阅读说明：本技术 电解铜箔制造工艺中快速溶铜的方法 (Method for quickly dissolving copper in electrolytic copper foil manufacturing process ) 是由 陈智栋 孙玉法 王文昌 明小强 王朋举 于 2021-06-01 设计创作，主要内容包括：本发明属于电解铜箔制造技术领域,涉及一种快速溶铜技术,用于制造电解铜箔用的电解液,具体为一种电解铜箔制造工艺中快速溶铜的方法,包括如下步骤：将待溶解的铜料置于预先装有硫酸水溶液的溶铜罐中,然后将氧气通过纳米气泡发生装置引入到溶铜罐中,溶解过程中控制溶铜罐中的硫酸水溶液的浓度大于电解液硫酸浓度。基于本发明方法,不仅可以快速溶铜,而且可以避免有效减少一价铜离子的生成,本发明的快速溶铜技术可完全满足电解铜箔的生产需求。(The invention belongs to the technical field of electrolytic copper foil manufacturing, relates to a rapid copper dissolving technology, is used for manufacturing an electrolyte for an electrolytic copper foil, and particularly relates to a rapid copper dissolving method in an electrolytic copper foil manufacturing process, which comprises the following steps: placing a copper material to be dissolved in a copper dissolving tank which is filled with a sulfuric acid aqueous solution in advance, introducing oxygen into the copper dissolving tank through a nano bubble generating device, and controlling the concentration of the sulfuric acid aqueous solution in the copper dissolving tank to be greater than the sulfuric acid concentration of an electrolyte in the dissolving process. Based on the method, the copper can be dissolved quickly, the generation of monovalent copper ions can be avoided and reduced effectively, and the quick copper dissolving technology can completely meet the production requirement of electrolytic copper foil.)

1. A method for quickly dissolving copper in an electrolytic copper foil manufacturing process is characterized by comprising the following steps: the method comprises the following steps:

and (2) placing the copper material to be dissolved in a copper dissolving tank which is filled with a sulfuric acid aqueous solution in advance, introducing oxygen into the copper dissolving tank through a nano bubble generating device, and controlling the concentration of the sulfuric acid aqueous solution in the copper dissolving tank to be greater than the sulfuric acid concentration required in the electrolyte in the dissolving process.

2. The method for rapidly dissolving copper in the manufacturing process of electrolytic copper foil according to claim 1, characterized in that: and the nano oxygen bubbles are introduced from the bottom of the copper dissolving tank.

3. The method for rapidly dissolving copper in the manufacturing process of electrolytic copper foil according to claim 1, characterized in that: the gas introduced by the nano bubble generating device is oxygen or mixed gas of oxygen and air.

4. The method for rapidly dissolving copper in the manufacturing process of electrolytic copper foil according to claim 1, characterized in that: the temperature in the copper dissolving tank is controlled to be 50-65 ℃ in the copper dissolving process.

5. The method for rapidly dissolving copper in the manufacturing process of electrolytic copper foil according to claim 1, characterized in that: the concentration of sulfuric acid in the copper dissolving tank is 100 g/L.

Technical Field

The invention belongs to the technical field of electrolytic copper foil manufacturing, relates to a rapid copper dissolving technology, is used for manufacturing an electrolyte for an electrolytic copper foil, and particularly relates to a rapid copper dissolving method in a manufacturing process of the electrolytic copper foil.

Background

Dissolving the metal copper material meeting the production requirement of the electrolytic copper foil,the preparation of the electrolyte is the first process for producing the electrolytic copper foil. Due to Cu²⁺The standard electrode potential of Cu is 0.337V, elemental copper cannot be dissolved in the aqueous solution of sulfuric acid under normal conditions, and metallic copper is stable in the aqueous solution of sulfuric acid at any pH value if oxygen or other oxidizing agents are not present, which means that the aqueous solution of sulfuric acid cannot be used to transfer copper into solution in the absence of oxygen or other oxidizing agents for the copper dissolution and liquid making process. However, metallic copper becomes unstable in aqueous solutions of any pH if oxygen or other oxidizing agents are present. In practice, in order to achieve the dissolution of metallic copper, the production generally adopts an oxidation dissolution method:

2Cu+O₂+2H₂SO₄＝2Cu²⁺+2H₂O+2SO₄ ^2-

the copper dissolution is generally divided into normal pressure copper dissolution and high pressure copper dissolution. The high-pressure copper dissolution is to introduce oxygen into a closed copper dissolution tank, and the oxidation tendency of copper is increased along with the increase of the pressure of the oxygen, so that the rapid dissolution of the copper is achieved. The high-pressure copper dissolution has the characteristics of high copper dissolution speed, high efficiency, complex equipment and large investment. Therefore, in the current electrolytic copper foil production process, copper dissolution is generally carried out under normal pressure. For normal-pressure copper dissolution, air or oxygen is required to be added for oxidation, in order to accelerate the dissolution of copper, besides the dissolution temperature is improved, a large amount of improvement is also made on an air inlet mode, but even if the dissolution temperature is improved, the copper dissolution speed is still required to be improved.

