Effectiveness of saponified D2EHPA in Zn(II) selective extraction from concentrated sulphuric solutions

Selective extraction of Zn(II) from industrial leach solutions containing Fe, Ni and Co is still a challenging task. In this paper solvent extraction of Zn(II) with D2EHPA and 5% saponified D2EHPA from sulphuric solutions has been performed. Experimental tests carried out on concentrated solutions allowed to select the operative conditions that allow to obtain both high Zn(II) extraction yield and selectivity. On the basis of the experimental results, a separation process has been proposed for the selective recovery of Zn from a solution containing 60 g/L of Zn. Zn extraction with saponified D2EHPA has been carried out in two different steps. In the first one 2 M D2EHPA has been used for extracting Fe(III) and part of Zn, while in the second one 1 M D2EHPA has been used for recovering the remaining Zn with less than two theoretical stages.