JPH0625771A - Production of alkaline earth metal chloride and method for recovering valuable copper component - Google Patents

Abstract

PURPOSE:To obtain a high-purity alkaline earth metal chloride and to recover a valuable copper-component by bringing a soln. of an alkaline earth metal sulfide and a waste liquid of copper board etching into reaction. CONSTITUTION:The soln. of the alkaline earth metal sulfide, such as barium sulfide, and the etching liquid of copper printed circuit boards are mixed and are brought into reaction under stirring. These solns. are converted to the alkaline earth metal chloride, such as barium chloride and copper sulfide which are then respectively recovered by a sepn. of a liquid from solid. The leaching liquid of the product of reduction and roasting of barite ore or celestite ore is usable as the alkaline earth metal sulfide.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an alkaline earth metal chloride and a method for recovering a valuable copper component, and more specifically, for treating an etching waste liquid of a copper plate which is generated in a large amount in the field of electronic materials industry. The present invention relates to a method for producing an alkaline earth metal chloride with high purity.

[0002]

2. Description of the Related Art Conventionally, the industrial production method of an alkaline earth metal chloride is mainly a method of adding hydrochloric acid to a barium sulfide aqueous solution or a strontium sulfide aqueous solution obtained by reducing roasting and leaching of barite or celesite ore. It is carried out based on the reaction of the following formula (1). MeS + 2HCl = MeCl ₂ + H ₂ S (1) (In the formula, Me represents Ba and Sr)

In this method, however, hydrogen sulfide gas is produced as a by-product during the above reaction, but since this hydrogen sulfide gas is toxic and highly corrosive, its safe handling and detoxification treatment are required. Various measures are essential,
Not only is the incidental equipment required for the detoxification treatment costly, but the production of alkaline earth metal chlorides such as barium chloride and strontium chloride itself is often affected by the treatment of hydrogen sulfide gas. It was

On the other hand, as a method for producing barium chloride without generation of such toxic hydrogen sulfide gas, for example, barite, carbon and calcium chloride are mixed and roasted at a high temperature and the following (2) ), The reaction of BaSO ₄ + 4C + CaCl ₂ = BaCl ₂ + CaS + 4CO (2) The method of adding hydrochloric acid to barium carbonate to carry out the reaction of the following formula (3), BaCO ₃ + 2HCl = BaCl ₂ + CO ₂ + H ₂ O (3) A method of reacting barium chloride with chlorine gas at 600 to 800 ° C., and the like are known.

However, in these methods, unstable and toxic by-products such as calcium sulfide are produced in large amounts, expensive raw materials such as barium carbonate are required, and chlorine gas, which is highly corrosive, is added. None of these methods are practical because they have to be handled at high temperatures and have drawbacks such as a low reaction rate.

[0006] As another method for producing barium chloride,
A method for producing barium chloride by introducing chlorine gas diluted with an inert gas into a barium sulfide aqueous solution is known.
(Japanese Patent Publication No. 53-27238).

On the other hand, in the electronic industry, a large amount of processing liquid for etching a copper printed wiring board (hereinafter referred to as "copper plate etching waste liquid") is generated. Conventionally, such copper plate etching waste liquid is collected and utilized as cuprous oxide which is an antifouling pigment such as a ship bottom paint (for example, JP-A-55).
-71629, JP-A-56-155020). As another method, it is known to recover copper salts or copper powder.

[0008]

As described above, in the barium salt or strontium salt manufacturing industry, usually, an alkaline earth metal sulfide solution obtained by leaching a reduced roasted product of barite or celestite ore with water is used as a starting material. In order to
The production cost of barium salts, etc.
_In connection with the processing cost of ₂ S gas, in many cases, it is difficult to render H ₂ S gas harmless and the cost is high.

Further, none of the methods for producing barium chloride, which does not produce H ₂ S gas as a by-product, has no industrial advantage.
It has not reached the stage of implementation. On the other hand, although the copper plate etching waste liquid has been attempted to be recovered as various copper valuable substances as described above, not only is there a problem in treating chloride as secondary waste water, but there are limits to the current treatment method. Since it is not digested, the disposal of copper plate etching waste liquid is still required to be solved as a serious contemporary problem in the industry.

The inventors of the present invention took the above problems seriously and conducted diligent research. As a result, by reacting an alkaline earth metal sulfide solution with a copper plate etching waste liquid, an extremely high purity alkaline earth metal chloride was obtained. The inventors have completed the present invention by discovering that substances and sulfides can be recovered.

