skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

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

Abstract

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.

Authors:
 [1];  [2]
  1. (Chemical Technology Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States))
  2. (Energy Technology Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States))
Publication Date:
Research Org.:
Argonne National Laboratory (ANL), Argonne, IL
OSTI Identifier:
5185872
DOE Contract Number:  
W-31109-ENG-38
Resource Type:
Journal Article
Journal Name:
Journal of Materials Research; (United States)
Additional Journal Information:
Journal Volume: 9:3; Journal ID: ISSN 0884-2914
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; CALCIUM CHLORIDES; CHEMICAL REACTIONS; CALCIUM FLUORIDES; CALCIUM OXIDES; MOLTEN SALTS; TITANIUM OXIDES; CERAMICS; THERMODYNAMIC MODEL; ALKALINE EARTH METAL COMPOUNDS; CALCIUM COMPOUNDS; CALCIUM HALIDES; CHALCOGENIDES; CHLORIDES; CHLORINE COMPOUNDS; FLUORIDES; FLUORINE COMPOUNDS; HALIDES; HALOGEN COMPOUNDS; MATHEMATICAL MODELS; OXIDES; OXYGEN COMPOUNDS; PARTICLE MODELS; SALTS; STATISTICAL MODELS; TITANIUM COMPOUNDS; TRANSITION ELEMENT COMPOUNDS; 360204* - Ceramics, Cermets, & Refractories- Physical Properties; 400201 - Chemical & Physicochemical Properties

Citation Formats

Johnson, I., and Maiya, P.S. Thermodynamic modeling of chemical interactions between CaO--TiO[sub 2] ceramics and molten salts. United States: N. p., 1994. Web. doi:10.1557/JMR.1994.0739.
Johnson, I., & Maiya, P.S. Thermodynamic modeling of chemical interactions between CaO--TiO[sub 2] ceramics and molten salts. United States. doi:10.1557/JMR.1994.0739.
Johnson, I., and Maiya, P.S. Tue . "Thermodynamic modeling of chemical interactions between CaO--TiO[sub 2] ceramics and molten salts". United States. doi:10.1557/JMR.1994.0739.
@article{osti_5185872,
title = {Thermodynamic modeling of chemical interactions between CaO--TiO[sub 2] ceramics and molten salts},
author = {Johnson, I. and Maiya, P.S.},
abstractNote = {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.},
doi = {10.1557/JMR.1994.0739},
journal = {Journal of Materials Research; (United States)},
issn = {0884-2914},
number = ,
volume = 9:3,
place = {United States},
year = {1994},
month = {3}
}