JP2017066514A - Additive for high purity copper electrolytic refining and high purity copper manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an additive for copper electrolytic refining which manufactured high purity copper having largely reduced impurities such as sulfur or silver concentration, small in warpage, preferably no warpage and a manufacturing method for the high purity copper using the additive.SOLUTION: There are provided an additive for high purity copper electrolytic refining containing an ethylene oxide addition article with IOB value in an organic conceptual figure of 1 to 2 and average molecular weight of 150 to 20000 and used for copper electrolytic refining, or an additive for high purity copper electrolytic refining mainly containing the ethylene oxide addition article and containing a stress relaxation agent with IOB value of 2.0 to 9.5 and average molecular weight of 6000 to 150000, and a manufacturing method of the high purity copper using the additive.SELECTED DRAWING: None

Description

  The present invention relates to an additive for copper electrolytic refining for producing high-purity copper having a significantly reduced impurity such as sulfur and silver concentration, and having a small warp, preferably no warp, and a high-purity copper using the additive. It relates to a manufacturing method.

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 in combination, the copper surface is smooth and high purity with less silver and sulfur impurities. Methods for producing electrolytic copper are known.

Japanese Patent Publication No. 08-990 Japanese Patent Laid-Open No. 2001-123289 JP 2005-307343 A JP 2011-32509 A Japanese Patent No. 5297481 JP, 2014-80419, A

"New edition organic concept diagram basics and application", Yoshio Koda, Shiro Sato, Yoshio Honma, Sankyo Publishing, published on November 30, 2008

  As in the manufacturing method of Patent Document 1, the manufacturing method in which electrolysis using a copper sulfate bath and electrolysis using a copper nitrate bath are two-steps has a problem that the electrolysis is troublesome. In addition, the use of nitric acid has a problem that the environmental load is high and the wastewater treatment becomes complicated. Furthermore, since nitric acid dissolves copper itself, the yield decreases due to dissolution of both the cathode and anode, and the copper concentration in the liquid gradually increases, so a dilution process is required to periodically reduce the copper concentration. become.

  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.

  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, dendrites are likely to occur on the surface of the electrolytic copper, and there is a problem that the sulfur content of the electrolytic copper is high. If PVA is used to solve the problem, the surface of the electrolytic copper becomes smooth. However, the impurity silver is not sufficiently reduced.

  In addition, if the cathode deposition reaction is suppressed by the additive, stress is generated inside the electrolytic copper during the deposition, causing peeling from the cathode, dendrites due to current concentration at the end due to the curvature of the electrode, and rough deposition. There is a problem that the purity is reduced.

  Furthermore, in order to prevent silver from being co-deposited on the cathode, it is known that chloride ions are added to the electrolytic solution to convert the silver in the solution into silver chloride to precipitate and remove the chloride ions themselves. There is a problem in that the concentration of chloride increases, the purity of electrolytic copper decreases, and dangerous chlorine gas is generated during the casting of electrolytic copper.

  The present invention solves the above-mentioned problems in conventional production methods for the production of high-purity copper. By using an additive composed of an organic compound identified by using the IOB of the organic conceptual diagram as an index, sulfur and silver are used. It is intended to produce high-purity copper with a significantly reduced content, and by using a stress relaxation agent together with the above-mentioned additives, it is possible to produce high-purity copper with less warpage. . The present invention provides an additive for producing high-purity copper, the additive and a stress relaxation agent, and a method for producing high-purity copper using these additives.

