Method for manufacturing electrolytic copper and apparatus for manufacturing electrolytic copper

Abstract

To provide a method for producing electrolytic copper and an apparatus for producing electrolytic copper capable of reducing the number of times of extra flapping and improving production efficiency.SOLUTION: A method for producing electrolytic copper using a permanent cathode method comprises a step of supplying a pyrolytically treated glue solution into an electrolytic cell and electrolytically refining as an extra flapping suppressant for suppressing the number of times of stripping operation when stripping electrolytic copper electrodeposited on the surface of a cathode plate from the cathode plate.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for manufacturing electrolytic copper and an apparatus for manufacturing electrolytic copper.

Background Art

[0002] There has been conventionally known an electrolytic refining process of copper using a permanent cathode method (PC method) in which electrolytic copper electrodeposited on the surface of a stainless steel cathode plate is peeled off to obtain a product. In the PC method, a gap is previously created at the upper end portion of the plate-shaped electrolytic copper electrodeposited on the surface of the cathode plate, and with the cathode plate standing vertically, both ends of the upper end portion of the electrolytic copper floating from the surface of the cathode plate are gripped with a gripper and tilted horizontally, and at that position, a tensile stress is applied to cause a crack in the lower end portion of the electrolytic copper, and an operation called "flapping" is performed to separate one surface of the electrolytic copper from the other surface.

[0003] A V-shaped groove (V-groove) is provided at the bottom edge of the cathode plate used in the PC method. Due to the effect of this V-groove, the electrolytic copper is divided into two sheets at the bottom edge. However, when the depth of the V-groove becomes shallow due to impact, wear, aging deterioration, etc., the electrolytic copper may not be divided at the bottom when the electrolytic copper is opened horizontally. In such a case, an operation (extra flapping) of further repeating the opening and closing operation with the bottom edge of the electrolytic copper as a fulcrum is performed to fatigue and break the bottom edge of the electrodeposited copper. However, since such an extra flapping operation leads to a delay in the work by the amount of the extra flapping operation, as a result, the manufacturing efficiency of the electrolytic copper may be reduced. In addition, since the bottom edge is fatigue fractured, defective products with a bent shape at the lower part of the electrolytic copper may occur.

[0004] As a method for suppressing the number of extra flapping operations, for example, Japanese Patent Application Laid-Open No. 2006-274299 (Patent Document 1) describes a method for determining the processing and repair timing of the V-groove at the bottom edge of the cathode plate by measuring the number of flapping operations of the peeling machine when peeling the electrodeposited copper from the permanent cathode plate.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] As described in Patent Document 1, it is considered that one of the reasons for the increase in extra flapping is the deterioration of the V-groove of the cathode plate. When the present inventors introduced a V-groove maintenance machine or the like as the number of flapping increased, a certain improvement was observed. However, it was found that even when a V-groove maintenance machine or the like was introduced, the number of extra flapping times may not be reduced from a certain number. In order to further improve the production efficiency of electrolytic copper, it is useful to consider other countermeasures other than the above-mentioned measures for preventing the deterioration of the V-groove as a measure for suppressing the increase in the number of extra flapping times.

[0007] In view of the above problems, the present disclosure provides a method for producing electrolytic copper and an apparatus for producing electrolytic copper that can reduce the number of extra flapping times and improve the production efficiency of electrolytic copper.

Means for Solving the Problems

[0008] In order to solve the above problems, according to the present disclosure, in a method for producing electrolytic copper using the permanent cathode method, as an extra flapping inhibitor for suppressing the number of stripping operations when stripping electrolytic copper electrodeposited on the surface of the cathode plate from the cathode plate, there is provided a method for producing electrolytic copper including a step of supplying a nikawa solution subjected to a thermal decomposition treatment into an electrolytic cell and performing electrolytic purification.

[0009] According to another aspect of the present disclosure, in a method for manufacturing electrolytic copper using the permanent cathode method, as an additive for controlling the electrodeposition of electrolytic copper on the cathode plate, a first nikawa solution is supplied into the electrolyte, and as an extra flapping inhibitor for suppressing the number of stripping operations when stripping the electrolytic copper electrodeposited on the surface of the cathode plate from the cathode plate, a second nikawa solution subjected to heat decomposition treatment is supplied into the electrolyte, and a method for manufacturing electrolytic copper including an electrolytic refining step is provided.

