RECOVERY OF URANIUM FROM SEAWATER .14. SYSTEM ARRANGEMENTS FOR THE RECOVERY OF URANIUM FROM SEAWATER BY SPHERICAL AMIDOXIME CHELATING RESINS UTILIZING NATURAL SEAWATER MOTIONS

In order to evaluate performs of lightly cross-linked highly porous amidoxime resins in uranium-adsorption systems utilizing natural seawater motions, uranium uptake by the resins from seawater was studied by different approaches, such as simulated sea current exposure tests, towing trials, and/or mooring trials. In general, the efficiency of uranium uptake became higher with a decrease in the thickness of packing layers, indicating important roles of fluidization of the resin particles. On the basis of these fundamental data, mooring tests in the natural sea current were designed and conducted. By mooring flat adsorption beds (base area 260 cm2, height 3.0 cm) packed with 780 mL of the resin for 40 h, promising uranium uptake as high as 44 mg/kg of resin (9.9 mg/L of resin) was achieved under sea conditions in which the velocity of sea currents and the vertical velocity of waves were 5.5-49.7 cm/s and 3.4-27 cm/s, respectively.