Study on the adsorbent with amidoxime functional group utilized to recover useful metals from sea-water

Japan Atomic Energy Research Institute has developed fibrous polymer containing amidoxime chelating functional group adsorbent (FPAO) for recovering U from Seawater. Recovery of uranium from seawater provides an additional head-end option to nuclear fuel cycle. Fundamental experiments showed that FPAO absorbs U (VI) the best around pH 6.0, and that adsorptive reaction is a thermo-activated process having activation energy of 28.54 KJ·mol-1. Uptake values for metals in FPAO which was immersed to actual seawater for 2 months, were determined to be 9690 for Mg, 0.026 for Ir, 0.0036 for Au, 320 for V, 290 for U, 0.97 for La, 0.83 for Ce, 8.6 for Ti, and 0.97 for Zr, as in unit of μg·(g-dry FPAO)-1. From batch desoption experiments, it is suggested to possible to recover Mg, U or La/Ce separately by using HCl and H2C2O4 (oxalic acid) as elutants. (author)