Abstract
Waste printed circuit board was co-pyrolyzed with iron oxides and iron salts. Solid, liquid and gaseous products were collected and characterized. Co-pyrolysis with FeCl2, FeCl3 or FeSO4 was able to increase the yield of liquid product which was rich in phenol and its homologues. Also, the addition of co-pyrolysis reagents reduced the release of brominated organics to liquid as Br was either fixed as FeBr3 in solids or released as HBr. In particular, FeCl2 showed the best ability to reduce the release of Br-containing organics to liquid compared with FeCl3 and FeSO4. Solid residuals were rich in iron oxides, glass fibers and charred organics with surface areas of 20.6-26.5 m2/g. CO2 together with a small amount of CH4 and H2 were detected in the gaseous products. Overall, co-pyrolysis could improve the quantity and quality of liquid oil which could be reused as chemical or energy sources. Pyrolysis of waste printed circuit board was promising as a method for recycling.
The results of the electric discharge crushing of PCB (printed circuit boards) to millimeter-sized fractions suitable for separation of the metal from the dielectric are presented. The crushing was performed on a high-voltage repetitively pulsed generator with varying the number of pulses. It was determined the dependences of the fractional composition of crushing products on the number of pulses in the cycle. Crushing products were studied for definition separation of metal from the dielectric with optical microscope. The results of the work confirm the possibility of electric discharge crushing various types of PCB, including fiberglass PCB with four layers.
Keywords: high voltage fragmentation, waste printed circuit board, recycling
Co-Pyrolysis of Waste Printed Circuit Boards With Iron Compounds for Br-Fixing and Material Recovery
