JP2017043834A - Additive for high purity electrolytic copper refinery and high purity copper manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an additive to prevent generation of slime and to manufacture high purity copper which sulfur concentration and silver concentration are drastically reduced, and a manufacturing method using the additive.SOLUTION: An additive for high purity electrolytic copper refinery added in copper electrolytic solution of electrolytic refining manufacturing high purity copper contains: a main agent consisting of nonionic surfactant having hydrophobic group including aromatic rings and hydrophilic group including polyoxyalkylene group; and a stress relaxant consisting of polyvinyl alcohol or the derivative. A manufacturing method of high purity copper uses the additive.SELECTED DRAWING: None

Description

  The present invention relates to an additive for high-purity copper electrolytic refining for producing high-purity copper with greatly reduced impurities such as sulfur and silver concentration, and a production method using the additive.

As described in Patent Document 1, as a method for producing high-purity copper, a copper sulfate aqueous solution is electrolyzed, copper deposited on the cathode is used as an anode, and further, a low current density of 100 A / m ² or less in the copper nitrate aqueous solution. There is known a method of performing two-stage electrolysis with re-electrolysis.

  In addition, as described in Patent Document 2, a mechanical effect is obtained by using a polyoxyethylene-based surfactant such as PEG (polyethylene glycol) in combination with a copper sulfate electrolyte containing chlorine ions, glue, and the like, and an active sulfur component. There is known a method for producing an electrolytic copper foil with improved mechanical properties and cathode adhesion. Furthermore, as described in Patent Document 3, by using a smoothing agent such as PVA (polyvinyl alcohol) and a slime accelerator such as PEG, the copper surface is smooth and the content of silver or sulfur as impurities A method for producing high-purity electrolytic copper with a low content is known.

Japanese Patent Publication No. 08-990 Japanese Patent Laid-Open No. 2001-123289 JP 2005-307343 A

  As in the manufacturing method of Patent Document 1, the two-stage manufacturing method in which the electrolysis of the copper sulfate bath and the copper nitrate bath has a problem that the electrolysis takes time. In addition, the use of nitric acid has a problem that the environmental load is high and the wastewater treatment becomes complicated.

When conventional additives (PVA, PEG, etc.) are used, it is difficult to increase the current density, and when liquid agitation is performed to increase the current density, slime rises, which adheres to the cathode and lowers the purity of electrolytic copper. In addition, since the additive strongly suppresses dissolution of the anode, the anode dissolution overvoltage is increased, so that a large amount of slime is generated during anode dissolution, the yield of the cathode is reduced, and the amount of slime attached to the cathode is increased. Further, since the conventional additive suppresses the deposition reaction of the cathode, there is a problem that the purity of the electrodeposited copper is increased and the purity is lowered when the electrolytic solution contains a sulfate group.
In addition, conventional additives (such as PEG) act strongly on the cathode as well as the anode. Therefore, stress is generated in the cathode during electrodeposition and the cathode warps, and the cathode falls off the SUS base plate during electrolytic refining. There was a problem.

  Also, water-soluble polymer additives such as PEG and PVA are extremely hydrophilic, have poor UV absorption, are difficult to perform quantitative analysis by high performance liquid chromatography (HPLC), and have a high decomposition rate. Accurate concentration management is difficult. Furthermore, when PEG is used, there is a problem that dendrites on the surface of the electrolytic copper are likely to occur. When PVA is used to solve this problem, the surface of the electrolytic copper becomes smooth but the impurity silver is not sufficiently reduced. Furthermore, the production method using a surfactant such as PEG described in Patent Document 2 has a high sulfur content of electrolytic copper and it is difficult to obtain high-purity electrolytic copper.

  The present invention solves the above-mentioned problems in conventional production methods for the production of high-purity copper, and uses an additive containing a main agent composed of a surfactant having a specific hydrophobic group and a hydrophilic group and a stress relaxation agent. In this way, it is possible to produce high-purity copper in which generation of slime is suppressed and impurities such as silver and sulfur are greatly reduced, and a manufacturing method using the additive and the additive is provided. .

