JPH059798A - Method for dissolving metal powder in electro-plating - Google Patents

Abstract

PURPOSE:To extremely easily dissolve the metal powder in electroplating without need for a special device such as a metal powder recovery means. CONSTITUTION:A part of the metal powder charged into a solution tank 2 is mixed into a plating soln. to be sent to a suspended matter treating system 4 consisting of a cushion tank 5, a filter 6, a dehydrator 7, etc., and discharged, and a part of the dissolving action in the solution tank is assigned to the suspended matter treating system.

Description

Detailed Description of the Invention

[0001]

This invention relates to electroplating,
The present invention relates to a method for dissolving metal powder when supplying metal ions to a plating solution.

[0002]

2. Description of the Related Art For example, iron-based electroplating is performed in a plating solution.
Fe²⁺Electroplating is performed by ion precipitation reaction.
However, as the plating process progresses, Fe in the plating solution²⁺ion
Is Fe due to the oxidation reaction³⁺It will generate ions. Servant
This plating solution is Fe²⁺Fe is replenished with ions
³⁺Ions need to be reduced and are typically stirred or flow
The Fe is added to the dynamic tank³⁺Circulate the plating solution containing ions
Then, while iron powder is added to this, this iron powder is dissolved
By Fe ²⁺Ion supply and Fe³⁺To reduce the ions
We are trying to reuse the plating solution.

Such a treatment of the plating solution does not greatly change in the electroplating of other metals as well as in the case of the above-mentioned iron-based electroplating except for the reducing action. Since various suspensions are mixed in the plating solution during this treatment, the suspension in the plating solution is suspended by a suspension treatment system consisting of a filtration device etc. in the process of returning from the dissolution tank to the plating equipment. Remove turbidity.

On the other hand, the metal powder charged into the melting tank was dissolved as soon as possible from the viewpoint of controllability of the amount charged and the like, so as not to escape to the suspension treatment system as much as possible. Therefore, as disclosed in, for example, Japanese Patent Application Laid-Open No. 59-126799, there is a method of recovering unreacted powder or particles that carry over when circulating a plating solution and recycling to the reaction tank.

[0005]

[Problems to be Solved by the Invention] If the metal powder charged into the melting tank is to be dissolved quickly and completely, the capacity of the stirrer or the like will be increased, and the melting tank itself will be inevitably large. Further, the method disclosed in JP-A-59-126799 requires a device for recovering unreacted powder or particles, and even in this case, if a complete recovery is attempted, a considerably large device is installed. It must be taken into consideration, and considering the maintenance and so on, it will be a great financial burden and a problem.

The present invention uses the dissolution tank and the suspension treatment system which have been conventionally used as they are, and the iron powder put into the dissolution tank is added without any increase in the burden economically and in process. The object is to provide a method capable of completely dissolving.

[0007]

A method for dissolving metal powder in electroplating according to the present invention comprises a metal powder dissolving tank and a suspension for removing a suspension in a plating solution delivered from the dissolving tank. A method for dissolving metal powder in electroplating, which comprises dissolving a metal powder into a plating solution in the dissolution tank by using a plating solution treatment facility having a treatment system, wherein the introduced metal powder The problem of the above-mentioned conventional technique was solved by sharing the above-mentioned dissolution in the dissolution tank and in the suspension treatment system.

[0008]

[Operation] The plating solution returned from the dissolution tank to the plating equipment is passed through a suspension treatment system such as a filtration device in order to remove the suspension as described above. This invention was made with a focus on what is said. In other words, the metal powder added to the plating solution in the melting tank does not need to be completely dissolved in the melting tank, and some undissolved metal powder is lost in the plating solution returned to the plating equipment. Even if it is released, this escaped metal powder is not discarded together with the suspension that is finally discarded, but the suspension treatment system works in the same way as the dissolution tank to completely dissolve it until then. I thought that it would cause.

Therefore, in the present invention, the dissolution of the metal powder charged in the plating solution in the dissolution tank is shared between the dissolution tank and the suspension treatment system. It was also found that there is no particular limitation on the share, and rather the equipment and pipes installed in the suspension treatment system can be put to practical use sufficiently if they do not become worn out too much by the passing metal powder. ..

[0010]

EXAMPLE FIG. 1 shows an outline of iron-based electroplating solution treatment equipment including a dissolution tank and a suspension treatment system. In the figure, reference numeral 1 denotes a circulation tank from which a plating solution is fed to an electroplating cell (not shown) and receives a plating solution returned from the electroplating cell.

A part of the plating solution in the circulation tank 1 is sent to the dissolution tank 2 through the pipe 10, and in the dissolution tank 2, Fe ²⁺ ions are replenished and Fe ^{3 +} is added as described above. ⁺ Ions are reduced. The dissolution tank 2 in this example is a stirring type, and the iron powder and the plating solution charged by the stirrer 3 are stirred, but this may be a dissolution tank of another type such as a fluid type.

