JPS61149479A - Treatment of spent chemical copper plating solution - Google Patents

Abstract

PURPOSE:To recover efficiently high purity copper and a copper ion complexing agent from a spent chemical copper plating soln. in a short time by adjusting the plating soln. to a high pH, depositing metallic copper on a metallic catalyst such as copper under reduced pressure, and adding an inorg. acid to crystallize the complexing agent. CONSTITUTION:A spent chemical copper plating soln. contg. bivalent copper ions, a copper ion complexing agent, pH adjusting agent and a reducing agent as principal component is adjusted to >=11.0pH with an alkali such as NaOH and introduced into a vacuum tank contg. a metallic plating catalyst such as Cu, Pd, Pt or Ni. The tank is evacuated to deposit copper ions in the spent plating soln. on the catalyst as metallic copper. After the deposited copper is recovered, the remaining soln. contg. practically no copper ions is adjusted to 1-2pH with an inorg. acid such as H2SO4 to crystallize the complexing agent such as EDTA, which is then separated by filtration and recovered.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for recovering cake and complexing agent from chemical copper plating waste liquid.

[Technical background of the invention and its problems 1 Divalent copper ion, its complexing agent and PH adjuster.

To recover copper and complexing agent from chemical copper plating waste liquid containing reducing agent as the main component, after breaking the bond between copper and complexing agent, the pH of solution F is set to 1 to 2 and the complexing agent is crystallized. A method of analysis and recovery is used. Conventionally, the first method has been used to break the bond between copper and a complexing agent.

Namely, ① A method in which excess formalin and sodium hydroxide are placed in waste liquid and heated to precipitate copper.

■Method of adsorbing palladium in waste liquid, adding activated carbon, and depositing it on palladium as metal steel〇■Method of adding a chemical to break up copper-copper-lead complexing agent bonds.

However, in these methods, (1) is carried out at a high temperature, N, and pH, which requires 10 hours to - day and night to completely precipitate copper, so the Cannitzaro reaction proceeds.

Requires a large amount of formalin and hydroxide). 0■, which requires a considerable amount of energy and time for heating and cooling, cannot sufficiently remove copper ions from the waste liquid. It is expensive because it uses a large amount of palladium.5 It is unsuitable for reuse because the recovered complexing agent is contaminated with impurities. The process of recovering the chemicals that break the bonds becomes complicated. [Objective of the Invention] The present invention eliminates the above-mentioned drawbacks of the prior art and efficiently uses high-purity copper and a complexing agent. [Summary of the Invention] The present invention provides a method for treating chemical copper plating waste liquid that can be easily recovered in a short time. PHvl of chemical copper plating waste liquid
1, a step of increasing the temperature to 0 or more, and a reduced pressure tank equipped with a catalyst metal selected from copper, palladium, platinum, and nickel.
a step of introducing the chemical copper plating waste solution; a step of reducing the pressure in the vacuum tank to precipitate copper ions in the chemical copper plating waste solution onto the plating catalyst metal as metal steel; and adding inorganic RG to the solution in the vacuum tank. , to adjust the pH to 1.0-2.0.
A method for treating chemical copper plating waste liquid, comprising a step of crystallizing and recovering a complexing agent for valence copper ions.

In other words, chemical copper plating waste liquid with a pH of 11 or higher,
By reducing the pressure in a vacuum tank equipped with a plating catalyst metal, copper is deposited on the catalyst metal as metal steel and recovered, and the pH of the residual liquid is adjusted to 1.0 to 2.0 to recover a high purity complexing agent. There it is.

According to the present invention, the conventional drawbacks can be overcome as follows.

(1) Copper in wastewater can be almost completely removed. (2) No need to raise the temperature to break the bond between copper and complexing agent. No extra energy or time required. (3) 0(4) High purity copper and complexing agent can be efficiently recovered in a short time without the need for a large amount of formalin and sodium hydroxide to prevent the Canitzaro reaction from proceeding.

(5) Can be implemented on an industrial scale 〇 [Examples of the Invention Examples of the present invention will be described in more detail below.

Example 1 The plating waste liquid used in this example is as follows. Plating solution composition; Cu804・5Hs0 0.03 mob/J-E
DTA(4Na) 0.06 rHCHOO,
10# Amount α, α′ dipyridyl to make NaOHPH 12.5 10 Misaki/J2MBT
It was used in the field for one week at 1°Ol.

