Due to its content of highly functional and strategically important metals, Waste Electric and Electronic Equipment (WEEE) has been recently discussed as an upcoming source for raw materials. Recovery of critical metals from WEEE is, in opposite to the recovery of base and precious metals, very limited in current practice. A study quantitying the flows of nine trace metals associated with end-of-life mobile phones in Germany in 2007 shows that all the steps of the recycling chain, including collection, pre-processing and end-processing, show dissipative losses and lead to low end-of-life recycling rates. The UPGRADE project aims at enhancing the recovery of trace metals along the value chain by developing new liberation and separation steps (mechanical, thermal, chemical) considering the requirements of final recovery processes. "Upgrading" material flows along the recycling chain does not aim at a 100% recovery. It is the result of a transdisciplinary decision making and optimization inside recycling networks.