Title :
Recovery of Red (Y2O3:Eu³+), Blue(Sr,Ca,Ba)10(PO4)6Cl2:Eu²+ and Green(LaPO4:Tb³+,Ce³+) Rare Earth Phosphors from Waste Phosphor Sludge by Liquid/Liquid Extraction
Author :
Guangjun Mei ; Kefeng Xie
Author_Institution :
Sch. of resource & Environ. Eng., Wuhan Univ. of Technol., Wuhan
Abstract :
A new method for recovery of red (Y2O3:Eu3+), blue (Sr,Ca,Ba)10(PO4)6Cl2:Eu2+ and green (LaPO4:Tb3+,Ce3+) rare earth phosphors from waste phosphor sludge by liquid/liquid extraction is proposed in this paper. At first ,the recommended pretreatment process is effective to remove the adhesive binder such as Al2O3 and the other impurities from the spent florescent powder complex, which including treatment by nitric acid solution of pH 2 for 1-5 minutes, by sodium hydroxide solution of pH 12.5 for 12 minutes and rinsing by 99.5% ethanol and distilled water. The subsequent separation for dried florescent powder was carried out in the heptane/ DMF (N, N-Dimethylformamide) system in presence of DAA (laurylamine) surfactant. Through two steps extraction process with different DAA concentration. Satisfactory separation results have been achieved; the grade and recovery of recovered red, blue and green product reach 86.0% and 80.3%, 74.8% and 95.6%, 81.2% and 79.5%, respectively. This invention provides a new possibility for the recycling of valuable rare earth phosphor from spent fluorescent lamps in the future.
Keywords :
chemical technology; fluorescent lamps; phosphors; rare earth compounds; recycling; separation; waste recovery; (SrCaBa)10(PO4)6Cl2:Eu2+; LaPO4:Tb3+Ce3+; Y2O3:Eu3+; adhesive binder; blue rare earth phosphors; green rare earth phosphors; heptane-N,N-dimethylformamide system; laurylamine surfactant; liquid-liquid extraction; nitric acid solution; pretreatment process; recycling; red rare earth phosphors; sodium hydroxide solution; spent florescent powder; spent fluorescent lamps; waste phosphor sludge; Aluminum oxide; Chemical analysis; Fluorescent lamps; Glass; Phosphors; Powders; Protection; Recycling; Sludge treatment; Yttrium;
Conference_Titel :
Bioinformatics and Biomedical Engineering, 2008. ICBBE 2008. The 2nd International Conference on
Conference_Location :
Shanghai
Print_ISBN :
978-1-4244-1747-6
Electronic_ISBN :
978-1-4244-1748-3
DOI :
10.1109/ICBBE.2008.327
