Abstract
The extraction of palladium by didodecylmonothiophosphoric acid is carried out, using a highly stirred tank and a stirred transfer cell to clarify the extraction mechanism. Measurements of palladium-loading capacity and of interfacial adsorption equilibrium of the extractant are also conducted. The dependency of the extraction rate on the concentration of the chemical species taking part in the extraction is examined.
An interfacial reaction model in which four chloro-palladium complexes take part is proposed. The experimental results are analyzed by the model to obtain the reaction rate constants of these four complexes with the extractant. The order of magnitude of the reaction rate constants is explained qualitatively by the trans-effect.
