JP2002153889A - Method for treating copper chloride-containing waste etching solution, treating agent and method for recovering copper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for efficiently treating a copper chloride- containing waste etching solution with a reduced amount of sludge generated. SOLUTION: In the method for treating a copper chloride-containing waste etching solution, the pH of the solution to be treated is adjusted to the range of 5-14 in the presence of (i) phosphate ions, (ii) calcium ions, (iii) iron ions and (iv) a carboxyl-containing hydrophilic high polymer and/or its hydrolyzate and dissolved copper ions are precipitated as a slightly soluble material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for treating an etching waste solution containing copper chloride, a treating agent, and a method for recovering copper.

[0002]

2. Description of the Related Art A circuit of a printed wiring board is formed by etching a copper-clad laminate having a copper foil laminated thereon or a substrate which has been previously subjected to electroless copper plating using an etching solution containing cupric chloride. Widely used. In this etching step, cupric chloride reacts with metallic copper to produce cuprous chloride. At this time, in order to prevent a decrease in etching ability due to dissolution of copper, chemical regeneration and concentration adjustment of the etching solution are necessary, and an increased amount due to the added chemical is discharged from the etching apparatus as an etching waste solution. This etching waste liquid is generally collected by an etchant manufacturer or an industrial waste treatment company, and is treated in various ways. But,
A serious problem is that the cost of transportation is increasing with the increase in the amount of waste liquid, and the processing cost is soaring because the processing capacity has reached its limit.

[0003]

DISCLOSURE OF THE INVENTION The present invention relates to a method for efficiently and efficiently treating a copper chloride-containing etching waste liquid with a reduced amount of sludge, a copper chloride-containing etching waste liquid treating agent used therein, and copper. An object of the present invention is to provide a method for recovering copper from sludge.

[0004]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have completed the present invention. That is, according to the present invention, in the method for treating an etching waste liquid containing copper chloride, (i) phosphate ions,
(Ii) calcium ion, (iii) iron ion and (iv)
In the presence of a carboxyl group-containing hydrophilic polymer substance and / or a hydrolysis product thereof, the pH of the liquid to be treated is adjusted to 5 to 14
And a method for treating a copper chloride-containing etching waste liquid, wherein the dissolved copper ion is precipitated as a hardly soluble substance. Further, according to the present invention, there is provided an agent for treating a copper chloride-containing etching waste liquid,
(I) a phosphate compound, (ii) a calcium compound, (ii)
A copper chloride-containing etching waste liquid treating agent comprising i) an iron compound and (iv) a carboxyl group-containing hydrophilic polymer substance and / or a hydrolysis product thereof. Further, according to the present invention, an alkaline solution is added to a sludge obtained by separating the precipitate obtained by the above method from the liquid to form a suspension, and a polymer flocculant is added to the suspension. To agglomerate the suspension in the solution, and separating the aggregated suspension. A method for recovering copper is provided.

[0005]

DETAILED DESCRIPTION OF THE INVENTION One embodiment of the copper chloride-containing etching waste liquid treating agent of the present invention (hereinafter, also simply referred to as a treating agent) comprises (i) a phosphate compound, (ii) a calcium compound,
It consists of a mixture of (iii) an iron compound and (iv) a carboxyl group-containing hydrophilic polymer substance and / or a hydrolysis product thereof. The treating agent of the present invention is usually used in the form of a powder or an aqueous solution.

[0006] Phosphoric acid compounds include, in addition to phosphoric acid (H ₃ PO ₄ ), compounds that hydrolyze in water to generate phosphoric acid, for example, sodium phosphate, disodium hydrogen phosphate, sodium dihydrogen phosphate , Potassium phosphate, dipotassium hydrogen phosphate, potassium dihydrogen phosphate, sodium hexane metaphosphate, sodium tripolyphosphate and the like.
These phosphate compounds can be used alone or in the form of a mixture.

[0007] Calcium compounds include calcium chloride,
Examples include calcium carbonate and calcium hydroxide. The calcium compound used as the treating agent component in the present invention can be used alone or in the form of a mixture.

[0008] Iron compounds include polyiron chloride, polyiron sulfate,
Examples include ferrous chloride, ferric chloride, ferrous sulfate, and ferric sulfate. These iron compounds can be used alone or in the form of a mixture.

