[en] For the isolation of uranium from process-solution containing sulfuric acid, a series of ionic exchange resins were tested. Amberlite XE-299 showed the best mechanic, physical and chemical qualities for this procedure. The capacity was 40 g U₃O₈ per resin equivalent at a medium sulfuric acid concentration of 27,4 g/1 and an pH-value of 1,8. For elution 5 - 6 resin volumina and a time of 5 hours were sufficient, and the concentration of the effluent 16 g U₃O₈/1 was rather high. The precipitated ADU was of nuclear grade and the procedure could be successfully performed in a pilot plant. (author)