With the rapid update of electronic products, the waste of printed circuit boards (PCB), the main component of electronic waste, is also increasing. The pollution caused by PCB waste to the environment has attracted the attention of many countries. In the waste PCB, it contains lead, mercury, hexavalent chromium and other heavy metals. In the waste PCB, it contains nearly 20 kinds of non-ferrous metals and rare metals, which has high recycling value and economic value, and is a real mine waiting for exploitation. In fact, the environmental protection method of waste circuit board is to use “pulverization method”, which will get mixed metal powder after wind separation, magnetic separation, remaining aluminum alloy, copper powder, solder and epoxy resin powder mixture, and then recycling. Non-polluting physical recovery method.

1. Physical method. Physical method is a method to realize recycling by using mechanical means and different physical properties of PCB.

2. The purpose of crushing is to dissociate the metal in the waste circuit board with the organic matter as much as possible so as to improve the sorting efficiency. It is found that when the crushing is 0.6mm, the metal can basically achieve 100% dissociation, but the choice of crushing mode and grade depends on the subsequent process.

3. Separation: separation is realized by using the differences of physical properties such as density, particle size, electrical conductivity, magnetic conductivity and surface characteristics of materials. At present, there are some widely used technologies, such as wind turbine, flotation separation, cyclone separation, flotation separation and electrostatic separation.

Electronic waste is a valuable resource. It is of great significance to strengthen the research and application of metal recycling technology of electronic waste from both economic and environmental perspectives. Due to the complex and diverse characteristics of electronic waste, it is difficult to recover the metal with any single technology. In the future, the development trend of electronic waste treatment technology should be: industrialization of treatment forms, maximization of resource recovery, and scientific treatment technology.

To sum up, the research on recycling of waste PCB can not only protect the environment and prevent pollution, but also be beneficial to the recycling of resources, save a lot of energy and promote the sustainable development of economy and society.