PURPOSE: To allow U in seawater to be adsorbed on a hydrated metal oxide absorbent in a high yield and recover the U by removing one of calcium and carbonate ions from seawater and treating the seawater with the adsorbent.
CONSTITUTION: Seawater is adjusted to pH 2W4 with hydrochloric acid or sulfuric acid and allowed to stand, or it is heated to remove carbonate ions such as NaHCO3. Otherwise, by adjusting seawater to pH about 9 and adding a small amt. of Na2CO3, CaCO3 is precipitated and filtered, or by adding dil. sulfuric acid to the seawater, CaSO4 is precipitated and filtered to remove Ca ions in the seawater. After removing one of carbonate and Ca ions as mentioned above, to the seawater are added one or more kinds of hydrated oxides of Ti, Al, Zr, Si, etc. as a U absorbent. Thus, the U in the seawater is absorbed on the absorbent in a high yield, separated from the seawater, and recovered.
OZAWA YOSHIHIRO
MAEKOYA CHIAKI
FUJITA KAZUNORI
TAKADA YOSHITADA
NAKASHIMA FUMITO
