How to make copper sulfate electrolyte

Abstract

A method for manufacturing an electrolytic copper foil according to one embodiment of the present invention includes a copper melting process in which a raw material containing copper (Cu) is melted in a melting furnace to produce molten copper; an atomizing process in which the molten copper is sprayed using an atomizer to produce copper powder; a leaching process in which the copper powder is dissolved in a leaching process feed solution in a leaching bath to form a copper sulfate solution; a refining and filtering process in which impurities contained in the copper sulfate solution are removed; and a conditioning process in which an electrolytic bath circulating solution is mixed with the copper sulfate solution from which the impurities have been removed to produce an electrolytic feed solution in an electrolytic bath.

Description

[Technical field]

[0001] The present invention relates to a method for producing a copper sulfate electrolyte, which can easily remove impurities contained in copper raw materials and at the same time greatly improve the leaching reaction time in the leaching process. The copper sulfate electrolyte is used in the manufacture of electrolytic copper foil. [Background technology]

[0002] The raw material for copper used in non-ferrous smelting processes to produce pure copper is mainly copper ore extracted from mines. Copper ore is chalcocite (Cu 2 S), Chalcopyrite (CuFeS 2 ), Bornite, Cu 5 FeS 4 ) or in the form of sulfide ores such as Cuprite (Cu 2 O), Malachite, Cu 2 CO 3 (OH) 2 ) and contains a large amount of impurities. Oxide ores dissolve in dilute sulfuric acid, while sulfide ores are formed when the iron contained in them is reacted with sulfuric acid and oxygen to form Fe 2 (SO 4 ) 3 After being leached as trivalent iron ions in the form of iron oxide (ferric ions), it acts as a catalyst to dissolve sulfide ores and dissolves copper in copper sulfate aqueous solution under normal pressure conditions.

[0003] However, the copper sulfate solution, which is the leaching filtrate of copper ore, also contains a large amount of impurities. If it contains iron ions, the Fe +2 / Fe +3This causes a significant decrease in current efficiency due to a reversible oxidation-reduction reaction, so the leachate produced by the above process cannot be used directly as an electrolyte for manufacturing electrolytic copper foil of several micrometers thickness made of 99.9% or more pure copper. In particular, if the copper sulfate solution contains a large amount of impurities, these impurities are mixed into the product, lowering the purity of the product and causing a decrease in the performance of the secondary battery, so an impurity removal process including a complex purification process must be added.

[0004] To solve this problem, Patent Document 1 proposes a solvent extraction method in which 2-hydroxy-5-nonylacetophenone oxime is diluted with kerosene from a copper sulfate leachate to recover copper from low-grade copper oxide and copper slag using a hydrometallurgical copper recovery method, using an organic solvent as a copper extractant. Patent Document 2 proposes a method of removing impurities in a two-stage process in which copper is precipitated and separated from a primary leachate obtained by leaching copper from copper ore using zinc concentrate, and the recovered copper precipitate is then subjected to a secondary leaching in a sulfuric acid solution containing iron.

[0005] In particular, in the process of manufacturing high-purity electrolytic copper foil for the current collector of the cathode of secondary batteries, which are mainly used in electric vehicles, energy storage devices (ESS), mobile phones, etc., a raw material in the form of pure copper is used to manufacture copper sulfate electrolyte without a complicated impurity refining process. For example, high-purity copper cathode (Cu Cathode), waste copper foil, waste electric wire (without coating), copper bar, and various copper scraps are used. According to the CRC Handbook of Chemistry and Physics, copper has a standard reduction potential of +0.34V, which is higher than that of hydrogen, which is 0V, so it is classified as a noble metal and generally does not dissolve in sulfuric acid.

[0006] According to Patent Document 3, in order to extract copper as copper sulfate from various raw materials containing metallic copper, copper in the divalent oxidation state (Cu +2 A technology has been reported in which raw materials are added to a reaction solution that is a mixture of copper (Cu) and sulfuric acid, and then oxygen is aerated to dissolve metallic copper as copper sulfate. 0 ) in the reaction solution with copper ions (Cu +2 ) to produce copper (Cu) in the +1 oxidation state. +1 ) and then used with oxygen and sulfuric acid to make cupric sulfate (CuSO 4 ) was dissolved.

