JPH0459997A - Electrolytically treating equipment of metallic strip and electrolytic treatment - Google Patents

Abstract

PURPOSE:To obtain a plated metallic sheet which is free from unevenness of plating thickness and has stabilized quality by constituting an electrolytically treating equipment of a plating liquid tank, a fluidized tank and rolls and also providing a screen and a dispersion plate, etc., to the fluidized tank and smoothly introducing and discharging a granular consumable anode. CONSTITUTION:The electrolytically treating equipment is constituted of a communicated plating liquid tank 1, a fluidized tank 13, a contact roll and a backup roll, etc., and formed into a horizontal type. The fluidized tank 13 is provided oppositely to the rear surface of a strip 2 and has apertures in the upper part and the lower part. These apertures are communicated with the means 10, 16 through which plating liquid E flows. Furthermore, the fluidized tank 13 is provided with a second screen 3, a first screen 4, and a dispersion plate 12. A chamber 15 is limited by the screen 4 and the dispersion plate 12. A granular consumable anode 15 is packed hereinto. The chamber 15 is communicated with the feed port 11 of the anode. The consumed anode 5 is passed through the first screen 4 and discharged through a passage 16.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a metal strip electroplating apparatus and an electroplating method.

<Prior art> In conventional electroplating equipment, the anode for the metal strip to be plated is an insoluble anode (insoluble anode) using Pt or PB alloy, and a soluble anode using a blanked metal directly as an anode. (soluble anode) is known.

An electroplating apparatus using an insoluble anode has the advantage that the anode is not consumed by electrolysis, so there is no need to replace the anode, and the thickness of the plated metal on the metal strip is less likely to be uneven. However, in an electroplating apparatus using an insoluble anode, plating metal ions must be supplied separately, so a plating metal ion supply apparatus is required. Additionally, since 02 gas is generated from the insoluble anode during electrolysis, uneven plating may occur.
Furthermore, when a plating solution containing halogen-based anions is used, toxic halogen gas is generated, and a device for processing the halogen gas is also required, which increases equipment costs.

On the other hand, in an electroplating apparatus using a soluble anode, the soluble anode acts as an anode for the metal strip, and the anode itself dissolves and becomes a source of plating metal ions, so a plating metal ion supply device is not required.
Another advantage is that no gas is generated. but,
Soluble 11! In an electroplating apparatus using electrodes, the anodes are constantly worn out, requiring new anodes to be inserted and worn out anodes to be removed.

Reference will now be made to anode replacement in electroplating equipment using conventional soluble anodes.

Conventionally, in order to facilitate the replacement of such soluble anodes, as shown in FIG. A method has been adopted in which the anode is loaded and the exhausted anode is removed from the other. However, with this method, the work of replacing the anode is burdensome, and the thickness of the anode, that is, the rate of wear, is affected by the width of the metal strip 2 and the energization state of the anode, and the plated metal on the metal strip is There were problems such as uneven thickness.

Therefore, a method has been proposed to facilitate the replacement of the anode in an electroplating apparatus that uses a soluble anode.

The first method is a method using a granular anode proposed in Japanese Patent Application Laid-Open No. 58-1099.

In this method, it is easy to load the anode, but it is difficult to discharge the exhausted anode.

The second method is a method using a granular anode proposed in Japanese Patent Application Laid-Open No. 62-4899.

In this method, granular anode is applied to a vertical plating tank, fresh granular anode is fed from the top of the basket, and exhausted granular anode is taken out from the bottom, but granular anode is preferentially distributed from the part facing the cathode. Therefore, both the depleted anode and the undepleted anode are present at the bottom of the basket, and only the depleted anode is selectively excluded from the discharge.

Furthermore, this method is applied to vertical cells, and cannot be applied to horizontal cell type plating equipment in which the strip runs horizontally.

<Problems to be Solved by the Invention> As described above, improvements have been proposed for electroplating apparatuses using soluble anodes to facilitate loading and discharging of the anodes. However, in addition to the ease of charging and discharging the anode, the electroplating equipment has performance that can withstand practical use, such as ensuring that there is no uneven thickness of the plated metal. No plating equipment is known.

