Study on Metals Recovery from Discarded Printed Circuit Boards Using a Pulsing Liquid-Solid Fluidized Bed

摘要

According to the density difference of metals and nonmetals, a pulsing liquid-solid fluidized bed was used to recover metals from printed circuitboard (PCB), which was milled and separated into four size fractions: 1-0.5, 0.5-0.25, 0.25-0.125, 0.125-0.074 mm. The results indicated that metal recovery decreased as the operation velocity increased. The separation tests of 1-0.074 mm electronic waste in pulsing waterflow classifier were conducted, adopting Design-Expert 7.1 software to do the orthogonal experiments and analyzing the results. A Quadratic model between separation efficiency and different operation variable was obtained, which showed that the interaction of waterflow velocity and pulsing frequency on separation efficiency was significant. The separation efficiency could achieve 91.41% after optimizing the operating condition.