[0007] Cu 0 +Cu +2 =2Cu +1 (1)

[0008] 4Cu +1 +O 2 +4H +1 =4Cu +2 +2H 2 O (2)

[0009] This reaction has a very low copper leaching reaction efficiency per unit time, and is difficult to apply to raw materials with a small surface area per unit weight, such as plate, stick, or wire shapes, due to problems such as the need for a long leaching time, increased oxygen consumption, increased external energy (heat source) consumption to maintain the reactor temperature, and increased processing costs.

[0010] Patent Document 1 and others have proposed a copper raw material pretreatment process including a first crushing step of crushing raw materials with a jaw crusher, a second crushing step of crushing the crushed material with a hammer crusher, a sieving step of separating the second crushed material with a screen filter, and a tank charging step of feeding the crushed material on a 2-10 mm screen selected in the sieving step into a leaching tank via a belt conveyor and feeding the crushed material less than 2 mm into a stirring tank for stirring and leaching in order to shorten the leaching time. According to these proposals, not only are relatively easy-to-crush raw materials such as low-grade copper oxide and copper slag used, but the crushed material obtained in the two-stage crushing process also has a wide particle size distribution, so complicated processes and equipment are required, such as sieving the material based on a size of 2 mm, and then feeding each separated crushed material into a separate tank for dissolving.

[0011] However, although raw materials such as waste electric wires can be cut into fine particles called chopping copper using a chopping machine, there is a limit to the size of the cuts, and because copper is an element with high ductility and malleability, it cannot be applied to raw materials in plate or stick form.

[0012] Accordingly, Patent Document 4 and others have proposed to manufacture copper strips, which are raw copper materials, into a wave shape through oriental pressing and a cutting machine in order to increase the contact area between the copper material and sulfuric acid, instead of crushing the raw copper material. According to these reports, the wave-shaped copper strips include peaks and troughs, and the horizontal distance between the peaks and troughs is 20 to 140 mm, and the vertical height difference between the peaks and troughs is 1 to 80 mm. When a wave-shaped copper strip having a thickness of 8 mm, a width of 5 mm, a horizontal distance of 80 mm, a height difference of 25 mm, and a weight of 11.48 kg was dissolved in 121 L of 100 g / L sulfuric acid solution at a temperature of 60°C for 24 hours, the dissolution rate was 4.7% (weight after dissolution: 10.94 kg), which was improved compared to a copper sheet (2.64%) under the same conditions. However, the dissolution rate was still low at less than 5%, and the copper concentration in the solution was also very low at 4.5 g / L.

[0013] Various contaminants may be mixed into waste electric wires from the outside during the process of separating the coating and during the transportation and distribution of the thin-skinned copper wire. + (0.80V), Hg +2 (0.85V), NO 3 +2 (0.96V), Co +3 Components with a reduction potential greater than that of Cu, such as nitrate ions (NO 3 ) (1.92 V), are dissolved during the copper sulfate solution manufacturing process and then electrolytically deposited together with copper during the electrolysis process, acting as impurities that reduce the purity of the product. 3 +2 ) is a typical air pollutant, NO, which is produced during the electrolysis process. x These substances may cause environmental pollution problems, such as being decomposed into various forms and being released into the atmosphere.

[0014] In the process of producing electrolytic copper or copper foil using electrolysis, the metallic copper contained in the copper raw material is reacted with sulfuric acid and oxygen to produce copper sulfate electrolyte, and the sulfuric acid generated in the electrolysis process is reused as the main source of sulfuric acid. In other words, by using the electrolysis waste (Cu Spent) discharged from the electrolysis cell in the electrolysis process as the dissolving solution, the amount of new sulfuric acid used from outside can be reduced and the loss of copper contained in the electrolysis waste can be prevented.

