METHOD OF PURIFYING NITRATE SOLUTIONS FROM AMERICIUM Russian patent published in 2020 - IPC C22B60/02 G21F9/00 

FIELD: radiochemical technology.

SUBSTANCE: invention relates to radiochemical technology and can be used for purification from americium of raffinate of extraction separation of production of mixed uranium-plutonium fuel. Purification of nitrate solutions from americium involves coprecipitation of americium with calcium oxalate from solutions containing compounds of accompanying metals, followed by calcination to oxides. Initial americium-containing solution is neutralized to pH in range of 0.7–1.2, after which the calcium-containing reagent is added to reach its concentration in solution of 1.5–3.5 g/l. Oxalic acid and/or salt thereof is added to the obtained solution in an amount which is not less than stoichiometric with respect to the sum of the accompanying metals, followed by holding the pulp to form a precipitate. Obtained americium-containing precipitate is filtered and washed with 0.5–50 g/l of oxalic acid solution having pH in range of 1–2.

EFFECT: invention enables to purify raffinate nitrate from americium, significantly reduces heat generation and activity of the raffinate to be recycled, and also enables to obtain an americium-containing compact product suitable for thermal treatment both for recycling and further extraction of americium.

5 cl, 1 dwg, 2 ex