The article aims at introducing the methods for recycling copper from scrap PCB boards, including chemical method and physical method.
Every one ton baseboards of PCB include about 40% metal materials and 60% nonmetals, containing almost all the common elements in the periodic table. By estimating, one ton computer circuit board contains 0.5kg gold, 130kg copper, 10kg iron, 60kg plumbum, 40kg tin, 36kg nickel, 40kg antimony . And some other rare precious metal, like platinum, palladium, etc. Copper obviously takes a big part of the composition of PCB boards.
Recycling copper of PCB boards can not only observably contribute to the refurbishment and reuse of copper but also reduce the need to heavy metal mining. The ways to recycle copper from PCB boards mianly includes chemical method and physical mechanical method nowadays.
The chemical method is to incinerate PCB boards into ash and then leach copper with chemical reagents after physical pre-treatment of scrap PCB boards such as shreddering and crushing. It is commmon method that using sulfuric acid-hydrogen peroxide to strip copper in the ash and adopting electrolysis to electrolyze the copper sulfate leaching solution to recover copper.
The chemical method is more complicated to operate compared with physical method and easy to cause environment pollution.
The physical extraction and recovery of copper in PCB boards requires the complete set of PCB boards recycling equipment. The whole recycling process is composed of crushing system, grinding system and sorting system. Waste PCB boards recycling equipment include shredder, crusher, magnetic separator, plastic pulverizer, airflow separator, electrostatic separator and pulse dust collector,etc. These machines operate in coordinate with each other.
Its working principle is to separate copper and resin powder based on different specific gravity and conductive property with the purpose to achieve copper. According to gravity difference between copper powder and resin powder. The airflow separator sort out copper powder with bigger particle size and heavier weight. The remaining smaller particles of copper and resin are sent to secondary separation by electrostatic separator. The electrostatic separator sort and collect copper and resin respectively according to different conductivity.
The physical mechanical treatment of circuit board is thorough and without dust leakage and pollution. What’s more ,the separation rate of metal and non- metal can be up to 99%.
The above is relevant introduction to ways to recycle copper from waste printed circuit boards, Wanrooe is an professional manufacturer in the production of e-waste recycling equipment. If you have any question about circuit boards recycling line and mechanical equipment, please feel free to contact us.