Parametric optimization of Sm(III) extraction from nitrate media by employing hollow fiber membrane using Taguchi analysis

ABSTRACT

The present work elaborates studies on samarium (Sm) extraction and transport behavior from aqueous stream by employing hollow fiber membrane. Percentage extraction and percentage transport of Sm(III) have been investigated under wide range of experimental parameters such as type of organic extractant, concentration of organic extractant, aqueous phase acidity, flow rate in the module, strip phase acidity and metal ion concentration. Taguchi method utilizing L-18 orthogonal array has been adopted to identify the most influential process parameters responsible for higher degree of extraction and transport of Sm(III) from nitric acid feed medium. A total of 18 experimental runs (each repeated thrice) were carried out under the combination derived from Taguchi array. In Taguchi analysis, the extraction of Sm(III) ions was directed into a precise signal-to-noise ratio for a “high is better” response. Analysis of variance indicated that the selection of organic extractant is the most influential factor controlling extraction and transport, followed by aqueous phase acidity. The experiment performed under the optimum conditions as predicted by Taguchi method resulted in 99.9% extraction of Sm(III) from the feed solution and 98.8% transport of Sm(III) across the membrane with minimum standard deviation.

KEYWORDS:

• Rare earths
• samarium
• hollow fiber membrane
• Taguchi analysis
• ANOVA

Disclosure statement

No potential conflict of interest was reported by the author(s).

Novelty statement

This study presents a novel approach for the recovery of samarium from scrap and used magnetic materials by employing hollow fiber membrane (HFM) technology. The study investigates the extraction and transport behavior of Sm(III) ions under a wide range of experimental parameters such as type and concentration of organic extractant, aqueous phase acidity, flow rate in the module, strip phase acidity, and metal ion concentration. By adopting the Taguchi method utilizing L-18 orthogonal array, the most influential process parameters for the efficient extraction and transport of Sm(III) from nitric acid feed medium were identified. The analysis of variance (ANOVA) indicated that the selection of organic extractant was the most influential factor, followed by aqueous phase acidity, for controlling extraction and transport.

The optimized experimental conditions, as predicted by the Taguchi method, resulted in an impressive 99.9% extraction of Sm(III) from the feed solution and 98.8% transport of Sm(III) across the membrane with minimum standard deviation. The study offers a breakthrough approach to recovering samarium that can augment the existing supply of the material, and this has significant implications for the future of rare earth metals recovery.