The carboxyl group-containing hydrophilic polymer includes various water-soluble polymers. Such polymeric substances include alginic acid, dielan gum, xanthan gum, pectin, pectic acid, pectinic acid,
Examples include polysaccharides such as anionized starch, propylene glycol alginate, carboxymethyl cellulose, starch glycolic acid, and cellulose glycolic acid, and metal salts thereof. In the present invention, it is particularly preferable to use sodium alginate or calcium alginate. In the case of using these, the content ratio (molar ratio) of mannummalonic acid (M) and guluronic acid (G) constituting alginic acid [ M] / [G] in the range of 0.1 to 4.0, preferably 0.1 to 3, is preferably used.
The higher the content of guluronic acid, the better the floc-forming property.

The carboxyl group-containing hydrophilic polymer substance and / or its hydrolysis product used in the present invention can be used alone or in the form of a mixture. As the mixture, it is preferable to use a mixture containing alginic acid or a salt thereof.

The alginic acid and / or its hydrolysis product used in the present invention can be used alone or in the form of a mixture. In this case, preferred mixtures containing alginic acid or a salt thereof include (i) alginic acid or a salt thereof, (ii) dielan gum, xanthan gum,
Examples thereof include a mixture with at least one hydrophilic high-molecular substance selected from pectin, pectic acid, pectinic acid and salts thereof. When the mixture ratio is shown, for example, when a mixture of sodium alginate and another anion group-containing hydrophilic polymer is used, the mixture of sodium alginate (A) and another anion group-containing hydrophilic polymer (B) is used. The weight ratio [A] / [B] is 1 to 100, preferably 2 to 50.

When the treating agent of the present invention is preferably produced,
First, a carboxyl-containing hydrophilic polymer, for example, alginic acid, is heated in water containing an alkaline substance,
Hydrolyze and dissolve in water. For example, sodium alginate is present in water containing sodium hydroxide as an alkaline substance, and heated to dissolve the sodium alginate. The heating temperature at this time is preferably 70 ° C. or higher and less than 100 ° C., which does not boil, more preferably 75 ° C. to 90 ° C., and further preferably 80 ° C.
C to 85C. The heating time is not particularly limited as long as the carboxyl group-containing hydrophilic substance is dissolved,
About 0.5 to 2 hours is sufficient. Next, a phosphoric acid compound, a calcium compound, and an iron compound are mixed with the obtained alkaline aqueous solution containing a carboxyl group-containing hydrophilic polymer substance and / or a hydrolysis product thereof.

The ratio of the carbonyl group-containing hydrophilic polymer substance and / or the hydrolysis product thereof to the phosphoric acid compound in the treating agent of the present invention is not particularly limited, but generally, the proportion of the carboxyl group-containing hydrophilic polymer is high. 1 part by weight of the molecular substance and / or its hydrolysis product
0 to 10000 parts by weight, preferably 50 to 5000 parts by weight, more preferably 100 to 1000 parts by weight, and the calcium compound is 100 to 200,000 parts by weight, preferably 500 to 100,000 parts by weight, more preferably 1000 to 1000 parts by weight. 50,000 parts by weight, and the iron compound is 1 to 10,000 parts by weight, preferably 2 to 500 parts by weight.
0 parts by weight, more preferably 5 to 1000 parts by weight.

In order to treat the copper chloride-containing etching waste liquid according to the present invention, the pH is increased in the presence of a phosphate polymer, a calcium ion, an iron ion and a carboxyl group-containing hydrophilic polymer and / or a hydrolysis product thereof. It may be adjusted to 5 to 14, preferably 6 to 12. In this case, an alkaline substance is usually used as the pH adjuster,
The alkaline substance is not particularly limited, but it is preferable to use sodium hydroxide to reduce sludge.

The ratio between the phosphoric acid compound and the calcium compound is 0.001 to 100, preferably 0.01 to 50, and more preferably 0.1 to 50 in terms of the molar ratio [P] / [Ca] of phosphorus and calcium. 01 to 10. The ratio of the phosphoric acid compound to the iron compound is determined by the molar ratio of phosphorus to iron [P] /
[Fe] 1 to 10,000, preferably 10 to 500
0, more preferably 50 to 1,000. The ratio of the phosphoric acid compound is 0.1 mol / mol of copper ions in the liquid to be treated.
The amount is from 5,000 mol, preferably from 1 to 1,000 mol, more preferably from 1 to 500 mol.

