High-purity copper powder can be produced by electrolysis, with a purity of over 99.99%. Produced via electrolysis, it is known for its high purity and fine particle size, making it ideal for electronic components.
Our electrolytic cell is capable of producing high-purity copper powder. It uses a copper plate as the soluble anode and a stainless steel plate as the cathode. By carefully controlling conditions (such as electrolyte concentration and current density), copper powder can be obtained directly.
In our electrolytic cell, a brush and water-spraying device is installed on the stainless steel cathode. Meanwhile, the electrolytic cell is equipped with an ultrasonic vibration device. These two devices enable the copper powder on the cathode to fall off smoothly. Additionally, our electrolytic cell is matched with an exhaust gas treatment system and an electrowinning cell for copper ion recovery from tail liquid.
Below is a project case from our U.S. customer: 5 kilograms of copper powder are produced per day.
Principle of Copper Powder Production by Electrolysis
The principle of producing copper powder by electrolysis involves using a highly polished stainless steel plate as the cathode and an electrolytic copper plate as the anode. A direct current is passed through a sulfate-based electrolyte solution. During this process, copper ions are generated in the electrolytic cell, and these copper ions deposit on the cathode, forming fine and loose powder. The desired copper powder can be obtained by regularly collecting it with a brush.
Electrolysis Process
High-purity cathode copper is used as the anode, a stainless steel plate as the cathode, and a copper sulfate solution as the electrolyte. The particle size of the powder is controlled by adjusting parameters such as current density, temperature, and acidity. A powder-brushing process is adopted on the cathode to collect the powder at regular intervals.
Precautions for Production
1.Influence of Ion Types and Concentrations
In the preparation of electrolytic copper powder, ion concentration directly affects the particle size characteristics of the copper powder. For instance, a high ion concentration leads to coarser copper powder particles, an increase in bulk density, and may even result in the formation of a dense metal coating. On the other hand, a low ion concentration produces dispersed fine powder with a reduced bulk density. It should be noted that an excessively low ion concentration will also affect the electrical conductivity of the solution, thereby lowering the current efficiency. Taking [H⁺] as an example, it not only controls the acidity of the solution but also influences the fineness of the powder. Experiments have shown that when the [Cu²⁺] in the electrolyte is controlled at 7g/L and [H⁺] at 90g/L, all indicators of the copper powder are optimal.
2.Importance of Current Density
When the concentration of metal ions is kept constant, current density becomes a key factor determining whether powder can be precipitated. In particular, current density affects the particle size of copper powder and the deposition rate, making it a crucial parameter in the preparation process.
3.Function of Additives
In the production process of electrolytic copper powder, two types of additives are usually used: electrolyte additives and non-electrolyte additives. Adding an appropriate amount of Cl⁻ can optimize the particle size and structure of copper powder, while the addition of non-electrolyte additives such as gelatin helps in the formation of fine powder.
4.Influence of Powder-Scraping Cycle Time
The length of the powder-scraping cycle is crucial for controlling the particle size of copper powder. A shorter cycle results in a smaller variation range of current density, thus producing finer copper powder.
5.Influence of Electrolyte Temperature
As the temperature of the electrolyte rises, its electrical conductivity increases, which in turn improves the current efficiency. However, excessively high temperatures will accelerate the diffusion rate and the grain growth rate, leading to coarser powder particles.
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