[0010] According to still another aspect of the present disclosure, an electrolytic cell for attaching electrolytic copper to the surface of a cathode plate by immersing a copper anode plate and a cathode plate in an electrolyte and performing electrolytic refining, an adjustment tank for adjusting the flow rate of the electrolyte supplied to the electrolytic cell, an additive supply means for supplying an additive for controlling the electrodeposition of electrolytic copper into the electrolyte, a drainage tank for storing the drained electrolyte discharged from the electrolytic cell, a circulation mechanism for removing suspended substances in the drainage and circulating it to the adjustment tank, and as an extra flapping inhibitor for suppressing the number of stripping operations when stripping electrolytic copper from the cathode plate, an inhibitor supply means for supplying a nikawa solution subjected to heat decomposition treatment into the electrolyte are provided, and a manufacturing apparatus for electrolytic copper is provided.

Advantages of the Invention

[0011] According to the present disclosure, it is possible to provide a method for manufacturing electrolytic copper and a manufacturing apparatus for electrolytic copper that can reduce the number of extra flapping and improve the manufacturing efficiency of electrolytic copper.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0013] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiments shown below illustrate devices and methods for embodying the technical idea of this invention, and the technical idea of this invention does not specify the structure, arrangement of the device, or the order of the method, etc. to the following.

[0014] As shown in FIG. 1, the electric copper manufacturing apparatus according to an embodiment of the present invention includes an electrolytic cell 1, an adjustment tank 2 for adjusting the flow rate of the electrolytic solution supplied to the electrolytic cell 1, an additive supply means 3 for supplying an additive for controlling the electrodeposition of electric copper into the electrolytic cell 1, a drain tank 4 for storing the drained liquid of the electrolytic solution discharged from the electrolytic cell 1, a circulation mechanism 5 for removing suspended substances in the drained liquid and circulating it to the adjustment tank 2, and an inhibitor supply means 6 for supplying a glue solution subjected to thermal decomposition treatment into the electrolytic solution.

[0015] In the electrolytic cell 1, a copper anode plate (not shown) formed of rough copper or the like and a permanent cathode plate made of stainless steel or the like are provided at a predetermined interval. The electrolytic solution is supplied into the electrolytic cell 1 through an adjustment tank 2 that adjusts the flow rate of the electrolytic solution to be constant. By immersing the copper anode plate and the permanent cathode plate in the electrolytic solution and performing electrolytic refining, electric copper adheres to the surface of the permanent cathode plate.

[0016] An additive supply means 3 is connected to the adjustment tank 2. As the additive that the additive supply means 3 adds to the adjustment tank 2, a glue solution (first glue solution) containing glue is used. Glue has a function of adsorbing to the convex portions on the surface of electrolytic copper to suppress electrodeposition and smoothing the surface of electrolytic copper. Since glue is typically a solid mainly composed of gelatin, this glue is dissolved in water or warm water in a glue dissolution tank 7a to prepare a first glue solution. The first glue solution is supplied into the adjustment tank 2 via the additive supply means 3 and mixed with the electrolytic solution in the adjustment tank 2.

[0017] While glue functions as an electrodeposition inhibitor for suppressing abnormal electrodeposition of electrolytic copper, if it is supplied in an amount above a certain level, it may cause defects in the electrodeposition state such as roughness on the surface of electrolytic copper. Therefore, it is preferable to control the supply amount of the first glue solution so that it falls within an appropriate range according to the electrodeposition state of electrolytic copper. The supply of the first glue solution may be carried out in a batch mode or a continuous mode.

[0018] Other additives supplied by the additive supply means 3 include thiourea, abitone, etc. Thiourea has a function of promoting electrodeposition in the concave portions on the surface of electrolytic copper and smoothing the surface of electrolytic copper. Abitone, like thiourea, has a function of smoothing the surface of electrolytic copper and also has a function of suppressing bubble adhesion and particle adhesion to the surface of electrolytic copper due to the action of a surfactant. These additives other than the glue solution may also be prepared and managed in separate dissolution tanks (not shown) in advance to have a predetermined concentration and independently supplied via the additive supply means 3. Additives such as thiourea and abitone may be mixed with the first glue solution in advance and supplied to the adjustment tank 2 simultaneously.

[0019] The drained electrolytic solution used for electrolysis in the electrolysis tank 1 is sent to the drainage tank 4 and temporarily stored in the drainage tank 4. The drained liquid in the drainage tank 4 is heated by a heat exchanger 41 connected to the drainage tank 4 and then circulated to the adjustment tank 2 via a circulation mechanism 5. The circulation mechanism 5 can be composed of, for example, pipes, pumps, one or more storage tanks, etc., and the specific configuration is not particularly limited.

