A METHODOLOGICAL APPROACH FOR THE CHARACTERIZATION OF PRINTED CIRCUIT BOARDS FROM SMARTPHONES BY MICRO X-RAY FLUORESCENCE

In this study, a methodological approach based on micro X-ray fluorescence (micro-XRF) was developed in order to characterize end-of-life (EOL) printed circuit boards (PCB) from smartphones. An in-depth recognition of chemical elements on the PCB allows to set up an optimal processing strategy for recycling purposes. Moreover, a good knowledge of PCB composition can help to correctly manage such a waste maximizing the recovery of base, rare and precious metals. The possibility to carry out analyses both on entire PCB sample and on shredded particles resulting from milling was explored in order to check the chemical element concentration in the different size classes. This information is essential to set up the optimal mechanical processes able to preconcentrate valuable elements inside the different size class fractions, before that final chemical element recovery occurs. Obtained results showed as the adopted technique is useful to characterize both entire PCBs and milled particles allowing to improve the recycling strategies with “ad hoc” recycling strategies and plant architectures.