In the present invention, the liquid to be treated contains:
A carboxyl group-containing hydrophilic polymer substance and / or a hydrolysis product thereof is present. The ratio is 0.0001 to 0.1 part by weight, preferably 0.0002 to 0.01 part by weight, more preferably 0.1 to 0.1 part by weight per part by weight of the phosphoric acid compound.
0005 to 0.01 parts by weight.

When the etching waste liquid containing copper chloride is treated according to the present invention, if the liquid to be treated is acidic or neutral, it is preferable to adjust the pH so that precipitation occurs after the addition of the treating agent. The pH is generally in the range 5-14, preferably in the range 6-12.

In the present invention, the pH can be adjusted by any method such as a method of adding an alkali after adding a treating agent to a liquid to be treated, or a method of adding a treating liquid to which a treating agent is added to an aqueous alkali solution. Good.

In the present invention, a coagulant is preferably used in combination. The flocculant in this case is one used for flocculation of floc, such as a cationized modified product of polyacrylamide, poly (dimethylaminoethyl acrylate), poly (dimethylaminoethyl methacrylate), Includes cationic organic coagulants such as polyethyleneimine and chitosan; nonionic organic coagulants such as polyacrylamide; anionic organic coagulants such as polyacrylic acid, copolymers of acrylamide and acrylic acid, and salts thereof. Is done. The amount of the coagulant used is 1 to 200 mg / L, preferably 1 to 200 mg / L in water.
00 mg / L.

The liquid to be treated containing the floc of the precipitate after the completion of the pH adjustment step is subjected to a solid-liquid separation treatment. As the solid-liquid separation method in this case, a conventional method, for example, filtration separation, centrifugation, sedimentation and the like can be mentioned. By this solid-liquid separation treatment, precipitates in the liquid are removed and sludge is formed.
Although this sludge is mainly composed of copper, it contains chlorine as an impurity and must be removed. In the present invention, copper is recovered by removing chlorine in the sludge. In order to remove chlorine contained in the sludge, an alkaline aqueous solution is added to the sludge to form a suspension, and a polymer flocculant is added to the suspension to coagulate the suspension in the liquid. The aggregate suspension is separated.

In the aqueous alkali solution to be added to the sludge, examples of the alkali include sodium hydroxide, sodium carbonate, sodium hydrogen carbonate, potassium hydroxide and the like. The alkali concentration in the aqueous solution is 0.01 to 10
%, Preferably 0.1 to 5%. The concentration of the sludge suspension in a suspension obtained by adding an aqueous alkali solution to the sludge is 0.1 to 20%, preferably 0.5 to 1%.
0%.

Specific examples of the polymer flocculant to be added to the suspension include those described above. The addition amount is 0.1 to 50 ppm, preferably 1 to 10 ppm.

The separation of the flocculated suspension from the suspension can be carried out by filtration,
Conventional solid-liquid separation methods such as centrifugation and sedimentation are employed.

As described above, a solid (sludge) mainly composed of copper is obtained. The copper content in the solid is 10% or more, preferably 20% or more, more preferably 20% or more on a dry matter basis. Is 30% or more. Further, the chlorine content in the solid matter is 30% or less, preferably 15% or less, more preferably 5% or less on a dry matter basis. The copper compound contained in the solid is usually in the form of a copper hydroxide.

[0025]

According to the method of the present invention, it is possible to efficiently treat copper chloride etching waste liquid, which has been a major problem in environmental protection, and recover reusable copper from the waste liquid.

[0026]

Next, the present invention will be described in more detail by way of examples.

REFERENCE EXAMPLE 1 In a 500 ml beaker, 2% sodium alginate was added to 300 ml of 1N NaOH.
Heat to 5 ° C and stir for 30 minutes to 1 hour. After the stirred solution was allowed to cool to room temperature (25 to 35 ° C.), 300 ml of the room temperature sodium alginate solution and 5700 ml of 85% phosphoric acid solution were mixed in a 10 L beaker. Next, this solution and an aqueous solution of ferric chloride (FeCl
₃ : 37.5% (weight)) at a volume ratio of 4.9: 0.1. Further, the mixed solution and a 35% aqueous solution of calcium chloride were mixed at a volume ratio of 5:95 to obtain a treating agent [I].