Disclosure of Invention

The invention aims to solve the problem of too low copper dissolution speed in the electrolytic copper foil production process, and provides a method for quickly dissolving copper in the electrolytic copper foil production process, so that quick copper dissolution is realized.

In order to realize the purpose of the invention, the adopted technical scheme is as follows: the method for quickly dissolving copper in the electrolytic copper foil manufacturing process comprises the following steps:

placing a copper material to be dissolved in a copper dissolving tank which is filled with a sulfuric acid aqueous solution in advance, introducing oxygen into the copper dissolving tank through a nano bubble generating device, and controlling the concentration of the sulfuric acid aqueous solution in the copper dissolving tank to be greater than the sulfuric acid concentration of an electrolyte in the dissolving process, wherein the sulfuric acid aqueous solution in the copper dissolving tank is preferably about 100g/L, so that the dilution or the addition of sulfuric acid can be avoided.

Preferably, the nano oxygen bubbles are introduced through the bottom of the copper dissolving tank. Specifically, when preparing copper electrodeposition liquid, a nano bubble generator is connected with an air inlet hole at the bottom of a copper dissolution tank, oxygen is introduced into the copper dissolution tank through a nano bubble generating device, and due to the characteristics of large specific surface area of nano oxygen bubbles, long residence time in sulfuric acid aqueous solution and self-pressurization dissolution, the oxygen concentration in the sulfuric acid aqueous solution in the copper dissolution tank becomes abnormally large compared with the common ventilating and stirring sulfuric acid aqueous solution, so that the rapid dissolution of copper is realized. Meanwhile, due to the increase of the oxygen concentration, the occurrence of disproportionation reaction during copper dissolution, namely the generation of monovalent copper, is effectively inhibited, and the yield during copper foil electrolysis is greatly improved. Since the preparation of the copper electrolyte is carried out in a non-sealed container, once the copper-dissolving tank is saturated with oxygen, there is no direct relationship with the rate of supply of nano-oxygen bubbles, and in this case, it is sufficient to ensure that the consumption of oxygen is compensated.

Meanwhile, in order to ensure the stirring effect of the gas, the introduced gas can be mixed gas of oxygen and air or nano bubbles of the air.

The heating is not needed in the copper dissolving process, because the dissolution of copper in sulfuric acid is an exothermic process, when sulfuric acid is added in the subsequent sulfuric acid concentration adjustment, the exothermic process is also performed, but when the temperature of the copper dissolving tank is too low, the copper dissolving tank needs to be heated, in order to ensure the speed of dissolving copper, preferably, the temperature of the copper dissolving tank is generally controlled to be 50-65 ℃, the temperature is too low, the speed of dissolving copper is reduced, so that the production efficiency of electrolytic copper foil is reduced, otherwise, when the temperature of the dissolved copper is too high and is more than 65 ℃, because the temperature deviation from the temperature during copper electrodeposition is too large, a cooling measure needs to be introduced instead, so that the compensation is not realized. The optimum temperature is close to the electrodeposition temperature of copper and ensures the rapid dissolution of copper, and usually about 50 ℃ is selected.

Compared with the prior art, the invention has the following beneficial effects: based on the characteristics of high specific surface area of nano bubbles, long-time stay in water and self-pressurization dissolution, nano oxygen bubbles can be easily led into the copper dissolution tank through the nano bubble generating device, so that the concentration of dissolved oxygen in a sulfuric acid aqueous solution medium is greatly improved, and the rapid copper dissolution is realized. Due to the existence of a large amount of oxygen in the copper electrolyte, the disproportionation reaction of copper to produce monovalent copper can be well inhibited, which is conducive to the production of high-quality electrolytic copper foil. The dissolving method is simple and easy to implement, and the required equipment is also simple. The preparation method of the copper electrolyte is not only suitable for manufacturing the electrolytic copper foil of the printed circuit board, but also suitable for the electrolytic copper foil of the lithium ion battery.

Drawings

FIG. 1 is a schematic view of a method for preparing a copper electrolyte according to an embodiment of the present invention.

The reference numbers in the figures are: 1. the device comprises an oxygen inlet pipe, 2 a nano bubble generating device, 3 a nano bubble outlet pipe, 4 a copper material feeding port, 5 an electrolytic copper circulating liquid inlet, 6 a copper dissolving tank, 7 a sulfuric acid aqueous solution, 8 a copper material and 9 an electrolytic copper circulating liquid outlet.

Detailed Description

The present invention will be further described with reference to the following examples. The examples show detailed embodiments and specific procedures, but the scope of the present invention is not limited to the following examples.

