Consideration on the Method for Determining the Reducibility of Iron Ores

Abstract

Reductions of iron-oxide pellets in fixed bed and single pellet with CO gas were fundamentally studiedin order to determine the reducibilities of pellets. The results are summarized as follows.
On the reduction of pellets in fixed bed with CO gas:
1) Since distribution of gas concentration changed in axial direction, reduction degree of pelletbecame different between the upper and lower layer in fixed bed. As a result, critical value of gasflow was not obtained.
2) Size of pellet affected largely its reducibility, then the size of sample should be selected to benarrow range of ± mm.
3) Both the equation of 1st order reaction proppsed by German researchers and other equations sometimeswere satisfied with the experimental values, but they must be studied in more datail to beused as the method for indicating the reducibility of pellet.
From the present experimental results, it can be concluded that method for reduction of single: pellet isto that in fixed bed because the parameters (for example, k or D) obtained from its test are able to apply the process analysis.