shown in Fig. 1, 90% of leached metals can be
already recovered after 6 hours leaching.
The leachate coming from the first leaching
step contains Ag, Pb, Fe and Cu which can be
separated through a fractioned precipitation process.
After their recovery, Ag and Cu are treated to obtain
the elements as metals via electrowinning and/or
chemical reductive processes.
Finally the leached boards resulting
completely cleaned from metals on the surface, but
still containing significant amounts of Cu inside,
were triturated and subjected to new leaching
treatment to recover remaining Cu.
As a results of this hydrometallurgical
process, a metal recovery up to 99% as yield and
purity grade was achieved. Furthermore this process
allows treating the whole PCBs, avoiding any
preliminary trituration step. The developed
hydrometallurgical process is reported in Fig. 2.
3.2. The recovery of mixed plastics from small
appliances
3.2.1. Plastic components FT-IR analysis
As it has been previously stated, WEEE
plastic fractions enclose a large number of different
polymers.