Copper is a purple-red metal, commonly known as “copper,” “red copper,” or “red copper.” Brass, bronze, and white copper are often alloys of copper and zinc, tin, and cobalt (nickel). Copper is slightly hard, extremely tough, wear resistant, and has good ductility, good thermal conductivity and electrical conductivity. Copper and some of its alloys have good corrosion resistance and are stable in dry air, but in the moist air, a layer of green basic copper carbonate can be formed on the surface. This is called patina. Copper is soluble in nitric acid and hot concentrated sulfuric acid, slightly soluble in hydrochloric acid, and easily eroded by alkali. In terms of applications, copper is a non-ferrous metal that is closely related to human beings. It is widely used in electrical, light industry, machinery manufacturing, construction industry, national defense industry, etc., and is second only to aluminum in the consumption of non-ferrous metal materials in China.
Copper powder is an important powder raw material for powder metallurgy, mainly including pure copper powder and copper alloy powder. The pure copper powder is mainly a powder of copper as a raw material, and the copper alloy powder is a mixed powder of copper and other metals, wherein the copper powder is a rose red or brownish red powder.
Electrolytic copper powder is a kind of copper powder. At present, copper powder on the market mainly consists of electrolytic copper powder and atomized copper powder, which are prepared by electrolysis and atomization.
Electrolytic copper powder is mainly obtained by melting, electrolysis, washing powder, vacuum drying and classification of electrolytic copper plates. Electrolytic copper powder has high purity, dendritic powder and large specific surface area. However, the production of copper powder by electrolysis has the disadvantages of serious environmental pollution and high energy consumption. It is worth mentioning that the electrolysis method has a long history of production and mature technology. In 1958, China began the trial production of copper powder. At that time, the production test of electrolytic copper powder was carried out. In the mid-1960s, the trial production of electrolytic copper powder was successful and it was invested in small batch production. In the mid-1970s, China established the first production line of electrolytic copper powder.
The atomized copper powder is mainly obtained by melting, atomizing, oxidizing, drying and reducing, crushing, anti-oxidation treatment and sieving (grading) of the electrolytic copper block. The atomized copper powder is irregular, with high purity, low oxygen, long storage time, good filling and formability, loose bulk density and adjustable particle distribution. The atomized copper powder can completely replace the electrolytic copper powder in application.
The industrial preparation method of copper powder is generally an electrolysis method, an atomization method, a reduction method and a mechanical grinding method, wherein the electrolysis method is the mainstream, that is, electrolytic copper powder. Although the copper powder prepared by the electrolysis method is simple in process, there are some problems such as high energy consumption and easy preparation of the copper powder to be oxidized. The atomization method is to use a high-speed air stream or a water stream to directly crush the metal to obtain a powder, which is a development direction of the copper powder, but has high production cost, expensive equipment, and complicated process. Regardless of the process, equipment or product output and quality, China has great gaps with advanced countries such as the United States and Germany. It is worth mentioning that in 2007, the structure of copper powder produced by China’s major copper powder production plants is basically: electrolytic copper powder accounts for 65% of total output, atomized copper powder accounts for 30%, and the rest is redox copper powder, chemical. Restore copper powder, etc.
Copper powder (electrolytic copper powder) is widely used in electromechanical parts such as powder metallurgy, electric carbon products, electronic materials, metal coatings, chemical catalysts, filters, heat pipes, and electronic aviation. Specifically, copper powder products include powder metallurgy parts, oil-impregnated bearings, friction materials, diamond tools and other traditional materials, as well as electromagnetic, electrical contact materials, thermal materials and other new materials.