Solvent extraction separation of nickel and cobalt from a sulfate solution containing iron(II) and magnesium using versatic 10

The separation of nickel and cobalt from a synthetic sulfate solution that contains iron(II) and magnesium via solvent extraction techniques using a neodecanoic acid, Versatic 10, as extractant was explored. The extraction behavior of the metals was investigated by varying the operating pH while the stripping behavior was investigated by varying the acidity of the stripping agent which was sulfuric acid. The experimental results demonstrate that nickel, cobalt and iron(II) can be separated easily from magnesium via selective extraction using 20% Versatic 10 as extractant and 5% tri-n-butyl phosphate (TBP) as phase modifier at pH 7.0, while the nickel and cobalt in the loaded organic phase can be separated from iron(II) by selective stripping of the two metals using 0.1 mol/L sulfuric acid solution leaving iron(II) in the organic phase. Attempts to optimize the extraction and stripping processes were reported.