AMERICIUM EXTRACTION METHOD Russian patent published in 2019 - IPC C22B60/02 C22B3/26 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of extracting americium from raffinates from extraction processing of plutonium-containing nitrate solutions carried out for purification of plutonium. Method involves preparation of solutions for extraction, use of different radical phosphine oxide (DRPO) as an extractant and re-extraction of americium. Nitric acid solution containing americium is neutralized till residual acid content corresponds to range of pH=1.5–2.5. Neutralization is carried out in two stages. At the first step, an alkaline reagent is used, preferably sodium hydroxide or carbonate with the end of the first stage at pH=0.8–1.0. At the second step, a buffer reagent, preferably aminoacetic acid (glycine) is used in an amount which provides in the neutralized solution a pH range of 1.5–2.5. Prepared solution is used to extract americium with DRPO solution in inert diluent with subsequent re-extraction of americium from organic phase. Extraction and re-extraction operations are carried out in mass exchange separators at direct-flow movement of phases in separating layer.

EFFECT: increased extraction and concentration of americium.

3 cl, 1 tbl, 1 ex