Solvent extraction of rhodium chloride from aqueous solutions and its separation from palladium and platinum

Liquid–liquid extraction/separation of platinum(IV) and rhodium(III) from acidic chloride solutions using tri-iso-octylamine

“…The extraction mechanism corresponds to an anion exchange, in which a complex of stoichiometric formula (R 3 NH + ) 2 PtCl 6 2− is formed in the organic phase liberating at the same time Cl − ions in the aqueous phase [9]. Some extractants are reported for extraction separation of platinum from palladium [10][11][12][13][14][15][16][17][18][19][20] but very less number of extractants is utilized for separation of platinum from rhodium [21,22]. The LLE literatures reviewed showed that, despite a large number of studies, no system has been identified as yet to yield quantitative extraction of rhodium from concentrated solutions [23][24][25][26][27].…”

Application of commercially available anion exchange resins for preconcentration of palladium(II) complexes from chloride–nitrate solutions

“…At higher pH values than 8, formation of another hydroxide-chloride or hydroxide complexes begins [27,28].…”

Selective extraction of Pd(II) ions from automotive catalyst residue in Cl− media by O-thiocarbamoyl-functionalized thiacalix[n]arenes

“…The phosphine sulfide, Cyanex 471-X, has been proposed as an alternative to the aforementioned reagents for Pd separation; the process is similar to that of alkyl sulfides (Rydberg, 2004). The conventional solvent extraction reagents for PGM recovery are not very effective and mutual separations are not complete (Fujii et al, 2001;Levitin and Schmuckler, 2003;Ueda et al, 2014). Narita et al (2008a) studied the durability of thiodiglycolamide and di-n-hexyl sulfide for Pd(II) separation in a mixed solution of HNO 3 and HCl.…”