A method for electrolytic refining of high-impurity blister copper

Abstract

The application relates to an electrolytic refining method of high-impurity crude copper and belongs to the field of metallurgical engineering. The electrolytic method comprises the following steps: preparing anode plates with a certain high-quality copper raw material into anode plates with a specified size, placing the anode plates and cathode plates into an electrolytic cell with prepared electrolyte according to a certain interval, and inputting direct current into the electrolytic cell. The electrolysis is started at the same time, and a constant temperature device, an electrolyte circulating pump and a magnetic field generating device are started. The scheme provided by the application can improve the electrolytic efficiency and the quality of the cathode copper, and reduce the formation of harmful gas and acid mist.

Description

Technical Field

[0001] This invention belongs to the field of metallurgical engineering, and further to the field of hydrometallurgy, specifically relating to a method for electrolytic refining of high-impurity copper. Background Technology

[0002] With the development of the copper smelting industry and the deterioration of raw material procurement, existing copper raw materials have lower copper grades and more complex impurity compositions. The content of impurities such as arsenic, antimony, and bismuth in copper anode plates processed in copper electrolysis processes has increased exponentially, with the content of primary copper dropping below 98%. This poses a greater challenge to traditional copper electrolysis processes. Traditional copper electrolysis processes have several problems when processing high-impurity copper. High impurity content easily leads to anode passivation, reducing electrolysis efficiency. Simultaneously, some suspended anode sludge generated during electrolysis easily adheres to the cathode surface, forming particles that affect the quality of high-purity cathode copper and cause significant loss of precious metals. Furthermore, traditional processes are energy-intensive, highly polluting, and have long processes, making resource reuse inefficient. In addition, the presence of impurities can alter the properties of the electrolyte, increasing the difficulty and cost of purification. Therefore, developing a process that can effectively address the electrolysis of high-impurity copper is urgently needed. Summary of the Invention

[0003] The purpose of this invention is to provide an electrolytic refining method for high-impurity crude copper. This method introduces a magnetic field to enhance electrolysis under traditional electrolysis conditions, which can adapt to electrolysis conditions with high impurities in the anode plate, effectively reduce the occurrence of passivation, and improve electrolysis efficiency and the quality of cathode copper.

[0004] This application provides an electrolytic refining method for high-impurity crude copper, the electrolytic method comprising the following steps: S1, high-purity copper and copper ore are smelted by fire and cast into anode plates; S2 is a high-purity copper electrolyte prepared from copper sulfate and sulfuric acid; the high-purity copper electrolyte contains 45-48 g / L of copper, 160-170 g / L of sulfuric acid, and ≤15 g / L of arsenic. S3, the anode plate and stainless steel cathode plate obtained in S1 are placed into an electrolytic cell containing the high-impure copper electrolyte prepared in S2, and direct current is passed into the electrolytic cell for electrolysis. At the same time as electrolysis, the constant temperature device, the electrolyte circulation pump and the magnetic field generating device are started.

[0005] Furthermore, the temperature of the constant temperature device in S3 is 60-70℃.

[0006] Furthermore, the magnetic field strength of the magnetic field generating device in S3 is 1-6T, and a vertical orientation magnetic field is adopted.

[0007] Furthermore, in the S3 magnetic field generating device, the flow rate of the electrolyte is 0.2-1.2 m / s; the magnetization time is 30-60 min.

[0008] Furthermore, the speed of the electrolyte circulation pump in S3 is 3L / min.

[0009] Furthermore, the stainless steel cathode plate is composed of conductive rods, stainless steel plates, and insulating edge strips.

[0010] Furthermore, the anode plate has dimensions of 88×85mm, a thickness of 8-11mm, and a weight of 0.6-0.7kg.

[0011] Furthermore, the number of anode plates and stainless steel cathode plates in S3 is 7 each.

[0012] Furthermore, the DC current density in S3 is 285-335 A / m. 2 .

[0013] Furthermore, the total electrolysis time in S3 is 12 hours.

