JPH04214900A - Device for supplying metal ion in electroplating - Google Patents

Abstract

PURPOSE:To prevent drainage of fine metallic particles into plating solution tank and to prevent generation of press scratches in the plated products in a supplying device of metal ion in the case of electroplating by using insoluble anode. Additionally, to effectively remove sludge and to prevent quality deteriora tion of the plated products. CONSTITUTION:In the case of draining plating solution having increased concentration of metal ion into plating solution tank, as the filter 10 is provided in free board part 8 of the main body of the metal dissolution tank 19 to prevent the drainage of fine particles, generation of pressed scratches in plated products and deterioration of plated products are diminished. Also, by disposing sludge removal tank 11 in lower part of packed tank part 5 of the main body of the metal dissolution tank 19, sludge (mainly consist of Zn, Fe, Ni, Pb.) are removed regularly and preventing redissolution of harmful metals such as Fe, Ni, Pb and to diminish deterioration of characteristic value of the plated products.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for supplying metal ions in electroplating using an insoluble anode.

0002

[Prior Art] In recent years, in electroplating of steel materials, steel plates, etc., insoluble anodes that do not elute plating metal ions into the plating solution are used to stabilize the amount of plating metal ions dissolved in the plating solution and to reduce power consumption. Electroplating using Although various metal platings are used, Zn will be described as a typical example.

[0003] In Zn plating using an insoluble anode, a sulfate bath is generally used, and the reactions at the anode and cathode are as follows:
Cathode Zn2++2e→Zn
...(1)
Anode SO42- +H2O →H
2SO4 + 1/2O2↑+2e (2). That is, in the plating solution, Zn according to formula (1)
Since a decrease in 2+ and a decrease in pH according to equation (2) occur, it is necessary to supply metal ions and adjust the pH continuously and periodically.

[0004] In the case of Zn plating, there are Zn metal or its oxides, hydroxides, carbonates, etc. as a supply source of metal ions, and from the viewpoint of cost and workability, Zn metal is used to reduce Zn2+ ions. The method used is to immerse it in a plating solution and dissolve it. The reaction at this time is
Zn+H2SO4 →Zn
SO4 +H2↑ …(3
), and an increase in metal ions (Zn2+) and a rise in pH occur. That is, by the reaction of this formula (3),
This is advantageous because it can simultaneously compensate for the decrease in Zn2+ ions and the decrease in pH described above.

Conventional methods for supplying metal ions in a plating solution include a packed bed method and a barrel method. The packed bed method is disclosed, for example, in Japanese Patent Application Laid-Open No. 58-151489, and as shown in FIG. 2
8. Pass through the filling zinc particles 29 and discharge gap 3 at the top of the filling tank
0 and sent to the electrolytic cell again. Note that the generated hydrogen gas 32 is discharged from the piping at the top of the filling tank.

On the other hand, there is a barrel method disclosed in Japanese Utility Model Application Publication No. 60-25761. As shown in FIG. 6, in the liquid tank 33, a hollow rotary barrel 37 is immersed in the plating solution 34, has a large number of holes 35 on the outer periphery, and has metal grains 36 inside. It is provided. The metal particles are supplied from the hopper 38 and the plating solution in the plating bath with reduced metal ion concentration is supplied from the introduction pipe 39 to the hollow rotary body 37, and the hollow rotary body 37 rotates to prevent the metal particles 36 from coming into contact with each other. This process destroys the hydroxide film formed on the surface of each metal particle 36 to promote dissolution of the metal particles 36, and as a result of this dissolution, the plating solution with increased metal ion concentration is discharged through the outlet pipe 40. This is a method in which the water is extracted from a tank 33.

[0007]

[Problems to be Solved by the Invention] However, in the packed bed method disclosed in the above-mentioned Japanese Unexamined Patent Application Publication No. 58-151489, etc., when the plating solution is delivered to the plating bath, there is no filter attached, so fine particles are removed. If the metal powder is drawn out or even flows into the plating bath and adheres to the rolls, it may cause press scratches on the plated product and significantly impair the properties of the plated product. Furthermore, it has drawbacks such as the inability to remove sludge.

[0008] Furthermore, in the barrel method disclosed in Japanese Utility Model Application Publication No. 60-25761, etc., what controls the supply of metal ions is the pH of the plating solution, as described above.
This method also has the problem that the dissolution rate is extremely reduced when the pH approaches 4, and that sludge cannot be removed. An object of the present invention is to provide a metal ion supply device for electroplating that solves these problems.

