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The Pyrochlore Line in the System CaO—ZrO2—TiO2: Implications on Synroc Phase Assemblages

Published online by Cambridge University Press:  25 February 2011

M. Ondina Figueiredo
Affiliation:
Centro de Cristalografia e Mineralogia, IICT, Al. Afonso Henriques, 41–4ºE, 1000 Lisboa, Portugal Dept. Engenharia de Minas, Instituto Superior Técnico, UTL, Av. Rovisco Pais, 1000 Lisboa, Portugal
António Correia dos Santos
Affiliation:
Dept. Quimica, Fac. Ciências, Univ. Lisboa, Rua Ernesto de Vasconcelos, edificio Cl, 1700 Lisboa, Portugal
Carmen Parada Cortina
Affiliation:
Dept. Quimica Inorganica, Fac. Quimicas, Univ. Complutense de Madrid, 28006 Madrid, España
M. Joao Basto
Affiliation:
Dept. Engenharia de Minas, Instituto Superior Técnico, UTL, Av. Rovisco Pais, 1000 Lisboa, Portugal
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Abstract

Results of further studies on phase equilibria in system CaO—ZrO2—TiO2 along the “pyrochlore” line ( Ca Zrx Ti3-x 07 ) are reported concerning the possible substitution of cerium for either calcium or zirconium in nominal “Ca Zr2 Ti 07”. The dominant tetragonal phase in this composition was identified as calzirtite. The structural role of zirconium and its tendency towards 7—coordination environments are discussed. Possible implications on high—level nuclear waste immobilizers like SYNROC are brieflyconsidered.

Type
Research Article
Copyright
Copyright © Materials Research Society 1992

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References

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