The present invention has been made in view of the above facts, and is an electroplating apparatus using a soluble anode, which allows smooth charging and discharging of the anode, thereby preventing uneven thickness of paddy and plating metal. An object of the present invention is to provide a horizontal type metal strip electrolytic treatment device that is difficult to use, and an electrolytic treatment method using such a device.

Means for Solving the Problems> The first aspect of the present invention is a horizontal metal strip electrolytic treatment apparatus, which is composed of a plating solution tank, a fluidization tank, a conductor roll, and a backup roll. The fluidization tank communicates through a means for flowing the plating solution, and the fluidization tank has an upper opening disposed opposite to the lower surface of the metal strip and a means for flowing the plating solution toward the upper opening. The flow tank further has a second screen, a first screen and a dispersion plate in order from above, and the first screen and the dispersion plate define a chamber for filling the granular consumable anode. is defined, the chamber communicates with a particulate consumable anode supply port for continuously supplying the particulate consumable anode, the first screen is a screen having a pore size through which the particulate consumable anode does not pass prior to depletion; The second screen is comprised of a screen with a smaller pore size than the first screen, and further includes means for discharging the particulate consumable anode that has been exhausted and passed through the first screen through a passage between the first and second screens. The present invention provides an apparatus for electrolytic treatment of metal strips, which is characterized by:

In a second aspect of the present invention, the electrolytic treatment apparatus is used to apply a plating solution at a flow rate such that the granular consumable anode filled in the chamber for filling the granular anode is pressed against the first screen. The present invention provides a method for electrolytically treating a metal strip, characterized in that the electrolytic treatment is carried out by flowing the metal strip from the lower opening toward the upper opening of a fluidized tank.

The present invention will be explained in detail below.

First, the electrolytic treatment apparatus according to the first aspect of the present invention will be described with reference to preferred embodiments shown in the accompanying drawings.

FIG. 1 is a schematic cross-sectional view of a plane in the direction of movement of a metal strip, showing an example of the electrolytic treatment apparatus of the present invention, and FIG. 2 is a schematic partial cross-sectional view of a plane perpendicular to the direction of movement of the metal strip. be.

As shown in FIGS. 1 and 2, the electrolytic treatment apparatus of the present invention includes a plating solution tank 1, a fluidization tank 13, a conductor roll 8, and a backup roll 9.

The plating solution tank 1 is composed of a container having upper and lower openings, and is arranged opposite to the lower surface of the metal strip 2. The upper opening of the cleaning liquid tank 1 allows the flow a! Collect the plating solution E flowing down from 13. In addition, the lower opening of the plating solution all is connected to a fluidization tank 13 via a pump 10.
It will be communicated to. This pump 10 may be replaced by other means capable of sending the plating solution E from the plating solution tank 1 to the fluidization tank 13.

The fluidizer [13 is disposed in the plating solution tank 1 facing the lower surface of the metal strip 2 so that the plating solution E can be circulated between the fluidization tank 13 and the plating solution tank 1,
It is composed of, in order from the top, an upper opening, a second screen 3, a first screen 4, a dispersion plate 12, and a lower opening.
In addition, in FIGS. 1 and 2, the second screen 3
A passage 16 is defined between the first screen 4 and the first screen 4, a chamber 15 is defined between the first screen 4 and the dispersion plate 12, and a passage 16 is defined between the first screen 4 and the dispersion plate 12.
The space between the lower opening and the lower opening is referred to as a rectifying section 14.

The configuration of the fluidized tank 13 will be explained in order from the bottom.

The lower opening communicates with the paddy husk 1 through the pump 10, and serves as a part where the plating solution E flows into the fluidization tank 13.

The dispersion plate 12 is located above the flow 4!13 and is made of a material such as polyvinyl chloride or polypropylene, and usually has a thickness of about 10 to 30 mm. The dispersion plate 12 has many holes with a diameter of about 0.5 to 1.0 mm, and the plating solution E rises through these holes, and the chamber 1 on the dispersion plate 12 rises.
This prevents the granular consumable anode 5 filled in the granular anode 5 from falling into the rectifying section 14.