[0009]

[Means for Solving the Problems] The present invention provides a solution in which a metal chip is dissolved in a circulating plating solution in which the concentration of metal ions is reduced and the concentration of metal ions is increased from a plating bath in which predetermined metal plating is carried out. , a metal ion supply device for electroplating for supplying to the above or other plating baths, which has a plating solution supply port at the bottom and a plating solution discharge port at the top, and fills and holds metal chips. A dissolving tank main body, a filter that is located in a freeboard part of the metal dissolving tank main body and filters the plating solution discharged to the discharge port, and a bottom part that is connected to the lower part of the metal dissolving tank main body via a perforated plate. This is a metal ion supply device for electroplating, characterized in that it has a sludge removal tank which is inclined at an angle of 30 to 60° with respect to a horizontal plane and has a sludge extraction port at the lowest position of the bottom. The present invention also provides a metal ion supply device for electroplating, wherein the sludge removal tank has a spray nozzle for a fluid for cleaning and removing sludge.

[0010] Furthermore, the sludge removal tank has a spray nozzle for a fluid for cleaning and removing sludge. Furthermore, the metal dissolving tank main body has a metal chip supply port at the top, and the metal dissolving tank main body has an inert gas supply port and an H2 gas discharge port at the top.

[0011]

[Operation] The operation of the present invention will be explained with reference to the drawings. In the metal ion supply device of the present invention, as shown in FIG. 2, a filter 10 is installed in the freeboard portion 8 of the metal dissolution tank main body 19, so that the plating solution with increased metal ion concentration is supplied to the plating solution tank. Since the fine metal powder is not extracted when the plating bath is taken out, the metal powder that has flowed into the plating bath will adhere to the roll and cause scratches on the plating product.
There is no risk of damaging the characteristic values of the plating product.

Furthermore, since the sludge removal tank 11 (inclined at 30 to 60 degrees) is installed at the bottom of the filling tank section 5 of the metal dissolution tank main body 19, sludge (mainly Zn, Fe,
(contains Ni and Pb) and removes Fe and Ni that are harmful to plating.
, Pb, etc. can be prevented from being redissolved, eliminating the risk of damaging the characteristic values of the plated product. In addition to the above, sludge removal tank 11
A device having a spray nozzle 12 for cleaning and removing sludge can effectively discharge sludge out of the system.

Further, as shown in FIG. 4, the metal melting tank body 19
In the case where the metal chip supply port 20 is provided at the upper part, the metal chips can be continuously melted by periodically supplying the metal chips from the metal chip hopper 21 to the metal melting tank, for example. In addition, as shown in FIG. 4, the metal melting tank body 1
9 has an inert gas supply port 24 and an H2 gas discharge port 2 at the top.
5, by diluting H2 generated as the metal chip melts with an inert gas such as N2 gas,
Explosion and combustion caused by H2 gas can be prevented, which is advantageous in terms of safety.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be explained based on the drawings. FIG. 1 is an overall configuration diagram of a first embodiment in which a metal ion supply device of the present invention is installed in plating equipment, and FIG. 2 is a detailed diagram of the metal ion supply device in the first embodiment. In FIG. 1, 1 is a plating bath, 2 is a metal ion supply device of the present invention, and 3 is a circulation tank.

The circulation tank 3 has a liquid tank 3a through which a plating solution with a reduced metal ion concentration passes, and a liquid tank 3b through which a plating solution with an increased metal ion concentration passes, and the liquid tank 3a has a pipe 14, The liquid tank 3b is connected to the plating bath 1 and the metal ion supply device 2 through pipes 16 and 17, respectively. 18 is a pump.

Then, the plating solution whose metal ion concentration has been reduced in the plating bath 1 is sent from the pipe 14 to the liquid tank 3a to the pipe 15 to the perforated plate 7 to the metal ion supply device 2 via the pump 18. In the metal ion supply device 2, the metal ion concentration of the plating solution increases as the electroformed Zn chip 4 is dissolved. This plating solution with increased metal ion concentration is supplied again to the plating bath 1 or another plating bath via the pipe 16→liquid tank 3b→pipe 17.

Next, in FIG. 2, inside the metal ion supply device 2, an electroformed Zn chip 4 is made of SUS316L or T
It is arbitrarily filled so as to contact the filling tank part 5 manufactured by i. Reference numeral 6 denotes a plating solution supply port provided at the lower part of the filling tank section 5. 7 is a perforated plate provided above the supply port 6;
Made of SUS 316L or Ti, 2mm at 5mm intervals
A hole of φ is drilled.

8 is a sludge settling tank section. Reference numeral 9 denotes a discharge port for a plating solution provided at the top of the freeboard section 8 to increase the concentration of metal ions. 10 is a 5-10 μm fluororesin filter that filters the plating solution discharged from the discharge port 9. The filter 10 prevents fine metal powder contained in the plating solution from being discharged from the plating solution outlet.

