Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Tamada, Masao; Seko, Noriaki; Kasai, Noboru; Shimizu, Takao*
FAPIG, (169), p.3 - 12, 2005/03
Braid adsorbent having functional group of amidoxime is a promising material for the recovery of uranium dissolved in the seawater. This braid adsorbent was made by polyethylene multi-fibers in which amidoxime groups were introduced by radiation-induced graft polymerization and subsequent chemical treatment. Reaction time for graft polymerization was 5 h and the resulted braid adsorbent had 2.8 mmol/g-adsorbent of amidoxime group. The braid adsorbent obtained was moored at the offing of Okinawa Island. The adsorption of uranium reached 1.5g/kg-adsorbent for 30 d soaking. The mooring system for braid adsorbent has possibility which reduced the cost for the recovery of uranium from seawater. It is shown that 134 km
of mooring area is needed for annual product of 1200 tons of uranium. In addition, there is 6000 km and more of suitable sea area for the collection of the uranium in the regions from Okinawa Islands to Tosa Bay in Japan.
Tamada, Masao
Enerugi Rebyu, 22(4), p.24 - 26, 2002/03
The Black Current conveys 5.2 million tons of uranium toward the offing of Japan, though uranium concentration is only 3.3 ppb in seawater. Recovery of 0.2% of this resources can supply the uranium for all atomic power plants in Japan. Graft polymerization is a promising technique to prepare adsorbent having high selectivity to uranium in seawater and enough durability in severe sea conditions. To evaluate the activity of the adsorbents the equipment for the recovery of rare metals from seawater was set at the 7 km offing of Mutsu-Sekine, Aomori prefecture on September, 1999. In three years (1999 - 2001) 9 mooring experiments of adsorbents were carried out and 1 kg uranium as yellow cake was recovered. This experiment suggested that hydrophilic monomer and trunk polymer should be improved to realized the higher activity for uranium recovery from seawater.