Selective removal of iron(Ⅲ) from highly salted chloride acidic solutions by solvent extraction using di(2-ethylhexyl) phosphate

Metal ions including Fe^(3+),Ca^(2+),Mg^(2+),Ni^(2+),Co^(2+) and Cu^(2+) are commonly found in the leaching solution of laterite-nickel ores,and the pre-removal of Fe^(3+) is extremely important for the recovery of nickel and cobalt.Di(2-ethylhexyl)phosphate acid(D2EHPA)showed high extraction rate and selectivity of Fe^(3+) over other metal ions.The acidity of the aqueous solution is crucial to the extraction of Fe^(3+),and the stoichiometry ratio between Fe^(3+) and the extractant is 0.86:1.54.The enthalpy for the extraction of Fe^(3+) using D2EHPA was 19.50 kJ/mol.The extraction of Fe^(3+)was ≥99% under the optimized conditions after a three-stage solvent extraction process.The iron stripping effects of different reagents showed an order of H_(2)C_(2)O_(4)>NH_(4)HCO_(3)>HCl>NaCl>NaHCO_(3)>Na_(2)SO_(3).The stripping of Fe was ≥99% under the optimized conditions using H_(2)C_(2)O_(4) as a stripping reagent.