Extraction of metals using supercritical fluids

Abstract

Solvent extraction is a well-established process within the inorganic chemical and hydrometallurgical industries for transfer of cations or anions from an aqueous phase into an organic phase [1]. As direct extraction of ionic species is energetically very unfavorable, transfer is accomplished by forming organic-soluble neutral complexes in the aqueous phase by reactions between the ionic species of interest and an appropriate organic compound (extractant).