The present invention relates to an additive for high-purity copper electrolytic refining having the following configuration and a method for producing high-purity copper.
[1] An additive added to a copper electrolyte for electrolytic refining for producing high-purity copper, comprising a nonionic surfactant having a hydrophobic group containing an aromatic ring and a hydrophilic group containing a polyoxyalkylene group And a stress relieving agent comprising polyvinyl alcohol or a derivative thereof.
[2] Described in the above [1], wherein the hydrophilic group of the main agent contains a polyoxyethylene group, a polyoxypropylene group, or a polyoxyethylene group and a polyoxypropylene group, and the hydrophobic group of the main agent contains a phenyl group or a naphthyl group Additive for high purity copper electrolytic refining.
[3] The additive for high-purity copper electrolytic refining as described in [1] or [2] above, wherein the number of added moles of the polyoxyalkylene group in the hydrophilic group of the main agent is 2 to 20.
[4] The high-purity copper according to any one of [1] to [3] above, wherein the stress relaxation agent is polyvinyl alcohol or a derivative thereof having a saponification rate of 70 to 99 mol% and an average degree of polymerization of 200 to 2500. Additive for electrolytic production.
[5] The additive for high-purity copper electrolysis production as described in [4] above, wherein the polyvinyl alcohol derivative is carboxy-modified polyvinyl alcohol, ethylene-modified polyvinyl alcohol, or polyoxyethylene-modified polyvinyl alcohol.
[6] A main agent composed of a nonionic surfactant having a hydrophobic group containing an aromatic ring and a hydrophilic group containing a polyoxyalkylene group and a stress relaxation agent consisting of polyvinyl alcohol or a derivative thereof are added to the copper electrolyte. A method for producing high-purity copper that performs copper electrolysis.
[7] The concentration of the main agent in the copper electrolyte is 2 to 500 mg / L, and the concentration ratio (Y / X) of the main agent (X) to the stress relaxation agent (Y) is 0.01 to 1. The method for producing high-purity copper according to the above [6], wherein the copper electrolysis is performed so that the range is 0.
[8] The method for producing high-purity copper as described in [6] or [7] above, wherein the copper electrolyte is a copper sulfate solution, a copper nitrate solution, or a copper chloride solution.
[9] A copper sulfate solution having a copper concentration of 5 to 90 g / L, a sulfuric acid concentration of 10 to 300 g / L, a nitric acid concentration of 0.1 to 100 g / L, or a hydrochloric acid concentration of 10 to 300 g / L The method for producing high-purity copper according to any one of [6] to [8] above, wherein a copper chloride solution is used as an electrolytic solution.
[10] The high concentration according to any one of [6] to [9] above, which produces high-purity copper in which both the sulfur concentration and the silver concentration are 1 ppm or less and the glossiness of the electrolytic copper surface is 1 or more. A method for producing pure copper.

[Specific description]
Hereinafter, the present invention will be specifically described.
The additive of the present invention is an additive added to a copper electrolyte solution for electrolytic refining for producing high-purity copper, and has a nonionic property having a hydrophobic group containing an aromatic ring and a hydrophilic group containing a polyoxyalkylene group A high-purity copper electrolytic production additive comprising a main agent comprising a surfactant and a stress relaxation agent comprising polyvinyl alcohol or a derivative thereof, and the production method of the present invention uses the additive. This is a method for producing high purity copper.

