Recycling of waste electrical and electronic equipment

Some elements, such as precious metals, exhibit low concentrations in common ores. In secondary resources, e.g. waste electrical and electronic equipment (WEEE), these metals are more concentrated than in primary raw materials. Furthermore some other special metals, such as rare earth elements (REE), are contained in WEEE. This generally forms a big advantage for the recovery of these metals, but there are further aspects, which must be considered.

The challenge for an appropriate recycling process of WEEE is due to the complex and varying compositions of these materials. Another reason for the difficulty of the handling of these resources are hazardous substances, which are added during the fabrication of such products (e.g. printed circuit boards). For example, the danger of the formation of various harmful off-gases, such as halogenated dioxins and furans is given during a combustion of these fractions. Additionally some valuable elements attain to the slag or to the dust during a pyrometallurgical treatment. They are lost if a suitable recycling process of these by-products did not occurs. Due to these facts, detailed information and data will be systematically obtained on how different elements (especially metals) and their compounds behave under diverse processing conditions.

Subsequently, this knowledge constitutes the fundamentals for the elaboration of convenient process routes for the exploitation of WEEE with special regards to technological metals.  Investigations are made in terms of fractions gained by pyrometallurgical processes of WEEE, where metal, slag and dust phases are formed. These different products shall be further treated with different techniques, such as hydro- and electrometallurgical methods, to be appropriate regained.