An environmentally friendly process for the separation of rare earths from the transition metals copper, cobalt, iron, manganese and zinc by solvent extraction with the ionic liquid trihexyl(tetradecyl)phosphonium chloride has been developed. The solvent extraction process is carried without the use of organic diluents or extra extraction agents and it can be applied as a sustainable hydrometallurgic method for removing transition metals from neodymium-ironboron or samarium-cobalt permanent magnets. The recycling of rare earths is of high importance because of the possible supply risk of these elements in the near future. The method was tested for the removal of cobalt and iron from samarium and neodymium, respectively. The highest distribution ratios for cobalt and iron were found with 8.5 and 9 M HCl. At the tested conditions, the concentration of neodymium and samarium in the ionic liquid were below 0.5 mg L-1 (0.5 ppm), even for feed concentrations of 45 g L-1. The separation factors of Nd/Fe and Sm/Co are 5.010 6 and 8.010 5 and, respectively. The percentage extraction of iron is still higher than 99.98% at loadings of the ionic liquids with 70 g L-1 of iron. The viscosity of the ionic liquid containing the tetrachloroferrate(III) complex [FeCl 4 ]is lower, and less depending on the feed concentration, than in the case with a tetracobaltate(II) anion [CoCl 4 ] 2-. After extraction, cobalt can be stripped very easily from the ionic liquid phase with water. However, due to the very high distribution ratio, iron could only be stripped by forming a water-soluble iron complex with ethylenediaminetetraacetic acid (EDTA). Also the possibility to extract chromium, nickel, aluminium, calcium and magnesium with trihexyl(tetradecyl)phosphonium chloride has been investigated, but the distribution ratios of these elements are very low in the tested conditions. Table of contents An environmentally friendly hydrometallurgic method for the separation of the transition metals iron, cobalt, copper, manganese and zinc from the rare earths neodymium and samarium with the undiluted ionic liquid trihexyl(tetradecyl)phosphonium chloride has been developed.

Cellulose acetate (CA) is an attractive membrane polymer for CO2 capture market. However, its low CO2 pe1meability hampers its application as part of a membrane for most relevant types of CO 2 containing feeds. This work investigates the enhancement of CA separation performance by incorporating ionic liquid-like pendants (1methylimidazol, 1-methylpyrrolidine, and 2-hydroxyethyldimethylamine (HEDMA) on the CA backbone. These CA-based polyelectrolytes (PEs), synthesised by covalent grafting of cationic pendants with anion metathesis, were characterised by NMR, FfIR, DSC/TGA, and processed into thin-film composite membranes. The membrane performance in C0 2 /N 2 mixed-gas permeation experiments shows a decrease in CO 2 and N 2 permeability and an initial decrease and then gradual increase in C0 2 /N 2 selectivity with increasing HEDMA conrenr. The an1otmt of HEDMA attached to the CA backbone determines overall separation process in bifunctional PEs. This indicates that the hydroxy-substituted cationic pendants alter interactions between PEs network and permeating CO2 molecules, suggesting possibilities for further improvements.