JP4110295B2 - Method for simultaneously treating copper etching waste liquid and resist waste liquid and chemicals used therefor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method of simultaneously processing by mixing a copper etching waste liquid and a resist waste liquid and a chemical used therefor.
[0002]
[Prior art]
From the printed circuit board factory, copper etching waste liquid (very strong acidity, copper concentration of several thousand ppm, TOC about 1.5%, sulfuric acid about 1.5%, hydrogen peroxide containing 10% and more) and resist waste liquid (resin These are difficult to process, and there is a need for the development of efficient processing techniques.
Etching waste liquid discharged from the copper etching process is strongly acidic and the concentration of copper is usually as high as 8 to 20%, but the chlorine concentration that hinders the recovery and reuse of copper is also usually 5 to 30%. And high. Since there is no technology for recovering only copper from waste liquid containing a large amount of chlorine ions, the etching waste liquid is generally collected as waste by an industrial waste disposal company and disposed of without being reused.
The photoresist waste liquid is alkaline and is generally dissolved with an alkali-soluble resin as a main component. A method for treating a photoresist development waste solution or a stripping waste solution has been performed by adding sulfuric acid, hydrochloric acid, or the like to the waste solution to make the resist insoluble, and separating and removing the insoluble resist. The separated resist has been disposed of by incineration or industrial waste. However, in view of the current increase in disposal costs due to the recent shortage of disposal sites and the need for zero emissions, there is a strong demand for the development of a method for treating resist waste liquid that does not generate waste. In addition, the acidized and insolubilized resist has a problem of high viscosity and very difficult to separate and remove.
[0003]
[Patent Document 1]
JP-A-5-123681 [Patent Document 2]
Japanese Patent Laid-Open No. 10-104844 [Patent Document 3]
Japanese Patent Laid-Open No. 11-60239
[Problems to be solved by the invention]
The present invention establishes an efficient treatment method for both the strongly acidic copper etching waste liquid and the alkaline resist waste liquid that is discharged from the printed circuit board factory and is difficult to treat, so that both waste liquids are mixed and processed simultaneously. In addition, an object of the present invention is to provide a treatment method capable of obtaining copper sludge having a high copper content and a low chlorine content so that copper can be recovered and reused.
[0005]
[Means for Solving the Problems]
As a result of intensive studies to solve the above problems, the present inventors have found the following matters and completed the present invention.
That is, the present invention
(1) a copper etching waste liquid and the resist liquid waste mixed, in the presence of a rare earth compound, by adjusting the pH to 8 to 13 by adding an alkali, it is precipitated separating said copper as a sparingly soluble substance and, the A method of simultaneously processing by mixing a copper etching waste liquid and a resist waste liquid, wherein organic substances in the waste liquid are precipitated.
(2) The method of mixing and simultaneously treating the copper etching waste liquid and the resist waste liquid according to (1), wherein the rare earth compound is lanthanum or a mixture of lanthanum and another rare earth compound.
(3) The copper according to (1) or (2), wherein a flocculant is added to the treated water containing copper, in which a rare earth compound is added to a mixture of a copper etching waste liquid and a resist waste liquid. A method in which etching waste liquid and resist waste liquid are mixed and processed simultaneously.
(4) The chemical | medical agent used for the method of any one of (1)-(3) term | claim, Comprising: The rare earth compound supplied is comprised as a chemical | medical agent, The chemical | medical agent is a rare earth element. An agent comprising at least one selected from the group consisting of an aqueous solution of an oxide, a hydroxide, a carbonate, or a halide, a hydrochloric acid solution, or a sulfuric acid solution is provided.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail.
In the present invention, in the presence of a copper etching waste liquid and the resist waste liquors and rare earth compound, by adjusting the pH to 8 to 13 by adding an alkali, and precipitating separation of copper as a sparingly soluble substance, in waste liquid To precipitate organic matter. This rare earth compound serves as a copper remover (hereinafter also simply referred to as a remover) and an organic matter remover. The rare earth element to be added may be in any state as long as the object of the present invention can be achieved, but it is preferably added as a rare earth element-containing solution, and rare earth element oxide, hydroxide, carbonate, or halogen is added. It is preferable to add to the water to be treated as an aqueous solution of a compound, a hydrochloric acid solution or a sulfuric acid solution. The concentration is not particularly limited, but in consideration of operability, for example, in the case of a rare earth element oxide hydrochloric acid solution, the rare earth element in the hydrochloric acid solution is preferably 10 to 60% by mass, more preferably Preferably it is 30-50 mass%.