That is, the present invention intends to solve all the problems of manufacturers of barium salts and the like and manufacturers of printed wiring boards of copper by reacting an alkaline earth metal sulfide solution with a copper plate etching waste solution. By doing so, it is intended to produce and recover high-purity alkaline earth metal chlorides and alkaline earth metal chlorides.

[0012]

A method to be provided by the present invention is characterized in that an alkaline earth metal sulfide (hereinafter referred to as "barium sulfide etc.") solution and a copper plate etching waste liquid are reacted. As an alkaline earth metal chloride
(Hereinafter referred to as "barium chloride etc.") and copper valuable components are manufactured and recovered.

In the present invention, the solution such as barium sulfide as a starting material does not have to be critical in terms of production history and concentration, but in many cases, a leachate of a reduced roasted product of barite or Celestite ore is particularly industrially useful. It is advantageous.

The richer the leachate, it is better to consider the later step. In many cases, Me (Me represents Ba and Sr) is 100 to 500 g / liter, preferably 2
Practical use is from 0 to 500 g / liter.

However, a solution having a low MeS concentration, such as a washing solution of a reduced roasted product, may be used. Further, in the present invention, the meaning of a solution such as barium sulfide is a generic term of not only alkaline earth metal sulfides but also soluble alkaline earth metal sulfides contained in a solution such as polysulfides and hydrosulfides.

On the other hand, the copper plate etching waste liquid is a treatment liquid obtained by etching a copper printed wiring board with a cupric chloride aqueous solution or a hydrochloric acid solution containing an oxidizing agent such as hydrogen peroxide. Stuff is included. CuCl: 0~50g / l CuCl _2: 30~300g / l free HCl: 10 to 200 g / l Other: 0~30g / l

Other components include Ni ²⁺ , Zn ²⁺ , F
Heavy metal ions such as e ³⁺ , anions such as PO ₄ ³⁻ and F ⁻ , or organic substances are contained in a small amount, but the main composition is an aqueous cupric chloride solution containing free hydrochloric acid.

In the present invention, the above copper plate etching solution can be used as it is as a raw material, but if necessary, it is used after being filtered or subjected to oxidation treatment such as air oxidation or hydrogen peroxide.

According to the present invention, the two solutions are mixed and reacted,
It is converted into barium chloride and copper sulfide, and then solid-liquid separation is performed to recover each. As the reaction method, any method may be used, such as a method of simultaneously adding both solutions, a method of adding a copper plate etching waste solution to a barium sulfide solution, or the opposite method, but the simultaneous addition method is operationally free.

In this reaction, a quantitative balance is a problem due to the properties of both solutions, but if it is desired to consume more barium sulfide etc. by using the copper plate etching waste solution, design the waste solution as needed. Amount of hydrochloric acid and / or chloride second
By adding copper and reacting, both liquids can be disposed reasonably and arbitrarily.

Since the present invention proceeds extremely stoichiometrically and rapidly, it is not necessary for the temperature and concentration to be critical, but in terms of the subsequent solid-liquid separation operation, the filterability is such that copper sulfide is produced. It is preferable to set various conditions and, if necessary, perform an aging treatment under heating after the completion of the reaction.

Further, it is advantageous that the barium sulfide solution and the copper plate etching waste liquid are concentrated in consideration of the subsequent operations such as concentration and crystallization.

Further, although this reaction is a neutralization reaction of barium sulfide and the like, as long as Cu ²⁺ is present in the reaction system, the precipitation reaction of copper sulfide has priority and hydrogen sulfide generation is not recognized.
However, in order to suppress the generation of hydrogen sulfide gas and perform a safer operation, it is preferable that the pH of the reaction is 4 or less, especially on the acidic side.

Therefore, by measuring the redox potential of the reaction system, it is possible to operate safely and to know the end point of the reaction.

After completion of the reaction, after aging for a while, solid-liquid separation is performed by filtration or centrifugal treatment, and the precipitate is washed and dried to recover as a valuable component of copper sulfide, which is used as a raw material for smelting copper. Can be reused.

On the other hand, the recovered mother liquor is subjected to purification and concentration operations, if necessary, and then crystallized to obtain a crystalline substance such as barium chloride (BaCl ₂ .2H ₂ O or SrCl ₂ .6).
H ₂ O).

Despite the fact that the copper etching waste liquid is used as a raw material, barium chloride and the like obtained by the method according to the present invention are more predictable than barium chloride and the like which is based on the reaction between a leachate such as barium sulfide and hydrochloric acid, which is a conventional method. It turned out to be highly pure. The reason for this is that all heavy metal ions and other impurities contained in the copper plate etching waste liquid are precipitated or adsorbed as sulfide with copper sulfide precipitation, and the solubility of sulfide is extremely low. Therefore, the mother liquor is converted into high-purity barium chloride or the like.