[0020] In the example of FIG. 1, the circulation mechanism 5 includes a pre-filtration tank 51 that stores the drained liquid discharged from the drain tank 4 and supplies the drained liquid to the filtration device 52, and a filtration device 52 that includes an ultrafilter or the like for removing unnecessary substances such as fine particles in the drained liquid. And a liquid supply tank 53 for sending the clarified electrolytic solution filtered by the filtration device 52 into the electrolytic cell 1 via the adjustment tank 2. The adjustment tank 2 absorbs the liquid level fluctuations of the liquid supply tank 53 and stabilizes the liquid supply flow rate to the electrolytic cell 1.

[0021] Connected to the drain tank 4 is an inhibitor supply means 6 for supplying an extra flapping inhibitor into the electrolytic solution to suppress the number of stripping operations when stripping the electrodeposited electrolytic copper from the surface of the cathode plate. Here, in this specification, the "extra flapping inhibitor" refers to an additive added to suppress the number of operations called "extra flapping" in which the peeling operation of the electrolytic copper electrodeposited on the surface of the permanent cathode plate does not succeed in one time and the opening and closing operation is further repeated with the bottom edge of the electrolytic copper as a fulcrum. As the extra flapping inhibitor, a nikawa solution (second nikawa solution) subjected to pyrolysis treatment is used.

[0022] Nikawa has a function of suppressing local current concentration during electrolytic refining and improving uniform electrodeposition properties. Generally, gelatinous nikawa is dissolved in water or the like while heating to obtain a nikawa solution, and then supplied into the electrolytic solution. However, nikawa is easily decomposed, and when the decomposition progresses, the function as an electrodeposition inhibitor cannot be sufficiently obtained. When nikawa decomposes, more nikawa must be added, so the amount of nikawa used increases. Therefore, as a conventional method, a method of supplying nikawa into the electrolytic solution without decomposing it as much as possible has been used.

[0023] On the other hand, in this embodiment, contrary to the conventional method, when a heat treatment was performed, that is, a nikawa solution obtained by applying a predetermined heat treatment to the nikawa solution to promote the decomposition of nikawa was supplied into the electrolytic solution, it was found that the number of extra flapping of electrolytic copper was significantly reduced. The reason is not clear, but it can be speculated as follows.

[0024] The main component of fish glue is gelatin, and since gelatin is a heat-denatured substance of collagen, it contains a lot of protein and various amino acids such as arginine, alanine, aspartic acid, glutamine, glycine, and proline. Here, FIG. 2 is a graph showing an example of the relationship between the added concentration of an amino acid and the hardness Hv of a nickel (Ni) plating film when arginine is added as an amino acid to produce the nickel plating film ("Codeposition of Amino Acids in Electrodeposited Nickel Plating Films", Taichi Nagai et al. (Graduate School of Engineering, Nagaoka University of Technology), Surface Technology, Vol. 66, No. 2, 2015, p59 - 64). As shown in FIG. 2, for the Ni plating film produced by adding an amino acid, as the added amount of the amino acid increases, the value of the hardness Hv gradually increases, and then gradually decreases while converging to a certain value.

[0025] Based on the example of nickel in FIG. 2, assuming that in the production of electrolytic copper, a similar trend as the result in FIG. 2 is shown, in this embodiment, as the fish glue decomposes, the amino acid concentration in the fish glue solution increases, and as the amino acid concentration in the electrolyte increases, it is considered that the hardness of the electrolytic copper generated in the electrolyte increases. As a result, it is estimated that the electrolytic copper becomes less likely to bend, and a phenomenon occurs where breakage is likely to occur in the V-groove provided at the bottom of the permanent cathode plate.

[0026] Therefore, as an extra flapping inhibitor, by subjecting the fish glue solution to a predetermined thermal decomposition treatment so that amino acids are generated and actively decomposing the components in the fish glue, and supplying the fish glue solution into the electrolyte, it is considered that electrolytic copper harder than before can be obtained. Thereby, it is considered that the number of flapping times during the stripping of the electrolytic copper can be significantly reduced, and the production efficiency of the electrolytic copper can be improved.

[0027] The "hide glue solution subjected to thermal decomposition treatment" used as an extra flapping inhibitor means a hide glue solution obtained by subjecting a hide glue solution prepared by dissolving hide glue in water or the like to heat treatment by holding it at 50°C or higher, more preferably 60°C or higher, still more preferably 65°C or higher for 1 hour or longer, more preferably 2 hours or longer, still more preferably 4 hours or longer.

