Input-Output Analysis of a WEEE Treatment Facility

In order to evaluate the separation of valuable fractions as well as the removal of hazardous substances, a material flow analysis according to the ÖNORM S 2096 guideline was carried out within a Master Thesis, the results of which are reported here. The material flow analysis was also needed to plan the enlargement of the treatment facilty by additional treatment steps. The mixture of the so called "passage", which accounts for up to 40 % of the output, had a yet unknown composition. It was sorted into 14 different fractions. The fine fraction (< 12 mm), which is being sieved off after the QZ, was also analysed in order to find an appropriate way of further treatment or recovery. It was found that this material stream, i.e. the passage, contains 63 % plastics, 3 % ferrous metals, 8 % non-ferrous metals, 4 % circuit boards, 2 % cables, 11 % other composites and about 1 % hazardous wastes. The valuable materials such as circuit boards or metals are mainly bound within composites. The fine fraction has a high calorific value of 8,500 kJ/kg DM but it is not suitable for co-incineration according to Austrian law due to its high heavy metal (e.g. Hg 10 mg/kg DM) and chlorine (5,000 mg/kg DM) content. Moreover, it contains about 5 % iron and 2 to 3 % copper. These are bound within composites and would only be recoverable by further expended disintegration. Looking at the output fractions of the whole WEEE treatment facility, the recovery of iron can be viewed as very satisfactory because 95 % of the iron are collected. Aluminum and copper on the other hand are recovered to a significantly smaller extent. Half of the aluminum and a quarter of the copper remain in the "passage" – stream after treatment. - the paper is written in german -