Control of Peripheral Gas Flow and Design of Burden Quality for Low Reducing Agent Rate Operation of Blast Furnace

Abstract

Concepts and targets of operational conditions and burden qualities for reduction of exhaust carbon dioxide (CO₂) are discussed with consideration of an energy balance at Steel works. Lowering a reducing agent rate (RAR) with reduction of a heat loss and increase in a shaft efficiency is desirable measures to decrease in the exhaust CO₂. Suppressed gas flow at a peripheral part of furnace contributes to improvement of both heat loss and shaft efficiency, however, promoted gas flow at that part is necessary for a stable state of gas permeability with low quality burden against degradation behavior. To apply for the operational design, effects of sinter RDI and coke TI on the RAR and exhaust CO₂ through the changes in peripheral gas flow are clarified on the basis of analyses of the operational results and simulations by using of the mathematical model. For example, improvement with -10.4% of RDI and 0.69% of TI contributes the reduction of RAR by 10 kg/t through changes of heat loss by 78.3 MJ/t and shaft efficiency by 0.014.