Fractional factorial design of ultrasonic-assisted metal recovery from waste printed circuit board

The complexity of waste printed circuit boards makes their recycling difficult. The process requires robust and expensive technologies to achieve separation. In this study, a simple novel technology was developed that used ultrasonication to separate metals from the substrate fiberglass layer. The technology used a customized tank to do the separation. The effectiveness of the process is determined by several factors. Five parameters were tested: ultrasonic frequency, particle size, ultrasonication time, bubbling, and mass. The ultrasound was used to enhance the separation of metals and substrate fiberglass layer. The test was done on two frequencies: 40 kHz and 58 kHz. It was shown that at 40 kHz, copper recovery was higher than at 58 kHz. It was found that ultrasonication time and particle size are the most significant parameters in the process. A copper recovery of 86.91% was achieved using this method. The statistical analysis showed the potential of the novel technology.