In the present invention, barium salts and strontium salts are industrially used as the alkaline earth metal salts, but calcium salts can be applied in the same manner.

[0029]

The present invention resides in that a barium sulfide solution and a copper plate etching waste liquid are mixed to recover barium chloride and a valuable copper component, respectively. In the above mixing process,
Barium is shown as a representative, but Sr and Ca are also the same,
The main reaction of the following formula occurs. BaS + CuCl ₂ → BaCl ₂ + CuS ↓ (4)

Further, the heavy metal ions of Cu ²⁺ or less in the copper plate etching waste liquid are precipitated as sulfides as in the reaction of the formula (4), and other dissolved impurities are also substantially adsorbed by this precipitate.

That is, since the copper etching waste liquid contains free hydrochloric acid, hydrogen sulfide gas should be generated by the reaction of the following formula BaS + 2HCl → BaCl ₂ + H ₂ S ↑ (5) during neutralization with the barium sulfide solution. In Although,
As long as heavy metal ions such as Cu ²⁺ are dissolved in the reaction system, Me ²⁺ + S ^2- → MeS ↓ (6) (In the formula, Me ²⁺ is Cu ²⁺ , Ni ²⁺ , Zn ^2+, etc. All of the above reactions precipitate as metal sulfides with very low solubility.

Finally, in the method according to the present invention, substantially
Without observing the generation of hydrogen sulfide gas as in formula (5),
Extremely stoichiometric and rapid production of barium chloride and copper sulfide.

Therefore, according to the present invention, high-purity barium chloride or the like can be produced from the mother liquor, and it can also contribute to the recycling of copper resources using copper sulfide as a smelting raw material.

[0034]

【Example】

Example 1 (continuous reaction) 1361 parts by weight of a barium sulfide solution (BaS: 12.44%) obtained by reduction roasting and leaching of barite ore, copper plate etching waste liquid (CuCl ₂ : 22.52%, F-).
HCl: 1.57%, Zn ²⁺ 80.5ppm, Mn ²⁺ : 0.2
1 ppm, Ni ²⁺ : 54.4 ppm, Cr ³⁺ : 0.15 ppm,
F ⁻ : 27 ppm, COD: 78 ppm) (597 parts by weight) were simultaneously added to the reaction vessel and mixed with stirring.

The reaction in this case was carried out at room temperature while maintaining the redox potential of the system at 0 to 100 mV and keeping the pH within a predetermined range, but no H ₂ S gas was generated until the reaction was completed. I was able to operate it safely. Then, after aging for 30 minutes, the treated solution was neutralized to pH 6.5 with barium carbonate and separated by filtration (Ba yield in the reaction completed solution was 97%). Heavy metal ions and reducing substances were not detected in the separation liquid, so they were concentrated and crystallized to give B.
It was recovered as a crystalline product of aCl ₂ .2H ₂ O. When this crystal product was analyzed, the results shown in Table 1 below were obtained. On the other hand, the black precipitate was washed and dried to recover as copper sulfide powder, which could be sent as a copper smelting raw material.

Example 2 (batch reaction) The same copper plate etching waste liquid (CuCl ₂ : 2) as in Example 1 was used.
2.52%) 299 parts by weight was placed in a reaction vessel, and barium sulfide solution (BaS: 12.44%) 68 was added at room temperature while stirring.
2 parts by weight were gradually added. The pH at the end of the reaction is 0.
5. The oxidation-reduction potential was 50 mV, and the generation of H ₂ S gas was not observed, and the operation was safe. Then, after aging for 30 minutes, the treated solution was neutralized with barium hydroxide to pH 6.5 and separated by filtration (Ba yield in the reaction completed solution was 98.1%). Almost no heavy metal ions and reducing substances were detected in the separated mother liquor. Therefore, the concentrated mother liquor was concentrated and crystallized to recover BaCl ₂ .2H ₂ O crystals. The crystals were analyzed and the results shown in Table 1 below were obtained. On the other hand, the black precipitate was washed and dried to recover as copper sulfide powder, which could be sent as a copper smelting raw material.

