CETMIC   05378
CENTRO DE TECNOLOGIA DE RECURSOS MINERALES Y CERAMICA
Unidad Ejecutora - UE
artículos
Título:
Kinetic study of Zn-Fe2O4 formation from mechanochemically activated Zn-Fe2O3 mixtures.
Autor/es:
P.M. BOTTA E.F. AGLIETTI, J. M. PORTO LOPEZ
Revista:
MATERIALS RESEARCH BULLETIN
Editorial:
Elsevier
Referencias:
Año: 2006 vol. 41 p. 714 - 723
ISSN:
0025-5408
Resumen:
Abstract
The kinetics of ZnFe2O4 formation starting from mechanochemically activated ZnFe2O3 powders are studied. Mixtures of
metallic Zn and hematite were activated under air atmosphere in a high energy mill and thermally treated at temperatures between
500 and 650 8C during several holding times. During the activation, morphological and compositional changes were observed, but
ZnFe2O4 formation was not detected. The ZnFe2O4 content in heated samples was determined using quantitative X-ray diffraction
analysis. The resulting conversiontime curves were fitted using different kinetic models of solid-state reaction, calculating the
kinetic parameters of the studied reaction. The comparison with the conventional synthesis method revealed that the mechanochemical
treatment provoked a change of the rate-controlling step and a significant decrease of the activation energy, which was
more evident for the more activated mixtures.
# 2005 Elsevier Ltd. All rights reserved.
Keywords: A. Ceramics; C. X-ray diffraction; D. Diffusion