An Overview of the Physiochemical Nature of Metal-Extractant Species in Organic Solvent/Acidic Organophosphorus Extraction Systems

Abstract

The interfacial behavior of metal-extractant species in the liquid/liquid extraction of metal ions still remain incompletely understood at the molecular level under high loading conditions. Traditionally, metal-extractant complexes in the organic phase under dilute conditions have been characterized by slope analysis. At high loading, the metal-extractant aggregates structure appears to change. The metal-extractant aggregates have been described as either polymers or reversed micelles. This behavior is difficult to confirm by direct experimental measurements. Recently, molecular modeling was used to study the molecular structure of metal-extractant aggregates. The study confirmed that the metal-extractant species are reversed micelles at high loading conditions.

Keywords:

• divalent metals
• molecular modeling
• reversed micelles
• solvent extraction