PALLADIUM EXTRACTION BY A MALONAMIDE DERIVATIVE (DMDOHEMA) FROM NITRATE MEDIA: EXTRACTION BEHAVIOR AND THIRD PHASE CHARACTERIZATION

摘要

Liquid-liquid extraction of palladium(II) from nitric media was carried out using, N, N'-dimethyl, N, N'-dioctylhexylethoxymalonamide (DMDOHEMA) in n-heptane. To this purpose, various experimental parameters such as reaction time, extractant concentration, pH, and nitrate concentration were investigated in detail. Efficient extraction of palladium can then be achieved, with good distribution coefficients (D up to 10) and performing kinetics (equilibration time ca. 30 min). In some cases, a solid phase appears at the interface between aqueous and organic layers. It was characterized as a palladium(II) complex with DMDOHEMA with appropriate techniques, and the conditions of its formation are discussed.