Recovery of Y and Eu from Waste Phosphors of CRT TVs and the Preparation of Yttrium Europium Oxide

Abstract:

Yttrium (Y) and Europium (Eu) were recovered from waste phosphors of TV screens via several processes, including roasting waste phosphors with ammonia chloride, dissolving yttrium chloride and europium chloride with water from roasted waste phosphors, purification with sodium sulfide, precipitating in the presence oxalic acid and calcining at high temperature. The optimal conditions for roasting was investigated, and it was found that when 1 g sample reacts with 8 g ammonia chloride, the recovery rate of Y and Eu can be 92.12% and 90.38% after 30min reaction at 90°C, respectively. Moreover, the optimal pH value for recovering Y and Eu was also investigated. It was found that at pH=1, the stoichiometric ratio of B/A (A: S^2-, B: Zn²⁺, etc) is 1:1, the stoichiometric ratio of B/A (A: Y³⁺, B: C₂O₄^2-, etc) is 2:1, the content of Y and Eu can be reached 98.10% and 96.30%, respectively. And yttrium europium oxide was finally synthesized, which produce the red light when the excitation wavelength was 242 nm.

• Periodical: Applied Mechanics and Materials (Volumes 295-298)
• Pages: 1840-1845
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.295-298.1840
• Online since: February 2013
• Authors: Xiao Yong Pan, Ling Peng, Wei Hua Chen, Jie Wang, Zheng Chen
• Keywords: Ammonia Chloride, Recovery, Roasting, Waste Phosphors, Yttrium Europium Oxide

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