the direction of gravity;
a bearing case having insulating properties and housing the bearing;
a load cell arranged in the space and measuring the load of the rotating cathode received by the bearing case through the shaft;
a vibration reduction section that reduces vibration of the shaft;
an electrolytic recovery device.
The vibration reduction section has a support for suspending the load cell in the space,
The electrolytic recovery device according to claim 1.
The vibration reducing section has a vibration absorbing sheet disposed between the load cell and the bottom surface of the space.
The electrolytic recovery device according to claim 1.
The vibration reduction unit is
a support for suspending the load cell in the space;
a vibration absorbing sheet disposed between the load cell and the support;
having
The electrolytic recovery device according to claim 1.