Preparation and Properties of Americium(VI) in Aqueous Carbonate Solutions

Separation of curium from americium using composite sorbents and complexing agent solutions

“…Americium(VI) remains in solution while curium(III) is precipitated as CmF 3 [22,23]. Americium can be released from hydroxide suspension in NaHCO 3 solution when oxidized to Am(VI) by bubbling ozone [24,25]. The other possibility represents precipitation of Am(V) in form of KAmO 2 CO 3 after americium oxidation by KClO in K 2 CO 3 solution while Cm(III) remains in solution [26].…”

Alkaline chemistry of transuranium elements and technetium and the treatment of alkaline radioactive wastes

“…The yield for ='Am a-particles is 4 ions/100 eV (Coleman et al 1963). This yield is close to the yield observed in perchloric acid solutions (Pikaev et al 1983).…”

Selective Separation of Trivalent Actinides from Lanthanides by Aqueous Processing with Introduction of Soft Donor Atoms

“…If a solution of 2 M Na 2 CO 3 is used, Am(III) is oxidized with ozone to Am(VI) at room and lower temperatures with an accumulation of Am(V) occurring at higher temperatures. [40][41] In 0.03-0.1M KHCO 3 , Am(V) precipitates as the salt KAmO 2 CO 3 . Without a consideration of the possible complexes that can be formed with americium, the oxidation of Am(III) could be described by the following equations.…”

“…[42] Am(VI) has been produced in aqueous 2 M carbonate solutions as well through the oxidation of Am(III), Am(IV), or Am(V) with ozone giving an intensely red-brown Am(VI) carbonate complex. [40] Basic carbonate solutions form strong complexes with hexavalent actinide ions. [43] The terminal complex, AnO 2 (CO 3 ) 3 4-ion, has been observed in U, Pu and Np and is the dominate species at relatively low carbonate concentrations between pH ≈ 7-11.…”