JPS5884975A - Regenerating method for treating liquid for chemical dissolution of copper and copper alloy - Google Patents

Abstract

PURPOSE:To perform recovery of metals and regeneration of aged liquid continuously by cooling the aged liquid of treating liquid for dissolution of copper alloys to allow metallic salts to deposit, dissolving the same, recovering metals, and regenerating and circulating the aged liquid after the treatment. CONSTITUTION:The aged liquid of treating liquid for chemical dissolution of copper and copper alloys contg. hydrogen peroxide and persulfate and mineral acids, etc. is cooled to >=250 deg.C under stirring to deposite and separate the metallic salts dissolved in the liquid. The separated metallic salt crystals are transferred into a dissolving cell or electrolytic cell where metals are recovered until concn. of Cu<++> attains 0.05-20g/l. The soln. after the treatment is circulated to the aged liquid separated of the metallic salts and the hydrogen peroxide or persulfate and mineral acids, and additives of the consumed amts. are replenished to prepare regenerated liquid, whereby the liquid is controlled. The regenerated liquid is returned to a tank for the treating liquid for chemical dissolution and is used cyclically.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention recovers metals and active ingredients from an aging solution of a chemical dissolution treatment solution for steel and copper alloys containing hydrogen peroxide or persulfate and mineral acids as main components, and Liquid continuously? !
More specifically, regarding the method of producing the metal salt, the metal salt is precipitated and separated from the aged liquid, the metal salt is dissolved, the metal is recovered by electrolysis, and then the electrolytically treated am liquid is used in a dissolving tank in which the metal salt is dissolved. Alternatively, the present invention relates to a method for regenerating an aged liquid using an electrolytic bath or a closed system in which the metal salt is circulated through a separated mother liquid, the aged liquid is continuously regenerated, and the liquid pipe is salted to be used again as a dissolution treatment.

Traditionally, chemical and chemical dissolution treatment solutions containing hydrogen peroxide and mineral acids such as sulfuric acid, phosphoric acid, nitric acid, hydrofluoric acid, hydrochloric acid, or 7-amino acids as main components are used for chemical polishing of steel and copper alloys. It is used as a chemical solution for pickling, etching, etc.

When copper and copper alloys are subjected to dissolution treatment using this chemical dissolution treatment solution, the degree of dissolution decreases to an industrially unsatisfactory degree, resulting in aging. This aging liquid recovers valuables and is regenerated. Known methods for recovering this valuable material, essentially metals, include electrolysis, adding chemicals, and cooling.

In the electrolytic method, the aged solution is generally subjected to electrolysis as it is, and useful metals are deposited in the negative [iK]. If a large amount of useful hydrogen peroxide is contained in addition to salt and it is electrolytically treated, the useful hydrogen peroxide decomposes before the metal is deposited during electrolysis, resulting in a large loss of hydrogen peroxide. In addition to stabilizers for hydrogen peroxide, the aging solution contains additives such as brighteners and surfactants, and some of these additives may decompose or change in quality during electrolysis. It is inconvenient to use the treated liquid as a regenerated liquid.

In addition, methods for adding chemicals include, for example, adding hydrazine to the aging solution to reduce dissolved metal ions to precipitate metals, and adding oxalic acid to reduce the solubility of dissolved metal salts. Alternatively, phosphoric acid and alkali may be added to precipitate metal salt crystals, or metal powder may be added to forcibly age the aging solution to recover metal salts. There are known methods to do this. However, these methods are not industrially preferable because the chemicals added are expensive and the cost is high.Additionally, the adding method is complicated, and the aged liquid after one metal recovery is used as a regenerating liquid. It is inconvenient to do so.

Therefore, useful metals are recovered from the aged liquid without using the above-mentioned chemicals, without loss due to decomposition of hydrogen peroxide, and without decomposition or alteration of additives present in the aged liquid. A cooling method has been proposed as a method for regenerating aged liquid (41-kai No. 1846-17049). This method cools an aging solution for steel treatment containing water peroxide and sulfuric acid as main components to precipitate crystals of sulfuric acid steel, and separates and collects these crystals from a solution containing hydrogen peroxide. This is a method of regenerating the aged liquid from which the crystals have been separated and removed, by replenishing the active ingredient.

According to the cooling method as described in the above newsletter,
The precipitated metal salt crystals grow and aggregate to form coarse crystals, and these crystals tend to settle and stick to the bottom of the cooling tank or inside the piping, and it is necessary to break up the fixed crystal flow. The separation operation using a cooling tank is troublesome and complicated.

41, when cooling is rapidly cooled to a low temperature of 10℃ or less,
Crystallization progresses quickly, but it is different as a block-like coarse crystal flow is generated.

