Copper recovery from small devices populated on waste printed circuit boards

Present study discusses the recovery of copper (Cu) from discarded small devices depopulated from waste printed circuit boards (WPCBs) and the same get
discarded during its manufacturing. Among all small components, semiconductor
devices, especially, metal oxide semiconductor field effect transistors (MOSFETs) are in
abundant and selected for Cu recovery. MOSFETs were crushed, leached in HNO and 3
the results were validated thermodynamically. Almost 99% Cu was recovered using 3M
HNO at 90°C for 30 min maintaining pulp density 10 g/L. Leach liquor generated was 3
mixed with tri-butyl phosphate (TBP) to extract HNO completely, which requires 3
3 stages at O/A ratio 3:1 and mixing time 15 min. Further, air sparging was carried out to
remove the Fe content from the solution in order to intensify the efficiency of electrowinning
later used to extract pure Cu metal sheet from the solution. The spent electrolyte
containing other metals can be stored for further processing or sent to effluent treatment
plant.