[0007]
Of the rare earth elements, use of lanthanum or cerium is preferable, and use of lanthanum is more preferable.
In addition, the rare earth element-containing solution used as a removal agent in the present invention can be used in the form of a rare earth element mixture solution, or a rare earth element alone or a mixed solution. The use of lanthanum and cerium and ytterbium solutions is preferred, and a solution of lanthanum and cerium is more preferred. As a preferable specific example, a hydrochloric acid solution of lanthanum, cerium, and ytterbium (concentration is 50% by mass as an oxide, and the composition thereof is 95% by mass of lanthanum, 4.9% by mass of cerium, and 0.1% by mass of ytterbium). is there.
[0008]
The removing agent used in the present invention can be prepared by, for example, removing impurities from ores containing rare earth elements and then dissolving them in hydrochloric acid. The hydrochloric acid concentration at this time is preferably 0.1 to 12 N, more preferably 5 to 12 N, and still more preferably 8 to 12 N, and the concentration of rare earth element ions is an oxide considering operability. Preferably, it is 10-60 mass%, More preferably, it is 20-50 mass%, More preferably, it is 30-50 mass%. The dissolution time may be completely dissolved, and is not particularly limited, but about 0.5 to 2 hours is sufficient.
[0009]
In the present invention, the amount of rare earth element added depends on the concentration of copper in the water to be treated, but is preferably 0.1 to 50 mol, more preferably 0.5 to 20 mol, and still more preferably per mol of copper. Is 1 to 10 moles.
[0010]
In the present invention, when the copper etching waste liquid, the resist waste liquid, and the rare earth element aqueous solution are mixed, the order of mixing them may be any order, and the resist waste liquid is added to the etching waste liquid to which a remover is added. The etching waste liquid may be mixed with the resist waste liquid added with the removing agent, or the removing agent may be added with the etching waste liquid mixed with the resist waste liquid.
[0011]
In the present invention, when the copper etching waste liquid, the resist waste liquid, and the rare earth element aqueous solution are mixed, it can be carried out after adjusting the pH of the strongly acidic etching waste liquid to near neutral. Usually, when the copper etching waste liquid and the resist waste liquid are mixed, the pH of the resist waste liquid is lowered and the resin is precipitated. However, the resin can be prevented from being precipitated by adjusting the pH of the copper etching waste liquid to near neutral in advance. The pH at this time is not particularly limited, but is in the range of pH 4 to 9, preferably 6 to 8.
[0012]
In the present invention, when the copper etching waste solution adjusted in pH, the resist waste solution, and the rare earth element aqueous solution are mixed, the order of mixing them may be any order, and is removed to the etching waste solution adjusted in pH. The resist waste liquid may be mixed with the additive added, the etching waste liquid adjusted with pH may be mixed with the resist waste liquid added with the removal agent, or the etching waste liquid adjusted with the pH and the resist. You may add a removal agent to what mixed the waste liquid.
[0013]
In the present invention, after mixing the copper etching waste liquid, the resist waste liquid, and the removal agent, the pH is adjusted so as to cause precipitation of copper and organic matter, and the copper and organic matter dissolved in the waste water are removed. The pH is generally in the range of 8-13, preferably in the range of 9-13, more preferably in the range of 10-13.
[0014]
When adjusting the pH of the water to be treated to an alkaline region or an acidic region, a pH regulator is used. Examples of such a pH regulator include sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, and calcium hydroxide. Or an alkaline substance such as hydrochloric acid, sulfuric acid or nitric acid is used.
[0015]
In the present invention, it is preferable to use a flocculant in combination. The flocculant in this case is used for floc aggregation, such as calcium chloride, bis (dihydrogen phosphate) calcium, ferrous chloride, ferric chloride, sulfuric acid In addition to inorganic flocculants such as ferrous sulfate, ferric sulfate, ferrous polysulfate, polyferric sulfate, aluminum sulfate, polyaluminum chloride, etc., polyacrylamide cation-modified products, polyacrylic acid dimethylaminoethyl ester , Cationic organic flocculants such as polymethacrylic acid dimethylaminoethyl ester, polyethyleneimine and chitosan, nonionic organic flocculants such as polyacrylamide, polyacrylic acid, copolymers of acrylamide and acrylic acid and / or salts thereof Anionic organic flocculants such as are included. For example, in the case of a polymer flocculant, the amount added to the water to be treated is preferably 0.1 to 100 ppm, more preferably 0.2 to 80 ppm, and still more preferably 1 to 50 ppm.