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] Addition for high-purity copper electrolytic refining characterized in that it contains an ethylene oxide adduct having an IOB value of 1-2 in the organic conceptual diagram and an average molecular weight of 150-20000, and is used for copper electrolytic refining Agent.
[2] A main agent composed of an ethylene oxide adduct having an IOB value of 1-2 in the organic conceptual diagram and an average molecular weight of 150-20000, an IOB value of 2.0-9.5, and an average molecular weight of 6000 The additive for high-purity copper electrolytic refining according to the above [1], comprising ˜150,000 stress relaxation agents.
[3] The additive for high-purity copper electrolytic refining according to the above [2], wherein the concentration ratio of the stress relaxation agent to the main agent (stress relaxation agent / main agent) is 0.005 to 1.5.
[4] High purity for performing copper electrolytic refining by adding an additive containing an ethylene oxide adduct having an IOB value of 1 to 2 and an average molecular weight of 150 to 20000 to an electrolytic solution of copper electrolytic refining Copper manufacturing method.
[5] A main agent composed of an ethylene oxide adduct having an IOB value of 1-2 in the organic conceptual diagram and an average molecular weight of 150-20000, and an IOB value of 2.0-9.5 and an average molecular weight of 6000 An additive containing a stress relaxation agent of ˜150,000 and a concentration ratio of the stress relaxation agent to the main agent (stress relaxation agent / main agent) of 0.005 to 1.5 is added to the electrolytic solution of copper electrolysis. The method for producing high-purity copper according to [4] above, wherein refining is performed.
[6] The above [4] or [[] wherein the IOB value of the organic conceptual diagram is 1 to 2 and the concentration in the copper electrolyte of an ethylene oxide adduct having an average molecular weight of 150 to 20000 is 2 to 500 mg / L. [5] A method for producing high-purity copper according to [5].
[7] The method for producing high-purity copper according to any one of [4] to [6] above, wherein the copper electrolyte is an aqueous copper sulfate solution, an aqueous copper nitrate solution, an aqueous copper chloride solution, or an aqueous copper pyrophosphate solution.
[8] The high-purity copper according to any one of [4] to [7] above, which produces high-purity copper having a copper surface glossiness of 1 or more and a silver and sulfur content of 1 ppm or less. Production method.

[Specific description]
Hereinafter, the present invention will be specifically described.
The first additive of the present invention includes an ethylene oxide adduct having an IOB value of 1 to 2 in an organic conceptual diagram and an average molecular weight of 150 to 20000, and is used for copper electrolytic refining. It is an additive for high purity copper electrolytic refining.
Moreover, the 2nd additive of this invention is the main ingredient which consists of an ethylene oxide adduct whose IOB value of an organic conceptual diagram is 1-2, and whose average molecular weight is 150-20000, and the said IOB value is 2.0-9. And an additive for high-purity copper electrolytic refining that includes a stress relaxation agent having an average molecular weight of 6000 to 150,000.

  An organic conceptual diagram characterizes an organic compound using two indicators, an organic value (OV) and an inorganic value (IV), on the plane coordinates of the X axis of the organic value and the Y axis of the inorganic value. It is shown. The organic value (OV) indicates the organic property based on the covalent bond, the inorganic value (IV) indicates the inorganic property based on the ionic bond, and the physical property is determined by the position occupied by the organic compound in the coordinates. Judgment can be made. In general, a compound closer to the X axis (organic axis) has higher hydrophobicity, and a compound closer to the Y axis (inorganic axis) has higher hydrophilicity.

  The organic conceptual diagram is described in detail in Non-Patent Document 1 above. Moreover, the said patent document 3, patent document 4, and patent document 5 describe the substance which specified the organic value and the inorganic value of the organic conceptual diagram as a parameter | index. Note that Patent Documents 3 to 4 do not relate to copper electrolytic refining.

  The organic value (OV) and the inorganic value (IV) are determined based on the structural formula of the compound. Specifically, the organic value (OV) is a value obtained by multiplying the number of carbon atoms of the compound by 20, and the inorganic value (IV) is an inorganic value given to each substituent contained in the compound ( This is the total value of IV). An inorganic value table for each substituent is generally published, and based on this table, the inorganic values (IV) of the substituents contained in the compound may be summed.

For example, since ethylene glycol has 2 carbon atoms, the organic value (OV) is 40, the inorganic value (IV) is 100 for the OH group, 0 for the CH ₂ group, and the total is 200. Further, polyoxyethylene glycol having a polymerization degree of 10 employs an organic value of 30 and an inorganic value of 60 of ethylene oxide unit described in p.97 of Non-Patent Document 1, and is multiplied by a polymerization degree of 10 to give an organic The property value (OV) 300 and the inorganic value (IV) 600.

  The IOB (Inorganic / organic Balance) in the organic conceptual diagram is a ratio (IV / OV) of the inorganic value (IV) to the organic value (OV). For example, the IOB value of polyoxyethylene glycol is IOB = (IV60) / (OV30) = 2.0. On the organic conceptual diagram, a compound having an IOB value of 1 or more is located on the Y-axis side (inorganic axis side), and a compound having an IOB less than 1 is located on the X-axis side (organic axis side). Hereinafter, the IOB value of the organic conceptual diagram is simply referred to as the IOB value.

