Separation method for ions of elements of the III., IV., VI. and VIII. groups of periodical system

A method is described of concentrating and separating the ions of the elements of the IIIrd, IVth, and VIIIth groups of the periodic system by ion exchangers to which the ions are double-bonded. The new type of ion exchangers applied consists of the polycondensates of phenol with aldehydes or ketones, or of the polymers of substances with a double bond and containing an atom of phosphorus, arsenic or antimony and an atom of sulphur or oxygen in their molecule. The method described may be used to advantage for the removal of the ions of uranium, thorium and its daughters, lanthanum, yttrium, and iron from waste waters. (L.K.)