Extraction of palladium from nitrate solution by CYANEX 471X

In this work, the extraction of Pd(II) with triisobutylphosphine sulfide (CYANEX 471X) in kerosene from nitric acid medium has been studied. The effects of different parameters affecting the extraction of the investigated metal ion such as nitric acid, extractant, metal ion concentration and temperature were separately investigated. The stoichiometry of the extracted metal species was found to be Pd(NO3)2.CYANEX 471X. The stripping of the extracted metal species was carried out using stabilized thiosulfate solution. The results indicate the possibility of separation of palladium from some interfering ions namely; Co(II), Fe(III), Cu(II), Cd(II) and Zn(II). Extraction of Pd(II) from hydrochloric and sulfuric acid media was also carried out. Thereafter, the method developed was applied for the recovery and separation of Pd and other metal ions from a synthetic solution similar in composition to that expected from the leaching of spent automotive catalyst in hydrochloric acid.

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► This work indicates the effective extraction of Pd(II) from nitrate medium using CYANEX 471X.
► The extraction was found to be an exothermic reaction.
► The stripping of the loaded organic phase was performed using stabilized thiosulfate solution.
► The method was applied for the recovery of Pd(II), Pt(IV) and Rh(III) from spent automotive catalyst.