Example 3 (mixed use with HCl) The same copper plate etching waste solution as in Example 1 (CuCl ₂ : 2)
2.52%, F-HCl: 1.57%) 90 parts by weight and hydrochloric acid
A solution prepared by mixing 73 parts by weight of reagent first-grade HCl: 35% was placed in a reaction vessel, and 706 parts by weight of a barium sulfide solution (BaS: 12.44) was gradually added with stirring at room temperature. This batch was added at room temperature, the pH at the end of the reaction was 4, the redox potential was -400 mV, and H ₂
The S gas started to be generated after the inflection point of the redox potential, and was generated until the end of the reaction. After the dissolved H ₂ S gas was degassed by aeration, it was aged for 30 minutes, the treated liquid was neutralized to pH 7.0 with barium hydroxide, and separated by filtration.

In the separated mother liquor, a trace amount of iron ions and a reducing property were detected, and thus the precipitate formed after the oxidation treatment was adjusted to pH 7.0 and separated by filtration. The filtrate was concentrated and then crystallized to recover BaCl ₂ .2H ₂ O crystals. The crystals were analyzed and the results shown in Table 1 below were obtained. On the other hand, the black precipitate was washed and dried to recover as copper sulfide powder, which could be sent as copper smelting.

[0039]

[Table 1] Quality characteristics Example 1 Example 2 Example 3 BaCl ₂ .2H ₂ O (%) 99.5 99.3 99.4 Water insoluble matter (%) 0.0010 0.0008 0.0027 Iodine reducing substance (%) 0.0001 or less 0.0001 or less 0.0001 Fe (%) 0.00002 0.00004 0.00004 Cu (%) 0.0001 or less 0.0001 or less 0.0001 or less The JIS-K-1414 barium chloride standard is sufficiently passed by any method.

Example 4 A strontium sulfide solution (SrS: 4.60%) obtained by reducing roasting and leaching treatment of Celestite ore 26
02 parts by weight and the same copper plate etching waste liquid (Cu as in Example 1)
Cl ₂ : 22.52%) (597 parts by weight) was mixed into the reaction vessel while stirring at the same time. The reaction by this mixing is performed at room temperature while maintaining the redox potential of the system at 0 to 100 mV.
Although H was maintained within a predetermined range, H ₂ S was not generated until the reaction was completed, and safe operation was possible.

Next, the post-treatment liquid which had been aged for 30 minutes was neutralized to pH 6.5 with strontium carbonate and separated by filtration.
(The Sr yield in the reaction completed liquid is 96.5%). Almost no heavy metal ions and reducing substances were detected in the separated mother liquor. Therefore, the concentrated mother liquor was subjected to crystallization treatment after concentration, and SrCl ₂
6H ₂ O crystals were recovered. When this crystal product was analyzed, the results shown in Table 2 were obtained. On the other hand, the black precipitate was washed and dried to recover as copper sulfide powder, which could be sent as a copper smelting raw material.

[0042]

[Table 2]

[0043]

According to the method of the present invention, high-purity barium chloride can be produced while treating the copper plate etching waste liquid. In particular, as long as heavy metal ions such as Cu ²⁺ are dissolved, hydrogen sulfide gas is not substantially generated, and barium sulfide and a copper plate etching waste liquid are arbitrarily and rationally reacted to produce barium chloride. It is possible to recover valuable copper components in parallel with manufacturing. This, conventionally, in the barium salt manufacturing industry, in the generation of hydrogen sulfide gas, when considering the difficulty and great cost of the treatment, the industrial significance of the method according to the present invention is said to be of great significance. I can do it.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Komitsu Uno 9-15-1, Kameido, Koto-ku, Tokyo Nihon Kagaku Kogyo Co., Ltd.

Claims (4)

[Claims] 1. A method for producing an alkaline earth metal chloride and recovering a valuable copper component, which comprises reacting an alkaline earth metal sulfide solution with a copper plate etching waste liquid. 2. The alkaline earth metal sulfide solution and the copper plate etching waste liquid are reacted in the presence of Cu in the reaction system, and the mother liquor separated by solid-liquid separation is converted into alkaline earth metal chloride crystals by a crystallization operation. On the other hand, a method for producing an alkaline earth metal chloride and recovering a valuable copper component, which comprises recovering a solid matter as copper sulfide. 3. The method for producing an alkaline earth metal chloride and recovering a valuable copper component according to claim 1 or 2, wherein the alkaline earth metal sulfide is a leachate of a reduced roasted product of barite or Celestite ore. 4. The copper plate etching waste liquid is CuCl: 0 to 5
The alkaline earth metal according to claim 1 or 2, which is an aqueous solution having a chemical composition of 0 g / liter, CuCl ₂ : 30 to 300 g / liter, free HCl: 10 to 200 g / liter, and other components: 0 to 30 g / liter. Method for producing chloride and recovering valuable copper components.