Efficient recovery of valuable metals in the disposal of waste printed circuit boards via reverse flotation

The recycling of waste printed circuit boards (PCBs) has been an emerging problem due to its hazardous nature. In this work, the flotation performances of metallic elements were investigated and evaluated at various temperature and collector dosage. The content of metals in flotation products was measured by the X-ray fluorescence spectrometer. When using 740 g/t diesel oil (DO) as the collector at 20 degrees C, recovery efficiency of Cu, Al, Zn and Ag reached the maximum values of 91.06%, 82.50%, 95.87% and 90.87%, respectively. When using laurylamine (LAM) as the collector at 20 degrees C, recovery efficiency of Cu, Al, Zn and Ag reached the respective maximum values with corresponding LAM dosage of 370 g/t, 740 g/t, 370 g/t and 1110 g/t, respectively. The flotation results indicated that using DO can achieve the better recovery of these metals from waste PCBs than using LAM. Finally, an environmentally friendly process for recovering valuable metals from waste PCBs using reverse flotation was considered. (C) 2020 Elsevier Ltd. All rights reserved.