Influence of High Temperature Interaction on the Softening and Melting Behaviors of Iron Bearing Materials in the Blast Furnace

摘要

>The cohesive zone in the blast furnace is largely affected by the softening and melting behaviors of ferrous burden. The Visual High Temperature Method (VHTM) has been employed, in present work, to explore the softening and melting behavior of sinter, two different types of lump ores, and one acid pellet. All iron bearing materials are observed to swell before they shrink. This observation is more dominant in case of dense structured lump ore B. The shrinking temperature intervals are different from one another. This contributes to the gas permeability of ore layer in the cohesive zone because “ore window” is formed. In addition to this, the softening and melting behavior of mixed burdens (consist of sinter and other acid materials) have also been studied. Results display that the softening and melting behavior of all materials are improved. This observation is more dominant for lump ore A. It is attributed to high temperature interactions between sinter and acid iron bearing materials. The high temperature interactivity is largely influenced by the chemical compositions, pore structure, and contact condition. Experimental results of two groups of integrated burdens verify the importance of high temperature interaction for improving the softening and melting characteristics of iron bearing materials.