The precipitated metal salt crystals are not only recovered as they are as metal salts, but also used to recover metals such as steel by electrolyzing the metal salts in an aqueous solution of water and mineral acids. At this time, in the case of coarse crystal lumps, the dissolution rate in water and mineral acid aqueous solution or liquid is slow, and the electrolytic efficiency is poor. For this reason, the work is undesirably complicated, as it is necessary to crush the coarse crystal mass in advance in order to dissolve it in the electrolyte solution in a suitable manner.

Metal salts are precipitated from the aged solution, and then the metal salts are dissolved in an aqueous mineral acid solution and electrolyzed to recover the metal.Meanwhile, the aged solution after removing the metal salts is regenerated and used as a chemical dissolution treatment solution. In the case of coarse crystals such as those mentioned above, the metal salt is transferred to an electrolytic bath or a dissolution bath. There are various disadvantages when transferring with an IK pump.

The present inventors precipitated metal salts from an aged solution of chemical dissolution treatment solutions for steel and copper alloys, then electrolyzed the cough metal salts to recover the metals, and recovered the precipitated metal salts from the electrolytically treated solution. The present invention was developed after conducting various studies on a so-called closed system, which is a method of continuously recovering metals and regenerating the aged liquid by circulating the aged liquid from which 1 or metal salts are separated into a dissolving tank or an electrolytic tank to dissolve metal salts. I did it.

4. The present invention provides a method for cooling an aged solution of a chemical dissolution treatment solution for steel alloys containing as main components a persaponide or a persulfate and a mineral acid at a temperature of at least 25° C. or higher with stirring. , the metal salt dissolved in the aging solution is precipitated, the precipitated metal salt crystals are separated from the aging solution, the separated metal salt crystals are transferred to a dissolution tank or an electrolytic tank, and the metal salt is dissolved in the tank. If the salt is dissolved and dissolved in an electrolytic bath, it continues to be in the 9/# range 8.
The metal is recovered until it becomes Ilc, and the solution after electrolytic treatment II is used in the above-mentioned dissolving tank or electrolyzed*t, or a part of it is recycled into the aged liquid from which the metal salts have been separated. The present invention relates to a method for regenerating a chemical dissolution treatment solution for copper and steel alloys, in which the solution is regenerated, the solution is managed, and the metal is recovered to be used again as a dissolution solution, and the aged solution is continuously regenerated.

The present invention is a closed method for chemically dissolving copper and copper alloys in which metals are recovered from a 3m aging solution by electrolysis, and the aging solution is circulated 1illL without loss of the active ingredients in the aging solution to continuously regenerate the aging solution. The system provides a

Copper and copper alloys to which the present invention is applied include copper and metal containing copper as a main component, such as pure copper, brass, phosphorescent copper, and nickel silver.

In addition, the aging solution is treated by chemical polishing, Al cleaning, etching, etc. using a chemical dissolution treatment solution containing hydrogen peroxide or persulfate and mineral acid as main components, and the dissolution rate is Kl! The liquid has been reduced to a level below which the metal ions mentioned above can be removed by salts of mineral acids, such as sulfuric acid.
1 is a pot which is dissolved in the above chemical dissolution treatment solution to a near saturation concentration at the dissolution treatment temperature.

The chemical dissolution treatment solution in Zero-Hatsu@ contains hydrogen peroxide or persulfate as a main component in an amount of 20 fl/l or more, preferably S011/l to 3ooV7. Mineral acids such as sulfuric acid, phosphoric acid, hydrofluoric acid, nitric acid, hydrochloric acid, or sulfamino acid at 10%
/g or more, preferably 2011A to 10011/l. These mineral acids can be used alone or in a mixture if desired, and usually 4il is used alone, but sulfuric acid and other mineral acids are used in combination depending on the type of steel alloy to be treated.

