title: Selective extraction and recovery of rare earth metals from phosphor powders in waste fluorescent lamps using an ionic liquid system.
abstract: The recycling of rare earth metals from phosphor powders in waste fluorescent lamps by solvent extraction using ionic liquids was studied. Acid leaching of rare earth metals from the waste phosphor powder was examined first. Yttrium (Y) and europium (Eu) dissolved readily in the acid solution; however, the leaching of other rare earth metals required substantial energy input. Ionization of target rare earth metals from the waste phosphor powders into the leach solution was critical for their successful recovery. As a high temperature was required for the complete leaching of all rare earth metals, ionic liquids, for which vapor pressure is negligible, were used as an alternative extracting phase to the conventional organic diluent. An extractant, N, N-dioctyldiglycol amic acid (DODGAA), which was recently developed, showed a high affinity for rare earth metal ions in liquid-liquid extraction although a conventional commercial phosphonic extractant did not. An effective recovery of the rare earth metals, Y, Eu, La and Ce, from the metal impurities, Fe, Al and Zn, was achieved from the acidic leach solution of phosphor powders using an ionic liquid containing DODGAA as novel extractant system.
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, 744 Motooka, Fukuoka 819-0395, Japan.
authors.forename: Fan
authors.initials: F
authors.lastname: Yang
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, 744 Motooka, Fukuoka 819-0395, Japan.
authors.forename: Fukiko
authors.initials: F
authors.lastname: Kubota
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, 744 Motooka, Fukuoka 819-0395, Japan.
authors.forename: Yuzo
authors.initials: Y
authors.lastname: Baba
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, 744 Motooka, Fukuoka 819-0395, Japan; Center for Future Chemistry, Kyushu University, 744 Motooka, Fukuoka 819-0395, Japan.
authors.forename: Noriho
authors.initials: N
authors.lastname: Kamiya
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, 744 Motooka, Fukuoka 819-0395, Japan; Center for Future Chemistry, Kyushu University, 744 Motooka, Fukuoka 819-0395, Japan. Electronic address: m-goto@mail.cstm.kyushu-u.ac.jp.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Goto
mesh_terms: D006016:Glycolates / Q000737:chemistry*; D006794:Household Articles; D052578:Ionic Liquids / Q000737:chemistry*; D008029:Lighting; D059625:Liquid-Liquid Extraction; D008674:Metals, Rare Earth / Q000737:chemistry*; D011208:Powders; D059027:Recycling / Q000379:methods*; D014866:Waste Products
chemical_list: D006016:Glycolates; D052578:Ionic Liquids; D008674:Metals, Rare Earth; C581676:N,N-dioctyldiglycol amic acid; D011208:Powders; D014866:Waste Products