Figure 1 is a flowchart of the present invention.
The plating waste liquid is made to have a pH of 11.0 or more with sodium hydroxide, and then the pressure is reduced to precipitate - on the catalyst metal.
Add H2SO4 and adjust the pH to 1-2, preferably 1.5-2
Adjust to 0 to precipitate EDTA. Separate this EDTA precipitate, neutralize it with fJ solution with sodium hydroxide, and discard. On the other hand, BDTA d is recovered by washing with water and reused as a chemical copper plating solution.0 Figure 2 shows a companion device used in the present invention based on the drawing.
0 mesh copper mesh) and is immersed in the waste liquid 3.

Reference number 5 used a vacuum pump with an ultimate vacuum level of 5xlOTorr, number O1 used a vacuum gauge using a Pillary vacuum gauge, and number 6 was adjusted to a predetermined temperature using a heater. In addition, 7 in the figure is the valve, 8Lr
i pumps are shown respectively.

Figure 3: pH of plating waste liquid is 12.5. Temperature 30℃, catalyst gold pA surface area s 6m2/l, degree of vacuum 5 x 10-
The relationship between the time when copper is deposited at 1 Torr and the residual copper content is 0. It can be seen that the residual copper content can be removed to 0.3 ppm in about 5 hours.

FIG. 4 shows the relationship between the treatment PH and the residual copper content when the PR of the plating waste solution was varied from 11.0 to 13.5 and the plating was deposited for 5 hours under the same conditions as above.

As can be seen from this figure, when the pH is 11.5 N, the concentration of copper remaining in the liquid returned after 5 hours rapidly decreases. Therefore, the PHtri of the waste liquid is preferably 11.5% or more. Especially, 12.5 or above is good]
Ru.

FIG. 5 shows the relationship between temperature and residual copper concentration when plating was deposited for 5 hours under the same conditions as above with the temperature of the plating waste solution varied from 10 to 50°C. A temperature of 30°C was most efficient. Moreover, when the temperature rose to 30° C. or higher, the copper concentration in the residual liquid tended to increase. This is PH and HCH
Since the O9 degree decreases more rapidly than that of 30 degrees Celsius, the Canitzaro reaction progresses and is considered to be the 99th ED.
Considering acid treatment for TA recovery, the temperature of plating waste liquid Fi20
It is found that the temperature is preferably 25 to 35°C, preferably 25 to 35°C.

After removing the copper ions, the pH of the remaining solution was adjusted to 1.5, EDTA was passed through the recovery port, and after rinsing with water several times, this was used again to prepare a chemical copper plating solution with the above composition, It has been recognized that the plating results do not have any adverse effects on the gloss, physical properties, bath stability, and deposition rate of the plating film.

[Effects of the Invention] As is clear from the above description and examples, the present invention uses an extremely simple device and operation.

Waste liquid treatment of chemical copper plating solution can be carried out on an industrial scale.

Furthermore, the drawbacks of the prior art can be eliminated, high purity copper and complexing agent can be efficiently recovered, and these can be adjusted and plated again, so the plating cost can be extremely reduced.

[Brief explanation of drawings]

FIG. 1 is a flowchart of the method of the present invention, FIG. 2 is a schematic diagram of an apparatus using the method of the present invention, and FIGS. 39 to 5 are characteristic diagrams using the method of the present invention. 1... Pillary vacuum gauge 2... 200 mesh copper mesh 3... Plating waste liquid 4... Decompression tank 5... Vacuum pump 6... Heater 7... Valve
8... Pump agent Patent attorney Nori Chika Kensuke (and 1 other person) Toki (/-/) Me ξ Ori PH No. 5 Zuyu [・C]

Claims (1)

[Claims] A step of increasing the pH of a chemical copper plating waste solution containing divalent copper ions, a complexing agent thereof, a PH adjuster, and a reducing agent to 11.0 or higher, copper, palladium, platinum, A step of introducing the chemical copper plating waste liquid into a pressure reduction tank in which a plating catalyst metal selected from nickel is arranged, and reducing the pressure in the pressure reduction tank to transfer copper ions in the chemical copper plating waste liquid onto the plating catalyst metal. and a step of adding an inorganic acid to the solution in the reduced pressure tank to adjust the pH to 1 to 2 to crystallize and recover a complexing agent for divalent copper ions. Processing method for chemical copper plating waste liquid.