REFERENCE EXAMPLE 2 A mixture obtained by using a polyiron salt aqueous solution (containing at least 11% of Fe ³⁺ ) in place of the ferric chloride aqueous solution in Reference Example 1 is referred to as a treating agent [II]. .

Example 1 To 10 ml of a copper etching waste liquid having a pH of -0.98, a copper ion concentration of 118 g / L and a chlorine concentration of 250 g / L, 3,000 ppm of the treating agent [I] was added and stirred for 3 minutes. This liquid was added to 71 ml of an aqueous sodium hydroxide solution (1N) (addition amount: about 9.2 ml), and stirred for 3 minutes to obtain a liquid having a pH of 10. Next, a polymer flocculant Diafloc (AP12
0C) was added and stirred for 2 minutes. The resulting precipitate was filtered. When the concentration of copper ions in the treatment liquid was measured with an ICP apparatus, the concentration of copper ions was 0.5 mg / L. The amount of sludge at this time was 1.9 g (absolutely dry). The sludge was dissolved in 0.5N nitric acid, and the concentrations of copper and chlorine were measured by ICP and ion chromatography, respectively. The composition of copper and chlorine in the sludge (on a dry matter basis) was determined. Weight) and 24% (weight) chlorine. Next, this sludge (water content 80%) was
The suspension was suspended in 0 ml of an aqueous sodium hydroxide solution (0.1 N) (sludge concentration: 1%), stirred for 10 minutes, added with 2.5 ppm of Diafloc AP120C, and stirred for 2 minutes. The solid and liquid were separated by filtration, and after drying, the concentrations of copper and chlorine were measured by the method described above. The composition of copper and chlorine in the sludge was 62% by weight of copper and 1.2% by weight of chlorine.
High copper recovery was obtained. A similar result was obtained when one half of the aqueous sodium hydroxide solution used for the recovery of copper from the sludge was reused and used for sludge treatment in the next waste liquid treatment.

Example 2 Treatment agent [I] was added to 10 ml of the copper etching waste liquid of Example 1.
3,000 ppm was added and stirred for 3 minutes. To this solution was added 71 ml of an aqueous sodium hydroxide solution (1N), and the mixture was stirred for 3 minutes to obtain a solution having a pH of 10. Next, 5 ppm of polymer flocculant Diafloc (AP120C) was added (1 ppm).
) And stirred for 2 minutes. The resulting precipitate was filtered. When the concentration of copper ions in the treatment liquid was measured with an ICP apparatus, the concentration of copper ions was 0.4 mg / L. The amount of sludge at this time was 1.8 g (absolutely dry). This sludge was dissolved in 0.5N nitric acid, and the concentrations of copper and chlorine were measured by ICP and ion chromatography, respectively. When the composition of copper and chlorine in the sludge was determined, 58% (weight) of copper and 23% of chlorine were detected. % (Weight). Next, this sludge was added to a 200 ml aqueous solution of sodium hydroxide (0.1 ml).
N) (1% sludge concentration) and stirred for 10 minutes, 2.5 ppm of Diafloc AP120C was added, and the mixture was stirred for 2 minutes. When the concentration of copper and chlorine was measured by the above-mentioned method after solid-liquid separation by filtration, the composition of the sludge was copper 60% (weight) and chlorine 1.5% (weight),
High copper recovery was obtained.

Example 3 A treating agent [II] was added to 10 ml of the copper etching waste liquid of Example 1.
3,000 ppm was added and stirred for 3 minutes. To this solution was added 70 ml of an aqueous solution of sodium hydroxide (1N), and the mixture was stirred for 3 minutes to obtain a solution having a pH of 10. Next, 5 ppm of a polymer flocculant Diafloc (AP120C) was added (1 pp).
m) and stirred for 2 minutes. The resulting precipitate was filtered. When the concentration of copper ions in the treatment liquid was measured with an ICP apparatus, the concentration of copper ions was 0.6 mg / L. The amount of sludge at this time was 2.0 g (absolutely dry). This sludge was dissolved in 0.5N nitric acid, and the concentrations of copper and chlorine were measured by ICP and ion chromatography, respectively. When the composition of copper and chlorine in the sludge was determined, copper 54% (weight) and chlorine 26 % (Weight). Next, the sludge was added to a 100 ml aqueous solution of sodium hydroxide (0.1 ml).
N) (2% sludge concentration) and stirred for 10 minutes, 2.5 ppm of Diafloc AP120C was added, and the mixture was stirred for 2 minutes. The solids and liquids were separated by filtration, and after drying, the concentrations of copper and chlorine were measured by the method described above. The composition of copper and chlorine in the sludge was 59% copper (by weight) and 2% chlorine (by weight). A recovery was obtained.

