Reduction, softening and melting behaviour of olivine pellets in the experimental blast furnace Book Chapter

Khanna, R, Lee, SH, Gupta, SK et al. (2012). Reduction, softening and melting behaviour of olivine pellets in the experimental blast furnace . 67-92.

cited authors

  • Khanna, R; Lee, SH; Gupta, SK; Sahajwalla, V; Lindblom, B; Hallin, M

authors

abstract

  • The effect of olivine on reduction, softening and melting behaviour of magnetite pellets in an experimental blast furnace (EBF) was examined. As the pellets descended into the EBF, up to 75% of reduction was completed above the cohesive zone while the remaining reduction was completed within the cohesive zone. The reduction rate of iron oxides of the pellet showed a linear correlation with EBF height at least up to the upper part of cohesive zone followed by an abrupt rise of the reduction rate within the cohesive zone. A similar trend of abrupt change in reduction rate was also noted under controlled laboratory conditions. The presence of olivine in the pellets did not display any significant impact on the extent of reduction at least up to 1100°C but increased the rate of reduction as the pellets exceeding 1100°C such as in the cohesive zone of the EBF. The effect of olivine on the reduction kinetics of iron oxides can be attributed to increased amount of molten iron oxide formation within the pellets with increasing temperature. On the basis of the extent of reduction, the excavated pellets were originated from the cohesive zone. The initial slag phase in the olivine pellets proceeded from the fayalite followed by reduction of FeO present in slag leading to precipitation of FeO lean slag with high melting point. The study established that carburization of iron-olivine pellets in the EBF is controlled by the reduction kinetics of iron oxides as carburization did not commence without completion of the reduction of iron oxides in the pellets. © 2012 by Nova Science Publishers, Inc. All rights reserved.

publication date

  • December 1, 2012

International Standard Book Number (ISBN) 13

start page

  • 67

end page

  • 92