Recovery of rare earth elements from simulated fluorescent powder using bifunctional ionic liquid extractants (Bif-ILEs)
✍ Scribed by Hualing Yang; Wei Wang; Hongmin Cui; Dongli Zhang; Yu Liu; Ji Chen
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 2011
- Tongue
- English
- Weight
- 142 KB
- Volume
- 87
- Category
- Article
- ISSN
- 0268-2575
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✦ Synopsis
BACKGROUND: Numerous high purity ammonium-type ionic liquid extractants have been prepared for engineering purposes. Bifunctional ionic liquid extractants (Bif-ILEs) have been widely applied to separate and extract rare earths and metal ions with high extraction efficiencies and selectivities. In the present study, new Bif-ILEs [A336][P204] and [A336][P507] have been used to extract rare earths from a simulated solution of a fluorescent powder in a high concentration of Al(NO 3 ) 3 . RESULTS: Bif-ILEs were prepared from Aliquat336 (A336) and the commercial organophosphorus acid extractants, P204 and P507. These extractants [A336][P204] and [A336][P507] have similar characteristics to neutral organophosphorus extractants. When these Bif-ILEs were used to extract RE(III) from a simulated waste fluorescent powder system a third phase appeared which could be eliminated by the addition of 10% isopropanol modifier. The coexisting Al 2 O 3 in the fluorescent powder was changed to a salting-out agent (Al(NO 3 ) 3 ) in the extraction process and promoted the extraction efficiency of RE(III). Using a countercurrent extraction process at a phase ratio V o : V w = 4 : 1 and pH = 0.56, the RE(III) recovery reached 95.2% in 5-7 stages. Finally, the extractabilities of these bifunctional extractants were compared with the neutral organophosphorus extractants P350, TBP and Cyanex923 at different concentrations, initial pHs and temperatures. CONCLUSIONS: By comparison with other neutral organophosphorus extractants, Bif-ILEs [A336][P204] and [A336][P507] can be considered efficient potential extractants for separating and recycling REEs and Al 2 O 3 from waste fluorescent powder.