Ionic Liquids in the Context of Rare Earth Separation and Utilization

Abstract

With the rapid development of science and technology, rare earths (REs) are playing a vital role in economic and social development due to their unique electronic structure and physicochemical properties. REs are widely used in lighting, electrical, and magnetic field as a crucially strategic resource. Being the upstream of the RE industry supply chain, RE separation is crucial throughout the whole industry. The primary issues about RE separation are reviewed in this chapter. Conventional organic solvent extractants expose some inherent questions in the long-term application, while ionic liquids as "green solvents" show great potential in the separation processes. This chapter also overviewed RE resources in the world and the issues associated with these separation processes. A brief introduction to ionic liquid-based RE functional materials has been also made. Rare EarthsThe rare earths (REs) are a group of chemically similar elements in the entire periodic table, consisting of scandium (Sc), yttrium (Y), and the lanthanides. The lanthanides are the series of elements with atomic numbers from 57 to 71, including lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu).Based on the electronic structure and physicochemical properties, REs can be classified as light REs and heavy REs. Light REs are also called "cerium subgroup," including La, Ce, Pr, Nd, Sm, Eu, and Gd. Heavy REs are also called "yttrium

Optimizing the extraction of cobalt ions under response surface methodology and without organic solutions

“…However, as a result of the use of toxic, dangerous, and costly organic solvents in their removal, new and environmentally friendly practices have been developed today. [1][2][3][4] One of these secure, cost-effective, and environmentally friendly methods is the aqueous two-phase system. [5] Aqueous two-phase systems offer an excellent alternative to solvent extraction, which is compatible with green chemistry.…”

“…However, as a result of the use of toxic, dangerous, and costly organic solvents in their removal, new and environmentally friendly practices have been developed today. [ 1–4 ] One of these secure, cost‐effective, and environmentally friendly methods is the aqueous two‐phase system. [ 5 ]…”

Unusual seeding mechanism for enhanced performance in solid-phase magnetic extraction of Rare Earth Elements

“…Solvent extraction is industrially the most extensively used separation technique at present141516171819 and although it is possible to accomplish rather high extraction and separation factors, it is associated with considerable challenges such as the need in big volumes of extractant in high concentrations, which translates into elevated costs and environmental hazards. Ionic liquids (IL) have been also intensively investigated20212223 and appeared as a promising and environmentally friendlier alternative to compared to conventional solvent extraction. However, they usually require operation at elevated temperatures (which results in high costs), and some of them, for instance fluorinated IL, being harmful compounds both for human health and environment.…”