The extration kinetics and mechanism of Pd(II) from chloride medium with primary amine N1923 were studied by using a PVC membrane Pd(II) ion-selective electrode and a constant interfacial area-stirred cell. The experimental results show that the extration process is controlled by the interfacial reactions: PdCl42- + 2RNH3Cl(1) J PdCl4(RNH3)2(1) + 2Cl- (K1, K-1) and PdCl4(RNH3)2(1) + 2RNH3Cl(0) J PdCl4(RNH3)2(0) + 2RNH3Cl(1) (K2, K-2), where (1) and (0) represent the interface and the organic phase, resp. The values of K1, K-2, and K2/K-1 were calculated and the temperature, acidity, and additive (n-octanol) effects on the extration rate are discussed.

Key words: REACTION MECHANISM, REACTION KINETICS, EXTRACTIVE AGENT, SOLVENT EXTRACTION, ION SELECTIVE ELECTRODE, PALLADIUM, PRIMARY AMINE, ION CONCENTRATION