Separation of iron from cobalt in nitrate medium using Cyanex-923 as extractant

A method for the separation of Fe(III) from Co(II) in nitric acid medium has been developed using 30% Cyanex-923 in n-dodecane. Nitric acid extraction studies (0.5 to 6.0M) as a function of Cyanex-923 concentration (10-30%) suggest the probable extraction of more than one species of Cyanex-923. HNO3 complex. Third phase formation was observed at 8.0M HNO3. Extraction of Fe(III) increases monotonously with acidity (1.0-7.0M) whereas that of Co(II) is negligible at all acidities. Fe(III) was quantitatively loaded in the organic phase in two contacts at 7.0M HNO3