Extraction of Iron(III) from Chloride Nickel Solutions with Aliphatic Ketones

Extractive recovery of iron(III) from chloride nickel solutions with macromolecular aliphatic ketones was studied. It was found that the extraction of Fe(III) grows with increasing concentration of chloride ions in solution. For the hydrochloric acid solution, the maximum degree of extraction (99%) is observed at an HCl concentration < 6 mol dm−3. For the nickel chloride solution the highest extraction (95%) is reached at a Cl− concentration ≥ 8 mol dm−3. A high selectivity of ketones with respect to iron(III) was demonstrated, they hardly extract such microscopic impurities as Cu2+ and Co2+, as well as the macroscopic component Ni2+. The optimal ratio between the organic and aqueous phases for washing the extract to remove the carried-away nickel was determined. Enlarged laboratory tests on deep separation of iron and nickel were performed. As a result, a solution of ferric chloride with Fe(III) concentration of 76.8 g dm−3 with total content of nickel(II), cobalt(II), and copper(II) impurities less than 0.022 g dm−3.