The chamber 15 on the distribution plate 12 is a filling chamber for the granular consumable anode 5 . This chamber 15 communicates with the granular consumable anode supply port 11 via a granular consumable anode supply section 19 provided, for example, at the upper side of the fluidization tank 13 . Furthermore, this...
It is preferable to arrange an insoluble anode 6 for electricity supply in the chamber 15. In addition, the height of the chamber 15 is 50 to 100 m.
It should be about m.

The upper end of the chamber 15 is defined by the first screen 4 . The first screen 4 is made of a material such as polyvinyl chloride or polypropylene, and its pore diameter is large enough that the granular consumable anode 5 before consumption does not pass therethrough.

More specifically, the particle size of the granular consumable anode 5 is typically 1
Since the particle size is 0 to 0.5 mm, a screen with a hole size of about 70 to 50% of the particle size is used as the first screen 4.

Further above the first screen 4 of the fluidization tank 13,
A second screen 3 is provided.

The second screen 3 is made of a material such as polyvinyl chloride or polypropylene, and its pore diameter is smaller than that of the first screen 4. More specifically, the size is such that the granular consumable anode 5 after consumption does not substantially pass through, and the particle size of the granular consumable anode 5 after consumption varies depending on the size before consumption, but is 7.0 to 0. Since the diameter is about .25 mm, a screen with a hole diameter of about 70 to 50% of the particle diameter after consumption is used as the second screen 3.

The height of the passage 16 defined between the first screen 4 and the second screen 3 is usually about 7 to 10 mm, and the distance between the second screen 3 and the metal strip 2 is usually about 10 mm. It is about 20 mm.

The passage 16 communicates with a consumable anode discharge lower located at a position extending from the outer wall of the fluidization tank 13, and the consumable anode discharge lower separates the consumed particulate consumable anode 5 and discharges it out of the plating solution E circulation system. It opens towards a consumable anode separator 17 for use. Examples of the consumable anode IIi device 17 include a filter, a sedimentation separator, and the like. In addition,
As for the consumable anode separator 17, the plating solution E passes through the consumable anode separator 17, rather than a type in which the plating solution E is collected and separated together with the granular consumable anode 5.
It is preferable to use a method in which the particles are collected as they are in the plating solution aiI.

The upper end of the tank wall and/or side wall parallel to the running direction of the metal strip 2 of the fluidization tank 13 may have a height corresponding to the position of the metal strip 2;
It is preferable to extend above the height corresponding to the position of , and to provide overflow pipes 60 and 61 so that the plating solution E comes into contact with the metal strip 2 more reliably.

In particular, as shown in FIG.
If the wall 52 on the metal strip 2 side of the granular consumable anode supply section 19 for filling the granular consumable anode supply section 5 corresponds to the side wall parallel to the running direction of the metal strip 2 of the fluidization tank 13, the volume of the granular consumable anode supply section 19 In order to ensure that the plating solution E on the second screen 3 flows into the chamber 15 from the granular consumable anode supply port 11, the upper end of the side wall corresponds to the position of the metal strip 2. It is better to extend upwards rather than in height.

In addition, when the upper ends of the tank walls and side walls parallel to the running direction of the metal strip 2 of the fluidization tank 13 are made lower than the height corresponding to the position of the metal strip 2, the liquid level of the plating liquid tank 1 should be adjusted to the position of the metal strip 2. It should be above the height corresponding to .

In such a case, the granular consumable anode supply port 11 and the consumable anode separator 17 are provided outside the plating solution tank 1,
Plating solution E recovered by the consumable anode separator 17
It is also preferable to provide a means for returning the plating solution to the plating solution 1.

Further, at the widthwise end of the metal strip 20 between the second screen 3 and the metal strip 2 at the upper part of the fluidization tank 13,
It is preferable to provide an edge mask 18. Thereby, overcoating (edge overcoating) of the widthwise ends of the metal strip 2 can be prevented. Further, the edge mask 18 is preferably movable. This allows the edge mask 18 to accommodate metal strips 2 of various widths.

The conductor roll 8 and the back-arrangement roll 9 may be of known type.

The configuration of the electrolytic treatment apparatus according to the first aspect of the present invention has been described above, and its operation will now be described.