[0015] Anode:H 2 O+SO 4 -2 →1 / 2O 2 +2H 2 SO 4 +2e - (3)

[0016] Cathode: CuSO 4 +2e - →Cu+SO 4 -2 (4)

[0017] Total: CuSO 4 +H 2 O→Cu+H 2 SO 4 +1 / 2O 2 (5)

[0018] The amount of electrolytic effluent used in the leaching process can be determined by the copper concentration difference in the electrolyte in the electrolysis process and the copper concentration difference in the leaching process. For example, if the concentration difference between the electrolyte feed and effluent in the electrolysis process is 1 g / L and the copper concentration in the leaching process is increased by 1 g / L, the entire amount of electrolytic effluent must be fed to the leaching process. The more the concentration difference between the reaction stock solution and the leaching solution in the leaching process is increased, the less the amount of electrolytic effluent fed to the leaching process is, and the capacity of the leaching reactor and the equipment downstream is also reduced, so that an economical process can be provided.

[0019] The copper concentration in the leaching solution can be increased to the level of the solubility of copper sulfate, but if the copper leaching rate in the reaction tank is slow, the dissolution and leaching time must be very long to obtain a high-concentration copper sulfate solution, so the concentration difference must be small to ensure smooth process operation. In the conventional manufacturing technology for copper sulfate electrolyte used to manufacture electrolytic copper foil, copper is leached by directly feeding waste electric wires and waste copper sheets that have been subjected to washing processes such as water washing or acid washing into a leaching tank without pretreatment such as crushing, shredding, or cutting, and then feeding the electrolytic wastewater generated in the electrolytic tank into the leaching tank. Since the size of the raw material is large, the leaching tank is operated by forcibly circulating the reaction solution using a circulation pump, and since the dissolution rate of copper is slow, the copper concentration difference between the raw leaching solution and the leaching solution is low, at less than a few g / L.

[0020] Therefore, most of the electrolytic effluent must be fed into the leaching tank, which requires a large capacity and an increased number of leaching tanks, which in turn requires a large capacity and large amount of auxiliary equipment, such as leaching solution filtering equipment, equipment for measuring the copper and sulfuric acid concentrations in the leaching filtrate, and a process solution circulating pump, etc. This makes process management difficult, and inevitably increases the process operation costs, such as an increase in the number of process management personnel, and makes process management difficult to maintain the copper and sulfuric acid concentrations in each leaching tank due to the increase in the number of reaction tanks. [Prior art documents] [Patent documents]

[0021] [Patent Document 1] Korean Patent No. 10-1465457 [Patent Document 2] Korean Patent No. 10-1043398 [Patent Document 3] Korean Patent No. 10-1837307 [Patent Document 4] Korean Patent No. 10-1191715 Summary of the Invention [Problem to be solved by the invention]

[0022] The present invention aims to solve the problem of a method for producing copper sulfate electrolyte by easily removing impurities contained in copper raw materials and at the same time greatly improving the leaching reaction time in the leaching process. In addition, the present invention aims to solve the problem of a method for producing copper sulfate electrolyte by improving the leaching conditions to further shorten the leaching reaction time and increasing the copper concentration in the leaching solution to enable the downsizing of the equipment and significantly reduce the process operation costs. [Means for solving the problem]

[0023] A method for manufacturing a copper sulfate electrolyte according to an embodiment of the present invention includes a copper melting process in which a raw material containing copper (Cu) is melted in a melting furnace to produce molten copper; an atomizing process in which the molten copper is sprayed using an atomizer to produce copper powder; a leaching process in which the copper powder is dissolved in a leaching process input liquid in a leaching bath to form a copper sulfate solution; a refining and filtering process in which impurities contained in the copper sulfate solution are removed; and a conditioning process in which an electrolytic bath circulating liquid is mixed with the copper sulfate solution from which the impurities have been removed to produce an electrolytic feed solution in an electrolytic bath.

[0024] The copper concentration of the copper sulfate solution after the purification and filtration processes is 84 g / L to 99 g / L.

[0025] The copper powder obtained in the atomizing process has an average particle size of less than 2 mm.

[0026] The diameter of the nozzle of the atomizer is 10 mm to 15 mm.

[0027] The copper powder obtained in the atomizing process has a spherical, platelet or flower-like morphology.

[0028] The atomizing process is carried out by injecting high pressure water into the molten copper through a nozzle.

[0029] The method may further include a step of transferring the molten copper produced in the copper melting step to a separate storage tank, the storage tank having a size smaller than that of a melting furnace for producing the molten copper.

[0030] The storage tank includes a temperature maintaining device capable of maintaining the temperature of the molten copper.

