ABSTRACT

Liquid-liquid distribution data were determined for the extraction of nitric acid, Am(III), Cm(III), and lanthanides(III) from 0.1–7 mol/L nitric acid into 0.5–1 mol/L N,N’-dimethyl-N,N’-dioctyl-2-[2-(hexyloxy)ethyl]-malonamide (DMDOHEMA) dissolved in kerosene. Nitric acid extraction was accurately modeled accounting for the adducts (HNO₃)L₂, (HNO₃)L, and (HNO₃)₂L. To model Am(III) extraction, the following complexes were taken into account, Am(NO₃)₃L₄, Am(NO₃)₃(HNO₃)L₃, and a third complex, Am(NO₃)₃(HNO₃)₂ L₃ (considering spectroscopic results) or Am(NO₃)₃(HNO₃)₂ L₂ (considering slope-analysis results). Separation factors for Am(III) over Cm(III) and the lighter lanthanides(III) are practically independent of nitric acid concentration. Am(III)/Ln(III) separation factors decrease with increasing nitric acid concentration for the heavier lanthanides(III).

摘要

确定了从0.1–7 mol / L硝酸到0.5–1 mol / L N，N'-中的硝酸，Am（III），Cm（III）和镧系元素（III）的萃取液-液分布数据。溶解在煤油中的二甲基-N，N'-二辛基-2- [2-（己氧基）乙基]-丙二酰胺（DMDOHEMA）。准确地模拟了硝酸萃取物中加合物（HNO ₃）L ₂，（HNO ₃）L和（HNO ₃）₂ L的建模。为模拟Am（III）萃取，考虑了以下配合物Am（NO ₃）₃ L ₄，Am（NO ₃）₃（HNO ₃）L ₃以及第三配合物Am（NO ₃）₃（HNO ₃）₂ L ₃ （考虑光谱结果）或Am（NO ₃）₃（HNO ₃）₂ L ₂ （考虑斜率分析结果）。Am（III）与Cm（III）和较轻的镧系元素（III）的分离系数实际上与硝酸浓度无关。对于较重的镧系元素（III），Am（III）/ Ln（III）分离因子随硝酸浓度的增加而降低。