Skip to Main content Skip to Navigation
Theses

Etude expérimentale de la cinétique et des mécanismes d'altération de minéraux apatitiques. Application au comportement d'une céramique de confinement d'actinides mineurs.

Abstract : The motivation for this study is to assess the potential of using apatite structured ceramics as long-lived actinide storage hosts. To assess their ability to resist aqueous corrosion, the dissolution of natural fluorapatite and synthetic Nd-britholite (neodymium is a proxy for the trivalent actinides) was studied. Mineral surfaces were characterized using a combined spectrometric, electrokinetic and potentiometric approach and dissolution rates were measured in closed and open system reactors as a function of solution composition. Experimental results suggest apatitic minerals dissolve via distinct step sequence: 1) fluoride release, 2) release of the calcium situated in the M1, and 3) the simultaneous removal of phosphate and calcium II via the breaking of only Ca-O bonds. TST based rate equations based in this mechanism accurately describe fluorapatite and synthetic britholite dissolution rates as a function of solution composition. Nd release rates are limited by precipitation of Nd-rhabdophane.
Document type :
Theses
Complete list of metadatas

Cited literature [210 references]  Display  Hide  Download

https://tel.archives-ouvertes.fr/tel-00011686
Contributor : Williams Exbrayat <>
Submitted on : Monday, February 27, 2006 - 11:33:09 AM
Last modification on : Thursday, October 15, 2020 - 4:07:16 AM
Long-term archiving on: : Tuesday, April 6, 2010 - 4:44:31 PM

Identifiers

  • HAL Id : tel-00011686, version 1

Collections

Citation

Claire Chaïrat. Etude expérimentale de la cinétique et des mécanismes d'altération de minéraux apatitiques. Application au comportement d'une céramique de confinement d'actinides mineurs.. Géochimie. Université Paul Sabatier - Toulouse III, 2005. Français. ⟨tel-00011686⟩

Share

Metrics

Record views

505

Files downloads

3338