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

3. Method 51
Table 8 Groups of equipment types considered in this investigation (see Appendix 1)
Group
Number of eq.
types
Mobile telephone 1
Examples of equipment types
Desktop personal computer 1 Includes the drives, excludes the monitors
CRT monitor 2 Cathode-Ray-Tube computer monitors, TV sets
Large high-grade equipment 12 DVD player, Video game console, Computer
LCD Monitor, Notebook
Small high-grade equipment 13 GPS, digital camera, MP3 player
Low-grade equipment 26 Vacuum cleaner, wall clock, radio control
vehicle, electrical drill, remote control
Total 55
High-grade equipment is defined as equipment containing printed circuit boards with a gold
concentration of at least 100 g/t. even though there are no sharp and universally accepted
criteria to differentiate between the different grades of printed circuit boards (Deubzer 2007),
the boundary of 100 g/t is often used by the precious metals industry to differentiate between
low and high-grade printed circuit boards. Regarding the differentiation between large and
small equipment, it was presumed that small equipment weighs less than one kilogram and
large equipment more than one kilogram. This rough criterion should not be considered too
strictly since due to the variety of models and manufacturers, some devices belonging to the
group ‘large high-grade equipment’ weigh less than 1 kg and some devices belonging to the
group ‘small high-grade equipment’ weigh more than 1 kg. The classification of the
equipment types into the equipment groups is presented in Appendix 1.
Gold and palladium contained in sWEEE are the focus of this substance flow analysis. As
introduced in chapter 2.3, precious metals are widely used for the manufacturing of EEE and
the recovery of precious metals from WEEE is very relevant from an economic and an
environmental point of view, but only few and uncertain data are available on cycles of
precious metals (see chapter 2.5). The life-cycle approach as defined in chapter 2.5.1 was
selected to set up the system boundaries of this investigation. The flows of gold and
palladium are tracked from the waste generation in Germany and in the USA in 2007 up to
the exit of the sWEEE management system as defined in chapter 2.4, regardless of when
this takes place.
3.2. Qualitative system modelling
As presented in chapter 2.4, end-of-life management consists of various phases: generation,
collection, and reuse/treatment/disposal.