Recovery of Stainless Steel from End-of-Use Dishwashers

Abstract

: Wastes of Electrical and Electronic Equipment (WEEE) include a variety of products, from house appliances to spacecraft equipment, turning them into a significant source of secondary raw materials. Stainless steel is one of the most useful and valuable products of WEEE. Large quantities of stainless steel can be recovered from dishwashers. In this research project, the preparation of the samples includes the separation of their components, according to the following successive procedure: the dishwashers are processed through a magnetic separator to hold the magnetic ferrous pieces, an eddy current separator to separate the non-ferrous metals and an induction sorting sensor to detect and separate the remaining metallic fractions. From this procedure, two outgoing streams are produced: the stainless steel stream with some impurities and the impurity stream. Thereinafter, the stainless steel stream passes through a high intensity magnetic separator in order to eliminate the contained impurities. The result of this high-intensity magnetic separation is a magnetic stream containing the stainless steel pieces and a non-magnetic stream which contains the impurities. The final step of this procedure is hand sorting, so that any remaining impurities in the magnetic stream are removed.