  The additive of the present invention includes a main agent composed of a nonionic surfactant having a hydrophobic group containing an aromatic ring and a hydrophilic group containing a polyoxyalkylene group. The aromatic ring of the hydrophobic group of the main agent is, for example, a phenyl group or a naphthyl group, and monophenyl, naphthyl, cumyl, alkylphenyl, styrenated phenylmonophenyl, naphthyl, cumyl, alkylphenyl, styrenated phenyl, distyrene And phenyl, tristyrenated phenyl, tribenzylphenyl and the like. The hydrophilic polyoxyalkylene group of the main agent is, for example, a polyoxyethylene group, a polyoxypropylene group, or the like, and may include both a polyoxyethylene group and a polyoxypropylene group.

  Specific compounds of the main agent contained in the additive of the present invention include, for example, polyoxyethylene monophenyl ether, polyoxyethylene methyl phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene dodecyl phenyl ether, polyoxyethylene naphthyl Ether, polyoxyethylene styrenated phenyl ether, polyoxyethylene distyrenated phenyl ether, polyoxyethylene tristyrenated phenyl ether, polyoxyethylene cumyl phenyl ether, polyoxypropylene monophenyl ether, polyoxypropylene methyl phenyl ether, Polyoxypropylene octyl phenyl ether, polyoxypropylene dodecyl phenyl ether, polyoxypropylene naphthyl ether, poly Polyoxypropylene styrenated phenyl ether, polyoxypropylene di-styrenated phenyl ether, polyoxypropylene tristyrenated phenyl ether, polyoxypropylene cumylphenyl ether, and the like.

  The additive of the present invention is used by being added to an electrolytic solution for copper electrolytic refining. In the copper electrolytic refining, the main agent contained in the additive of the present invention has a hydrophobic group of an aromatic ring and a hydrophilic group of a polyoxyalkylene group, so that silver ions and sulfur ions in the electrolytic solution are deposited on the cathode. Inhibits and significantly reduces the silver and sulfur concentrations of electrolytic copper. Furthermore, the additive of the present invention has less anode slime than when PEG or the like is used. Specifically, the additive of the present invention contains a hydrophobic group and a hydrophilic group of a polyoxyalkylene group, and does not excessively adhere to the cathode surface, so that the dissolution of the copper anode is not excessively suppressed. For this reason, the copper anode dissolves moderately, and the anode slime is less than when PEG or the like is used, so the amount of anode slime adhering to the surface of the electrolytic copper deposited on the cathode is reduced, and high purity electrolytic copper is obtained. Can do.

  Furthermore, since the electrodeposited copper deposited on the cathode surface becomes dense by the main agent contained in the additive of the present invention, the smoothness of the surface of the electrolytic copper is improved. For this reason, sulfur and anode slime in the electrolytic solution hardly adhere to and remain on the surface of the electrolytic copper, and it is difficult for them to be taken into the electrolytic copper, so that high-purity electrolytic copper with few impurities can be obtained.

  Conventional surfactants used in copper electrolytes, such as PEG, do not have this effect because they do not contain an aromatic ring in the hydrophobic group. Rather, conventional PEG or the like strongly adheres to the surface of the copper anode, so that dissolution of the copper anode is hindered excessively. For this reason, there is much generation of anode slime, which has the disadvantage of being taken into the surface of the copper electrode of the cathode and lowering the copper quality. Specifically, the sulfur content of electrolytic copper electrorefined by adding PEG or the like is much higher than when the additive of the present invention is used. On the other hand, the additive of the present invention can significantly reduce the sulfur content of electrolytic copper compared to conventional PEG and the like.

  The aromatic ring of the hydrophobic group of the main agent is preferably a monophenyl group or a naphthyl group. The hydrophilic polyoxyalkylene group of the main agent includes, for example, a polyoxyethylene group, a polyoxypropylene group, a mixture of a polyoxyethylene group and a polyoxypropylene group, and a polyoxyethylene group is particularly preferable. . The main agent contained in the additive of the present invention is preferably polyoxyalkylene monophenyl ether having 2 to 20 addition moles or polyoxyalkylene naphthyl ether having 2 to 20 addition moles.

