The processing of eWaste. Part 1: The
preparation and characterization of a metallic
alloy derived from the smelting of printed
circuit boards
DR Groot , JAN van der Linde
A brief overview is given of the issues regarding the processing of
waste electrical and electronic equipment (WEEE). The printed
circuit board component of WEEE is an exceptionally complex feed
to possible recycling processes.
Scrap printed circuit boards were selectively smelted at 1 200°C
to produce a metallic alloy. Iron and aluminium were found not to
be part of the alloy. The alloy was characterized by SEM-EDS, and
three phases were identified: alpha and delta bronzes, and a leadrich
phase. Calculations show that about 56 mass per cent of the
alloy is the alpha phase, 35 per cent delta phase and 9 per cent lead
phase.
A simplified approach using appropriate binary phase diagrams
was used to derive a phase composition for the alloy. This was
further backed by FactSage calculations, which showed that the
simplified approach was appropriate for this alloy. The experimental
findings and theory were found to agree well.