Then, the iron powder that has been introduced is mixed in the plating solution returned to the plating equipment side while being partially undissolved and sent to the suspension treatment system 4 through the pipe 11. Incidentally, in the past, a plating solution containing no iron powder was sent to the suspension treatment system 4 by a recovery means or the like.
As mentioned above, the iron powder that escaped from the product is mixed.

In the suspension treatment system 4, first, the cushion tank 5 stores a plating solution containing iron powder (hereinafter, the solution in this state is simply referred to as a plating solution). The cushion tank 5 functions as a buffer between the dissolution tank 2 and the suspension treatment system 4. This cushion tank 5
A small part of the iron powder mixed in is dissolved. Subsequently, the plating solution is sent to the filter 6 through the pipe 12. The filter 6 is capable of removing fine suspended matter, such as a leaf filter, and two or more filters are alternately used. Most of the iron powder is dissolved in the filter 6.
Here, the clean plating solution that has passed through the filter 6 is returned to the circulation tank 1 through the pipe 13 and used again.

On the other hand, when the filter cloth of the filter 6 is clogged to some extent, the suspension captured by the filter 6 is piped.
It is cleaned with a clean plating solution supplied through a cleaning pipe 14 branched from 13, and is sent to the dehydrator 7 through a pipe 15 in the form of a slurry together with this plating solution. Almost no iron powder remains in the suspension treated up to this point, but even if it remains, it will be completely dissolved during dehydration in the dehydrator 7. Then, the suspension after dehydration is taken out as a cake, carried out of the system by the conveyor 8 and discarded. In addition,
The plating solution separated by the dehydrator 7 is returned to the cushion tank 5 again via the pipe 16.

The iron powder thus escaped from the dissolution tank 2 and supplied to the suspension treatment system 4 together with the plating solution can be completely dissolved during the treatment process, and therefore is mixed with the suspension cake and discarded. There is no joy to be told. 2000 g of iron powder (per 1 m ^{3 of} plating solution, the same applies below) was added to the plating solution in the stirring type dissolution tank and dissolved, but part of the iron powder added at this time was mixed in the plating solution. Escape to the suspension treatment system. In this case, the amount of iron powder escaped from the melting tank is 305g.
(15.25% of the input amount). Then, the amount of iron powder remaining in each part of the suspension treatment system was investigated. As a result, it was 295g on the outlet side of the cushion tank (dissolved amount was 3.3% of the escaped amount), and about 7g in terms of the amount of plating liquid sent from the dissolution tank in the slurry-like liquid discharged from the filter, The amount dissolved in the filter was 288 g, which was 94.4% of the amount released. Further, there was no trace of iron powder remaining in the cake of the suspension discharged from the dehydrator or in the plating solution returned to the cushion tank.

From the above results, it was confirmed that the iron powder was completely dissolved in the process of treating the suspension even if the iron powder was allowed to escape from the dissolution tank to the suspension treatment system together with the plating solution. ..
The amount of iron powder that escapes from the melting tank does not have to be accurately controlled, and the approximate amount can be controlled by simple means such as adjusting the position of the plating solution outlet piping. is there.

In the above description, iron-based electroplating has been described, but this is also applicable to electroplating of metals having a large difference in ionization tendency from other H ⁺ ions, for example, metals such as Zn and Ni. Of course it will be done.

[0018]

When the method for dissolving metal powder in electroplating according to the present invention is carried out, it is not necessary to completely dissolve the metal powder charged in the plating solution in the melting tank, and therefore the metal powder It does not require a special device such as a recovery means and the conventional equipment can be used as it is, which is extremely economically advantageous.

Moreover, since there is almost no restriction on the share of the dissolution of the metal powder in the dissolution tank and in the suspension treatment system, there is an advantage that the dissolution work is extremely simple.

[Brief description of drawings]

FIG. 1 is a schematic explanatory diagram of an iron-based electroplating solution treatment facility including a dissolution tank and a suspension treatment system.

[Explanation of symbols]

 1 Circulation tank 2 Dissolution tank 3 Stirrer 4 Suspension processing system 5 Cushion tank 6 Filtration machine 7 Dehydrator 8 Conveyor 10-16 Piping

Claims (1)

Claim: What is claimed is: 1. A plating solution treatment facility having a metal powder dissolving tank and a suspension treatment system for removing a suspension in the plating solution delivered from the dissolving tank. A method for dissolving metal powder in electroplating, wherein the metal powder is dissolved while adding the metal powder to the plating solution in the dissolution tank, wherein the dissolution of the introduced metal powder is suspended in the dissolution tank and in the suspension. A method for melting metal powder in electroplating, characterized in that the method is shared with the inside of a material processing system.