Research output: Contribution in Book/Report/Proceedings - With ISBN/ISSN › Conference contribution/Paper › peer-review
Research output: Contribution in Book/Report/Proceedings - With ISBN/ISSN › Conference contribution/Paper › peer-review
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TY - GEN
T1 - Modelling the Hydrolysis of Actinide Complexed Hydroxamic Acid Ligands
AU - Andrieux, Fabrice
AU - Boxall, Colin
AU - Taylor, Robin
AU - Mason, C.
PY - 2006
Y1 - 2006
N2 - The separation of U from Np and Pu are major stages in the Purex process. Simple hydroxamic acids (XHA) are salt free, hydrophilic organic compounds, RCONHOH, with affinities for cations such as Fe3+, Np4+ and Pu4+. They are also redox active, capable of reducing a range of metal ions e.g. Np(VI) to Np(V). These two properties have led to them being identified as useful reagents for the control of Pu and Np in an Advanced Purex process. The kinetics of the acid hydrolysis of free formo- (FHA) and acetohydroxamic (AHA) acids to hydroxylamine and the parent carboxylic acid are well known. Hydrolysis of hydroxamates bound to metal ions also occurs and preliminary studies have shown that the Pu(IV)-FHA and AHA complexes are slowly reduced to free Pu(III) ions. An understanding of these processes is vital if they are to be controlled within the design of an Advanced Purex process. To this end, we have used UV-visible & nIR spectrophotometry to study and theoretically model the kinetics of the hydrolysis of metal-HA systems in nitrate media – Fe3+ / AHA (as a non-active analogue); Np4+ / FHA, Np4+/AHA – wherein the metal ion complexes with, but does not oxidise the ligand.
AB - The separation of U from Np and Pu are major stages in the Purex process. Simple hydroxamic acids (XHA) are salt free, hydrophilic organic compounds, RCONHOH, with affinities for cations such as Fe3+, Np4+ and Pu4+. They are also redox active, capable of reducing a range of metal ions e.g. Np(VI) to Np(V). These two properties have led to them being identified as useful reagents for the control of Pu and Np in an Advanced Purex process. The kinetics of the acid hydrolysis of free formo- (FHA) and acetohydroxamic (AHA) acids to hydroxylamine and the parent carboxylic acid are well known. Hydrolysis of hydroxamates bound to metal ions also occurs and preliminary studies have shown that the Pu(IV)-FHA and AHA complexes are slowly reduced to free Pu(III) ions. An understanding of these processes is vital if they are to be controlled within the design of an Advanced Purex process. To this end, we have used UV-visible & nIR spectrophotometry to study and theoretically model the kinetics of the hydrolysis of metal-HA systems in nitrate media – Fe3+ / AHA (as a non-active analogue); Np4+ / FHA, Np4+/AHA – wherein the metal ion complexes with, but does not oxidise the ligand.
M3 - Conference contribution/Paper
SN - 978-0-85404-678-2
VL - 305
SP - 626
EP - 628
BT - RSC Special Publication
A2 - May, Iain
A2 - Alvares, Rebeca
A2 - Bryan, Nicholas
PB - Royal Society of Chemistry
CY - Cambridge
ER -