  About the said main ingredient, a preferable specific example is shown below. Formula 1 is polyoxyethylene monophenyl ether, and Formula 2 is polyoxyethylene naphthyl ether. N in Formula 1 and Formula 2 is the number of added moles of the polyoxyethylene group.

  In the above main agent, the polyoxyalkylene group of the hydrophilic group preferably has 2 to 20 addition moles, and more preferably has 2 to 15 addition moles. When the added mole number is less than 2, the main agent is not dissolved in the electrolytic solution. When the added mole number exceeds 20, the adhesion of the additive to the anode surface becomes excessive and the dissolution reaction of the anode is excessively suppressed, so that a large amount of anode slime is generated and the yield of electrolytic copper is increased. descend. Furthermore, when the number of added moles exceeds 20, dentrite is likely to be generated on the surface of the electrolytic copper deposited on the cathode, and the smoothness is lowered. For this reason, since the anode slime and sulfur in the electrolytic solution easily adhere to the surface of the electrolytic copper and remain, the purity of the electrolytic copper is lowered. If the added mole number of the polyoxyalkylene group of the main agent is 2 to 20, dissolution of the anode proceeds appropriately, so that anode slime is less than when PEG or the like is used, and high purity electrolytic copper can be obtained. it can. Furthermore, the additive having a polyoxyalkylene group having 2 to 15 added moles can greatly reduce the sulfur content of electrolytic copper.

  In addition, since the electrodeposition reaction is affected by the bath temperature of the electrolytic solution, the preferred range of the added mole number of the polyoxyethylene group varies depending on the bath temperature. For example, the added mole number when the bath temperature is 20 to 55 ° C. is 2-15 are preferable, and when the bath temperature of electrolyte solution is 55 degreeC or more-75 degreeC, 9-20 are preferable.

A compound having no phenyl group or naphthyl group and having only a polyoxyethylene group or the like which is a hydrophilic group has a poor effect of suppressing electrodeposition on the cathode. For example, polyoxyethylene glycol having an addition mole number of 8 is compared with the case where polyoxyethylene monophenyl ether having an addition mole number of polyoxyethylene group of 8 is used as an additive, for example, at an electric current density of 200 A / m ^2. The copper surface, particularly the edges, become rough.

  The stress relaxation agent contained in the additive of the present invention comprises polyvinyl alcohol or a derivative thereof. The stress relieving agent relaxes the electrodeposition stress of the electrolytic copper deposited on the cathode and prevents the electrolytic copper from dropping from the cathode. By reducing the electrodeposition stress, the electrolytic copper is stably held on the cathode for a long time, so that an electrolytic copper with a smooth surface can be obtained. On the other hand, if the electrodeposition stress is accumulated without being relaxed, the copper is warped and peels off from the cathode and falls.

  The polyvinyl alcohol or derivative thereof as the stress relaxation agent is, for example, carboxy-modified polyvinyl alcohol, ethylene-modified polyvinyl alcohol, or polyoxyethylene-modified polyvinyl alcohol.

  The polyvinyl alcohol or derivative thereof preferably has a saponification rate of 70 to 99 mol%. When the saponification rate is less than 70 mol%, the effect of relaxing the electrodeposition stress becomes poor. On the other hand, a completely saponified product (saponification rate 100 mol%) has a markedly reduced solubility and cannot be dissolved in the electrolyte.

  The stress relaxation agent polyvinyl alcohol or a derivative thereof preferably has an average degree of polymerization of 200 to 2500. The basic structure of polyvinyl alcohol and its derivatives consists of a fully saponified type of hydroxyl group and a partially saponified type having an acetic acid group. The degree of polymerization of polyvinyl alcohol and its derivatives is the total number of both, and the average degree of polymerization is polymerization The average value of degrees. The average degree of polymerization can be measured based on the polyvinyl alcohol test method of JISK6726.