[0014] Beneficial effects Adding a magnetic field during high-impurity copper electrolysis can produce beneficial effects in terms of improving the quality of cathode copper, increasing electrolysis efficiency, and reducing energy consumption, as detailed below: Improving the quality of cathode copper: Magnetic field can enhance Cu 2+ The magnetic field enhances the diffusion properties of the cathode, promoting the precipitation of impurity ions such as arsenic, antimony, and bismuth, improving electrolyte clarity, and reducing the deposition of impurity ions at the cathode. Simultaneously, the magnetic field can regulate electrode reactions, reduce copper loss, improve the apparent quality of cathode copper, decrease the probability of cathode copper grain formation, refine cathode copper grains, reduce internal defects, and improve corrosion resistance.

[0015] Improving electrolysis efficiency: A magnetic field can accelerate the anode dissolution rate, increase the amount of copper deposited at the cathode, increase current efficiency, and reduce the residual electrode rate. After applying a magnetic field, the amount of copper deposited at the cathode increases by 10%, the current efficiency increases by 3%, and the residual electrode rate decreases by 9%.

[0016] Reduced energy consumption: An external magnetic field can increase the allowable current density and reduce the overpotential in the electrolytic treatment of industrial wastewater, thereby reducing the cell voltage and energy consumption.

[0017] Reduce the formation of harmful gases and acid mist: Magnetization treatment can change the molecular structure of the electrolyte and reduce its surface tension, thereby greatly reducing the evolution of arsine and the formation of acid mist, which is beneficial to improving the working environment and reducing environmental pollution.

[0018] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Detailed Implementation

[0019] The embodiments of this application will now be described in more detail. While embodiments of this application are shown below, it should be understood that this application can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to make this application more thorough and complete, and to fully convey the scope of this application to those skilled in the art.

[0020] Unless otherwise specified, all reagents and materials used in the following examples were purchased from the market.

[0021] The technical principle of this invention is as follows: In the electrolysis of high-impurity copper, the magnetic field mainly acts on the electrolyte and electrode surface through the Lorentz force and magnetic field gradient force, thereby affecting ion diffusion, impurity precipitation, and cathode copper quality. The specific mechanism is as follows: Enhanced ion diffusion: When the electrolyte flows through a perpendicularly oriented magnetic field, charged ions experience Lorentz forces. These forces break the hydrogen bonds between water molecules and ions, reducing the diffusion layer thickness and ion hydration, thereby enhancing Cu diffusion. 2+ The diffusion properties of Cu 2+ It can migrate to the cathode more quickly, increasing the deposition rate of copper at the cathode.

[0022] Promoting Impurity Settling: The magnetic gradient force amplifies the magnetic energy of diamagnetic ions and water molecules in the copper electrolyte, reducing the degree of hydrogen bond association between water molecules and the activation energy of the electrolysis system, thus accelerating the copper electrolysis reaction rate. This promotes the formation of precipitates such as SbAsO4, BiAsO4, and AsSbO4 from arsenic, antimony, and bismuth ions, while increasing dissolved oxygen and CaSO4 solubility. It also promotes the formation of an oxidizing protective film on the surface of nickel, iron, and zinc ions, thereby improving the clarity of the electrolyte, reducing the deposition of impurity ions at the cathode, and improving the quality of the cathode copper.

[0023] Regulating electrode reactions: The gradient force of a magnetic field can reduce the magnetic energy of paramagnetic ions, enhance ion hydration, and thus regulate the rates of anodic dissolution and cathode copper deposition. In this way, copper loss can be reduced, improving the apparent quality of the cathode copper. Furthermore, a vertically oriented magnetic field can suppress electron transfer and enhance the diffusion process. Since the cathode reaction rate is controlled by the electron transfer and diffusion steps, while the anodic reaction rate is controlled by the electron transfer step, the magnetic field has a more significant impact on the cathode reaction.

[0024] Effects on electrolyte properties: Magnetic fields affect ion hydration, altering the viscosity and surface tension of aqueous solutions. Under a vertically oriented magnetic field, the surface tension of the electrolyte initially decreases and then increases, reaching a minimum at a certain flow rate. This is because magnetic treatment can cause changes in the intermolecular forces between water molecules and ion molecules in the solution, such as weakening hydrogen bonds. Ion hydration affects the structure of water molecules, leading to changes in surface tension.

