JP2002294497A - Continuous plating equipment with device for collecting and concentrating rinse water for plating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To collect and concentrate rinse water for plating with a labor saving device, which does not need short-term maintenance and check, is suitable for enhancement of a strip passing speed and a continuous long-term operation of the plating equipment, and is not large-scale. SOLUTION: This plating equipment has an electrodialysis tank which employs polypropylene(PP) for a reinforcing material of an ion exchange membrane, and in addition, a two-fluid nozzle for cleaning of the plating liquid. Thereby, it can enhance the strip passing speed in the plating equipment, continuously work for a long time, collect and concentrate rinse water for plating by arranging just small electrodialysis cells, and in addition, efficiently collect and concentrate the plating liquid because the cells are resistant to a strong acid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a long metal strip used for various terminals such as a connector which is a connecting part for electric equipment and a lead material for an IC lead frame and the like, which is made of gold, nickel, tin, solder or the like. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous plating apparatus for performing plating, in which a plating solution adheres to a plated material and a plating solution taken out of a plating tank is collected and recycled by a collecting and concentrating mechanism.

[0002]

2. Description of the Related Art Conventionally, in a continuous plating apparatus for a long metal strip used for various terminals such as connectors, which are joint parts for electric equipment, and lead materials for IC lead frames, etc., it adheres to a plated material and forms a plating tank. The plating solution taken out of the plant may be collected and reused, but in most cases, the metal ion concentration is diluted to below environmental standards with washing water that cleans the plating material, and is then discharged as wastewater. I was The plating solution can be reused by returning the plating washing water to the plating tank as it is, by evaporating and concentrating the plating washing water and returning it to the plating tank as a plating solution, or by using a chelating resin or ion exchange resin to remove impurities. There is a method in which metal ions are removed, the removed plating washing water is used as an anolyte, and electrolysis is performed in a diaphragm electrolytic cell via an ion exchange membrane, and the resulting solution is circulated to the plating tank as a plating solution in which metal is dissolved. Further, as a technique for recovering plating components, there are an adsorption and recovery technique using a chelate resin and an adsorption and recovery technique using an ion exchange resin. However, the method of returning the plating solution to the plating bath as it is is effective in a system where the operating temperature of the plating solution is sufficiently high and natural evaporation of the solution volume can be sufficiently expected. Over. In addition, the method of heating and concentrating and reusing the plating solution requires a separate system for heating and evaporating, increasing the line cost, and is not an efficient method.

The technique of circulating a plating solution by using a chelate resin or an ion exchange resin requires a short-term resin exchange operation of the chelate resin or the ion exchange resin, and therefore requires a long-term increase in the plating machine passing speed. It is not a suitable technology for continuous operation. Also, in the case of a plating solution of a strong acid, the membrane deteriorated, and the replacement frequency was large, and the efficiency was poor. And since the plating solution taken out of the plating tank is diluted by a large amount of washing water, the concentration of plating metal ions is low,
Even if a recovery device is installed, recovery efficiency is poor, there is no merit in equipment, and recovery and reuse of cleaning water including plating has hardly been performed. On the other hand, when the line speed is increased to improve plating efficiency and continuous operation is performed for a long period of time, the amount of metal ions contained in the plating solution and flowing out increases, which is a main factor in soaring the cost of chemical raw materials. There has been a long-awaited need for a technology for efficiently collecting and reusing wastewater.

[0004]

Under these circumstances, short-term maintenance / inspection work is not required, the plating speed of the plating apparatus is improved, and long-term continuous operation is suitable, and large-scale equipment is not required. There is a long-awaited need for a technique for recovering and concentrating plating cleaning water using a facility that does not require any effort.

[0005]

Means for Solving the Problems The present inventors have diligently studied the above-mentioned problems, and collect plating washing water taken out of the plating tank in an electrodialysis tank via a cation exchange membrane and an anion exchange membrane. A continuous plating apparatus equipped with a plating and washing water collecting and concentrating mechanism characterized by collecting and concentrating plating washing water in the tank by electrodialysis treatment and supplying it as a new plating solution has been developed. That is, the present invention provides: (1) a continuous plating apparatus, in which washing water containing a plating solution after washing a material to which a plating solution is adhered is passed through an electrodialysis tank via a cation exchange membrane and an anion exchange membrane. It is characterized in that plating metal ions are concentrated by dialysis and supplied to the plating tank as a new plating solution.
Continuous plating equipment with a plating water recovery and concentration mechanism. (2) The electrodialysis tank is provided with a mechanism for collecting and concentrating plating washing water according to (1), wherein an anion exchange membrane and a cation exchange membrane are alternately arranged to form a compartment. Continuous plating equipment. (3) The cation exchange membrane of the electrodialysis tank is a hydrocarbon organic membrane containing a sodium group and an anion exchange membrane containing chlorine groups, and polypropylene is used as a reinforcing material for the exchange membrane. A continuous plating apparatus provided with a mechanism for collecting and concentrating plating cleaning water according to any one of (1) to (2). (4) In the electrodialysis layer, the desalted plating washing water is used as washing water for the washing tank (1) to (3).
4. A continuous plating apparatus provided with a collecting and concentrating mechanism for plating washing water according to 1. (5) In a washing tank after the plating tank, a mist-like mixture of pure water and gas is sprayed onto the plated material by a two-fluid nozzle to increase the concentration of plating washing water. (4) A continuous plating apparatus provided with a mechanism for collecting and concentrating plating cleaning water according to (4). It is.

