INFLUENCE OF SALTING-OUT EFFECTS, TEMPERATURE AND THE CHEMICAL-STRUCTURE OF THE EXTRACTANT ON THE RATE OF COPPER(II) EXTRACTION FROM CHLORIDE MEDIA WITH DIALKYL PYRIDINE DICARBOXYLATES

The kinetics of copper(II) extraction from chloride solutions with ACO RGA CLX-50 and three model dipentyl pyridine dicarboxylates having est er groups at various positions in the pyridine ring is investigated. I t is shown that the extraction occurs in a diffusional regime and that both the ionic strength and temperature have a strong effect on the r ate of copper extraction. Basically, the initial rate of copper extrac tion (denoted hereafter J(o)) increases as the ionic strength is incre ased, whereas J(o) increases or decreases versus temperature depending on the ionic strength. Such phenomena are explained in terms of salti ng-out effects and diffusion properties. Furthermore, ACORGA CLX-50 is shown to exhibit a good kinetic performance compared to the three mod el dipentyl pyridine dicarboxylates.