Direct hydrometallurgical separation of Zn(II) from brine leaching solution of zinc filter cake by simple solvent extraction process

The zinc leaching filter cake residue as a secondary resource is used for hydrometallurgical lead production from brine (chloride) media. In this method, zinc accumulation caused decrease in the lead leaching efficiency in feed solution as well as a defective cycle flowsheet in production process. Therefore, an experiment was designed for the solvent extraction (SX) of zinc from brine solution after lead cementation stage. The results indicated that approximately 98% zinc with a little contamination of other metals was extracted under optimum conditions (193.5 g.dm-3 of D2EHPA in kerosene as diluent, pH=3.5, contact time=5 min, temperature=40±2 °C and aqueous: organic ratio (A:O)=1:1). Also, according to the differences of ∆pH0.5 and separation factor values among Zn and other ions, D2EHPA as an organophosphorous extractant has suitable capability for zinc selective extraction from brine solution. Moreover, H2SO4 solution which was used for stripping to transfer Zn2+ ions to zinc conventional production sulphate media achieved high efficiency of 99%. McCabe-Thiele diagram was simulated to counter-current extraction route. The results showed that two stages were needed for both extraction and stripping.