In the electrolytic treatment apparatus of the present invention, plating solution E is sent from plating solution tank 1 into fluidized tank 13 by means such as pump 10 . In the fluidized tank 13, the plating solution E is
The rectifier 14, the chamber 15, and the passage 16 move. When the plating solution E flows into the chamber 15 from the rectifier 14, the dispersion plate 1
Since the plating solution E is passed through the holes No. 2, the plating solution E injected into the chamber 15 has uniform flow rate, plating solution composition, and other timing properties.

A chamber 15 defined by the distribution plate 12 and the first screen 4 is filled with a granular consumable anode 5 . Note that the granular consumable anode 5 is continuously supplied from the granular consumable anode supply port 11 . In this chamber 15, plating 7
The granular consumable anode 5 sold at night E7 is consumed by electrolysis and becomes smaller.

The granular consumable anode 5, which has become smaller due to consumption, passes through the first screen 4 together with the plating solution E and reaches the passage 16. Further, the plating solution E reaches the consumable anode separator 17 via the consumable anode discharge lower, where the consumed granular consumable anode 5 is separated, and at the same time, the plating solution E is returned to the plating solution tank 1.

A portion of the plating solution E does not go to the consumable anode separator 17, but is sent from the passage 16 through the second screen 3 to the electrolytic surface and takes part in the electroplating, after which it passes through the overflow tube 60.
．． 61 and is collected into plating solution [1].

Next, an electrolytic treatment method using the electrolytic treatment apparatus of the present invention will be described.

In electrolytic plating using the electrolytic treatment apparatus of the present invention, as described above, while circulating the plating solution E, electricity is applied to the granular consumable anode 5 through the insoluble anode 6, and electricity is applied to the conductor roll 8 to form the metal strip 2. This is done by running it. The granular consumable anode 5 may be energized via the side wall of the chamber 15 or the dispersion plate 12.

Furthermore, the flow rate (hydraulic pressure) of the plating solution E in the fluidization tank 13 during electroplating is controlled by means such as the pump 10. It is preferable to flow the plating solution E from the lower opening toward the upper opening of the fluidization tank 13 at a flow rate such that the filled granular consumable anode 5 is pressed against the 'fJ1 screen 3.

When electroplating is performed while flowing the plating solution E at such a flow rate, the upper surface of the granular consumable anode 5 is limited to the position of the first screen 3, so the distance between the upper surface of the granular consumable anode 5 and the metal strip 2 is reduced. It becomes constant, and the plating profile becomes uniform. Furthermore, the exhausted particulate consumable anode 5 may be smoothly discharged from the chamber 15 to the passage 16.

Note that the flow rate of plating solution E depends on the type of granular consumable anode,
Optimize by considering the particle size, density and viscosity of the plating solution, etc.

Other conditions during electroplating, such as the composition of the plating solution, the particle size of the granular consumable anode used, the plate passing speed, and the current applied, are as follows:
You can select it as appropriate. In addition, the pore sizes of the first and second screens are determined by considering the particle size of the granular consumable anode used.
It may be selected as appropriate within the range defined by the present invention.

<Example> Below, plating treatments by the method of the present invention and the conventional method will be described, and the effects of the present invention will be specifically shown.

(Example of the present invention) Using the electrolytic treatment apparatus shown in FIGS. 1 and 2, tin plating was performed on a steel plate under the following conditions.

At this time, electricity is applied to the insoluble anode,
Further, the plating solution flow rate was set at a flow rate at which the soluble anode was pressed against the first screen.

[Electrolytic plating conditions] Plating solution composition: Sn”=30g/n, F-=60g/u, Cu=30g/β, Brightener, bath temperature 50℃, Particle size of granular consumable anode: 2mm, First screen pore diameter: 1 mm.

Second screen pore diameter: 0.5 mm.

Plating solution flow rate: 8 cm/sec, metal strip (steel plate) passing rate = 200 mpm.

Metal strip width: 800mm.

The plating thickness was measured at 15 points in the width direction of the obtained tin-plated steel plate, and the profile is shown in Figure 4. The profile was almost uniform.

Further, when the particle size of the anode discharged after continuous 40 hours of plating was measured, it was 0.8 mm on average, and no consumed anode that had passed through the second screen was found.

