Extraction of Palladium(II) with Cyanex-923 and Cyanex-471X from Bromide Media and its Separation from Pt(IV), Rh(III) and Ir(III)

摘要

The distribution equilibria of Pd(II) between aqueous bromide media and Cyanex-923 as well as Cyanex-471X in toluene was studied as a function of the concentration of extractants and the acid concentration. The extraction behaviour of Cyanex-471X is compared with Cyanex-923 as they contain different donor atoms. The quantitative extractio of Pd(II) was observed with Cyanex-923 in toluene from 4.0-8.0 mol l~(-1) HBr media and was stripped out with 2.0 mol l~(-1) hydrochloric acid. Similarly Pd(II) was quantitatively extracted with Cyanex-471X in toluene from 6.0-8.0 mol l~(-1) HBr media and was stripped out with 7.0 mol l~(-1) NH_3 solution as well as 1.0 mol l~(-1) of stabilized sodium thiosulfate solution at pH 4.4. The stoichiometry of the Cyanex-923 and Cyanex-471X extracted species determined form slope analysis was 1:2 and 1:1, respectively. Palladium(II) was extracted and separated from its binary and ternary mixture. These methods were successfully employed for analysis of palladium in real samples.