[0031] In the leaching step, copper powder is added to the leaching tank and oxidized by stirring with an agitator to form copper oxide, and the copper oxide is leached with the leaching step solution to form a copper sulfate solution.

[0032] The electrolytic feed solution is used to manufacture copper foil and is discharged as electrolytic effluent after the manufacture of the copper foil. A part of the electrolytic effluent is fed as the leaching step feed solution, and the remainder is fed as the electrolytic cell circulating solution.

[0033] The amount of the electrolytic effluent fed as the leaching process feed liquid is 5 to 20% of the electrolytic effluent, and the amount of the electrolytic effluent fed as the electrolytic cell circulating liquid is 80 to 95% of the electrolytic effluent.

[0034] The refining step is a step of precipitating impurities contained in the copper sulfate solution formed in the leaching step, and the filtration step is a step of removing the precipitated impurities.

[0035] The temperature of the molten copper in the copper melting process is adjusted to 1,150°C to 1,300°C. Effect of the Invention

[0036] According to the present invention, a copper sulfate electrolyte can be produced from a copper raw material using simple equipment and a simplified process without a complicated refining process.

[0037] In addition, by melting the copper raw material at high temperatures through the copper melting process, it is possible to effectively remove total organic carbon (TOC) and fluorine (F), which are major impurities that can affect the production of electrolytic copper foil, as well as to increase the efficiency of removing various metal components contained in the raw material.

[0038] In addition, by producing copper powder having a small particle size from the high-temperature melted copper, the oxidation of the copper powder can be accelerated, thereby shortening the reaction time of the copper leaching process.

[0039] In addition, by increasing the reactivity of the leaching process, the concentration of the copper sulfate solution leached in the leaching process can be increased, and the amount of electrolytic wastewater fed to the leaching tank can be reduced, thereby providing an economical process that significantly reduces the capacity of the leaching tank, allows stable process management, and reduces processing costs.

[0040] In addition, as the amount of electrolytic effluent input to the leaching tank is reduced, external contamination of the electrolytic effluent can be minimized.

[0041] In addition, as the amount of electrolytic effluent fed into the leaching tank decreases, the amount of electrolytic effluent fed into the electrolytic tank can be increased, thereby enabling copper foil to be produced with a high yield and improving economic efficiency. [Brief description of the drawings]

[0042] [Figure 1] 2 is a process diagram for preparing a copper sulfate electrolyte according to an embodiment of the present invention; FIG. [Diagram 2] FIG. 4 is a process diagram for preparing a copper sulfate electrolyte according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0043] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention may be embodied in various different forms and should not be construed as being limited to the embodiments set forth herein.

[0044] Fig. 1 is a process diagram of a copper sulfate electrolyte according to an embodiment of the present invention. Referring to Fig. 1, the copper sulfate electrolyte manufacturing method includes a copper melting process (100), an atomizing process (200), a leaching process (300), a refining and filtering process (400), and a conditioning process (500), and the copper sulfate electrolyte (electrolytic feed solution) produced through the above processes is used to manufacture electrolytic copper foil.

[0045] The copper raw material (10) is directly put into the melting furnace without any separate pre-treatment process such as washing with water to remove surface impurities and drying, and the copper melting process (100) proceeds.

[0046] Here, the copper raw material 10 may be not only high-purity electrolytic copper, but also waste electric wires, waste bus bars, waste copper scraps including waste copper strips, etc., which are mainly composed of metallic copper. The raw material may be of any type, such as a plate type, a wire type, or a chopping copper type.

[0047] In particular, the copper raw material is characterized as being copper in a metallic state, but is not limited to pure copper. As the copper raw material, almost any raw material in a metallic form can be used, including precious metal elements such as gold and silver, component elements that are highly volatile at high temperatures or can be easily removed by oxidation at high temperatures, such as zinc (Zn), antimony (Sb), chlorine (Cl), fluorine (F), and carbon (C), and various copper alloys. However, bronze, which contains a large amount of tin (Sn), is excluded from the copper alloys.

[0048] As the melting furnace, an electric arc furnace (EAF), an induction furnace, etc. are all used. In particular, it is preferable to use an induction furnace, taking into consideration the ease of feeding the raw materials, the melting time, the method of tapping, the amount of carbon dioxide generated, and eco-friendliness.