11 is a sludge removal tank. The sludge that has fallen from the metal melting tank body 19 through the perforated plate 7 is
The sludge is introduced into a sludge removal tank 11, where it is periodically scraped off by spray nozzles 12 (pressure: 0.5 to 2 kg/cm2, installed at 10 cm intervals), and discharged outside the system by opening and closing an electromagnetic valve 13. This removes sludge containing Fe, Ni, and Pb that may impair plating quality.

Next, FIG. 3 is an overall configuration diagram of a second embodiment of the present invention, and FIG. 4 is a detailed diagram of a metal ion supply device in the second embodiment. In this embodiment, the metal melting tank body 1
9 has a metal chip supply port 20 at the top. Metal chips (or electroformed Zn chips) 4 are supplied to the metal chip supply port 20 from a metal chip hopper 21 .

22 is a vibrator which collects the metal chips (or electroformed Zn chips) in the metal chip hopper 21 and the metal chips (or electroformed Zn chips) in the metal chip supply port 20.
Vibration is applied to prevent chip) 4 from hanging on the shelf. 23 is a solenoid valve, and the Zn consumed in electroplating is
The amount of dissolved Zn is calculated and metal chips (or electroformed Zn chips) 4 are periodically cut out.

Further, 24 is an N2 gas supply port, and 25 is an N2 gas supply port.
This is an outlet for H2 gas diluted by gas, and H2 gas generated when the metal chip (or electroformed Zn chip) 4 is melted.
This is to prevent explosion of two gases.

[0023]

[Effects of the Invention] As described in detail above, according to the present invention, the plating solution with increased metal ion concentration is introduced into the plating bath by using an electroformed metal tip in a filled tank method for dissolving the plating metal. However, since there are no press scratches and the sludge can be discharged periodically, there is no risk of damaging the characteristic values of the plated product.

Furthermore, since the apparatus of the present invention is cheaper than the conventional barrel method, manufacturing costs can be significantly reduced. Furthermore, in the conventional method, a large amount of Zn(OH)2 and sludge are generated (metal powder falls from the barrel mesh and deposits), so these are mixed into the plating solution with increased metal ions, and are eventually carried into the plating bath. However, since electroformed metal chips are almost completely melted, they are less likely to be deposited as sludge in the melting device, and this risk is extremely small in the present invention.

Further, by providing a metal chip supply port in the upper part of the metal melting tank main body, continuous melting of metal chips is possible. In addition, by providing an N2 gas supply port on the top of the metal melting tank body to dilute the H2 gas generated when metal chips (or electroformed Zn chips) are melted, explosions and combustion can be prevented, and metal chips (or electroformed Zn chips) can be melted. It is also effective in preventing oxidation of electroformed Zn chips.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of a first embodiment of the present invention.

FIG. 2 is a detailed diagram of the metal ion supply device in the first embodiment of the present invention.

FIG. 3 is an overall configuration diagram of a second embodiment of the present invention.

FIG. 4 is a detailed diagram of a metal ion supply device in a second embodiment of the present invention.

FIG. 5 is an explanatory diagram of a conventional device.

FIG. 6 is an explanatory diagram of a conventional device.

[Explanation of symbols]

1 Plating bathtub 2
Metal ion supply device 3
Circulation tank 3a, 3
b Liquid tank 4 Electroformed Zn chip 5
Filling tank part 6
Supply port 7 Perforated plate 8 Free board part 9
Outlet 10
filter 11
Sludge removal tank 12
Spray nozzle 13
Solenoid valve 14, 15, 16, 17 pipe

Claims (4)

[Claims] 1. A metal chip is dissolved in the circulating plating solution in which the metal ion concentration has been reduced from a plating bath in which a predetermined metal plating is performed, and the solution in which the metal ion concentration has been increased is transferred to the above or another plating bath. A metal ion supply device in electroplating for supplying metal ions, which has a plating solution supply port at the bottom and a plating solution discharge port at the top, and includes a metal dissolution tank body for filling and holding metal chips, and a metal dissolution tank body for filling and holding metal chips, and A filter that is located in the freeboard part of the tank body and filters the plating solution discharged to the discharge port, and a filter that is connected to the lower part of the metal dissolution tank body via a perforated plate, the bottom of which is 30 to 60 mm with respect to the horizontal surface. 1. A supply device for metal ions in electroplating, comprising a sludge removal tank that is inclined at an angle of .degree. and has a sludge outlet at the lowest position of the bottom. 2. The apparatus for supplying metal ions in electroplating according to claim 1, wherein the sludge removal tank has a spray nozzle for a fluid for cleaning and removing sludge. 3. Claim 1, wherein the metal melting tank body has a metal chip supply port at an upper part.
Or the metal ion supply device for electroplating according to 2. 4. The apparatus for supplying metal ions in electroplating according to claim 1, 2 or 3, wherein the metal dissolution tank body has an inert gas supply port and an H2 gas discharge port at an upper portion thereof. .