(ECIC-172)Influence of Preliminary Metallization of Metallic Burden on Blast Furnace Processand Performance Parameters

摘要

The system of discrete material and thermal balancesin the radial annular cross-sections for 12 vertical and10 radial ring zones is used to describe the heat andmass transfer processes of iron ore reduction andmelting in blast furnace with respect to the variousdegree of preliminary metallization of the metallicburden. It was found that with increase in preliminarymetallization degree the heat demand on directreduction and the ratio between material and gas flowheat capacities are reduced, which leads to thedecrease in intensity of a heat transfer in the bottomsegment of the furnace. As a result, the height of thebottom segment of blast furnace is increased, whilethe height of the upper segment is decreased. Thegas isotherms move upwards, increasing heat lossesthrough the furnace top. The cohesive zone alsomoves up and increases in size. The influence ofmaterial distribution at the furnace top on parametersof blast furnace operation becomes weaker. Becauseof the decrease in the extent of direct reduction, theeffect of natural gas injection on coke rate is alsoreduced. As a result the reduction in coke rateassociated with the preliminary metallization of themetallic burden could not be fully realized if theburden metallization degree is greater than 20%.