Abstract
Abstract Solvent extraction is a widely used separation technique in extractive metallurgy. A conventional solvent extraction system consists of an aqueous phase and an immiscible organic phase. In this work, we show that replacement of water by a polar organic solvent can lead to superior metal separations. Cobalt(II) and samarium(III) chlorides dissolved in water and ethylene glycol (EG), respectively, with LiCl as chloride source, were extracted by Aliquat 336 diluted in toluene. Both cobalt and samarium were extracted from the aqueous solutions, but cobalt was extracted more efficiently from the ethylene glycol solutions than from the aqueous solutions, whereas samarium was not extracted at all from the ethylene glycol solutions. As a result, cobalt and samarium could be separated completely in a single extraction step from ethylene glycol solutions. The mechanisms of cobalt extraction by Aliquat 336 from the ethylene glycol and aqueous solutions were found to be similar, as validated by slope analysis and UV–VIS absorption spectroscopy. Samarium was extracted from the aqueous solution through the salting-out effect of LiCl. Interestingly, LiCl has a much lower salting-out effect for samarium in ethylene glycol than in water due to the lower dielectric constant of ethylene glycol and the lower solubility of LiCl in ethylene glycol. Consequently, samarium is not salted out from ethylene glycol, leading to a very efficient separation of cobalt and samarium. This separation effect can also be applied to the separation of other transition metal and rare-earth metal pairs, including iron/neodymium and zinc/europium.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.