Because of the availability of gases from the coke production and the basic oxygen furnace (BOF) process in an integrated metallurgical plant, a project of utilization of these gases is proposed. The gases are injected into the blast furnace to substitute reducing agents like heavy oil. The aim of this paper is to study the combustion characteristics of coke oven gas (COG) and a mixture of COG and gas from the BOF.

The modeling approaches used are the thermodynamic equilibrium, the plug flow reactor (PFR) model with detailed chemistry (with and without consideration of the mixing time) and Computational Fluid Dynamic (CFD) modelling. Each approach leads to additional aspects for an improved understanding of the combustion processes.

The COG/BOF gas mixture ignites earlier than the COG gas because of its different composition. The combustion of COG leads to a higher temperature due to its higher net calorific value so that the thermal strain on the tuyere is higher. The combustion of the COG gas results in higher H2O, H2 and CO and lower O2 and CO2 concentrations.