[0049] In the copper melting process (100), the copper raw material (10) is melted to produce molten copper at 1,150°C to 1,300°C. If the temperature of the molten copper exceeds 1,300°C, the molten copper reacts with oxygen in the air, accelerating the formation of copper oxide and increasing the amount of dross produced. If the temperature of the molten copper is below 1,150°C, the fluidity of the molten copper decreases when it is poured out, which can cause nozzle clogging during the atomizing process.

[0050] Zinc, lead, chlorine, fluorine, etc. are removed as dust in the copper melting process, and total organic carbon (TOC) mixed in from lubricants, insulating agents, grease, etc. is oxidized to carbon dioxide in the copper melting process and then released into the atmosphere, so the copper melting process (100) can achieve the primary purification effect of various impurities while melting copper. Molten copper (110) produced through the copper melting process (100) in the melting furnace is quickly poured into the atomizer.

[0051] The atomizing process (200) may be a dry process using high-pressure air or a wet process using high-pressure water. Preferably, the wet process using high-pressure water is used, considering the effective removal of residual heat from the copper powder and the method of treating exhaust gas when recovering the powder produced in the atomizing process.

[0052] The atomizing process (200) is performed by injecting high-pressure water into the molten copper through the nozzle of an atomizer, and copper powder is produced through the atomizing process.

[0053] Since the particle size of the produced copper powder is determined according to the diameter of the injection nozzle, the diameter of the injection nozzle may be varied according to the particle size of the copper powder to be produced.

[0054] In the present invention, the diameter of the injection nozzle can be adjusted in the range of about 8 mm to 20 mm. If the size of the injection nozzle is smaller than 8 mm, the nozzle clogging phenomenon increases due to the decrease in the fluidity of the molten copper during the atomizing process (200), and if the size of the injection nozzle is larger than 20 mm, coarse copper powder is obtained.

[0055] In order to obtain copper powder (210) having an average particle size of 2 mm or less, the diameter of the injection nozzle may be about 10 mm to 15 mm. In order to improve the reaction rate by dispersing the copper powder (210) throughout the leaching tank using an agitator used in the leaching step (300) described below and to increase the residence time of the copper powder (210) in the reaction solution and improve the reaction efficiency of oxygen, it is desirable for the copper powder (210) to have an average particle size of 2 mm or less so that the individual weight of the copper powder (210) is not large.

[0056] The copper powder (210) obtained in the atomizing process (200) may have a spherical, plate-like or flower-like shape, and preferably has a plate-like or flower-like shape. A flower-like shape has a curved surface, unlike a typical plate-like shape that has a flat surface, and the curved shape has a shape similar to a petal, and has a larger surface area than a typical plate-like shape. Since a plate-like or flower-like shape has a larger surface area than a typical ball-shaped powder, the surface area of ​​the copper powder (210) that comes into contact with oxygen in the leaching process (300) can be increased. The powder shape can be adjusted by the injection speed and pressure of the high-pressure water, the injection angle of the high-pressure water, the injection speed of the molten copper through the nozzle, etc.

[0057] The copper powder (210) produced in the atomizing step (200) is fed into a leaching tank for the leaching step (300).

[0058] When the copper powder is put into the leaching tank and stirred with an agitator while adding oxygen (320), the oxygen reacts with the copper and the surface of the powdered copper powder, which has a very large surface area per unit weight, to form copper oxide. The copper oxide formed is leached by the leaching process input solution (630), which is a mixed solution of copper sulfate and sulfuric acid, to form a highly concentrated copper sulfate solution.

[0059] The reaction in which copper powder is oxidized by oxygen to form copper oxide and the chemical reaction in which copper oxide is leached by the leaching process input liquid (630) are shown below.

[0060] Cu+1 / 2O 2 →CuO (6)

[0061] CuO+H 2 SO 4 →CuSO 4 +H 2 O (7)

[0062] The agitator that agitates the copper powder in the leaching tank not only improves the reaction speed by increasing the number of collisions between the solid and liquid by dispersing the solid copper powder, which has a high specific gravity, throughout the leaching tank, but also increases the residence time of oxygen in the reaction liquid by turning the oxygen fed into the leaching tank into fine bubbles, thereby improving the reaction efficiency of the copper powder and oxygen, minimizing oxygen loss and reducing process operation costs.