  When the average degree of polymerization of polyvinyl alcohol or a derivative thereof is less than 200, the effect of relaxing the electrodeposition stress becomes poor. In addition, polyvinyl alcohol or derivatives thereof having an average degree of polymerization of less than 200 are difficult to obtain because some of them are difficult to produce and are not generally used. Even when the average degree of polymerization exceeds 2500, the effect of relaxing the electrodeposition stress gradually disappears, and warpage occurs in the electrolytic copper deposited on the cathode. Furthermore, when the average degree of polymerization exceeds 2500, an electrodeposition suppressing effect is produced, and the yield of electrolytic copper tends to decrease.

  The main agent and the stress relieving agent may be mixed in advance to a predetermined concentration and added to the electrolytic solution, or may be added individually to a predetermined concentration in the copper electrolytic solution.

  The additive of the present invention is used by being added to a copper electrolyte. In the copper electrolyte, the concentration of the main agent is preferably in the range of 2 to 500 mg / L, and more preferably in the range of 10 to 300 mg / L. When the concentration of the main agent is less than 2 mg / L, the effect of addition is poor, so the smoothness of the surface of the electrolytic copper is lowered, and the sulfur in the electrolytic solution adheres to the electrolytic copper surface and is easily taken in. Increases sulfur concentration. On the other hand, if the concentration of the main agent exceeds 500 mg / L, the adhesion of the anode surface is too strong and the amount of slime generated increases, and this is taken into the cathode copper with an excessive amount of additive. Sulfur concentration and silver concentration increase.

  The concentration of the stress relaxation agent is preferably in a range where the concentration ratio (Y / X) of the stress relaxation agent (Y) to the main agent (X) is 0.01 to 1.0. When the concentration of the stress relaxation agent is higher than the concentration of the main agent and the Y / X ratio exceeds 1.0, rather, the electrolytic copper is slightly warped. On the other hand, when the concentration of the stress relaxation agent is low and the Y / X ratio is less than 0.01, the effect of the stress relaxation agent becomes poor.

  The copper electrolyte in which the additive of the present invention is used is a copper compound solution of a mineral acid such as a copper sulfate solution, a copper nitrate solution, or a copper chloride solution. When a copper sulfate solution is used as the electrolytic solution, the sulfuric acid concentration is preferably 10 to 300 g / L. If the sulfuric acid concentration is less than 10 g / L, copper hydroxide is generated in the electrolytic copper and the precipitation state deteriorates. On the other hand, when the sulfuric acid concentration exceeds 300 g / L, the amount of sulfuric acid taken up in electrolytic copper increases, and the sulfur concentration rises. When the electrolytic solution is a copper nitrate solution, the nitric acid concentration is preferably 0.1 to 100 g / L. When the electrolytic solution is a copper chloride solution, the hydrochloric acid concentration is preferably 10 to 300 g / L.

  When the electrolytic solution is a copper sulfate solution, a copper nitrate solution, or a copper chloride solution, the copper concentration of the electrolytic solution is preferably 5 to 90 g / L (20 to 350 g / L at a copper sulfate pentahydrate concentration, copper nitrate 3 The hydrate concentration is 19 to 342 g / L, and the copper chloride dihydrate concentration is 13 to 241 g / L). When the copper concentration is less than 5 g / L, electrolytic copper is precipitated in a powder form, so that the purity is lowered. On the other hand, when the copper concentration exceeds 90 g / L, the electrolytic solution is easily taken into the electrolytic copper, so that the purity is lowered.

  When the electrolytic solution is copper sulfate or copper nitrate, the electrolytic solution preferably has a chloride ion concentration of 200 mg / L or less. When the chloride ion concentration exceeds 200 mg / L, chloride is easily taken into electrolytic copper, and the purity of electrolytic copper is lowered.

