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Ohashi, Yusuke; Harada, Masayuki*; Asanuma, Noriko*; Ando, Shion; Tanaka, Yoshio; Ikeda, Yasuhisa*
Journal of Radioanalytical and Nuclear Chemistry, 311(1), p.491 - 502, 2017/01
Times Cited Count：1 Percentile：10.62(Chemistry, Analytical)In order to assess the feasibility of method for recovering U from wastes containing uranium (scrap uranium) using polyvinylpolypyrrolidone (PVPP) adsorbent, we have examined the adsorption and desorption behavior of metal species in HCl aqueous solutions dissolving scrap uranium. It was found that the U(VI) species are selectively adsorbed onto PVPP regardless of the presence of a large amount of Na(I) and Al(III), that the adsorbed U(VI) species are desorbed from PVPP column selectively by water. Pure uranium was efficiently recovered from the eluates. From these results, the PVPP resin is expected to be used as the adsorbent in the treatment process of scrap uranium.
Ohashi, Yusuke; Nomura, Mitsuo; Tsunashima, Yasumichi; Ando, Shion; Sugitsue, Noritake; Ikeda, Yasuhisa*; Tanaka, Yoshio
Journal of Nuclear Science and Technology, 51(2), p.251 - 265, 2014/02
Times Cited Count：9 Percentile：53.31(Nuclear Science & Technology)Sludge-like uranium-bearing wastes generated from uranium refining and conversion R&D facilities are stored at the Ningyo-toge Environmental Engineering Center. We have proposed an aqueous process for recovering uranium from spent filter aid and CaF
precipitate using hydrochloric acid. The distributions of the dissolved species in the sample solutions at different pH levels were calculated using the chemical equilibrium modeling system. Calculated results of fluorine contents of recovered uranium were compared with the experimental results. The fluorine content in the recovered uranium decreased as the aluminum concentration of the solution increased. On the other hand, uranium of spent filter aid was recovered selectively. The size of the particles of recovered uranium tends to decrease with increasing pH in the precipitation treatments. Also, the uranium concentration of the precipitate generated by the neutralization of the barren solution falls below 1 Bq/g.
Ohashi, Yusuke; Ando, Shion; Tsunashima, Yasumichi; Harada, Masayuki*; Ikeda, Yasuhisa*; Asanuma, Noriko*
no journal, ,
Sludge like uranium bearing waste and adsorbent were dissolved using hydrochloric acid. Uranium in the solution is recovered using PVPP. Recovered uranium was desorbed from PVPP using pure water and then uranium was recovered as uranium peroxide. As a result, it was confirmed that highly pure uranium was recovered.
Ohashi, Yusuke; Tsunashima, Yasumichi; Murashita, Shinji; Ando, Shion; Tanaka, Yoshio; Ikeda, Yasuhisa*
no journal, ,
The sludge - like uranium generated by neutralization of the acid water used for decontamination of metal wastes contains much iron. We have examined the aqueous method for recovering uranium from sludge - like uranium containing iron using N-cyclohexyl-2-pyrrolidone (NCP). Precipitation ratio of uranium in the solution prepared by dissolving sludge - like uranium containing iron using HNO
increases as additive amount of NCP increases and it became 97%. The precipitation ratio of iron, aluminum, fluorine and sulfate are less than 1% at all additive amounts of NCP investigated, which indicates that uranium can be selectively recovered by NCP.
