Mathematical simulation and experimental study on coke oven gas injection aimed to low carbon blast furnace ironmaking

摘要

Coke oven gas (COG) tuyere injection is recognised as one of effective measures to achieve low carbon blast furnace ironmaking. In this paper, simulation of blast furnace operation with COG injection was investigated by means of multi-fluid blast furnace model, and the softening-melting and dripping behaviours of mixed burden were studied on basis of simulation results. The model simulation shows that, with COG injection rate increasing, the concentration of inner-furnace hydrogen is enhanced obviously. Cohesive zone moves downwards and becomes thinner. The column permeability gets better. Hot metal productivity increases and CO2 emission reduces. Compared with conventional operation without COG injection, when COG injection rate is 152.34 Nm(3)/tHM, column pressure drop is decreased by 31.5% and hot metal productivity is increased by 26.36% and CO2 emission is decreased by 17.54%. Therefore, the simulation and experimental results reveal that it is achievable to improve blast furnace operation performance, such as hydrogen-enriched reduction, better column permeability, high efficiency, low carbon emission and so on.