Present status of study on extraction of uranium from sea water.

Abstract

The growth rate of the energy demand in the world has been lowered recently, however, the essenciality of the development of nuclear power generation has not been changed. Because of the limited resources of terrestrial uranium, the techniques of the extraction of uranium from sea water as the practically unlimited resources of uranium have been developed in Japan and other countries like F. R. Germany, Sweden, United States and others. Many fundamental results in the above field have been accumulated as well as some design studies and cost estimations have been conducted. In the last October, the International Meeting on Recovery of Uranium from Seawater was held in Japan organized by AESJ and IAEA. At this time moment, the up-to-date status of the studies including the selection of the chemical processes, development of adsorbents, design studies and cost estimations will be reviewed.

Recent International R&D Activities in the Extraction of Uranium from Seawater

“…Ordinary organic ion exchange resins, such as the resorcinol arsenic acid formaldehyde or 8-hydroxyquinoline resin, show good uptake of uranium, but their rapid deterioration with aging makes them unsuitable for the extraction of uranium from seawater (3,4). Some macrocyclic polydentate ligands were studies to improve the selectivity (3,4), but no further development work was reported in the later literature for unclear reasons.…”

“…Some macrocyclic polydentate ligands were studies to improve the selectivity (3,4), but no further development work was reported in the later literature for unclear reasons. For example, polymer-bound macrocyclic hexaketone ( Figure 1) was found to be capable of extract uranyl ion from seawater (4).…”

“…Solvent extraction, though feasible, is considered to be unsuitable for the extraction of uranium from seawater on a large scale, due to the requirements of complicated engineering setup/procedure and large amounts of chemicals and volatile solvents, and the problem of solvent loss by entrainment and dissolutin (3,4).…”

“…Several types of biological substances have been reported to be used for uranium extraction, including acid polysaccharides, phosphorylated polysaccharides (chitin phosphate, chitosan phosphate, cellulose phosphate). However, the adsorption capacity is low and there are problems of contacting microorganism with seawater and their collections (3,4).…”

Sequestering uranium from seawater: binding strength and modes of uranyl complexes with glutarimidedioxime

“…[2][3][4][5][6] Among these, 30 the Japanese process using amidoxime-based sorbents prepared by radiation grafting showed the best promise. 5,6 A sorption efficiency of 1.5 g-U/kg sorbent was achieved in 30-day marine tests and the estimated cost was $500/kg uranium, about 2-3 times the spot market price of uranium.…”