(Conventional Example) Using the ingot-shaped soluble anode 51 shown in FIG. 3, tin plating was performed on a steel plate under the following conditions.

[Electrolytic plating conditions] Plating solution composition: Sn" = 30g/J2, F- = 60g/
f, C1=30g/Jl.

Brightener, bath temperature 50℃, ingot-shaped soluble anode size near 0mm x 8
0mm x 760mm.

Meter & liquid flow rate: 0, 3 m/sec Passing speed of metal strip (wI plate): 200 mpm% Width of metal strip: 800 mm.

Current-carrying area: 120 dm2 Current: 6,000 A The plating thickness was measured at 15 points in the width direction of the tin-plated steel plate.
The profile is shown in Figure 4, and the plating thickness varied considerably.

Moreover, the replacement of the ingot-shaped soluble anode 51 is as follows:
This had to be done after about 4 hours of continuous plating.

<Effects of the Invention> The present invention provides an electroplating apparatus using a soluble anode, which enables smooth loading and unloading of the anode and prevents uneven thickness of the plated metal, which is a horizontal metal strip. An electrolytic treatment apparatus and an electrolytic treatment method using such an apparatus are provided.

By performing electrolytic treatment using the electrolytic treatment apparatus of the present invention, plated metal plates of stable quality can be obtained with simple operations, and there are no major drawbacks such as generation of toxic gas.
The electrolytic treatment apparatus and electrolytic/A burying method of the present invention have great practical advantages.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view of the method of advancing a metal strip, showing an example of the electrolytic treatment apparatus of the present invention. FIG. FIG. FIG. 3 is a diagram illustrating an electroplating apparatus using a conventional soluble anode. FIG. 4 is a graph showing the profile of the amount of tin deposited in the width direction of tin-plated steel sheets subjected to the metal plating process according to the present invention and the conventional method. Explanation of symbols 1...Plating? night soda, 2... metal strip, 3... second screen, 4... first screen, 5... granular consumable anode, 6... insoluble anode, 7... consumable anode exhaust pressure Port, 8... Conductor roll, 9... Backup roll, 10... Bonf, 11... Granular consumable anode supply port, 12... Dispersion plate, 13... Fluidization tank, 14... Rectifying unit, 15... Chamber, 16... Passage, 17... Consumable anode separator, 18... Edge mask, 19... Granular consumable anode supply unit, 51... Ingot-shaped soluble anode, 52...
Wall, 60.61...Overflow pipe, E...Plating night FIG, 1

Claims (5)

[Claims] (1) A horizontal electrolytic treatment apparatus for metal strips, which is composed of a plating solution tank, a fluidized tank, a conductor roll, and a backup roll. The fluidization tank has an upper opening disposed opposite the lower surface of the metal strip and a lower opening communicating with a means for flowing the plating solution toward the upper opening; , has a second screen, a first screen, and a dispersion plate in order from the top, and a chamber for filling the granular consumable anode is limited by the first screen and the dispersion plate, and this chamber is continuously supplied with the granular consumable anode. The first screen is a screen having a pore size through which the granular consumable anode does not pass through before being consumed, and the second screen is configured with a screen having a smaller pore diameter than the first screen. An apparatus for the electrolytic treatment of metal strip, further comprising means for discharging the particulate spent anode that has passed through the first screen through a passageway between the first and second screens. (2) Claim 1, wherein an insoluble anode for energization is disposed inside the chamber for filling the granular consumable anode.
An apparatus for electrolytic treatment of metal strips as described in . (3) The metal strip electrolytic treatment apparatus according to claim 1 or 2, wherein the tank wall and/or side wall of the fluidized tank parallel to the running direction of the metal strip extends to a position above the running metal strip. . (4) The apparatus for electrolytic treatment of a metal strip according to any one of claims 1 to 3, further comprising an edge mask at an end in the width direction of the metal strip between the second screen and the metal strip. (5) Using the electrolytic treatment apparatus according to any one of claims 1 to 4, the flow rate is such that the granular consumable anode filled in the chamber for filling the granular consumable anode is pressed against the first screen. 1. A method for electrolytic treatment of a metal strip, characterized in that the electrolytic treatment is carried out by flowing a plating solution from a lower opening to an upper opening of a fluidized tank.