Selective separation of yttrium and europium using Cyanex 572 for applications in fluorescent lamp waste processing
Journal article, 2016

The quest for a circular economy has directed attention towards processing of end-of-life products and industrial streams to recover the valuable fractions these contain. Fluorescent lamp waste is acknowledged to be an important source of yttrium and europium, two of the rare earth elements presently regarded as having critical supply risk. In this study, a commercial extractant for solvent extraction separations of REEs, Cyanex 572, was successfully applied to separate yttrium and europium from solutions obtained during processing of fluorescent lamp waste streams. Yttrium was selectively separated from europium at pHeq = 0, followed by further recovery of europium at pHeq = 1. Better extraction efficiencies of REEs were achieved using aliphatic diluents e.g. kerosene in comparison to aromatic diluents or long chain alcohols. Increases in temperature in the range 25–65 °C led to decreases in the separation factors between yttrium and europium. Stripping with hydrochloric acid solutions at concentrations higher than 3 M led to complete recovery of extracted yttrium and europium. Precipitation of these elements from their respective stripping products with oxalic acid, followed by calcination of the precipitate, led to yttrium and europium oxides of 99.82% and 91.60% purity, respectively. A flowsheet that encompass the main steps for fluorescent lamp waste processing is also presented.

Cyanex 572

Fluorescent lamps

Solvent extraction

Rare earth elements

Author

Cristian Tunsu

Industrial Materials Recycling

Jean Baptiste Lapp

National Graduate School of Chemistry and Chemical Engineering of Montpellier

Christian Ekberg

Chalmers, Chemistry and Chemical Engineering, Energy and Material, Nuclear Chemistry

Teodora Retegan

Chalmers, Chemistry and Chemical Engineering, Energy and Material, Nuclear Chemistry

Hydrometallurgy

0304-386X (ISSN)

Vol. 166 98-106

Subject Categories

Chemical Engineering

DOI

10.1016/j.hydromet.2016.10.012

More information

Created

10/8/2017