  The additive of the present invention includes a main agent composed of a nonionic surfactant having a hydrophilic group such as a polyoxyethylene group and a hydrophobic group such as a phenyl group or a naphthyl group, and the main agent has a strong UV-absorbing property. Since it has hydrophobicity, it can be quantitatively analyzed by high performance liquid chromatography (HPLC). Therefore, the concentration of the main agent is measured by HPLC, and the decrease in the main agent is replenished so as to maintain the concentration of the main agent in the range of 2 to 500 mg / L, more preferably in the range of 10 to 300 mg / L. Electrolytic refining is recommended.

  In the electrolytic refining of high purity copper, the silver concentration and sulfur concentration of electrolytic copper are greatly reduced by using the additive of the present invention. Further, since the surface of the electrolytic copper becomes smooth, it is difficult for the anode slime and the electrolytic solution to remain on the electrolytic copper surface, and high-purity electrolytic copper with few impurities can be obtained. For example, in copper electrolysis using a copper sulfate solution as an electrolytic solution, electrolytic copper having a remarkably low sulfur concentration can be obtained. For example, it is possible to obtain high-purity copper in which both the sulfur concentration and the silver concentration are 1 ppm or less and the glossiness of the electrolytic copper surface is 1 or more. Preferably, high-purity electrolytic copper having a sulfur concentration and a silver concentration of 0.5 ppm or less and a glossiness of 2 or more on the surface of the electrolytic copper can be produced.

  Since the additive of the present invention does not excessively adhere to the surface of the copper anode, the copper anode is appropriately dissolved, and there is less anode slime than when PEG or the like is used, and the yield of electrolytic copper is improved. Specifically, the yield of electrolytic copper is 70% or more. Further, since the anode slime is smaller than when PEG or the like is used, high-speed electrolysis can be performed while the liquid is stirred. Furthermore, since polyoxyethylene monophenyl ether of formula 1 and polyoxyethylene naphthyl ether of formula 2 do not contain sulfur in the molecular skeleton, when the additive of the present invention comprising these compounds is used, the sulfur content is extremely high. Low electrical copper can be obtained. In addition, an additive having 2 to 20 added moles such as a polyoxyethylene group is superior in stability because of its short molecular chain as compared with Nikakawa, and bath management is easy.

  The stress relaxation agent contained in the additive of the present invention relaxes the electrodeposition stress of the electrolytic copper deposited on the cathode and does not warp the electrolytic copper, so that the electrolytic copper is stably held on the cathode for a long time and densely deposited. An electrolytic copper with a smooth surface is obtained.

Examples of the present invention are shown below together with comparative examples.
The sulfur concentration and silver concentration of electrolytic copper were measured by GD-MS (glow discharge mass spectrometry). Moreover, the center part of electrolytic copper was measured. The glossiness of the copper surface was measured using a Nippon Denshoku product (HANDY GLOSSMETER PG-1M) at an angle of 60 °. When the glossiness is lower than 1, the electrolytic solution adhering to the surface of the electrolytic copper is not sufficiently washed with water and washed, so that it tends to remain on the surface of the electrolytic copper and the purity of the electrolytic copper is lowered. The warpage of electrolytic copper was judged by visual observation. A mark without a warp is indicated by a mark, a mark with a slight warp is indicated by a mark, and a mark having a large warp and clear peeling is indicated by a mark.
The slime generation rate was obtained by the following equation.
Slime generation rate (%) = 100− (weight of deposited copper) / (dissolution amount of anode) × 100

[Example 1]
A copper sulfate solution, a copper nitrate solution, and a copper chloride solution were used as the electrolyte. The electrolytic solution has an acid concentration of 50 g / L, a copper concentration of 50 g / L, and, except for the copper chloride bath, has a chloride ion concentration of 100 mg / L. 30 mg / L of the main agent (A to B) was added to the electrolytic solution, and the stress relieving agent (D to G) was added to the electrolytic solution in an amount such that the concentration ratio of the stress relieving agent / main agent was the value shown in Table 1. The anode uses electrolytic copper with a sulfur concentration of 5 ppm and a silver concentration of 8 ppm, electrolysis is performed at a current density of 200 A / m ² and a bath temperature of 30 ° C., and the main agent and stress relieving agent by HPLC using an ODS column every 12 hours. Then, the concentration of the main component was maintained at 30 mg / L, and the decrease was supplemented so that the concentration ratio of the stress relieving agent was maintained at the concentration ratio shown in Table 1, thereby producing electrolytic copper. The results are shown in Table 1 (No. 1 to No. 14).