[0006] With this apparatus, the ion exchange membrane can be managed by periodic maintenance, the plating speed of the plating apparatus can be increased, and long-term continuous operation can be supported. Recovery and concentration can be performed. Also, a durable ion exchange membrane is used for the strong acid plating solution,
Recovery and concentration by electrodialysis can be performed on any plating solution.

[0007]

Embodiments of the present invention will be described below. FIG. 1 is a schematic view of the plating apparatus of the present invention. The plating solution adheres to the material that has come out of the plating tank. The plating solution attached to the material is washed with a washing solution in a washing tank, and the washing solution containing the plating solution after the washing is treated in an electrodialysis tank, and is desalted with a concentrated solution in which plating metal ions are concentrated, The concentrate is divided into a desalinated solution having a low metal ion concentration, and the concentrated solution is stored in a storage tank and reused as a plating solution. Further, the desalted solution is reused as a washing solution. The inventions of claims 1 and 2 concentrate the plating metal ions by electrodialyzing the washing water containing the plating solution in an electrodialysis tank via a cation exchange membrane and an anion exchange membrane, and as a new plating solution. It is characterized in that it is supplied to a plating tank.

Referring to FIG. 3, one of the ion exchange membranes will be described.
The seed anion exchange membrane 24 is permeable to organic acid ions,
It has a high ion block rate for metal ions in the plating waste liquid. On the other hand, the cation exchange membrane 23 transmits metal ions in the plating solution symmetrically to the anion exchange membrane, and has a high ion block rate with respect to organic acid ions. In the electrodialysis tank, anion exchange membranes and cation exchange membranes are alternately arranged, and a washing liquid containing a plating solution adhered to the plated material is put in 25 as room fluid on the anode side across the cation membrane. On the other hand, a concentrated liquid concentrated via an ion-exchange membrane is put into 26 as a chamber liquid on the cathode side across the cation membrane. When these ion exchange membranes and chamber liquids are combined in multiple stages, and when electricity is supplied, various ions selectively pass through the ion exchange membrane. The solution containing metal ions that did not pass through the cation exchange membrane is used as the next chamber solution,
Collect and concentrate many metal ions in plating wash water.
On the other hand, the concentrated solution is also transferred to the next chamber solution to further concentrate and recover the plating solution. The electrodialysis system provides a plating apparatus having a mechanism for reusing plating washing water. Further, the plating cleaning water, which is substantially pure water after the electrodialysis treatment, is reused as the cleaning water as described in claim 4 to form a more closed system.

According to a third aspect of the present invention, the cation exchange membrane of the electrodialysis tank is a hydrocarbon-based organic membrane containing a sodium group and the anion exchange membrane contains a chlorine group.
It is characterized by using polypropylene (hereinafter referred to as PP). Polyvinyl chloride (PVC), which is generally used as an ion exchange membrane reinforcing material, has poor durability with a strong acid plating solution and is not suitable for long-term stable operation.
However, PP has acid resistance, and when used as a reinforcing agent, can be applied to a plating solution of a strong acid. Another reason for using a hydrocarbon-based organic membrane is that there is another fluorine-based ion-exchange membrane.The fluorine-based membrane is very excellent in durability, but the cost of the membrane is about Since it takes 20 times, an inexpensive hydrocarbon organic film was selected.

