Solvent extraction of copper(II) from chloride media using N-(thiocarbamoyl)benzamidine and N-benzoylthiourea derivatives

The distribution of copper(II) be tween aqueous solutions and cumene soluti ons of N-(thiocarbamoyl)benzamidine, 2a-2c, and N-benzoylthiourea derivativ es, 3a-3f, from chloride media (1 mol/l NaCl) has been studied in detail. T he metal extraction was greatly influenced by extractant structure of thiou rea derivatives. The extractability of Cu(II) with extractants 2a-2c and 3a -3f followed the order as: 3e>3d similar to 3c similar to 3f>3b>>3a similar to 2a similar to 2b similar to 2c, respectively. The N-thiocarbamoylbenzam ide derivatives (2a-2c) are comparatively poor extractants than N-benzoylth iourea derivatives (3a-3f). The organic reagents 3a-3e were selected for de tailed further studies owing to their better extraction behavior with coppe r(II). The extraction equilibria was studied as a function of total copper concentration, pH of the aqueous phase and total extractant concentration. It was shown by use of equilibrium modeling computer program LETAGROP-DISTR that the extraction of Cu(II) could be explained assuming the extraction o f the species CuL2, where L=3c. The equilibrium constants calculated by thi s program were also reported. (C) 1999 Elsevier Science B.V. All rights res erved.