The type and synthesizing methods of the ion-retardation resin were introduced, and the weak acid /alkali ion-retardation resin was synthesized with the alkali anion exchanges resin for cage resin by the method crylic acid polying in cage.

Results show that though the ion retardation of the low crosslinking degree resin decreases to some extent,but in concentrated salt solution,the swelling degree increases,the Donnan sorption strengthened,so the resolution is raised remarkably for separating the salt from gelatine.

The paper researched that the effect separation heavier rare earths is influenced by separate retaining ions with high pressure ion exchange displacement process.