The chemical dissolution contemplation WLK also includes Airecols, 7
Stabilizers for hydrogen peroxide such as i7tL carboxylic acid; Additives such as brighteners and surfactants, usually from 0°1V# to 101A
has been added. The treatment of steel and steel alloys with this rigorous treatment liquid is usually carried out at a temperature of 30° C. or higher, 40° C. to 70° C., and usually takes 5 seconds to rise and takes 10 seconds to 30 minutes. Then, the aged liquid whose dissolution rate has decreased below a predetermined rate is transferred from the *S treatment to the cooling tank. In the cooling tank, the aged liquid is cooled at a temperature of 25° C. or higher with stirring. Various methods can be used for cooling, for example, a method of installing a cooling water circulation pipe in the cooling treatment tank and passing the cooling water through this, or a method of installing a jacket on the cooling II & passage tank and creating a double wall. And how to pass cooling water through this, further K
Examples of methods include blowing cold air. Furthermore, the cooling tank is equipped with a stirring means for the aging liquid and an automatic temperature control device to maintain the liquid temperature at a predetermined temperature. Stirring can also be carried out by various methods, such as a method using a stirrer, a method using a circulating liquid itself, a method using bubbling, and other well-known methods can also be applied. If the stirring speed is too slow, it will not be possible to obtain fine crystals, while if the stirring speed is too fast, it may lead to decomposition of hydrogen peroxide, which is undesirable. A degree of one-turn change of ~60 Orpm is suitable. This stirring is carried out at a predetermined temperature of 25°C or lower, usually within 60 minutes, preferably within 50 minutes, after the metal salt crystals start to precipitate, and then left to stand for a while to separate the crystals and liquid. Ru. After the formation of metal salt crystal precipitation is observed, stirring may be stopped and the mixture may be allowed to stand still with N to precipitate crystals. The metal salt crystals generated by this stirring operation become moldy granular crystals, and even after the stirring is stopped, the crystals do not grow and become coarse in the form of nodules, and are used in subsequent operations, such as a separator. It is convenient for transporting metal salts and dissolving metal salts after separation.

After the above-mentioned cooling treatment, the produced crystals and liquid are separated, and this separation method can be performed using any known method such as filtration, centrifugation, decantation, etc. Ru. Peroxide ions derived from hydrogen peroxide or persulfate and additives remain in the liquid separated from the metal salts without decomposition or deterioration, so metals can be processed without decomposition or deterioration. Be sure to add enough hydrogen peroxide or persulfate and mineral acid to the amount consumed! Additives are replenished according to the aging process, the liquid is managed as a regenerating liquid, and the liquid is returned to the chemical dissolution treatment bath for circulation. It is transferred to an electrolytic cell, dissolved in water or/and an aqueous solution of mineral acid, and subjected to electrolysis. If the metal salt is dissolved in the dissolution tank, the solution is transferred to the electrolytic tank, and if the metal salt is dissolved in the electrolytic tank, it is subsequently electrolyzed. The method of dissolving in an electrolytic bath is preferable because it is inexpensive and uses both the #Is oak and the electrolytic bath.

Electrolysis uses insoluble metal materials such as graphite, stainless steel, titanium, lead oxide, peracid, ferrite, platinum, etc. as the anode, and in addition to the same materials used for the armpit anode, aluminum, zinc, steel, nickel, etc. 50'C with metal as cathode
If the metal is recovered until the temperature reaches 0 tK at ~80°C or until the CIJ++ degree in the electrolytic solution falls below the above range, the current efficiency will drop significantly, which is not preferable.

The solution containing the acid and metal ions after the electrolytic treatment is used for dissolving the metal salts mentioned above or is recycled as an electrolytic solution. Further, a part of the solution after the electrolytic treatment is used as a replenisher for regenerating the aged solution after the metal salt separation.

This makes it virtually impossible to neutralize the electrolytically treated solution containing acids and metal ions to treat wastewater.
A so-called closed system is possible, and by circulating it as a replenisher for regenerating the aged liquid, it is possible to prevent the amount of regenerating liquid from increasing excessively, and it is possible to continuously recover metals and regenerate the aged liquid. I can do it.

Thus, according to the present invention, only the metal dissolved in the aging solution is extracted from the aging solution of the chemical dissolution treatment solution for copper and steel alloys, and active ingredients such as hydrogen peroxide, mineral acids, or additives are efficiently recovered. This makes it possible to create a closed system for reusing aged liquids, and provides a conceptual method for recovering active ingredients from aged liquids and regenerating aged liquids.

Examples are described below.

Example 1 H,Osya ti/as u snow 80. 184
171°. -Butylamine 55μ single-sided steel-clad printed circuit board with a capacity of 1 using etching solution from 501ife.
01 paddle etcher tester, liquid temperature 50±2℃
Etching is performed at a constant etching speed while replenishing HsOs 5617 and HsOs 5617.
g%H*804 18511A% Cu4 S 117
An aged liquid was obtained containing g. 10.5 liters of this aged liquid was extracted from the bottom of the tank and transferred to a cooling tank with a capacity of 20 g. In the cooling tank, cooling water at 3 to 5°C was flowed through a stainless steel cooling pipe, stirred at a stirring speed of 60 rpm using a stirrer, and cooled with stirring for about 15 minutes until the temperature of the case reached 25°C. Thereafter, the mixture was allowed to stand for 10 minutes, and granular copper sulfate crystals with a length of 1 to 2% were precipitated. This aged liquid containing crystals of copper sulfate is gently stirred again to form a slurry, and this slurry is supplied to a suction-filtering machine in which an endless cloth rotates using a slurry pump to separate it into liquid V and crystals. 1.4
5KI#) Cu80m·5H30 crystals were obtained. Transfer this to the 5I electrolytic tank and 81804 245
Add 2I of an electrolytic solution obtained by electrolysis in advance containing 1/S, Cu6II/L, and use 7 Pb0m plates as anodes.
Electrolytic voltage 3.8V using 6 Cm plates as cathodes.