[Comparative Example 1]
The same copper sulfate solution as in Example 1 was used as an electrolyte solution, and 30 mg / L of the main agent (A to C) was added to the electrolyte solution. No. 15 to No. 17 were added with no stress relaxation agent. Added the stress relaxation agent D, and performed electrolytic refining in the same manner as in Example 1 to produce electrolytic copper. The results are shown in Table 1 (No. 15 to No. 18). Also, the same copper sulfate solution as in Example 1 was used as the electrolyte, and neither the main agent nor the stress relaxation agent was added (No. 19), or polyethylene glycol (PEG) was added (No. 20), Except for the above, electrolytic refining was performed in the same manner as in Example 1 to produce electrolytic copper. The results are shown in Table 1.

As shown in Table 1, No. 1 to No. 14 of the present invention have a remarkably low sulfur content in electrolytic copper and a low silver content. Moreover, the slime generation rate is 29% or less, and the glossiness of the electrolytic copper surface is 2 or more.
On the other hand, all of the comparative samples No. 15 to No. 17 which do not use a stress relaxation agent have a large warp of electrolytic copper and a low glossiness of the electrolytic copper surface. Further, Comparative Sample No. 18 using the stress relieving agent D together with the main agent C has a large content of sulfur and silver in electrolytic copper, a high slime generation rate, and a glossiness on the surface of electrolytic copper is significantly low. Unlike the main agents A and B of the present invention, the main agent C does not have a hydrophobic group of an aromatic ring, and therefore has no effect of suppressing slime generation. In addition, it can be seen that when the main agent C and the stress relaxation agent D are used in combination, the content of sulfur and silver in the electrolytic copper and the slime generation rate are remarkably increased, and the combined use of the main agent C and the stress relaxation agent is not preferable.

  As shown in No. 1 to No. 14 of the present invention, the main agent used in combination with the stress relaxation agent comprises a nonionic surfactant having a hydrophobic group containing an aromatic ring and a hydrophilic group containing a polyoxyalkylene group. It is preferable to use this main ingredient together with a stress relaxation agent comprising polyvinyl alcohol or a derivative thereof, so that the content of sulfur and silver in electrolytic copper is low, the slime generation rate is low, there is no warp, and the glossiness is high. Electro copper can be obtained.

  Comparative sample No. 19, which uses neither the main agent nor the stress relieving agent, has a low amount of slime because there is no anodic dissolution suppression by the additive, but the content of sulfur and silver in electrolytic copper is high, and the surface of electrolytic copper Becomes quite rough. For this reason, glossiness cannot be measured with a gloss meter. No. 20 using conventional PEG has a high slime generation rate, and the content of sulfur and silver in electrolytic copper is higher than No. 1 to No. 14 of the present invention. In addition, since the dendrite is likely to occur on the surface of the electrolytic copper, the glossiness cannot be measured. Further, in both No. 19 and No. 20, warpage is observed in the electrolytic copper.

[Example 2]
Using the copper sulfate solution (sulfuric acid concentration 100 g / L, copper concentration 40 g / L) or the copper nitrate solution (, nitric acid concentration 10 g / L, copper concentration 40 g / L) as the electrolyte, the main agent A (addition moles) of Example 1 5) and an additive consisting of a stress relaxation agent D (saponification rate 88 mol%, average polymerization degree 200), or main agent B (addition mole number 7) and stress relaxation agent E (saponification rate 78%) of Example 1 , Average polymerization degree 620), and the amount of these additives in the range shown in Table 2 was added to the electrolytic solution. Copper was produced. The results are shown in Table 2. As shown in Table 2, the concentration of the main agent is preferably in the range of 2 to 500 mg / L in any case.

