2018 Volume 43 Issue 3 Pages 191-196
In this research, we examined a method that separates and recovers metals from pulverized powder of printed circuit boards (PCBs) contained in discarded personal computers (PCs). It has been reported that more than 80% of valuable metals could be recovered after the following processes of crushing, pH adjustment, and melting. However, as this technique requires an extremely high temperature, it is too costly for practical use at the actual machine level. In particular, a lower cost separation technology is needed for common materials such as Cu, Fe, Ni, Sn and Pb. Instead of the melting process, we apply ferritization process to the PCBs for recovery of common metals by magnetic separation. The PCB slag recovered valuable metals was mixed with several iron oxides powder, and ferritized at a temperature of 1073–1273 K for 10–60 min under atmosphere. Ferritization of FeO–PCB powder was completed in 10 min at 1073 K. The powder collected on the magnetic side had a saturation magnetization of 7.54 emu/g. The largest amount of ferritized PCBs powder was collected by magnetic separation. And, 95mass% of the common metals were recovered.
