A Comprehensive Study of the Solubility, Thermochemistry, Ion Exchange, and Precipitation Kinetics of NO3 Cancrinite and NO3 Sodalite
NO3 cancrinite and NO3 sodalite haves been found as a common sodium alumino-silicate forming in strongly caustic alkaline aqueous solutions associated with radioactive High Level Waste (HLW) stored in many underground tanks and also in nuclear waste treatment facilities such as the Savannah River Site (SRS). The precipitation of alumino-silicate phases from caustic nuclear wastes has proven to be problematic in a number of processes in waste treatment facilities including radionuclide separations (cementation of columns by aluminosilicate phases), tank emptying (aluminosilicate tank heels), and condensation of wastes in evaporators (aluminosilicate precipitates in the evaporators, providing nucleation sites for growth of critical masses of radioactive actinide salts). Therefore, in order to prevent their formation an assessment of the relative stability, formation kinetics, and the ion-exchange characteristics of these two phases in HLW solutions needs to be investigated. The goals of this project are to: (1) Develop a robust equilibrium thermodynamic framework to accurately describe and predict the formation of NO3 cancrinite and NO3 sodalite. (2) Provide a comprehensive characterization of the solid precipitation rates and mechanisms using novel spectroscopic (e.g., NMR) and thermochemical techniques in conditions encountered in HLW waste solutions. (3) Characterize the precipitation kinetics of the aluminosilicates and study the effects of temperature and fluid composition. (4) Investigate the ion exchange capacity of these zeolitic phases with respect to radionuclides and RCRA metal species.
- Research Organization:
- Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); University of California, Davis, CA (US)
- Sponsoring Organization:
- USDOE Office of Science (SC) (US)
- DOE Contract Number:
- FG07-01ER63298
- OSTI ID:
- 834993
- Report Number(s):
- EMSP-81959-2003; R&D Project: EMSP 81959; TRN: US0407412
- Resource Relation:
- Other Information: PBD: 1 Jun 2003
- Country of Publication:
- United States
- Language:
- English
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A Comprehensive Study of the Solubility, Thermochemistry, Ion Exchange, and Precipitation Kinetics of NO3 Cancrinite and NO3 Sodalite
A Comprehensive Study of the Solubility, Thermochemistry, Ion Exchange and Precipitation Kinetics of NO3 Cancrinite and No3 Sodalite
Related Subjects
54 ENVIRONMENTAL SCIENCES
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ACTINIDES
AQUEOUS SOLUTIONS
EVAPORATORS
ION EXCHANGE
KINETICS
LIQUID WASTES
NUCLEATION
PRECIPITATION
RADIOACTIVE WASTES
RADIOISOTOPES
SODIUM
SOLUBILITY
STABILITY
TANKS
THERMODYNAMICS
WASTE PROCESSING