Through basic research on the separation of uranium isotopes by the isotopic equilibrium reaction of uranus and uranyl ions, we discovered that a novel redox chromatography in adsorption columns is most efficient for the enrichment of 235U. Further studies of kinetics and multicomplexes led to the formation of two very important equations that satisfactorily predict the degree of separation of uranium isotopes. Some results from extensive single-and multicolumn experiments and a model plant currently under design for recovery of 3% enriched uranium are also described.