[0028] If the heating temperature or time of the hide glue solution is too high or too long, evaporation of the solvent or a burden on the equipment may occur. Therefore, the hide glue solution used as an extra flapping inhibitor is heat-treated at 100°C or lower, more preferably 90°C or lower, still more preferably 70°C or lower.

[0029] The addition position of the extra flapping inhibitor is not limited to the example shown in FIG. 1, and it may be at any position of the adjustment tank 2, the drain tank 4, and the circulation mechanism 5. Among them, as shown in FIG. 1, by supplying the extra flapping inhibitor dissolved in the hide glue dissolution tank 7b into the drain tank 4 that stores the drain of the electrolytic solution discharged from the electrolytic cell 1 via the inhibitor supply means 6, it is possible to sufficiently secure the residence time until the drain is circulated back to the electrolytic cell 1 and supplied again. Therefore, the decomposition of the hide glue in the hide glue solution can be promoted during that time. The heat exchanger 41 connected to the drain tank 4 can heat the drain of the electrolytic solution to typically about 80 to 90°C. Therefore, by supplying a hide glue solution as an extra flapping inhibitor to the drain tank 4 and heat-treating the hide glue solution used as an extra flapping inhibitor via the heat exchanger 41, the heat source required for the heat treatment of the hide glue solution can be omitted.

[0030] Since the glue solution as an extra flapping inhibitor has undergone a certain degree of decomposition by thermal decomposition treatment, it is considered that the occurrence of electrodeposition abnormalities such as roughness on the surface of electrolytic copper generated when an excessive amount of glue is added into the electrolytic cell 1 is small. In the method for manufacturing electrolytic copper according to the embodiment of the present invention, in the method for manufacturing electrolytic copper using the permanent cathode method, a first glue solution is supplied into the electrolytic solution as an additive for controlling the electrodeposition of electrolytic copper, and as an extra flapping inhibitor, a second glue solution subjected to a predetermined thermal decomposition treatment is supplied into the electrolytic solution and electrolytically refined, whereby while suppressing the electrodeposition abnormality of electrolytic copper, the number of flapping times during stripping of electrolytic copper can be significantly reduced.

[0031] When the first glue solution and the second glue solution are supplied to the electrolytic copper manufacturing apparatus of FIG. 1, it is also conceivable that electrodeposition abnormalities of electrolytic copper may occur if the second glue solution is added in excess. Therefore, it is preferable that the second glue solution be supplied so as to be 10 to 40% by weight, more preferably 15 to 35% by weight, and still more preferably 20 to 30% by weight of the glue concentration added per day in the entire process of electrolytic refining. Thereby, while reducing the number of extra flapping times of electrolytic copper and improving the manufacturing efficiency, it is possible to improve the surface properties of electrolytic copper.

[0032] Also, in the present embodiment, it is preferable to control the supply amount, supply timing, and glue concentration of the first glue solution according to the electrodeposition state of electrolytic copper, and to control the supply amount, addition timing, and glue concentration of the second glue solution according to the measurement result of the number of flapping times when peeling electrolytic copper from the permanent cathode plate. In this way, by independently managing and controlling the supply of the first glue solution and the second glue solution respectively, the amount of glue used for the entire apparatus can be optimized. The supply amounts of the first and second glue solutions can be variously changed depending on the scale and processing conditions of the electrolytic copper manufacturing apparatus.

[0033] Figure 3 shows the change in the ratio of the amount of the first sizing solution to the amount of the second sizing solution added per day throughout the electrolytic refining process, taking into account the electrodeposition state of electrolytic copper. Figure 4 shows the relationship between the ratio of the amount of the first sizing solution to the amount of the second sizing solution added per day throughout the electrolytic refining process and the number of extra flapping times. In Figure 3, an example is shown where only the first sizing solution as an electrodeposition inhibitor is supplied in the first half of the electrolytic refining process, and the first sizing solution and the second sizing solution as an extra flapping inhibitor are supplied in the second half of the electrolytic refining process.

[0034] As shown in Figure 3, conventionally, when adding an amount of sizing exceeding a sizing addition ratio of 1.10, it had an adverse effect on the electrodeposition of electrolytic copper, so the amount of sizing added could not be increased. On the other hand, in this embodiment where, in addition to the conventional first sizing solution, a second sizing solution subjected to a thermal decomposition treatment was added to increase the overall amount of sizing added, even when the amount of sizing added was increased, the production of electrolytic copper could be carried out without any adverse effect on the surface properties of the electrolytic copper. Furthermore, as shown in Figure 4, when examining the sizing addition ratio that is effective in reducing the number of flapping times, by setting the sizing addition ratio to 1.10 or more, further 1.25 or more, and even more 1.35 or more, that is, by increasing the amount of sizing added, the number of extra flapping times can be reduced.

