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Kinetics for Reduction of Aciculate Ultrafineα-Fe2O3Particles to Fe3O4Particles

✍ Scribed by Chunzhong Li; Zhifu Hong

Publisher
Elsevier Science
Year
1997
Tongue
English
Weight
450 KB
Volume
134
Category
Article
ISSN
0022-4596

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✦ Synopsis

The reduction kinetics of aciculate ultrafine -Fe 2 O particles to Fe 3 O 4 in a mixture of H 2 and N 2 were studied by using the temperature-programmed reduction technique, and the optimum conditions for reduction were investigated for preparation of magnetic powder. The reduction of aciculate ultrafine -Fe 2 O 3 particles to Fe 3 O 4 was fitted to the nucleation and grain-growth model, and the reduction kinetic equation was written as d /dt ‫؍‬ 9.00؋10 3 exp(؊ 72.7؋10 3 /RT ) (1 ؊ ) 0.54 . There existed a maximum reduction rate at the degree of transformation approximately equal to 0.34, which was considered to be a result of induction effects. The optimum temperature of aciculate ultrafine -Fe 2 O 3 particle reduction for magnetic powder preparation was 630-670 K.

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