[0063] Next, the leachate (310) obtained in the leaching step (300) is purified and filtered in a purification and filtration step (400) to produce a mother liquor of copper sulfate electrolyte.

[0064] Here, in the purification and filtering process (400), a small amount of purification residue is generated during the process of precipitating and removing trace amounts of impurities contained in the leachate (310), and the purification residue is removed through a filtering device.

[0065] Various impurities that flowed in from the copper raw material are distributed to the refined residue that is subjected to solid-liquid separation in the filtration equipment and then discharged outside the system. The filtrate (410) is transferred to the conditioning process (500) as the mother liquor of the copper sulfate electrolyte for producing copper foil.

[0066] The conditioning process (500) is a step of producing an electrolytic feed solution (610), which is a copper sulfate electrolyte that is supplied to an electrolytic cell for producing copper foil. The electrolytic feed solution (610) is used to produce copper foil, and a portion of the electrolytic effluent (620) generated after the copper foil production is recycled to the electrolytic cell as electrolytic cell circulating liquid (640) and used in the conditioning process (500), and the remaining portion of the electrolytic effluent (620) is input to the leaching process (300) as leaching process input liquid (630) and used for leaching copper powder (210).

[0067] According to the present invention, the large surface area of ​​the copper powder produced in the atomizing process (200) allows the reaction time of the leaching process (300) for producing the copper sulfate solution to be significantly reduced. As a result, even with the same reaction time, the copper concentration of the leaching solution (310), which is a copper sulfate solution, and the copper concentration of the filtrate (410) can be improved.

[0068] In the present invention, the copper concentration of the filtrate (410) after the atomizing step (200), the leaching step (300), and the refining and filtering step (400) can be increased to 84 g / L to 99 g / L. As the copper concentration of the filtrate (410) is increased as described above, unlike the conventional technology in which the entire amount of the electrolytic effluent (620) discharged from the electrolytic cell is fed to the leaching cell as the leaching step feed liquid (630), the remaining amount of the electrolytic effluent (620) can be reused as the electrolytic cell circulating liquid (640).

[0069] The more the electrolytic effluent (620) is exposed to the outside of the electrolytic cell, the greater the possibility of contamination, but according to the present invention, only a small amount of the electrolytic effluent is sent to the leaching cell and circulated, minimizing external contamination of the copper sulfate electrolyte. In addition, the capacity of the leaching cell and the capacity of the pump for transporting the electrolytic effluent (620) to the leaching cell can be significantly reduced compared to the conventional system.

[0070] FIG. 2 is a process diagram for preparing a copper sulfate electrolyte according to another embodiment of the present invention.

[0071] According to this embodiment, the method for producing copper sulfate electrolyte may further include a transfer process (150) between the copper melting process and the atomizing process, in which the molten copper (110) produced in the copper melting process (100) is transferred to a separate storage tank, the storage tank having a size smaller than that of the melting furnace for producing the molten copper (110) in the copper melting process.

[0072] As described above in the description of FIG. 1, the molten copper (110) produced in the melting furnace can be directly fed into the atomizer to produce copper powder through the atomizing process (200). However, in order to reduce the operating time of the melting furnace, improve the efficiency of operation, and allow for continuous operation of the atomizer equipment and miniaturization of each equipment, a transfer process (150) may be added between the copper melting process (100) and the atomizing process (200).

[0073] In detail, the molten copper (110) transferred to the storage tank is mixed with molten copper and dross, which is a mixture of impurities and oxides. In this case, by using a storage tank that is smaller than a melting furnace, the dross separated in layers at the top of the storage tank can be easily removed. In order to prevent smooth layer separation between the molten copper (110) and the dross and loss of fluidity due to cooling of the molten copper (110) in the storage tank, the storage tank includes a temperature maintaining device that can maintain the temperature of the molten copper (110), and the temperature maintaining device can be any type, such as an electric furnace type, an induction furnace type, or a heating torch type, without any restrictions. The dross can be easily removed from the molten copper (110) through the transfer process (150), thereby improving the leaching efficiency in the leaching process (300).

[0074] The molten copper (160) from which the dross has been removed through the transfer process (150) is quickly poured into an atomizer, where the atomizing process continues.

