The sorption of ferric and ferrous ions from aqueous solutions on the silica powder, obtained from colloidal dispersion of silica (silica sol), was studied as a function of their concentrations and solution pH. The amount of sorbed ferric and ferrous ions increases with increasing final pH of the solution. The sorption isotherms are of high-affinity type. A sorption mechanism of ferric and ferrous ions from aqueous solutions on silica is proposed.