[0010] The invention of claim 5 is characterized in that a mist-like mixture of pure water and gas is sprayed on the plated material by a two-fluid nozzle in a washing tank after the plating tank, and the mixture is plated. By spraying, the cleaning efficiency is improved, the concentration of plating metal ions in the cleaning water after cleaning is increased, the plating metal ions are efficiently collected, and the cleaning water can be reused. FIG. 2 is a schematic view of a cleaning tank using a two-fluid nozzle. When a two-fluid nozzle is used, the mixing ratio of water and gas (such as air) is 1: 0.5 to 1: 2.
It is preferable to spray at a pressure of 0.1 kg / cm ² or more. As described above, by providing the electrodialysis system and the washing tank using the two-fluid nozzle, the concentration of the plating waste liquid can be effectively increased, and the plating waste liquid can be reused.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The best mode for carrying out the present invention will be described below with reference to tin plating. The amount of the plating solution adhered to the plating material was 1 mL / dm ² , and the carried-out amount of the plating solution calculated from the tin plating conditions was 6.3 L / h.
r, and about 360 g / hr of tin in the plating waste liquid adhering to the plating material is discharged. Conventionally, cleaning of the material after plating has been performed at 700 mL / min, and the tin concentration in the plating cleaning water has been 0.5 to 3 g / L. That is, 7 ~
Forty percent of the tin was recovered in the wash water, and the remaining tin-containing deposit was taken to a subsequent step. In the present invention, by using a two-fluid nozzle for this cleaning, equivalent cleaning is possible with a cleaning water amount of 70 mL / min, which is 1/10 of the amount.
Tin concentration in plating wash water using a two-fluid nozzle
It was 30 g / L, and highly efficient washing was performed.
Wash water after washing with this two-fluid nozzle, washing water tank,
When used as a washing solution of an electrodialysis system consisting of 50 chambers in each of the concentration tanks and dialysis using an organic acid solution as an electrode solution, after about 20 hours of dialysis, it is concentrated to the same tin concentration of 60 g / L as the plating tank We were able to. Further, the washing solution can be desalted to 10 mg / L or less, and the washing solution after dialysis is in a state close to pure water, and about 95% or more of tin can be recovered and concentrated. The concentrated solution after dialysis was circulated to a storage tank and used again as a plating solution.
On the other hand, the desalted liquid was reused as washing water for the two-fluid nozzle.

[0012]

According to the present invention, an electrodialysis tank is installed, polypropylene (PP) is used as a reinforcing agent for the ion-exchange membrane, and a two-fluid nozzle is used for cleaning the plating solution. Can also be applied, and efficient recovery and concentration of the plating solution has become possible.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a continuous plating apparatus of the present invention.

[Figure 2] Schematic diagram of cleaning tank

FIG. 3 is a schematic diagram of an electrodialysis system.

[Explanation of Codes] Plating tank 2. 2. Plating material washing tank Electrodialysis tank 4. Storage tank 5. Wash water 6. Concentrate 7. Desalting solution 8. Plating material 11. Two-fluid nozzle 12. Drainer roll 13. Plating material 14. Air flow 15. Wash water flow 21. Anode 22. Cathode 23. Cation exchange membrane 24. Anion exchange membrane 25. Washing water tank 26. Concentrated water tank 27. Pole room

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) C02F 1/469 C23G 3/00 A C23G 3/00 B C25D 5/48 C25D 5/48 7/00 H 7/00 21 / 18 B 21/18 H01L 23/50 D H01L 23/50 C02F 1/46 103 F term (reference) 4D006 GA17 MA13 MA14 MC73 MC77 PA02 PB08 PB27 PC22 4D061 DA08 DB13 EA09 EB13 EB19 FA09 4K024 AA07 BB10 BB13 BC16 CB26 DB10 GA10 4K053 PA12 QA06 RA07 SA04 XA22 YA13 YA15 5F067 DC01 DC05

Claims (5)

[Claims] In a continuous plating apparatus, washing water containing a plating solution after washing a material to which a plating solution is attached is electrodialyzed in an electrodialysis tank via a cation exchange membrane and an anion exchange membrane. To concentrate the plating metal ions,
A continuous plating apparatus equipped with a mechanism for collecting and concentrating plating washing water, which is supplied to a plating tank as a new plating solution. 2. The mechanism for collecting and concentrating plating washing water according to claim 1, wherein the electrodialysis tank has a compartment formed by alternately arranging anion exchange membranes and cation exchange membranes. Equipped continuous plating equipment. 3. The cation exchange membrane of the electrodialysis tank is a hydrocarbon-based organic membrane containing a sodium group and an anion exchange membrane containing a chlorine group, and polypropylene is used as a reinforcing material of the exchange membrane. Item 3. A continuous plating apparatus provided with a collecting and concentrating mechanism for plating washing water according to Item 1 or 2. 4. The continuous plating method according to claim 1, wherein the desalted plating washing water is used as washing water in the washing tank in the electrodialysis tank. apparatus. 5. A plating tank, wherein a mist-like mixture of pure water and gas is sprayed onto the plated material by a two-fluid nozzle in a washing tank after the plating tank, thereby increasing the concentration of plating washing water. 5. A continuous plating apparatus comprising the plating and washing water recovery and concentration mechanism according to any one of 1 to 4.