[0075] In addition to the above-described transferring process (150), the copper melting process (100), the atomizing process (200), the leaching process (300), the refining and filtering process (400), and the conditioning process (500) are the same as those described above with reference to FIG. 1, and therefore the description thereof will be omitted.

[0076] According to the present invention including the above-mentioned process, by melting the waste copper raw material at high temperature, it is possible to effectively remove total organic carbon (TOC) and fluorine (F), which are major impurities that may affect the production of electrolytic copper foil, as well as to provide a process with high efficiency of removing various metal components contained in the raw material.

[0077] In addition, according to the present invention, by producing copper powder having a large surface area and small particle size by using a wet process from high-temperature molten copper, it is possible to shorten the reaction time in the copper leaching process, significantly reduce the volume of the leaching tank, and provide an economical process that allows stable process management and reduces processing costs.

[0078] Those skilled in the art should understand that the present invention can be embodied in other specific forms without changing its technical idea or essential features. Therefore, the above-described embodiments are illustrative in all respects and should not be construed as limiting. The scope of the present invention is defined by the claims below, and all modifications or variations derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included in the scope of the present invention.

Claims

1. In the method for producing a copper sulfate electrolyte, A copper melting process in which a raw material containing copper (Cu) is melted in a melting furnace to produce molten copper; an atomizing process in which the molten copper is sprayed through an atomizer to produce copper powder; leaching the copper powder in a leaching tank to form a copper sulfate solution; A purification and filtration step for removing impurities contained in the copper sulfate solution; and A conditioning process in which the copper sulfate solution from which the impurities have been removed in the electrolytic cell is mixed with the electrolytic cell circulating liquid to produce an electrolytic feed solution. Including, The average particle size of the copper powder obtained in the atomizing process is 2 mm. How to make copper sulfate electrolyte.

2. The method for producing a copper sulfate electrolyte according to claim 1, wherein the diameter of the nozzle of the atomizer is 10 mm to 15 mm.

3. 3. The method for producing a copper sulfate electrolyte according to claim 1, wherein the copper powder obtained in the atomizing step has a spherical, plate-like or flower-like shape.

4. 2. The method for preparing copper sulfate electrolyte according to claim 1, wherein the atomizing step is performed by injecting high-pressure water into the molten copper through a nozzle.

5. The method further includes a step of transferring the molten copper produced in the copper melting step to a separate storage tank, The method for producing a copper sulfate electrolyte according to claim 1 , wherein the storage tank has a size smaller than that of a melting furnace for producing the molten copper.

6. The method for producing a copper sulfate electrolyte according to claim 5, wherein the storage tank includes a temperature maintaining device capable of maintaining the temperature of the molten copper.

7. 2. The method for producing a copper sulfate electrolyte according to claim 1, wherein the leaching step comprises forming copper oxide by stirring and oxidizing the copper powder charged in the leaching tank with a stirrer, and leaching the copper oxide with the leaching step charge to form a copper sulfate solution.

8. The method for producing a copper sulfate electrolyte according to claim 1, wherein the copper sulfate solution after the purification and filtration process has a copper concentration of 84 g / L to 99 g / L.

9. The electrolytic feed solution is used to manufacture copper foil, and is discharged as electrolytic effluent after the manufacture of copper foil; 9. The method for producing a copper sulfate electrolyte according to claim 8, wherein a part of the electrolytic wastewater is charged as the leaching step charge liquid, and the remainder is charged as the electrolytic cell circulating liquid.

10. 10. The method for producing a copper sulfate electrolyte according to claim 9, wherein an amount of the electrolytic effluent fed as the leaching step feed liquid is 5 to 20% of the electrolytic effluent, and an amount of the electrolytic effluent fed as the electrolytic cell circulating liquid is 80 to 95% of the electrolytic effluent.

11. 2. The method for producing a copper sulfate electrolyte according to claim 1, wherein the purification and filtering step includes a purification step of precipitating impurities contained in the copper sulfate solution formed in the leaching step, and a filtering step of removing the precipitated impurities.

12. 2. The method for producing a copper sulfate electrolyte according to claim 1, wherein the temperature of the molten copper in the copper melting step is adjusted to 1,150°C to 1,300°C.

Images