Processing of Electronic Scrap

摘要

The importance of electronic scrap recycling has become more evident over the last ten years. In the final Proposal for a Directive on the Waste from Electrical and Electronic Equipment (WEEE) and a Directive on the Restriction of Hazardous Substances which have been presented to the European Parliament and the European Council, energy recovery is still not seen as a part of recycling and with the very high re-use/recycling targets set, it is questionable whether industry will be able to reach the requirements set out in the Proposal. Metals, ceramics, glass and plastics are the major components in the scrap. The composition of those materials can vary widely depending on the type and age of the device. App. 30 % of the mass is due to the plastic fraction. Flame retardants, polychlorinated biphenyls (PCBs), unknown liquids in LCDs but also metals such as cadmium, chromium, lead and mercury are substances which need special consideration in the treatment of electronic scrap. Mechanical processing of the waste from electrical and electronic scrap separates the iron and non-ferrous fractions from the plastic fractions. However, some parts such as printed circuit boards are highly cross-linked which makes a mechanical separation too complicated and is therefore not economic. Pyrometallurgica! processes have to be applied to recover pure metals. The Department of Nonferrous Metallurgy at the University of Leoben, Austria, investigates different processes of melting and refining of these types of scrap to optimize the yield of base and noble metals.