PURPOSE: To recover metals of high purity by chromatographic sepn. by adsorbing anionic complexes of transition metal ions on an anion exchange resin, then lowering the complexing agent concn. in the soln. in accordance with different complex dissociation constants.

CONSTITUTION: The anion exchange resin is packed apart a backwashing head space 5A into a column to form a load area 5B and a sharpening area 5C. A waste hydrochloric acid stripping soln. contg. Fe3+, Zn2+, Cd2+ as complexes of Cl- is supplied into the column from the column top. As a result, the complexes of the metal ions described above are adsorbed in the load area 5B. Deionized water is injected into the column from the column top. As a result, the hydrochloric acid concn. is successively lowered and the respective ions of the Fe3+ of the large dissociation constant, then the Zn2+ and finally the Cd2+ of the smallest constant are dissociated according to the respective dissociation constants. The purity of these metallic ions is raised in the sharpening area 5C and the metal ions are successively taken out from the column bottom. The anion exchange resin is thereafter backwashed with hydrochloric acid and is thus regenerated.