Thermodynamics Research Center / ThermoML | Fluid Phase Equilibria

ABSTRACT

The aim of the paper is the selective extraction and stripping of Cd(II) from acidic iodide solutions containing Cd(II) and Ni(II) by liquid liquid solvent extraction technique using synthesized and characterized imidazolium salts as carriers, which are 3-butyl-1-methyl-1H-imidazol-3-ium bromide (IM1), 1,3-dibutyl-1H-midazol-3-ium bromide (IM2), 3-isobutyl-1-methyl-1H-imidazol-3-ium bromide (IM3), 1,3-diisobutyl-1H-midazol-3-ium bromide (IM4), in dichloromethane. The important parameters affecting extraction and stripping behavior of Cd(II) were studied experimentally. Complex formation and its stoichiometric rate between IMs and CdI4 2 was explained with comparison of ATR-FTIR spectrums of pure and CdI4 2 (aq) loaded IMs and slope analysis. According to these evaluations, the adduct formation was confirmed as IM2CdI4(org). In the light of obtained results, the symmetric IMs substituting n-butyl group on nitrogen atoms have been determined as the best appropriate IMs to transport of Cd(II). Under optimum conditions, 99.24% of Cd(II) has been extracted from acidic iodide solution containing 500 mg/L of Cd(II) and Ni(II). Ni(II) extraction percentages were observed as negligible throughout experiments. The extraction selectivity of Cd(II) over the other metal ion impurities has been identified in the order bCd/Ni greater thanbCd/Co greater thanbCd/Zn greater thanbCdCu.