著者
Takayuki MAEDA Yoichi ONO
出版者
The Iron and Steel Institute of Japan
雑誌
Transactions of the Iron and Steel Institute of Japan (ISSN:00211583)
巻号頁・発行日
vol.25, no.12, pp.1191-1193, 1985 (Released:2006-09-08)
参考文献数
2
被引用文献数
17 18

The reduction behavior of constituent minerals of iron ore sinter has been investigated microscopically by using two kinds of commercial sinter having different basicity and FeO content. The results are summarized as follows:(1) There is a difference in reducibility between hematite and magnetite, and hematite is reduced faster than magnetite.(i) Both hematite and magnetite are reduced rapidly to wustite, but there is a difference in the rate of reduction from wustite to iron.(ii) The reduction of wustite reduced from hematite does not proceed topochemically but homogeneously. Although the reduction of the wustite is comparatively fast in the almost whole period of reduction, part of the wustite becomes surrounded by dense iron and left unreduced in the final stage of reduction.(iii) In the reduction of wustite reduced from magnetite, almost all grains of wustite are surrounded by dense iron from the early stage of reduction, which causes the retardation of reduction.(2) Calcium ferrite is reduced much faster than the wustites mentioned above, which is shown by the fact that many grains of wustite are left unreduced even after calcium ferrite is reduced completely.(i) The reduction of calcium ferrite proceeds topochemically.(ii) Iron produced by the reduction of calcium ferrite is very porous and not sintered, which does not cause the retardation of reduction.(3) In many cases, reduction begins with the surface of mineral grains facing a macro-pore, which serves as a passage of reducing gas to each mineral grain to be reduced.