[0016]
After the series of steps, the water to be treated is subjected to solid-liquid separation treatment. Examples of the solid-liquid separation method in this case include conventional methods such as filtration separation, centrifugation, and sedimentation separation.
[0017]
【Example】
Next, the present invention will be described in more detail with reference to examples.
[0018]
Reference example 1
A hydrochloric acid solution of a rare earth oxide (the concentration of the rare earth element is 32.5% by mass as an oxide, the composition is 95% by mass of lanthanum, 4.9% by mass of cerium, and 0.1% by mass of ytterbium) is used as a remover. .
[0019]
Example 1
Etching waste liquid (pH 0.20, copper concentration 4750ppm, TOC 15000ppm) 500L / h, remover 10mL / L, stirred for 5 minutes, then mixed resist waste liquid (pH 13.7, copper concentration 27ppm, TOC 18800ppm) 2000L / h And stirred for 5 minutes. Aqueous NaOH (7%) was added to the mixture to adjust the pH to 12, and the mixture was stirred for 10 minutes. When the copper concentration of the treated water separated into solid and liquid was measured, it was 0.2 ppm and the TOC was 7300 ppm. The copper content in the sludge was 63% and the chlorine content was 0.5%, and it became clear that this sludge can be used as a copper resource on a fully profitable basis.
[0020]
Example 2
1 mL / L, 2 mL / L, and 5 mL / L of a removing agent were added to the resist waste liquid 2000 L / h, and after stirring each for 5 minutes, the etching waste liquid 500 L / h was mixed and stirred for 5 minutes. It exothermed and foamed, and a resinous material was formed at the top. Aqueous NaOH (7%) was added to adjust the pH to 12 and stirred for 10 minutes. When the copper concentration of the treated water separated into solid and liquid was measured, it was 1.16 ppm, 1.31 ppm and 0.88 ppm, respectively. The copper content in the sludge was 58% and the chlorine content was 0.7%, and it became clear that this sludge can be used as a copper resource on a fully profitable basis.
[0021]
Comparative Example 2
In Example 2, when it processed similarly except not adding a removal agent, the copper concentration of treated water was 43.7 ppm.
[0022]
Example 3
2 mL / L of the removing agent was added to 2000 L / h of the resist waste liquid and stirred for 5 minutes. On the other hand, an aqueous NaOH solution (7%) was added to 500 L / h of the etching waste liquid to adjust the pH to 7, followed by stirring for 10 minutes. Both were mixed, and further an aqueous NaOH solution (7%) was added to adjust the pH to 12, followed by stirring for 10 minutes. It was 0.12 ppm when the copper concentration of the treated water separated into solid and liquid was measured. The copper content in the sludge was 56% and the chlorine content was 0.6%, and it became clear that this sludge can be used as a copper resource on a fully profitable basis.
[0023]
【The invention's effect】
According to the present invention, in the presence of a copper etching waste liquid, a resist waste liquid, and a rare earth compound, the alkali is added to adjust the pH to 8 to 13, thereby precipitating and separating the copper as a hardly soluble substance and the raw material. Precipitate and separate organic substances in water.

Claims (4)

The copper etching waste liquid and the resist waste liquid are mixed, and in the presence of the rare earth compound, the alkali is added to adjust the pH to 8 to 13, thereby precipitating and separating the copper as a hardly soluble substance, and in the waste liquid A method of simultaneously processing by mixing a copper etching waste liquid and a resist waste liquid, wherein organic substances are precipitated. The method of mixing and simultaneously treating a copper etching waste solution and a resist waste solution according to claim 1, wherein the rare earth compound is lanthanum or a mixture of lanthanum and another rare earth compound. The copper etching waste liquid and the resist waste liquid according to claim 1 or 2, wherein a coagulant is added to the treated water containing copper, wherein a rare earth compound is added to a mixture of the copper etching waste liquid and the resist waste liquid. To process simultaneously. The chemical | medical agent used for the method of any one of Claims 1-3, Comprising: The rare earth compound supplied is comprised as a chemical | medical agent, The chemical | medical agent is a rare earth element oxide, hydroxylation. An agent comprising at least one selected from the group consisting of an aqueous solution of an acid, a carbonate or a halide, a hydrochloric acid solution or a sulfuric acid solution.