Separation of metals from metal-rich particles of crushed waste printed circuit boards by low-pressure filtration

Abstract

In recent years, recovery of metals from electronic waste (e-waste) within China has become increasingly important due to potential supply risk of strategic raw material and environmental concerns. Printed circuit boards (PCBs) contain lots of valuable metals together with plenty of hazardous materials, which are considered both an attractive secondary resource and an environmental contaminant. Pressure filtration is an effective and environmentally friendly method for separating and recycling comminuted PCBs. Present work is focused on the recovery of metals from PCBs by low-pressure filtration separation. A two-stage separation process was adopted to selectively recover Pb-Sn and Cu alloys at different temperatures. The results showed that the temperature and pressure had great influence on the recovery of metals in the separation process. After the two-stage separation process, the total recoveries of Pb, Sn, Cu and Zn were 79.96%, 89.91%, 88.80% and 68.57% respectively, when the temperature is 1350 °C and the pressure is 0.30 MPa. This is a high-efficiency, short-flow, clean-production, and environmental-friendliness that can improve the recovery of metals and realize the reuse of waste resources.