PCB Recycling 101: Part I – Recovering Gold, Copper, and More Safely

Apr 06,2016

Printed circuit boards are considered extremely important products by recycling organizations. The reason is that the boards are designed with a variety of valuable materials. A few examples include solder, gold, nickel, tin metal, palladium, and different types of copper (oxide, hydroxide, and sulfate solutions). Also, many PCB liquids like strong inks and acids are considered hazardous under environmental regulations. Hence, it is important to properly recycle printed circuit boards.

Just as the manufacturing process is a detailed one, the PCB recycling process comprises different stages. As it will not be possible to explain every process in one post, we are providing you a series of posts, which will elucidate on the different stages of the PCB recycling process.

PCB Dismantling for Management Purposes

A printed circuit board comprises avariety of expensive components, as well as hazardous substances. Theseneed to be separated from the PCB to ensure that the components can berecycled and reused. The following points elaborate the steps todismantle a PCB.

• Remove the Exterior Components: The first stageof the recycling process involves disassembling the PCB and sorting thecomponents. The first components that should be removed are the exteriorcables, capacitors, cell batteries, and engineered plastics. Thebatteries and capacitors should be removed manually, and disposed ofseparately. The other components can be removed using mechanicalseparation, which is an industrial operation for separating componentsand elements.
• Separate the Electronic Components: Semi-automatic approaches are utilized to separate electronic componentsfrom the PCB. A variety of soldered connections help keep thecomponents in place. A combination of shearing, heating, and impact andvibration forces can be used to open the connections. When using aheating apparatus, the temperature has to be up to 122o
• Physical Recycling – PCB Size Reduction: Materials such as ceramics, glass fibers, resins, and metals can be usedas fillers in new PCB resin matrix composites. To remove these from anold PCB, it is necessary to reduce the board’s size, so that thematerial fragments can be collected. First, the PCB needs to be cut intopieces between 1 and 2 cm using a shredder. This will quicken therecycling process. Next, use, cutting mills to break down the largepieces into particle sized pieces (about 5 or 10 mm). Use a sieve andplate at the bottom of the mill to collect the materials.
• Separate the Metallic and Non-metallic Particles: Use a magnetic or drum separator, or even Eddy or electrostatic currents toseparate the ferromagnetic metals from the non-ferrous materials.

With these steps, the first stage of thePCB recycling process is complete. In the next post, we will elaborateon the different processes used to recycle chemicals within a PCB.