Sticking Behavior of Burdens During Reduction Process in Gas‐Based Shaft Furnaces

Abstract

Gas‐based shaft furnaces (SFs) have garnered considerable attention because of their low CO2 emissions. The sticking behavior of their burden material influences the smooth operation of SFs. In this study, the effects of the reduction degree, temperature, and atmosphere on the sticking behavior of pellets are studied thoroughly under typical reduction conditions. The results demonstrate that the pellets will stick with each other as the reduction degree increases, the main phase of pellets at the maximum sticking index (SI) is iron, and the interconnection between iron whiskers results in the bonding phenomenon of pellets. The pellets exhibit a low SI at a relatively low reduction temperature. As the reduction temperature increases, the pellets stick, which is caused by thermal expansion and the large number of iron whiskers. With an increase in the proportion of H2 in the reducing gas, the iron particles become smaller, and the contact area between the particles decreases, effectively reducing the SI of the pellets. In general, choosing a reasonable reduction temperature and increasing the proportion of H2 in the reducing gas are helpful in controlling pellet sticking.