Kinetic Analysis on Gaseous Reduction of Agglomerates, Part 1, Reaction Models for Gaseous Reduction of Agglomerates

Gaseous Reduction Model for Sinter in Consideration of Calcium Ferrite Reaction Process (Unreacted-core Shrinking Model for Six Interfaces)

“…Here, C COb , C CO(0) : CO gas concentrations in the bulk gas and at the surface of the sample particle, [12][13][14]17) Relationships among the rates shown above can be derived by seeing Table 1 and the conceptual figure for the present unreacted-core shrinking model for six interfaces, given in Ref. 18).…”

“…The diffusion rate in a gas film, in which the effect of the resistance due to the rate of gas flow 17,19) is taken into account, can be written as Eq. (1), where k g * in R g * defined by Eq.…”

“…(30)-(32) can be derived. Finally, after CO gas diffuses through the 2nd layer, it is consumed by the reduction reaction from hematite to magnetite at the reaction interface hematite/magnetite, r i [12][13][14]17) From the above-shown rate equations and relations, the expression for the overall reaction rate can be derived by eliminating unknown variables, CO concentrations at six interfaces and the surface, C CO i and C CO(0) , in order.…”

“…10) interfaces, the rate equation for each process given below can be written by making reference to the previously reported unreacted-core shrinking model for three interfaces, [12][13][14]17) as follows:…”

“…10,[15][16][17] In the present work, the unreacted-core shrinking model has been used and applied as the one for six interfaces. Although the present model is not enough to represent the reaction fashion of sinter, this model makes it possible to include the differences of chemical equilibrium and reaction rate Fig.…”