Improving of Productivity on Sinter Operation by Preparatory Granulation Method in High Blending Ratio of Mill Scale

Abstract

Synopsis : Mill Scale has higher iron contents and produces heat by the oxidation reaction in the sintering process. For this reason, it is expected that use of Mill Scale in the sinter operation will reduce the amount of coke breeze consumption. For the purpose of examining the influence of Mill Scale on melt penetrability and sinterability, we carried out melt penetration tests and sinter pot tests. Melt penetrability in the sintering process is an important factor that affects the quality of iron ore sinter. Our melt penetration tests lead following conclusions. Melt penetrability of Mill Scale is so high that increased blending ratio of Mill Scale causes lower permeability, which eventually leads to lower productivity. We, however, anticipated that we may be able to control the melt penetrability if we blend Mill Scale closely with iron ore which has the nature of lower melt penetrability. We arranged that a higher ratio of Mill Scale can be blended with such iron ore in proximity in the preparatory granulation method. We used the granular in the pot tests. In the result, oxidation reaction of Mill Scale was inhibited because Mill Scale contained in the pseudo-particle had reduced contact area with air. We confirmed that both permeability and productivity were improved by the method to control the melt penetrability mentioned above, even at higher blending ratio of Mill Scale.