On the Mechanism of the Interfacial Reaction in Extraction of Rare Earth Metals by D2EHPA

✍ Scribed by Tomita, Akihiro ;Kanki, Tatsuo ;Sano, Noriaki ;Asano, Tsuyoshi ;Imai, Shingo

• Publisher: Curtin University of Technology
• Year: 2008
• Tongue: English
• Weight: 657 KB
• Volume: 11
• Category: Article
• ISSN: 0969-1855
• DOI: 10.1002/apj.5500110612

✦ Synopsis

Abstract

The mechanism of interfacial reaction was discussed based on the constituent of the crystal film which forms at the interface and the practical behavior of interfacial tension with the aid of intermolecular potential determined by ab initio molecular orbital calculation. It was shown that there are three different reaction zones depending on hydrogen ion and extractant concentrations. A couple of extractant monomer(s) and/or its anion(s) first react with a lanthanide ion to form 1:2 intermediate complex. At the concentration zone where the crystal formation occurs, the 1:2 intermediate complex reacts with adjacent extractant monomer or its anion to form crystallized 1:3 complex. At lower extractant concentrations, the 1:2 intermediate complex reacts with extractant monomer or its anion and further with extractant dimer to form the stable 1:6 complex which should dissolve into the organic phase. At higher extractant concentrations, the 1:2 intermediate complex reacts with extractant dimer to form the stable 1:6 complex dissolving into the organic phase.