Recovery of Eu and Y from waste fluorescent lamps

Abstract

Eu and Y were extracted from waste fluorescent lamps containing similar to 0.3% Eu and 7% Y by acidic leaching, hydrolytic precipitation and/or solvent extraction. The leaching tests showed that about 90% Eu and 95% Y were leached in 3M HCl or 3M HNO3 at 80 degrees C, liquid to solid ratio 10: 1 in 30 min. Leaching in H2SO4 provided lower Eu and Y extraction efficiency. Only around 85% Eu and 80% Y were extracted at temperatures higher than 70 degrees C. Eu and Y started precipitating simultaneously at pH 1.5 and the precipitation completed at similar to pH 2. Solvent extraction of Eu and Y from sulfate solutions using D2EHPA is strongly influenced by solution pH. At pH 1.4 about 80% Eu and 100% Y were extracted while at pH 1.16 only 25% Eu was extracted together with 90% Y.