Non-Dispersive Solvent Extraction and Stripping of Neodymium (III) using a Hollow Fiber Contactor with TODGA as the Extractant

Abstract

Membrane based non-dispersive solvent extraction (NDSX) of Nd(III) from aqueous nitric acid medium was carried out using a commercial liquid-liquid extraction system consisting of an extra-flow hollow fiber module with about 10,000 microporous hydrophobic polypropylene capillaries with an effective surface area of 1.4 m². The NDSX operation was carried out by pumping about 1 g/L Nd(III) solutions at a fixed nitric acid concentration of 3.57 M through the tube side and organic solvent (tetra-n-octyl-3-oxapentane-diamide (TODGA) in normal paraffin hydrocarbon (NPH)) through the shell side of the hollow fiber capillaries. NDSX studies were performed under different hydrodynamic conditions and the overall mass transfer was evaluated under counter-current flow conditions. Conditions for quantitative extraction and stripping were also identified. Reproducibility of the results from multiple runs was found to be excellent after five different identical runs.

Keywords:

• Amide
• Hollow fiber
• Non-dispersive solvent extraction
• TODGA

ACKNOWLEDGEMENTS

Authors are thankful to Dr. C.P. Kaushik and Dr. V.G. Katarni of the Waste Management Division, BARC for providing SHLW used in the present work. Thanks are due to members of the Spectroscopic section of the Radiochemistry Division for their help rendered in analysis.

Notes

BDL = below detection limit.

BDL = below detection limit.