  In the present invention, the interaction between the copper surface and the additive molecule is different depending on the organic and inorganic ratio of the additive molecule, and thus the action mechanism of the additive is changed depending on the organic and inorganic ratio, It has been found that by using an organic molecule having a ratio between the organic value and the inorganic value in a specific range as an additive, high-purity copper having high purity and no warpage can be produced. The present invention is based on the above findings.

  The first additive of the present invention includes an ethylene oxide adduct having an IOB value of 1 to 2 in an organic conceptual diagram and an average molecular weight of 150 to 20000, and is used for copper electrolytic refining. It is an additive for high purity copper electrolytic refining.

  Examples of the ethylene oxide adduct include polyoxyethylene monophenyl ether, polyoxyethylene naphthyl ether, polyoxyethylene distyrenated phenyl ether, and polyoxyethylene glycol.

  Substances with relatively low IOB values of 1 to 2 (ethylene oxide adducts) form a dense adsorption layer on the cathode surface when added to the copper electrolyte, thus making the electrolytic copper deposited on the cathode surface dense. It is possible to obtain electrolytic copper having a function, smooth surface and low contamination. Further, the ethylene oxide adduct having an IOB value of 1 to 2 can suppress anode slime and greatly reduce the amount of sulfur contained in the electrolytic copper deposited on the cathode. On the other hand, when the IOB value is less than 1, the solubility of the additive in the electrolytic solution is remarkably lowered. When the IOB value is more than 2, the anode dissolution suppressing effect is excessively increased, and the surface of the electrolytic copper deposited on the cathode becomes rough. , And anode slime tends to increase.

  The ethylene oxide adduct used as the additive of the present invention preferably has an average molecular weight of 150 to 20000. If the average molecular weight is less than 150, the effect of suppressing electrodeposition is poor, the effect of smoothing the surface of the electrolytic copper deposited on the cathode is insufficient, and the precipitated copper crystal particles are enlarged to easily take up sulfur in the liquid. . On the other hand, when the average molecular weight exceeds 20000, the anode dissolution suppressing effect is too high, the surface of the electrolytic copper deposited on the cathode becomes rough, and anode slime tends to increase. Furthermore, it is preferable to have an aromatic compound such as phenol or naphthol because analysis becomes easy. In addition, the said average molecular weight is an average molecular weight of the polymer | macromolecule defined in JIS specification (JIS K7252-1: 2008 3.3.3).

  The second additive of the present invention contains an ethylene oxide adduct having an IOB value in the organic conceptual diagram of 1 to 2 and an average molecular weight of 150 to 20000 as a main agent, and the IOB value is 2.0 to 9.5. In addition, a stress relaxation agent having an average molecular weight of 6000 to 150,000 is included.

  A substance having a relatively high IOB value of 2.0 to 9.5 (stress relieving agent) has a relatively high hydrophilicity, so that the stress relieving agent adsorbed on the cathode surface contains a lot of water and forms a rough adsorption layer. Therefore, although the action of densifying the electrolytic copper deposited on the cathode surface is poor, the action of the main component ethylene oxide adduct is reduced to reduce the electrodeposition stress (stress relaxation effect), and the warp of the electrolytic copper deposited on the cathode is reduced. Suppress.

  When the average molecular weight of the stress relaxation agent is less than 6000 and over 150,000, the stress relaxation effect is poor, and the warp of the electrolytic copper deposited on the cathode is likely to occur.

  As the stress relaxation agent, for example, polyvinyl alcohol, sodium polyacrylate, ethylene-modified polyvinyl alcohol, carboxy-modified polyvinyl alcohol, polyoxyethylene-modified polyvinyl alcohol, and the like can be used.

  The concentration ratio of the stress relaxation agent to the main agent of the ethylene oxide adduct (stress relaxation agent / main agent) is preferably 0.005 to 1.5. When the concentration ratio is less than 0.005 and more than 1.5, the stress relaxation effect is poor, and the warp of electrolytic copper deposited on the cathode is likely to occur.

