A printed circuit board is made of many different materials, the most valuable of which is copper. When you dispose of a printed circuit board, that copper can bleed into the environment through media like wastewater and solid waste. In addition to being damaging to the environment, this is extremely wasteful, as the copper in a printed circuit board can actually be quite valuable.
How to recycle copper and tin from PCB?
Here are some of the key ways copper can be reclaimed:
Recycling copper from edge Trim: To recycle the copper PCB from the edge trim of your printed circuit board, treat it with a stripping solution. This can dissolve precious metals like gold, silver and platinum, which you can also reuse. Then, use mechanical methods to separate the copper by shredding and grinding the trim and then using a cyclone separator to pull the copper from the plastic resin.
Recovering copper from wastewater sludge: To get at this copper, simply heat the sludge to 600 to 750 degrees Celsius to create copper oxide, and then use the smelter to turn it into copper metal.
Recycling copper from the spent basic etching solution: Adjust the solution to a weak acidic condition to produce copper hydroxide, then follow the process of removing copper from wastewater sludge. You can recover leftover copper in the filtrate with selective ion exchange resins.
Recovering copper hydroxide from the copper sulfate solution from the plated through holes process: Put the solution into your reactor and agitate while lowering the temperature to 10 to 20 degrees Celsius with a chiller. Use a centrifuge to recover the copper sulfate crystal and adjust the pH of the effluent to recover the remaining copper hydroxide.
What can we recycle from PCB?
Some of the valuable materials that can be recovered from printed circuit board waste include:
· Copper from the edge trim
· Copper oxide from treatment sludge
· Copper from the etching solution
· Copper hydroxide from the plated through holes process
· Copper from the rack stripping process
· Copper from the solder stripping process
· Tin from the hot air leveling process