Studies on the solvent extraction of indium (III) from aqueous chloride medium using Cyphos IL 104

Abstract

With inimitable chemical and physical properties makes indium critical for a wide variety of high technology, chemical, metallurgical and pharmaceutical industries. As conferred by its location in the periodic table near the borderline between metals and non-metals; indium shows ductility, malleability, conductivity and transparency. In particular, the last two properties are the main reason for indium use in the semiconductor industry for flat panel displays and screens manufacturing by far the most important applications of indium in technical uses. The present study emphasized the extraction ability of a phosphonium based ionic liquid Cyphos IL 104 (trihexyl(tetradecyl)phosphonium bis(2,4,4-trimethylpentyl) phosphinate) towards indium(III) extraction from acidic chloride medium. The effect of various parameters such as equilibrium time, acid concentration, chloride ion and hydrogen ion was investigated on In(III) extraction. Quantitative extraction of 97.2% was attained with 0.005 mol/L Cyphos IL 104 in toluene at 2.0 mol/L HCl. The effect of thermodynamic parameters i.e., ΔH°, ΔS° and ΔG° were also studied which suggested that the extraction process was endothermic and spontaneous that moves in the forward direction. Using 0.1 mol/L HCl, 100% of indium(III) was recovered from the loaded organic phase.