Thermodynamic modeling of chemical interactions between CaO--TiO[sub 2] ceramics and molten salts

Journal Article · Tue Mar 01 04:00:00 EST 1994 · Journal of Materials Research; (United States)

DOI:https://doi.org/10.1557/JMR.1994.0739· OSTI ID:5185872

Johnson, I ^[1]; Maiya, P S ^[2]

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1. Chemical Technology Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)
2. Energy Technology Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

The mixed-oxide compounds of CaO with TiO[sub 2] are of interest in the development of container vessels for actinide recycling processes in which Ca (dissolved in molten salt) is used to reduce the actinide oxide to actinide metal. The chemical interactions between the mixed-oxide compounds and molten salt saturated with Ca have been analyzed by applying thermodynamic principles. Although the solubility of CaO in molten salt is suppressed by the formation of mixed oxide with TiO[sub 2], thermodynamic calculations show that corrosion of CaO--TiO[sub 2] ceramics by molten CaCl[sub 2] or CaCl[sub 2]--20 mole% CaF[sub 2] that contains metallic Ca in solution occurs by dissolution of the CaO component of the mixed oxide-compounds in the molten salt and reduction of the TiO[sub 2] component by the metallic Ca. The thermodynamic predictions are consistent with the experimental observations. The corrosion products produced and the sequence of the various phases depend upon the activity of the CaO produced in the molten salt by reduction reactions. The results of this study show that ceramic materials in the CaO--TiO[sub 2] system are not suitable container materials for actinide recycling.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 5185872
• Journal Information: Journal of Materials Research; (United States), Journal Name: Journal of Materials Research; (United States) Vol. 9:3; ISSN JMREEE; ISSN 0884-2914
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201 -- Chemical & Physicochemical Properties
ALKALINE EARTH METAL COMPOUNDS
CALCIUM CHLORIDES
CALCIUM COMPOUNDS
CALCIUM FLUORIDES
CALCIUM HALIDES
CALCIUM OXIDES
CERAMICS
CHALCOGENIDES
CHEMICAL REACTIONS
CHLORIDES
CHLORINE COMPOUNDS
FLUORIDES
FLUORINE COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
MATHEMATICAL MODELS
MOLTEN SALTS
OXIDES
OXYGEN COMPOUNDS
PARTICLE MODELS
SALTS
STATISTICAL MODELS
THERMODYNAMIC MODEL
TITANIUM COMPOUNDS
TITANIUM OXIDES
TRANSITION ELEMENT COMPOUNDS