There are two main sources of discarded PCBs: one is printed circuit boards contained in discarded electronic and electrical products, and the other is edges and scraps formed by printed circuit boards in the production process. From computers, televisions to electronic toys, almost all electronic products contain printed circuit boards. Therefore, once the electronic and electrical products are discarded, there will be a lot of discarded circuit boards. With the rapid development of science and technology, electronic and electrical products are screened faster and faster, which will constitute a lot of abandoned circuit boards.

　　In addition, according to the relevant materials, the edge material produced by the cutting process in the production of printed circuit boards is up to 24%. Discarded circuit boards are mainly composed of organic reinforced resins, glass fibers, copper foil and electronic components, which contain many valuable metals such as copper, iron, aluminium, tin, lead, and precious metals such as gold, silver, platinum, palladium and so on. They have high value of resource recovery.

　　However, discarded circuit boards also contain lead, mercury, cadmium, chromium and other heavy metals and toxic and harmful substances such as polyvinyl chloride, halide flame retardants, which will cause serious secondary pollution to the environment if improperly treated. Therefore, how to effectively complete the harmless recovery of abandoned circuit boards and complete their recycling is of great significance to alleviate environmental pressure and prevent environmental pollution, improve the reuse rate of secondary resources, and ensure the sustainable development of China's economy, society and environment.

　　The mechanical treatment method is to break the discarded circuit board into fine particles, and then complete the separation according to the difference of the physical properties of each component. Generally, it includes crushing, grinding, sorting and other treatment processes. After removing components and solders, the scrap plate is crushed into powder less than 1 mm by using shear crusher and impact mill separately. After gravity separation and electrostatic separation, copper powders containing about 82% of copper can be obtained, and more than 94% of copper can be recovered. The powder size of resin and glass fiber mixtures is mainly between 100 and 300 microns, which can be used as additives for polymer products such as paints, coatings and building materials.

　　The article originated from Jiangmen PCB customization http://www.yonghongpcb.com