[0025] The specific steps are as follows: Preparation of crude copper anode plates: High-purity copper and copper ore are smelted by fire and cast into anode plates. The anode plates are 88×85mm in size, about 10mm thick, and weigh about 0.67kg.

[0026] Electrolyte preparation: A mixed solution prepared from copper sulfate and sulfuric acid. The copper content in the high-purity copper electrolyte is 45-48 g / L, the sulfuric acid content is 160-170 g / L, and the arsenic content is ≤15 g / L.

[0027] Magnetic field generation process parameters: Magnetic field strength: The magnetic field strength is controlled between 1 and 6T.

[0028] Magnetic field direction: A vertically oriented magnetic field is adopted. A vertically oriented magnetic field can suppress electron transfer, enhance the diffusion process, and has a more significant effect on the cathode reaction. Electrolyte flow rate: Controlled between 0.2-1.2 m / s. When the flow rate is too low, the magnetization effect is poor; when the flow rate is too high, the surface tension of the electrolyte will increase, causing the synergistic effect of the magnetic field to fail.

[0029] Magnetization time: 30-60 minutes. If the magnetization time is too short, the magnetic field cannot be fully utilized, resulting in poor magnetization; if the magnetization time is too long, it will lead to wasted costs.

[0030] Cathode Plate: The cathode is made of stainless steel plate. The stainless steel cathode method utilizes stainless steel plate as a reusable cathode deposition surface to precipitate high-purity plate-shaped cathode copper, making it one of the main process equipment for copper smelting and copper resource recovery. The stainless steel cathode plate consists of conductive rods, a stainless steel plate, and insulating edge strips.

[0031] Process: Anode plates of specified dimensions are prepared from high-quality copper raw materials. These anode plates and cathode plates are then placed at a certain interval into an electrolytic cell containing prepared electrolyte. Seven anode plates and seven cathode plates are used. Direct current is passed into the electrolytic cell, with the current density controlled at 285-335 A / m. 2Copper at the anode loses electrons to become copper ions, which enter the electrolyte. Under the influence of the electric field, these copper ions move towards the cathode, gain electrons, and are deposited on the cathode plate. Simultaneously, a thermostat is activated to maintain the electrolyte temperature between 60-70°C, and the electrolyte circulation pump is started at a rate of 3 L / min. A magnetic field generator is activated, with the magnetic field strength controlled between 1-6 T, the electrolyte flow rate controlled between 0.2-1.2 m / s, and the magnetization time between 30-60 min, using a vertically oriented magnetic field. Electrolysis lasts for 12 hours.

[0032] Example 1 Using copper raw material with a copper grade of 97.0%, arsenic content of 1.5%, antimony content of 0.85%, and bismuth content of 0.65%, an anode plate with dimensions of 88×85mm, a thickness of approximately 10mm, and a weight of approximately 0.67kg was fabricated. Seven anode plates and seven seven cathode plates were placed alternately in the electrolytic cell, spaced 99mm apart. A pre-prepared electrolyte was injected, containing 45g / L copper, 160g / L sulfuric acid, and 15g / L arsenic. A direct current was applied, with the current density controlled at 280A / m. 2 The electrolyte circulation rate was 3 L / min. After 12 hours of electrolysis, the power was stopped. The cathode plate was removed, and the pure copper was peeled off. Samples were taken for testing, and the purity of the cathode copper reached 99.93%.

[0033] Example 2 Using copper raw materials with a copper grade of 97.5%, arsenic content of 1.2%, antimony content of 0.75%, and bismuth content of 0.55%, an anode plate with dimensions of 88×85mm, a thickness of approximately 10mm, and a weight of approximately 0.67kg was fabricated. Seven anode plates and seven seven cathode plates were placed alternately in the electrolytic cell, spaced 99mm apart. A pre-prepared electrolyte was injected, containing 45g / L copper, 160g / L sulfuric acid, and 15g / L arsenic. A direct current was applied, with the current density controlled at 280A / m. 2 The electrolyte circulation rate was 3 L / min. The magnetic field equipment was activated, and the electrolyte flow rate was controlled at 0.5 m / s between 3T and 4T. The magnetization time was 30 min. After 12 hours of electrolysis, the power was stopped. The ultrasonic equipment was then put into use. When ultrasound propagates in the medium, some of its energy is converted into heat, causing the electrolyte temperature to rise uniformly by 5°C. This temperature increase not only reduces the electrolyte viscosity but also accelerates ion diffusion, improves the kinetic activity of the electrode reaction, and reduces electrochemical polarization resistance. The vibration energy reduces the adsorption and retention of hydrogen on the cathode surface, reducing the generation of defects such as pinholes and pores, thus increasing the density of the cathode copper by 10%. The cathode plate was removed, and pure copper was peeled off. Sampling and testing showed that the purity of the cathode copper reached 99.99%.

