EQUILIBRIUM DISTRIBUTION OF PALLADIUM(I I) BETWEEN HYDROCHLORIC ACID SOLUTION AND A MACROMOLECULAR RESIN CONTAINING TRI-n-OCTYLAMINE

Abstract

Studies have been conducted on the sorption characteristics of palladium (II) from hydrochloric acid media with a macromolecular resin containing tri-n-octylamine (TOA). Sorption equilibrium of Pd (II) on the TOA-impregnated sorbent can be expressed by a simple ion-exchange reaction between a tetrachloro complex of Pd (II) in the aqueous phase and an amine salt in the sorbent as follows: where the equilibrium constant was found to be 6.98x10⁴ kg/dm³. The elution of Pd (II) from the metal-loaded sorbent was also examined. Elution can be attained with either hydrochloric acid or aqueous ammonia: in particular, the latter gave a high elution ratio even at a concentration less than 1M. The effect of the pore diameter of the macromolecular resins on the Pd(II) sorption was also studied and two methods for preparating impregnated sorbent were examined.