Extraction separation of americium(III) and europium(III) by thermosensitive polymer gel copolymerized with TPEN derivatives

I&EC 166

Kenji Takeshita, takeshit@res.titech.ac.jp1, Keigo Ishida1, Yoshio Nakano2, and Tatsuro Matsumura, matsumura.tatsuro@jaea.go.jp3. (1) Chemical Resources Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan, (2) Department of Environmental Chem. and Eng, Tokyo Institute of Technology, Nagatsuta, Midori-ku, Yokohama, 226-8502, Japan, (3) Research Group for Actinide Separation Chemistry, Japan Atomic Energy Agency, Nuclear Science and Engineering Directorate, 2-4 Shirakata Shirane, Tokai-mura, Naka-gun, Ibaragi 319-1195, Japan
The extraction separation of trivalent MAs (minor actinides) from lanthanides was examined by a thermosensitive gel, poly-NIPA (N-isopropyl acrylamide) crosslinked with a TPEN derivative, N,N,N',N'-tetrakis(4-propenyloxy-2-pyridylmethyl) ethylenediamine (tppen), and the applicability of proposed process to the partitioning of trivalent MAs from HLLW (high-level liquid waste) was discussed. The NIPA-tppen gel showed the volume change with temperature, which is known as the volume phase transition, and the volume change was repeated reversibly by the thermal-swing operation between 5°C and 40°C. A trivalent actinide, Am(III), was extracted selectively into the swollen gel at 5°C and released easily by the volume phase transition of gel from the swollen state to the shrunken one by the increase of temperature from 5°C to 40°C. The separation factor between Am(III) and Eu(III) at 5°C and the difference of distribution ratios at 5°C and 40°C were evaluated as 20 and 50 times, respectively. These values are sufficient to establish a practical MA recovery process with thermal-swing operation.
 

Separation of f-Elements, Sponsored by Separation Science and Technology Sub-Division
9:00 AM-12:00 PM, Thursday, 14 September 2006 Moscone Center -- Room 250, Oral

Division of Industrial & Engineering Chemistry

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006