Electrolysis was carried out at 45 to 60° C. with a cathode current rating of 6.5 μm/al K, and 228 #II of dHrllKCa was recovered (total yield 9 s%).

HI304 417 I is used in the electrolyte after partially removing the metal.
ll s (:w 5 , 5 Ill tl'kratt
I'm in L Te'ri. This solution was used as a solution for dissolving metal salts.

On the other hand, Fl [K is H1o snow 75
JF/1% H*80g 1851/g%Cu 4
Since it contained 11% f, Hm O dew and Hx 80
Replenish a and rH snow 0 8 0 171% H*80
a 1 9 8 lagsCwa S 7 V
G? No regeneration liquid was used. When a steel-clad printed board was partially layered with this recycled lJj etching solution in the same manner as above, it was possible to perform etching with a nearly uniform dissolution rate - Example 2 Brass, 1 HsOm72171%Hx which was chemically polished continuously while replenishing H dew Om by dipping for 1 minute, crystals attached to the surface and good chemical polishing was no longer possible.
804155νg, Su7ken 311A, Nonionic surfactant 1 HI1%Cm 521/g, Ztx
Chemical polishing 1 including 251/g! ') Transfer the chlorinated liquid to a double-walled cooling tank with a jacket, pass cooling water through the jacket, and cool for about 25 minutes while stirring, until the temperature of the liquid reaches 28°C and metal salt crystals precipitate. When the stirring started, the stirring was stopped and the mixture was allowed to stand still for about 25 minutes. Thereafter, the mixture was gently stirred again to prepare a slurry, and the crystals were separated in the same manner as in Example 1. The crystals were transferred to an electronic tank, and H3804S 101/g, Zn, which had been previously obtained by electrolytic treatment, was added to the crystals.
Add an aqueous solution containing 51/e and heat to 50°C while stirring.
Using seven graphite sheets as anodes and six +tan plates as cathodes, the bath voltages S and SV and the cathode current density were set to 6.
Electrolysis was carried out at 4 A/m and 50-65°C. The crystals completely dissolved after 20 minutes, and 6 Hr ilK Cu was 8911
g1 was collected. At time point C, electrolysis was carried out using 6 mulch plates as the cathode at a bath voltage of 5.4 V and a cathode current density of 6.5 people/d, and 4 Hr @ K Zn was incubated at 40 I11 m.

The electrolyte after collecting the metal is HlSOa 41511
/g s Zt 41/g f including A+1"&'ri@
In addition to being used as an electrolyte for circulation, a portion of the electrolyte was also recycled. On the other hand, in the filtrate from which the metal salt crystals were separated, Hmon 69 Il1% H-deprived SOm was added.
152Fg.

Cu 2 @ Ill s and za 12 lag
It included trL. This solution was supplemented with 20% by volume of F#l and HsOm after the above electrolytic treatment.
m 801/Is Ha80a 1951/a
When chemical polishing was performed on a brass plate in the same manner,
4 sy, zg.

Good chemical polishing could be performed until Zn21JF/# was obtained.

License applicant: Mitsubishi Gas Chemical Co., Ltd. Representative Nagano Japanese Blind

Claims (1)

[Claims] An aged solution of a chemical dissolution treatment solution for copper and copper alloys containing hydrogen peroxide or persulfate and a mineral acid as main components is cooled with stirring at a temperature of at least 25°C, and 1% is added to the aging solution.
1% metal salt is precipitated, the precipitated metal salt crystals are separated from the aged liquid, and then the separated metal salt crystals are
When transferred to a IIJIF tank or an electrolytic tank, and dissolved in the electrolytic tank, 051/fl ~ 20 sheets
The oxidized metal is recovered until it reaches 11, while the solution after the electrolytic treatment is circulated to the dissolving tank or electrolytic tank, or a part of it is recycled to the aged solution from which the metal salts have been separated. A chemical dissolution #& treatment solution regeneration method for steel and steel alloys, characterized in that the metal is recovered to be used again as a dissolution treatment solution and the aging solution is continuously regenerated by controlling the solution.