2003 Volume 36 Issue 6 Pages 703-706
Indium is one of the most important strategic metal which has got wide application in advanced technology areas. The selectivity of indium extraction from various waste materials is the challenging work, where solvent extraction is one of the useful techniques that should be explored. The present investigation is based on the use of p-tolyl-α-thiopicolinamide for extraction of indium from alkaline media. The extraction system is investigated as a function of various parameters such as reagent concentration, variation of pH and temperature. Experimental data have been analyzed graphically and numerically, to determine the stoichiometry of extracted species. The effect of aqueous ionic strength on indium(III) extraction has also been studied. Another important feature of the proposed method is that extraction of indium with 0.35 M p-tolyl-α-thiopicolinamide and 10 vol% of n-decanol in xylene has resulted in 99% recovery in alkaline medium, in 5 minutes.
The different thermodynamic functions—enthalpy (ΔH), entropy (ΔS) and free energy (ΔG), have been evaluated.