Production process of atomized copper powder

Electrolytic copper plate - melting - water (gas) atomization - vacuum drying - high-temperature oxidation - crushing - reduction - crushing - classification

melting

During the copper smelting process, it is necessary to control the content of impurities to ensure that the finished powder has good flowability and high

Conductivity.

Normal operation is to heat to 1150-1200 ℃ in an intermediate frequency furnace or electric arc furnace. Melting is the most important process before atomization. By controlling the copper smelting process, the effect of reducing the bulk density of copper powder can also be achieved.

atomization

There are two types of atomized copper powder produced in industrial production: gas atomization method and water atomization method. The main difference between these two methods is that the atomizing medium used is different, and the principle of powder production is the same. According to the different gas media, it can be divided into air atomization and argon atomization. Meanwhile, supersonic atomization is used to obtain finer powders.

Production practice has proven that the effect of water atomization is better than that of gas atomization, and water atomization is achieved in air or inert gas.

reduce

The reduction process is relatively simple, with a reduction temperature of 400-600 ℃ and a time of 60-120 minutes. During the atomization process, some oxygen is oxidized on the surface, while the other part becomes copper oxide and penetrates into the interior of the particles. The required reduction temperature for removing oxygen is very high. Under this temperature condition, copper will naturally be sintered, which requires grinding these large amounts of sintered blocks. The newly developed water mist oxidation method eliminates the need for further reduction steps, shortens the process flow, and saves energy.

Antioxidant therapy

From a thermodynamic perspective, copper is unstable in air, so oxidation of copper powder in air is inevitable, especially in humid environments where the surface of copper powder easily absorbs water vapor from the air to form a water film. In addition, due to the formation of a thick water film at the surface pits of the particles, oxygen infiltration is less, and the oxygen concentration is lower. Therefore, it becomes a micro anode, forming a micro cathode at the convex and concave areas where oxygen is easy to reach. Therefore, the concentration of copper powder is poor. Under the action of the battery, copper powder is gradually oxidized. After being treated with antioxidants, the surface of copper powder is adsorbed and covered with a thin film, which produces antioxidant effect and can extend its service life. Benzotriazole (BTA), soap solution, gelatin, and protein hydrolysate all have good corrosion inhibition effects on water atomized copper powder.