The nano bubbles generally refer to micro bubbles with the diameter of 200nm existing in water, and compared with the traditional bubbles, the nano bubbles have small diameter, and the mass transfer characteristic and the interface property of the nano bubbles are obviously different from those of the traditional bubbles. The nano bubbles have three remarkable characteristics, namely, the nano bubbles have larger specific surface area, and the specific surface area of the nano bubbles is theoretically 100 times that of common bubbles under a certain volume. Secondly, the nano bubbles stay in the solution for a long time, for example, in the traditional oxygenation aeration, the diameter of the bubbles is large, the contact surface area with the water body is small, the bubbles quickly rise to the water surface and are broken and disappear, the stay time is too short, and the oxygen dissolving effect is poor. The nano bubbles rise in water at a slow speed, and the process from generation to rupture usually reaches tens of seconds or even minutes. It has been found that bubbles with a diameter of 1mm rise in water at a rate of 6m/min, whereas bubbles with a diameter of 10 μm rise at a rate of 3mm/min, the former being 2000 times the latter, whereas bubbles with a size of nanometers can exist in water for about 1 week. Thirdly, the nano bubbles can be dissolved by self pressurization, gas-liquid interfaces exist around the bubbles in the water, and the bubbles are subjected to the surface tension of the water due to the existence of the gas-liquid interfaces. For bubbles with a spherical interface, surface tension can compress the gas within the bubble, thereby making the gas more soluble in water, and an increase in pressure can increase the solubility of the gas. With the increase of the specific surface area, the speed of bubble reduction becomes faster gradually, and finally the bubble is completely dissolved.

The following examples were conducted based on the schematic diagram of fig. 1, in order to prevent splashing of the sulfuric acid aqueous solution, the nanobubble generator was connected to a 1000ml closed vessel with a drain, the copper cable was placed in the sulfuric acid aqueous solution, nano-oxygen bubbles were introduced and stirred, and the copper was accelerated in the oxygen-rich sulfuric acid aqueous solution. In fig. 1, arrows indicate the nanobubble flow direction. And the electrolytic copper circulating liquid outlet is used for flowing out the solution after dissolving copper and manufacturing electrolytic copper foil. And the electrolytic copper circulating liquid inlet is used for introducing copper electrolyte which is produced after the electrolytic copper foil is manufactured and hydrogen generated by electrolytic reaction is removed, and the copper electrolyte is used for dissolving copper again after entering the copper dissolving tank and adding sulfuric acid and controlling the sulfuric acid to meet the set concentration.

For the determination of the copper dissolution rate, a plasma emission spectrum was used to analyze the concentration of copper ions in the sulfuric acid aqueous solution after 2 hours of dissolution, the concentration of copper ions in the sulfuric acid aqueous solution stirred by introducing air was 1, and the remaining times thereof represented the dissolution rate.

The amount of monovalent copper ions generated when copper was dissolved in an aqueous sulfuric acid solution was determined by using 2, 2' -biquinolinium as a color-developing agent. The following are specific examples, and the claims of the present invention are not limited to the reaction conditions and the concentrations of the raw materials listed in the following examples.

Example 1 a 100g copper cable was placed in 600ml of 100g/L aqueous sulfuric acid solution, and stirring was carried out by introducing nano-oxygen bubbles, so that copper was dissolved by oxidation in an oxygen-rich aqueous sulfuric acid solution at a temperature of 50 ℃. The dissolution rate of copper and the concentration of monovalent copper ions are shown in Table 1.

Example 2 a 100g copper cable was placed in 600ml of 100g/L aqueous sulfuric acid solution, and stirring was carried out by introducing nano-oxygen bubbles, so that copper was dissolved by oxidation in an oxygen-rich aqueous sulfuric acid solution at an accelerated speed, and the temperature of the copper dissolution tank was maintained at 60 ℃. The dissolution rate of copper and the concentration of monovalent copper ions are shown in Table 1.

Example 3 a 100g copper cable was placed in 600ml of 100g/L aqueous sulfuric acid solution, and stirring was carried out by introducing nano-oxygen bubbles, so that copper was dissolved by oxidation in an oxygen-rich aqueous sulfuric acid solution at a temperature of 65 ℃. The dissolution rate of copper and the concentration of monovalent copper ions are shown in Table 1.

Comparative example 1A 100g copper cable was placed in 600ml of a 100g/L aqueous sulfuric acid solution, stirred with air introduced, and the temperature of the copper dissolution tank was 50 ℃. The dissolution rate of copper and the concentration of monovalent copper ions are shown in Table 1.

Comparative example 2A 100g copper cable was placed in 600ml of a 100g/L aqueous sulfuric acid solution, and stirred with oxygen introduced thereto at a copper dissolution tank temperature of 50 ℃. The dissolution rate of copper and the concentration of monovalent copper ions are shown in Table 1.

TABLE 1 copper dissolution Rate and monovalent copper ion concentration

Example (b)	Copper dissolution Rate/(factor of comparative example 1)	Cu+Concentration/mmoldm-3
			Example 1	689	0.06
Example 2	782	0.04
			Example 3	818	0.01
Comparative example 1	1	1.1
			Comparative example 2	10.2	0.6

From the results shown in Table 1, it is understood that in comparative example 1, the dissolution rate of copper is very low and the concentration of monovalent copper ions is the maximum when air is blown. The nano oxygen bubbles introduced in example 1 were 67.5 times the dissolution rate of the introduced oxygen in comparative example 2. While the concentration of monovalent copper ions decreased by a factor of 10. From the results, it was found that the introduction of nano oxygen bubbles accelerates the dissolution of copper, suppresses the generation of monovalent copper, and ensures the quality of the electrolytic copper foil.