Extractive separation of La and Nd using ionic liquid as extractant

Abstract

Significant amounts of Rare Earth Metals (REMs) are being used for various purposes because of their unique features. Therefore, it is necessary to develop a process which can extract and separate the individual REMs efficiently. The present investigation deals with the solvent extraction and separation of light rare earth elements such as La and Nd from the chloride medium using an ionic liquid (IL) such as [R3N+.Cy272-] as an extractant. Various parameters were investigated to optimize the conditions for separating La(III) and Nd(III) of 10-4 M concentration each. At pH 4.0, 90% Nd(III) and 20% La(III) were extracted from the chloride solution. The pH0.5 values for La(III) and Nd(III) were found to be 4.5 and 3.7 respectively. Extraction of La(III) and Nd(III) increased with the increase in IL concentration. At pH 4.5 and IL concentration of 0.01M separation factor (βNd/La) of Nd(III) over La(III) was found to be 49. This shows that synthesized ionic liquid has sufficient potential to separate lighter lanthanides (e.g. La and Nd) from their mixed solutions generated during the processing of the REMs from primary or secondary resources.