[0035] Thus, according to the electrolytic copper manufacturing apparatus and the manufacturing method using the same according to the embodiment of the present invention, by mixing the first sizing solution that does not undergo a thermal decomposition treatment and the second sizing solution that has undergone a thermal decomposition treatment into the electrolytic solution, the number of extra flapping times can be reduced, and it becomes possible to improve the manufacturing efficiency.

[0036] Although the present invention has been described using the above embodiments, it is not limited to each embodiment, and components can be modified and embodied without departing from the gist thereof. Also, various inventions can be formed by appropriately combining a plurality of components disclosed in each embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, components of different embodiments may be appropriately combined.

[0037] Figure 5 shows an example of the relationship between the temperature of the gelatin solution and the decomposition rate of gelatin ("Influence of various factors on the decomposition of gelatin in zinc electrolytic extraction", Hiroaki Nakano et al., (Graduate School of Kyushu University), Journal of MMIJ, Vol. 128 (2012), p584-589). According to this example, it can be seen that as the temperature of the gelatin solution increases, the decomposition rate of gelatin improves. Therefore, based on the temperature of the gelatin solution and the decomposition rate of gelatin, the operator can control the solution temperature and decomposition rate of the gelatin dissolution tank 7b within an appropriate range, thereby improving the production efficiency of electrolytic copper while reducing the number of extra flapping times.

Explanation of symbols

[0038] 1... Electrolytic cell 2... Adjustment tank 3... Additive supply means 4... Drainage tank 5... Circulation mechanism 6... Inhibitor supply means 7a... Gelatin dissolution tank 7b... Gelatin dissolution tank 41... Heat exchanger 51... Tank before filtration 52... Filtration device 53... Liquid supply tank

Claims

1. In a method for manufacturing electrolytic copper using the permanent cathode method, A method for manufacturing electrolytic copper, comprising a step of supplying a thermally decomposed nikawa solution into an electrolytic cell for electrolytic purification as an extra flapping inhibitor for suppressing the number of stripping operations when stripping the electrolytic copper electrodeposited on the surface of the cathode plate from the cathode plate.

2. As the extra flapping inhibitor, The method for manufacturing electrolytic copper according to claim 1, comprising using a nikawa solution obtained by dissolving nikawa in a solvent and holding it at 50°C or higher for 1 hour or more.

3. In a method for manufacturing electrolytic copper using the permanent cathode method, As an additive for controlling the electrodeposition of electrolytic copper on the cathode plate, a first nikawa solution is supplied into the electrolytic solution, A method for manufacturing electrolytic copper, comprising a step of supplying a thermally decomposed second nikawa solution into the electrolytic solution as an extra flapping inhibitor for suppressing the number of stripping operations when stripping the electrolytic copper electrodeposited on the surface of the cathode plate from the cathode plate, and performing electrolytic purification.

4. The method for manufacturing electrolytic copper according to claim 3, comprising supplying the second nikawa solution so that it becomes 10 to 40% by weight of the nikawa added per day throughout the electrolytic purification step.

5. The method for manufacturing electrolytic copper according to claim 3 or 4, comprising supplying the second nikawa solution into a drain tank for storing the drained electrolytic solution.

6. The method for manufacturing electrolytic copper according to claim 3 or 4, comprising controlling the addition amount of the extra flapping inhibitor according to the measurement result of the number of stripping operations when stripping the electrolytic copper from the cathode plate.

7. An electrolytic cell for attaching electrolytic copper to the surface of the cathode plate by immersing a copper anode plate and a cathode plate in an electrolytic solution for electrolytic purification, An adjustment tank for adjusting the flow rate of the electrolytic solution supplied to the electrolytic cell, Additive supply means for supplying an additive for controlling the electrodeposition of the electrolytic copper into the electrolytic solution, A drain tank for storing the drained electrolytic solution discharged from the electrolytic cell, A circulation mechanism for removing suspended substances in the drained solution and circulating it to the adjustment tank, Inhibitor supply means for supplying a thermally decomposed nikawa solution into the electrolytic solution as an extra flapping inhibitor for suppressing the number of stripping operations when stripping the electrolytic copper from the cathode plate An electrolytic copper manufacturing apparatus comprising.

8. The manufacturing apparatus for electrolytic copper according to claim 7, comprising a heat exchanger connected to the drainage tank, and thermally decomposing the glue solution used as the extra flapping inhibitor through the heat exchanger.

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