REEs are widely considered as critical materials for several reasons. Exhausted fluorescent lamps are special WEEE and rich secondary sources of REEs. The main purpose of this thesis is to get the advantages of a pretreatment of sieving on the lamps' powders. Analysis are performed with ESEM, FT-IR, XRD and TDGA. Different acid extractions, complex formation and relative boundary conditions are tested; a microwave treatment is performed to investigate the efficiency in the recovery of REE