The electronics industry is replacing products so quickly that the amount of discarded PCBS that come with it is staggering.More than 50,000 tonnes of discarded PCBS are used in the UK each year, compared with 100,000 tonnes in Taiwan.Recycling is the principle of resource conservation and green production. Besides, some materials in electronic products will be harmful to the environment. Recycling is inevitable.
PCB contains common metals: aluminum, copper, iron, nickel, lead, tin and zinc.Precious metals: gold, palladium, platinum, silver, etc.Rare metals such as rhodium and selenium.PCB also contains a large number of polymers, directly or indirectly derived from petroleum products, which have high calorific value and can be used to generate energy as well as related chemical products, many of which are toxic and harmful. If discarded, great pollution will be caused.
The PCB template consists of several elements that can be recycled even if they are not normally used.Then, how to recycle? We briefly introduce the steps:
1.Take off the lacquer
PCB surface coated with protective metal, the first process of recycling is to take off the paint.Paint remover includes organic paint remover and basic paint remover. Organic paint remover is highly toxic and harmful to human body and environment. It can be dissolved by heating with sodium hydroxide and corrosion inhibitor.
After PCB is removed, it will be broken by impact crushing, extrusion crushing and shear crushing.More commonly used is cryo-cryogenic crushing technology, which can lower the temperature of tough materials, crush them after embrittlement, and completely dissociate metals and non-metals.
The material after crushing shall be sorted according to the density, particle size, magnetic conductivity and other characteristics of each component, usually by dry method and wet method.Dry separation includes dry screening, magnetic separation, electrostatic, density and eddy current separation.The wet separation method includes hydrocyclone classification, flotation, hydraulic shaking table, etc.You can reuse the material.