SUbstance flow analysis of the recycling of small waste electrical ...

3. Method 59
1. The visible hazardous and disturbing components like batteries, large metal sheets
and motors and the “easy-to-remove” printed circuit boards are first manually
removed from the end-of-life appliances.
2. After a coarse pre-shredding, a second manual sorting takes place to remove the
remaining hazardous and disturbing components.
3. The remaining scrap is shredded and sorted automatically.
44 output material fractions were generated by the processing of waste IT,
telecommunications and consumer equipment (German collection group 3) in the second
facility (Paper 2).
3.3.2.3. Visits and interviews
The data gathered from the literature and from experimental tests were completed by the
visit of 20 industrial facilities and by numerous interviews of stakeholders of WEEE recycling,
i.e. non-governmental organisations, retail and distribution sector, municipalities and other
public authorities, pre-processing and recovery operators, associations of the recycling
industry and research groups. The exchange of information took place either directly through
meetings or at distance by mail, e-mail, fax or telephone. Some of the information is
confidential in the sense that it can be used for the research but the provider of the
information does not wish to be named.
Since every stakeholder has a point of view to defend, questions can legitimately be raised
as to how far this method allows to collect representative and reliable data. As far as
possible, the data quality was increased by crossing the information, i.e. by asking different
persons for the same information. Visits and interviews made it possible to collect information
that could not be collected experimentally or by the literature review.
3.3.2.4. Estimates
If necessary data were not available in the literature, could not be gathered experimentally or
were not provided by the stakeholders, they had to be estimated. Even though efforts were
made to produce plausible estimations, they are associated with very high uncertainties.
3.3.3. Uncertainties
The uncertainty is the doubt about a result, i.e. an evaluation of its quality and accuracy (DIN
V ENV 13005). As concerns the scientific disciplines, the numerical evaluation of the
uncertainty is usually considered as the best one, because it simplifies synthesis and
facilitates the communication of results (Caria 2000).
The ‘Guide to the Expression of Uncertainty in Measurement’ (German pre-standard DIN V
ENV 13005) aimed at developing a universal, self-consistent and transferable method to