Separation of Rare Metals by Solvent Extraction Employing Reductive Stripping Technique

Abstract

The Separation and purification of vanadium from V/Mo mixture and europium from Sm/Eu/Gd mixture by solvent extraction followed by chemical, electrochemical or photochemical reductive stripping, has been investigated. Vanadium (penta) was first extracted into organic phase along with molybdenum from their solution mixture, and the vanadium reduced either chemically by L-ascorbic acid, electrochemically using platinum electrode or photochemically using low pressure mercury or halogen lamp. The resulting vanadium(tetra) was then separated by selective stripping. In the case of mixed rare earths solution, Eu³⁺ was reduced to Eu²⁺ electrochemically using titanium plate electrode or photochemically using low or high pressure mercury lamp. The divalent europium thus obtained was then precipitated selectively to effect separation from samarium and gadolinium.

Keywords:

• Solvent extraction
• separation
• vanadium
• europium
• reductive stripping