Physical Separation And Recovery Of Scrap Electrical

With economy development, rubbish produced and cumulated are ever-increasing. Among wastes, the amount of waste of electrical and electronic equipment(weee) has been growing. From the points of protecting environment and resource regeneration, the studies of weee recycling has been urgent because of the double characters of weee which are polluted and valuable.In this paper, wasted Printed Circuit Board (PCB) is studied. The theory studies and experiments are conducted in order to identify shredding characteristic, materials composition and recycling techniques.The results show that the liberation degree of Cu in the -0.85mm PCB scrap is 94.5%.After the three-stage shredding flow, that the size distribution of outcome PCB scrap from plastic pulverizer is researched with the Fractal theory, the fractal dimension is 2.1569 and the expression of PCB scrap weight-size distribution, y = (x/x_max)^0.8431 has been obtained through screening method.The materials makeup of PCB scrap is ascertained by multi-analysis methods, that metals account for 41%, base metals such as copper, iron and aluminum, and precious metals as gold, silver and palladium, plastics account for 26%, glasses and crystallized account for 33%.The valuable components have been separated and recycled by gravity separation flowsheet, electric separation and magnetic separation density-based separation combined flowsheet and density-based separation flowsheet.(1) Optimal parameters of Table separation are 2.5° of grediant, 2500ml / min of water added and medium stroke, under the circumstance, the content of copper is up to 46.42%, copper is enriched by 3 times, the recovery of copper is more than 96 %; but for the subsequent separation between light metals and heavy metals, table separation is unsuitability, because the recovery of copper is only 46.99%.(2) the following results are obtained by Electric separation, magnetic separation and density-based separation combined flowsheet: after electric separation, not only copper is enriched by 3.5 times but alsothe same time, the recoveries of copper and iron are respectively 84.62% and 85.02%, the conductor is separated by magnetic separation, the recovery of iron is 80%, the recovery of copper is 84%.(3) PCB is separated by density-based separation in order to separate non-metal of PCB, the major plastics compound of ABS is within the range of -1.22 X 103Kg/m3+1.0X 103Kg/m3, the major plastics compound of PVC and Epoxy are within the range of -1.43 X 103Kg/m3+1.22 X 103Kg/m3.