Integrated micro X-ray fluorescence and chemometric analysis for printed circuit boards recycling
A novel approach, based on micro X-ray fluorescence (μXRF), was developed to define
an efficient and fast automatic recognition procedure finalized to detect and
topologically assess the presence of the different elements in waste electrical and
electronic equipment (WEEE). More specifically, selected end-of-life (EOL) iPhone
printed circuit boards (PCB) were investigated, whose technological improvement
during time, can dramatically influence the recycling strategies (i.e. presence of
different electronic components, in terms of size, shape, disposition and related
elemental content). The implemented μXRF-based techniques allow to preliminary
set up simple and fast quality control strategies based on the full recognition and
characterization of precious and rare earth elements as detected inside the electronic
boards. Furthermore, the proposed approach allows to identify the presence
and the physical-chemical attributes of the other materials (i.e. mainly polymers),
influencing the further physical-mechanical processing steps addressed to realize
a pre-concentration of the valuable elements inside the PCB milled fractions, before
the final chemical recovery.