SOLVENT EXTRACTION OF ZINC(II) BY ORGANOPHOSPHORUS ACIDS COMPOUNDS FROM PERCHLORATE SOLUTIONS.

Abstract
The extraction of zinc from perchlorate solutions at 0.1 mol.dm−3 of ionic strength by di(2-ethylhexyl)phosphoric acid (HDEHP), 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (HEH[EHP]) and di(n-octyl)phosphinic acid (H[DOP]) dissolved in toluene has been studied at 25 ° C. The distribution coefficient was determined as a function of pH and HA concentrations and the data were analyzed both graphically and numerically using the computer program LETAGROP-DISTR. The results showed that the data can be explained assuming the formation of ZnA2(HA)2 and ZnA2HA in organic phase for all the extractants used. A correlation between extracted species and concentration of the various extractants has been found. The predominance of the different species into the organic phase has been correlated with the difference between their extraction constants. The anion of the ionic medium is not extracted into the organic phase.