title: Rare earth elements recycling from waste phosphor by dual hydrochloric acid dissolution.
abstract: This paper is a comparative study of recycling rare earth elements from waste phosphor, which focuses on the leaching rate and the technical principle. The traditional and dual dissolution by hydrochloric acid (DHA) methods were compared. The method of dual dissolution by hydrochloric acid has been developed. The Red rare earth phosphor (Y0.95Eu0.05)2O3 in waste phosphor is dissolved during the first step of acid leaching, while the Green phosphor (Ce0.67Tb0.33MgAl11O19) and the Blue phosphor (Ba0.9Eu0.1MgAl10O17) mixed with caustic soda are obtained by alkali sintering. The excess caustic soda and NaAlO2 are removed by washing. The insoluble matter is leached by the hydrochloric acid, followed by solvent extraction and precipitation (the DHA method). In comparison, the total leaching rate of the rare earth elements was 94.6% by DHA, which is much higher than 42.08% achieved by the traditional method. The leaching rate of Y, Eu, Ce and Tb reached 94.6%, 99.05%, 71.45%, and 76.22%, respectively. DHA can decrease the consumption of chemicals and energy. The suggested DHA method is feasible for industrial applications.
authors.affiliation: School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, PR China.
authors.forename: Hu
authors.initials: H
authors.lastname: Liu
authors.affiliation: School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, PR China. Electronic address: zhangshengen@mater.ustb.edu.cn.
authors.forename: Shengen
authors.initials: S
authors.lastname: Zhang
authors.affiliation: School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, PR China.
authors.forename: Dean
authors.initials: D
authors.lastname: Pan
authors.affiliation: School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, PR China.
authors.forename: Jianjun
authors.initials: J
authors.lastname: Tian
authors.affiliation: School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, PR China.
authors.forename: Min
authors.initials: M
authors.lastname: Yang
authors.affiliation: School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, PR China.
authors.forename: Maolin
authors.initials: M
authors.lastname: Wu
authors.affiliation: Department of Mechanical Engineering, University of South Florida, Tampa, FL 33620, USA.
authors.forename: Alex A
authors.initials: AA
authors.lastname: Volinsky
mesh_terms: D000143:Acids; D002563:Cerium / Q000737:chemistry; D005063:Europium / Q000737:chemistry; D005374:Filtration; D006851:Hydrochloric Acid / Q000737:chemistry*; D008674:Metals, Rare Earth / Q000737:chemistry*; D010758:Phosphorus / Q000032:analysis* / Q000737:chemistry; D012995:Solubility; D012997:Solvents / Q000737:chemistry; D013725:Terbium / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D014961:X-Ray Diffraction; D015019:Yttrium / Q000737:chemistry
chemical_list: D000143:Acids; D008674:Metals, Rare Earth; D012997:Solvents; D014874:Water Pollutants, Chemical; D013725:Terbium; D010758:Phosphorus; D002563:Cerium; D005063:Europium; D015019:Yttrium; D006851:Hydrochloric Acid
keywords: Dual dissolution by hydrochloric acid; Leaching rate; Rare earth elements; Waste phosphor