  The additive of the present invention (referred to as an additive including the first additive and the second additive) is used by being added to an electrolytic solution of copper electrolytic refining. The additive of the present invention can be used for any copper electrolyte of an aqueous copper sulfate solution, an aqueous copper nitrate solution, an aqueous copper chloride solution, or an aqueous copper pyrophosphate solution. In general, the copper concentration in the electrolytic solution is preferably 5 to 90 g / L. Except for the conditions relating to the additive, the process can be carried out in the same manner as in ordinary copper electrolytic refining.

  In the additive of the present invention, the concentration of the ethylene oxide adduct in the copper electrolyte is preferably in the range of 2 to 500 mg / L, more preferably in the range of 10 to 300 mg / L. When the concentration of the additive is less than 2 mg / L, the effect is poor, so that the smoothness of the surface of the electrolytic copper is lowered, and the sulfur component in the electrolytic solution is easily attached to and taken in the electrolytic copper surface. On the other hand, when the concentration exceeds 500 mg / L, adhesion of the anode surface is too strong and the amount of slime generated tends to increase.

  The additive comprising the ethylene oxide adduct of the present invention can suppress the slime generation rate to 30% or less in copper electrolytic refining, the copper surface has a glossiness of 1 or more, and contains silver and sulfur. High purity copper of 1 ppm or less can be produced. Furthermore, high-purity copper with little warpage can be produced by using a stress relaxation agent together with the additive.

  In conventional electrolytic refining using a PEG additive, dendrites on the surface of electrolytic copper are likely to occur, and when the PVA additive is used, the surface of electrolytic copper becomes smooth but contains more silver, but the additive of the present invention Has no dendrites on the surface of the copper electrode, and the silver content is 1 ppm or less. Further, in the conventional copper electrolytic refining, it is known that chloride ions are added to a copper electrolyte solution, and silver in the solution is precipitated to be removed by silver chloride. Electrolytic refining does not require the addition of chloride ions.

  Since the copper electrolytic refining using the additive of the present invention can be carried out in the same manner as ordinary copper electrolysis under electrolysis conditions other than the additive, it can be easily carried out using existing copper electrolysis equipment. The ethylene oxide adduct that is an additive of the present invention includes, for example, those having an aromatic ring such as polyoxyethylene monophenyl ether, polyoxyethylene naphthyl ether, and polyoxyethylene distyrenated phenyl ether. Since quantitative analysis by chromatography (HPLC) can be performed, the management of additives can be performed quickly and accurately.

Examples of the present invention are shown below together with comparative examples.
In the examples and comparative examples, (a) the sulfur concentration and silver concentration of electrolytic copper were measured at the center of electrolytic copper by GD-MS (glow discharge mass spectrometry). (B) 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 2, the electrolytic solution adhering to the surface of the electrolytic copper is not easily washed with water, so that the electrolytic solution tends to remain on the surface of the electrolytic copper, and the purity of the electrolytic copper is lowered. (C) Warpage of electrolytic copper was judged by visual observation. A mark with no warpage was indicated by a circle, a mark with a small warpage was indicated by Δ, and a mark with a large warpage was observed by x. (D) The slime generation rate was determined by the following equation.
Slime generation rate (%) = 100− (weight of deposited copper) / (dissolution amount of anode) × 100

[Example 1]
Using the first additive (A, B, C, D) of the present invention, an acid concentration of 50 g / L, a copper concentration of 50 g / L, and a hydrochloric acid ion concentration of 100 mg / L other than hydrochloric acid, an aqueous solution of copper sulfate, an aqueous solution of copper chloride, An aqueous copper nitrate solution or an aqueous copper pyrophosphate solution is used as a copper electrolyte, and the above additives are added to the copper electrolyte to a concentration of 30 mg / L, and electrolytic copper with a sulfur concentration of 5 ppm and a silver concentration of 8 ppm is added to the anode. Use copper current at a current density of 200 A / m ² and a bath temperature of 30 ° C., measure the additive concentration by HPLC using an ODS column every 12 hours, and maintain the additive concentration at 30 mg / L. The decrease was replenished to produce electrolytic copper electrolytically. The results are shown in Table 1.
The first additive (A, B, C, D) used is shown below.
Additive A: Polyoxyethylene monophenyl ether additive B: Polyoxyethylene naphthyl ether additive C: Polyoxyethylene distyrenated phenyl ether additive D: Polyoxyethylene glycol As shown in Table 1, sulfur of electrolytic copper The silver content is 1 ppm or less, the glossiness is 1 or more, and the slime generation rate is 30% or less. Moreover, the warp of the electric copper is small.