Example 4 A treatment agent [I] was added to 10 ml of the copper etching waste liquid of Example 1.
3,000 ppm was added and stirred for 3 minutes. This solution was added to 71 ml of an aqueous sodium hydroxide solution (0.5 N) at a pH of 1
0 (added amount: about 4.6 ml) and stirred for 3 minutes. Next, a polymer flocculant Diafloc (AP12
0C) was added and stirred for 2 minutes. The resulting precipitate was filtered. The amount of sludge at this time was 0.9 g (absolutely dry). This sludge was dissolved in 0.5N nitric acid, and the concentrations of copper and chlorine were measured by ICP and ion chromatography, respectively. When the composition of copper and chlorine in the sludge was determined, 57% (weight) of copper and 5% of chlorine were detected. % (Weight).

 ──────────────────────────────────────────────────続 き Continued on the front page (71) Applicant 000005979 Mitsubishi Corporation 2-6-3 Marunouchi, Chiyoda-ku, Tokyo (74) The above three agents 100074505 Patent Attorney Toshiaki Ikeura (72) Inventor Kenji Tatsumi Ibaraki 16-3 Onogawa, Tsukuba, Japan Prefectural Institute of Technology, Resource and Environmental Technology Research Institute (72) Inventor Shinji Wada 16-3 Onogawa, Tsukuba, Ibaraki Pref., National Institute of Advanced Industrial Science and Technology (72) Inventor, Yasuhiro Yukawa Ibaraki Prefecture 2-1-6 Sengen, Tsukuba Mitsubishi Corporation Project Development Department Environmental Resources Research Laboratory F-term (reference) 4D015 BA19 BA23 BB05 CA20 DB02 DB15 DB23 DB32 EA14 EA15 FA01 FA11 4D038 AA08 AB68 AB81 BB13 BB18 4D062 BA19 BA23 BB05 CA20 DB02 DB15 DB23 DB32 EA14 EA15 FA01 FA11 4K001 AA09 BA21 DB08 DB23 DB26

Claims (7)

[Claims] 1. A method for treating a copper chloride-containing etching waste liquid, comprising: (i) a phosphate ion, (ii) a calcium ion, (iii) an iron ion and (iv) a carboxyl group-containing hydrophilic polymer substance and / or In the presence of the hydrolysis product, the pH of the liquid to be treated is adjusted to a range of 5 to 14,
A method for treating a copper chloride-containing etching waste liquid, wherein the dissolved copper ions are precipitated as a hardly soluble substance. 2. The carboxyl group-containing hydrophilic polymer substance comprises (i) alginic acid or a salt thereof, or (ii) a mixture of alginic acid or a salt thereof and another hydrophilic polymer containing an anion group. the method of. 3. The method according to claim 1, wherein a coagulant is added to said liquid.
Either way. 4. An agent for treating an etching waste liquid containing copper chloride, comprising (i) a phosphate compound, (ii) a calcium compound, (iii) an iron compound, and (iv) a carboxyl group-containing hydrophilic polymer substance. And / or a hydrolysis product thereof. 5. The carboxyl group-containing hydrophilic polymer substance comprises (i) alginic acid or a salt thereof or (ii) a mixture of alginic acid or a salt thereof and another hydrophilic polymer containing an anion group. Treatment agent. 6. The treating agent according to claim 4, wherein the phosphoric acid compound is phosphoric acid. 7. An aqueous alkali solution is added to sludge obtained by separating the precipitate obtained by the method according to claim 1 from the liquid to form a suspension. A method for recovering copper, comprising adding a polymer flocculant to flocculate a suspension in a liquid, and separating the flocculated suspension.