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Titolo:
Photochemical decomposition of oxalate precipitates in nitric acid medium
Autore:
Kim, EH; Chung, DY; Kwon, SW; Yoo, JH;
Indirizzi:
Korea Atom Energy Res Inst, Taejon 305600, South Korea Korea Atom Energy Res Inst Taejon South Korea 305600 305600, South Korea
Titolo Testata:
KOREAN JOURNAL OF CHEMICAL ENGINEERING
fascicolo: 3, volume: 16, anno: 1999,
pagine: 351 - 356
SICI:
0256-1115(199905)16:3<351:PDOOPI>2.0.ZU;2-8
Fonte:
ISI
Lingua:
ENG
Soggetto:
WASTE;
Keywords:
oxalic acid; photo-decomposition; nitric acid; oxalate precipitate; photochemical reaction;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Engineering, Computing & Technology
Citazioni:
11
Recensione:
Indirizzi per estratti:
Indirizzo: Kim, EH Korea Atom Energy Res Inst, POB 105, Taejon 305600, South Korea Korea Atom Energy Res Inst POB 105 Taejon South Korea 305600 orea
Citazione:
E.H. Kim et al., "Photochemical decomposition of oxalate precipitates in nitric acid medium", KOR J CHEM, 16(3), 1999, pp. 351-356

Abstract

This work has been performed as a part of the partitioning of minor actinides. Minor actinides can be recovered from high-level wastes as oxalate precipitates, but they tend to be co-precipitated together with lanthanide oxalates. This requires another partitioning step for mutual separation of actinide and lanthanide groups. Accordingly, the objective of this study was to decompose and dissolve oxalate precipitates into a dilute nitric acid solution by using a photochemical reaction. In order to do this, oxalic acid and neodymium oxalate precipitate were used in this study. Neodymium oxalatewas chosen as a stand-in element representing americium, curium and lanthanides. As a result, decomposition characteristics of oxalic acid were firstinvestigated and then on the basis of these results, the decomposition of neodymium oxalate precipitates was evaluated. From results using oxalic acid, the oxalate decomposition appeared to take place due to the reaction between the oxalate ion and hydroxyl radical generated from the nitric acid byphoto-radiation. And the oxalate decomposition rate was measured in the experiments for various nitric acid contents when a mercury lamp (lambda=254 nm) was used as a light source. The maximum decomposition rate was obtainedwhen the nitric acid concentration was around 0.5 M, while the decomposition rate was reduced with an increase in the nitric acid concentration at more than 0.5 M. The photo-decomposition rate of neodymium oxalate precipitates was found to be 0.0034 M/h at the condition of 0.5 M HNO3.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 24/09/20 alle ore 11:25:48