[Comparative Example 1]
The same conditions as in Example 1 using Additive A, Additive D, Additive E, Additive F other than ethylene oxide adduct, and Additive G whose IOB value or average molecular weight of the organic conceptual diagram is outside the scope of the present invention Copper electrolytic refining was performed to produce electrolytic copper. The additives EG used are shown below. The results are shown in Table 2.
Additive E: Polyoxyethylene alkyl ether additive F: Sodium dodecyl sulfate additive G: Sodium heptadencanate As shown in Table 2, the silver content of electrolytic copper is 0.2-2 ppm, but the sulfur content is It is as high as 1.1 to 6 ppm, the glossiness is low and less than 1, and the slime generation rate is as high as 31% to 45%. Further, peeling due to warping was observed in the electrolytic copper.

[Example 2]
Based on additives I to D of IOB values and average molecular weights shown in Table 3 as main ingredients, stress relaxation agents (D, H, I, J, K, L) of IOB values and average molecular weights shown in Table 3 were used in combination. Copper electrolytic refining was performed under the same conditions as in Example 1 to produce electrolytic copper. The used stress relaxation agents D to L are shown below. The results are shown in Table 3.
Stress relaxation agent H: Polyvinyl alcohol stress relaxation agent I: Sodium polyacrylate stress relaxation agent J: Ethylene-modified polyvinyl alcohol stress relaxation agent K: Carboxy-modified polyvinyl alcohol Stress relaxation agent L: Polyoxyethylene-modified polyvinyl alcohol As shown in Table 3 In addition, the content of sulfur and silver in electrolytic copper was as low as 0.9 ppm or less, the glossiness was 1 or more, and the slime generation rate was 30% or less. Moreover, the warp of the electrolytic copper is small or no warp is observed.

Claims (8)

  An additive for high-purity copper electrolytic refining, comprising an ethylene oxide adduct having an IOB value of 1-2 in an organic conceptual diagram and an average molecular weight of 150-20000, and being used for copper electrolytic refining.   An organic conceptual diagram having an IOB value of 1 to 2 and an average molecular weight of 150 to 20000 based on an ethylene oxide adduct, and an IOB value of 2.0 to 9.5 and an average molecular weight of 6000 to 150,000 The additive for high-purity copper electrolytic refining according to claim 1, comprising a stress relaxation agent.   The additive for high-purity copper electrolytic refining according to claim 2, wherein the concentration ratio of the stress relaxation agent to the main agent (stress relaxation agent / main agent) is 0.005 to 1.5.   Production of high-purity copper in which an IOB value in an organic conceptual diagram is 1 to 2 and an additive containing an ethylene oxide adduct having an average molecular weight of 150 to 20000 is added to an electrolytic solution of copper electrolytic refining to perform copper electrolytic refining Method.   An organic conceptual diagram having an IOB value of 1 to 2 and an average molecular weight of 150 to 20000 based on an ethylene oxide adduct, and an IOB value of 2.0 to 9.5 and an average molecular weight of 6000 to 150,000 The copper electrolytic refining is performed by adding an additive having a stress relaxation agent concentration ratio (stress relaxing agent / main agent) of 0.005 to 1.5 to the electrolytic solution of the copper electrolytic refining. The manufacturing method of the high purity copper described in Claim 4.   The IOB value of the organic conceptual diagram is 1 to 2, and the concentration in the copper electrolyte of an ethylene oxide adduct having an average molecular weight of 150 to 20000 is 2 to 500 mg / L. Manufacturing method of high purity copper.   The method for producing high-purity copper according to any one of claims 4 to 6, wherein the copper electrolyte is an aqueous copper sulfate solution, an aqueous copper nitrate solution, an aqueous copper chloride solution, or an aqueous copper pyrophosphate solution. The method for producing high-purity copper according to any one of claims 4 to 7, wherein a high-purity copper having a copper surface glossiness of 1 or more and a silver and sulfur content of 1 ppm or less is produced.