ISIJ International
Online ISSN : 1347-5460
Print ISSN : 0915-1559
ISSN-L : 0915-1559
Regular Article
In-situ X-ray Transmission Observation of Carbothermic Reduction of Magnetite Powder and Macroscopic Agglomeration of Reduced Iron
Kyosuke Hara Taishi MatsushitaKazuhiro Nagata
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2013 Volume 53 Issue 6 Pages 1010-1019


The agglomeration behaviour of reduced iron, made from magnetite powder by carbothermic reduction, was observed by using the in-situ X-ray transmission observation technique. The iron particles, above 1 mm, were clearly observed as black points. Further, the reduction speed was examined by using the thermogravimetric analysis. The bulk density of the packed powder layer and the grain size distribution of magnetite powder and carbon black powder were changed and the effects of them on the reduction speed and the agglomeration degree were examined. The agglomeration degree was evaluated with diameter of iron particles on the X-ray photographs, taken during heating, and the weight of collected iron particles after the observation experiments. Neither the bulk density of powder layer nor the grain size distribution of powder mixture affected to the reduction speed. The agglomeration degree decreased when the bulk density of the powder layer was increased by compacting. On the other hand, the agglomeration degree was increased when the grain size distribution of powder mixture was widened. Further, the height change of powder layer was also measured on the X-ray photographs and compared with the iron particles appearing behaviour to estimate the microscopic agglomeration behaviour. The mechanisms that grain size distribution affected the agglomeration degree were discussed.

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© 2013 by The Iron and Steel Institute of Japan
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