Thermodynamical, kinetic and structural properties of simple and mixed complexes of zirconium (IV) with the hydroxyl and carbonate ions. Study by potentiometry, Raman spectroscopy and NMR spectroscopy
Creators
Description
Most of zirconium production is used by the nuclear industry for the cladding of nuclear fuels and for the storage of radioactive wastes. The aim of this work is the qualitative and quantitative study of the complexes made by zirconium with the hydroxyl and carbonate ions in order to evaluate the long-term pollution risks linked with the corrosion of confinement containers. The zirconium(IV)/hydroxyl system is studied by proto-metry and follows a protocol which reduces the local over-concentrations of reagent and the precipitation of zirconium hydroxide. In potassium nitrate environment and in a pH range of 1.5 to 3.5, three soluble species are evidenced: Zr(OH)3+, Zr2(OH)7+ and Zr(OH)4. Their apparent constant of formation and the solubility product of zirconium hydroxide are determined with 4 ionic forces. Using these results, the corresponding thermodynamic constants are calculated by applying the theory of specific interactions. The formation of zirconium (IV) hydroxo-carbonate complexes is evidenced by proto-metry and 17O and 13C NMR. The number of carbonates fixed by zirconium varies from 0 to 4. The dialysis indicates that the degree of poly-condensation of species is an inverse function of the number of complex carbonates. The Raman polarized spectra and the 13C NMR results demonstrate for all complexes the bidentate character of the complexation mode of the carbonates. The dynamical study made by 13C NMR of the exchange between complexed carbonates of the tetra-carbonate-zirconate ion and free carbonates in solution allows to determine the kinetic constants and the corresponding velocity law. An associative mechanism is proposed, in agreement with the results obtained by mass spectroscopy with electro-spray ionization. These new thermodynamical and kinetic data allow to model the speciation of zirconium in natural waters. (J.S.)
Availability note (English)
Also available from Bibliotheque de lUniversite de Reims Champagne-Ardenne.Section sciences et techniques, Moulin de la Housse.R.des Crayeres BP 1040, 51687 REIMS CEDEX 02 (France)Abstract (French)
L'essentiel de la production de zirconium est utilise par l'industrie nucleaire pour le gainage des combustibles des reacteurs ainsi que pour le stockage des dechets radioactifs. L'objectif de ce travail est l'etude qualitative et quantitative des complexes formes par le zirconium avec les ions hydroxyle et carbonate afin d'evaluer, a long terme, les risques d'eventuelles pollutions dues a la corrosion des conteneurs de confinement. Le systeme zirConium(lV)/hydroxyle est etudie par protometrie en suivant un protocole reduisant les· surconcentrations lOeales de reactif et la precipitation de l'hydroxyde de zirconium. En milieu nitrate de potassium, dans une gamme de pH 1,5 a 3,5, trois especes solubles sont mises en evidence: Zr(OH)3+, Zr2(OH)7+ et Zr(OH)4. Leurs constantes appw.:entes de formation ainsi que le produit de solubilite de l'hydfoxyde de zirconium sont detennines a quatre forces ioniques. A partir de ces resultats, les constantes thennodynamiques correspondantes sont calculees par application de la theorie des interactions specifiques. La fomiation des complexes hydroxocarbonates du zirconium(IV) est mise en evidence par protometrie et RMN 17O et 13C. Le nombre de carbonates fixes par zirconium varie de 0 a 4; la dialyse indique que le degre de polycondensation des especes est fonction. inverse du nombre de carbonates complexes. Les spectres polarises Raman ainsi, que les resultats de RMN 13C prouvent, pour l'ensemble des complexes, le caractere bidente du mode decoinplexation des carbonates. L'etude dynamique suivie par RMN 13C de l'echange entre carbonates complexes de l'ion tetracarbonatoiirconate et carbonates libres en solution permet de determiner les constantes cinetiques et la loi de vitesse correspondante. Un mecanisme associatif est propose, en accord avec les resultats obtenus par spectrometrie de masse avec ionisation electrospray. Ces nouvelles donnees thetmodynamiques et cinetiques permettent de modeliser la speciation du zirconium dans les eaux naturelles. (auteur)Files
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Additional details
Additional titles
- Original title (French)
- Proprietes thermodynamiques, cinetiques et structurales de complexes simples et mixtes du zirconium (IV) avec les ions hydroxyle et carbonate. Etude par potentiometrie, spectrometrie raman et spectrometrie de resonance magnetique nucleaire
Publishing Information
- Imprint Pagination
- 193 p.
- Report number
- FRNC-TH--5402
INIS
- Country of Publication
- France
- Country of Input or Organization
- France
- INIS RN
- 55006273
- Subject category
- S37: INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; S38: RADIATION CHEMISTRY, RADIOCHEMISTRY AND NUCLEAR CHEMISTRY;
- Resource subtype / Literary indicator
- Thesis
- Descriptors DEI
- CHEMICAL REACTION KINETICS; CHEMICAL STATE; HYDROXY COMPOUNDS; MOLECULAR STRUCTURE; NMR SPECTRA; PH VALUE; POTENTIOMETRY; RAMAN SPECTRA; THERMODYNAMIC PROPERTIES; ZIRCONATES; ZIRCONIUM CARBONATES; ZIRCONIUM COMPLEXES; ZIRCONIUM HYDROXIDES
- Descriptors DEC
- CARBON COMPOUNDS; CARBONATES; CHEMICAL ANALYSIS; COMPLEXES; HYDROGEN COMPOUNDS; HYDROXIDES; KINETICS; ORGANIC COMPOUNDS; OXYGEN COMPOUNDS; PHYSICAL PROPERTIES; QUANTITATIVE CHEMICAL ANALYSIS; REACTION KINETICS; SPECTRA; TITRATION; TRANSITION ELEMENT COMPLEXES; TRANSITION ELEMENT COMPOUNDS; VOLUMETRIC ANALYSIS; ZIRCONIUM COMPOUNDS
Optional Information
- Notes
- 95 refs.; Available from the INIS Liaison Officer for France, see the INIS website for current contact and E-mail addresses; This record replaces 35009632