Example 3
A copper sulfate solution or a copper nitrate solution was used as the electrolytic solution, and the acid concentration and the copper concentration were adjusted as shown in Table 2. The additive of the present invention containing the main agent A (addition mole number 15) and the stress relaxation agent D (saponification rate 88 mol%, average polymerization degree 200) used in Example 1 was added, or the main agent B (addition mole number) 7) and the stress relaxation agent G (saponification rate 98 mol%, average polymerization degree 700) were added according to the present invention, and the others were electrolytically refined in the same manner as in Example 1 to produce electrolytic copper. The results are shown in Table 3. As shown in Table 3, the copper sulfate solution used as the electrolyte preferably has a sulfuric acid concentration of 10 to 300 g / L and a copper concentration of 5 to 90 g / L, and the copper nitrate solution has a nitric acid concentration of 0.1 to 100 g / L and copper. A concentration range of 5 to 90 g / L is preferred.

Claims (10)

An additive added to a copper electrolyte for electrolytic refining for producing high-purity copper, comprising a nonionic surfactant having a hydrophobic group containing an aromatic ring and a hydrophilic group containing a polyoxyalkylene group; And a stress relieving agent comprising polyvinyl alcohol or a derivative thereof. The high purity copper electrolysis according to claim 1, wherein the hydrophilic group of the main agent contains a polyoxyethylene group, a polyoxypropylene group, or a polyoxyethylene group and a polyoxypropylene group, and the hydrophobic group of the main agent contains a phenyl group or a naphthyl group. Refining additive. The additive for high-purity copper electrolytic refining according to claim 1 or 2, wherein the number of added moles of the polyoxyalkylene group in the hydrophilic group of the main agent is 2 to 20. The additive for high-purity copper electrolysis production according to any one of claims 1 to 3, wherein the stress relaxation agent is polyvinyl alcohol or a derivative thereof having a saponification rate of 70 to 99 mol% and an average degree of polymerization of 200 to 2500. . The additive for high-purity copper electrolytic production according to claim 4, wherein the polyvinyl alcohol derivative is carboxy-modified polyvinyl alcohol, ethylene-modified polyvinyl alcohol, or polyoxyethylene-modified polyvinyl alcohol. A copper electrolyte is added with a main agent made of a nonionic surfactant having a hydrophobic group containing an aromatic ring and a hydrophilic group containing a polyoxyalkylene group, and a stress relaxation agent made of polyvinyl alcohol or a derivative thereof. A method for producing high purity copper for electrolysis. The concentration of the main agent in the copper electrolyte is 2 to 500 mg / L, and the concentration ratio (Y / X) of the main agent (X) to the stress relaxation agent (Y) is in the range of 0.01 to 1.0. The method for producing high-purity copper according to claim 6, wherein copper electrolysis is performed so that The method for producing high-purity copper according to claim 6 or 7, wherein the copper electrolyte is a copper sulfate solution, a copper nitrate solution, or a copper chloride solution. Copper sulfate solution having a copper concentration of 5 to 90 g / L, a sulfuric acid concentration of 10 to 300 g / L, a nitric acid concentration of 0.1 to 100 g / L, or a hydrochloric acid concentration of 10 to 300 g / L The method for producing high-purity copper according to any one of claims 6 to 8, wherein the solution is used as an electrolytic solution. The method for producing high-purity copper according to any one of claims 6 to 9, wherein high-purity copper having both a sulfur concentration and a silver concentration of 1 ppm or less and a glossiness of an electrolytic copper surface of 1 or more is produced. .