Extraction of Nitric Acid, Americium(III), Curium(III), and Lanthanides(III) into DMDOHEMA Dissolved in Kerosene

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)₂L₃ (considering spectroscopic results) or Am(NO₃)₃(HNO₃)₂L₂ (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).

KEYWORDS:

• DMDOHEMA
• nitric acid
• americium(III)
• curium(III)
• lanthanides(III)
• extraction
• equilibrium model
• DIAMEX
• GANEX

Supplementary Material

Supplemental data for this article can be accessed on the publisher’s website.

Additional information

Funding

Financial support for this research was provided by the European Commission via the projects GENIORS (Horizon 2020 grant agreement № 755171), SACSESS (FP7-Fission-2012-323-282) and EUROPART (FI6W-CT-2003-508854).