[0034] Example 3 Using copper raw material with a copper grade of 97.0%, arsenic content of 1.5%, antimony content of 0.85%, and bismuth content of 0.65%, an anode plate with dimensions of 88×85mm, a thickness of approximately 10mm, and a weight of approximately 0.67kg was fabricated. Seven anode plates and seven seven cathode plates were placed alternately in the electrolytic cell, spaced 99mm apart. A pre-prepared electrolyte was injected, containing 45g / L copper, 160g / L sulfuric acid, and 15g / L arsenic. A direct current was applied, with the current density controlled at 280A / m. 2 The electrolyte circulation rate was 3 L / min. The magnetic field equipment was activated, and the electrolyte flow rate was controlled at 0.7 m / s within a 4T range. The magnetization time was 40 min. After 12 hours of electrolysis, the power was stopped. The ultrasonic equipment was then put into use. When the ultrasound propagates in the medium, some of its energy is converted into heat, causing the electrolyte temperature to rise uniformly by 8.5℃. This temperature increase not only reduces the electrolyte viscosity but also accelerates ion diffusion, improves the kinetic activity of the electrode reaction, and reduces electrochemical polarization resistance. The vibration energy reduces the adsorption and retention of hydrogen on the cathode surface, reducing the generation of defects such as pinholes and pores, thus increasing the density of the cathode copper by 15%. The cathode plate was removed, and pure copper was peeled off. Sampling and testing showed that the cathode copper purity reached 99.994%.

[0035] The various embodiments of this application have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A method for electrolytic refining high-impurity crude copper, characterized in that, The point-solving method includes the following steps: S1, high-purity copper and copper ore are smelted by fire and cast into anode plates; S2, a high-purity copper electrolyte prepared from copper sulfate and sulfuric acid; wherein the copper content in the high-purity copper electrolyte is 45-48 g / L, the sulfuric acid content is 160-170 g / L, and the arsenic content is ≤15 g / L; S3, the anode plate and stainless steel cathode plate obtained in S1 are placed into an electrolytic cell containing the high-impure copper electrolyte prepared in S2, and direct current is passed into the electrolytic cell for electrolysis. At the same time as electrolysis, the constant temperature device, the electrolyte circulation pump and the magnetic field generating device are started.

2. The electrolysis method according to claim 1, characterized in that, The temperature of the constant temperature device in S3 is 60-70℃.

3. The electrolysis method according to claim 1, characterized in that, The magnetic field strength of the magnetic field generating device in S3 is 1-6T, and a vertical orientation magnetic field is adopted.

4. The electrolysis method according to claim 1, characterized in that, The flow rate of the electrolyte in the magnetic field generating device in S3 is 0.2-1.2 m / s; the magnetization time is 30-60 min.

5. The electrolysis method according to claim 1, characterized in that, The speed of the electrolyte circulation pump in S3 is 3L / min.

6. The electrolysis method according to claim 1, characterized in that, The stainless steel cathode plate consists of a conductive rod, a stainless steel plate, and an insulating edge strip.

7. The electrolysis method according to claim 1, characterized in that, The anode plate has dimensions of 88×85mm, a thickness of 8-11mm, and a weight of 0.6-0.7kg.

8. The electrolysis method according to claim 1, characterized in that, The number of anode plates and stainless steel cathode plates in S3 is 7 each.

9. The electrolysis method according to claim 1, characterized in that, The DC current density in S3 is 285-335 A / m. 2 .

10. The electrolysis method according to claim 1, characterized in that, The total electrolysis time in S3 is 12 hours.