Softening Property of Iron Ore Sinter and Its Inflence on Gas Flow in Blast Furnace

Abstract

SynopsisThe softening test under the conditions simulated an actual blast furnace and the gas permeability test for the softened sinter bed were carried out. An attempt was made to express the pressure drop in the softened sinter bed by the pressure drop equation with the first and the second order terms of gas velocity.The effects of the softening properties at high temperature on the gas flow in blast furnace were evaluated by the use of the mathematical gas flow model. The main results are as follows.(1) When the gas flow resistance obtained from the softening test at high temperature increases, the radial gas flow becomes predominant in the cohesive zone and the permeability in the blast furnace becomes worse.(2) When the high temperature properties of sinter become worse, the formation of steep inverse V-shaped cohesive zone is expected to prevent the aggravation of the permeability in the blast furnace.

Formation of Primary Slag and Carburizing Behavior of Metal Iron in Cohesive Zone of Hydrogen-rich Blast Furnace

“…Proper improvement of ore reducibility can reduce the amount of primary slag in a blast furnace, thin the cohesive zone, and significantly improve the permeability of the feed column. [30][31] However, excessive reduction before the charge enters the cohesive zone or overdrop of the cohesive zone will not only affect the assimilation process of different charges in the blast furnace 17,32) , but also shorten the physical distance and time for the fusion and homogenization of the components of dripping slag-iron. Therefore, the proper charge structure, charging mode, coke selection, slag-making system and heating system should be adjusted to ensure the forward stability of blast furnace during hydrogen enrichment operation.…”