Selective recovery of Zn(II) and Fe(III) by liquid - liquid extraction using Cyphos IL 109 as extractant.

摘要

In this work a selective recovery of Zn(II) and Fe(III) from sulfate media by Liquid - liquid extraction using as extractant the ionic liquid (trihexyl) tetradecylphosphonium bis-(trifluoromethylsulfonyl) imide (Cyphos IL 109) was made. Several parameters were studied, such as: nature of aqueous phase (HC1, H2SO4 and NH_3/NH_4~+), extractant concentration, selectivity, and re-utilization of ionic liquid. Experimental results showed that in ammoniacal medium the extractant (Cyphos IL 109) has a higher affinity by Zn(II) than Fe(III), obtaining 98% extraction at pH = 9.2. On the other hand, in sulphuric acid medium (pH = 1.8), we got 96% of Fe(III) extraction and only 4.8% of zinc. Moreover, it was found that increasing the concentration of Cyphos IL 109 we could obtain higher percentages of extraction of both ion metals. The separation factor (S_(Zn/Fe)=110) indicated the possibility of selectively Zn(II) recover from Fe(III) when they are in the same solution, which can have a wide range of applications in industries such as electroplating, where these metals are presents at low concentrations and can be recovered. Also it was observed that the loaded extractant can be reused after several washes with H_2SO_4 (2.0 mol ? L~(-1)).