Secondary material sales are the ultimate source of cell phone recycling revenues. These revenues can therefore be estimated by multiplying the amounts of recovered metals
reported from three different cell phone recyclers with their market value [8, 49, 53, 54]. Table 3 shows that the results are in very good agreement with the revenue data obtained from the two e-waste recyclers.
Table 3 also shows that around 70% of the recycling revenues are from the gold contained in handsets, whereas from a mass point of view, cell phone recycling is essentially copper recycling. Again, the overall results are remarkably constant across time and geography. This is partially due to two countervailing trends: Whereas the precious metal content of phones has a downward trend over time, the prices of Cu, Ag, Au, and Pd have been increasing between 2003 and 2006 [54].
The decreasing amount of recoverable precious metals per handset is a compound effect of two trends, the reduction in handset mass over time and the reduction in precious
metals content over time.