Thermochemical model of a 2-stage smelting reduction process for ironmaking

The 2-stage smelting reduction process for ironmaking without post combusti on is analyzed by a thermochemical model based on materials and energy bala nces at steady state. The influence of various parameters like composition of hot metal and its tapping temperature, degree of metallization, slag bas icity, heat losses, coal rank, proportion of limestone to dolomite, etc., o n the technological parameters like coal rate, flux rate, slag rate, oxygen rate and the export gas amount is studied. The commercial scale data of a corex plant are used to verify the model predictions. The model is found to predict the plant data satisfactorily. The effect of metallization, slag b asicity, heat loss and the proportion of limestone to dolomite is presented in terms of incremental changes on the coal rate, slag rate, flux rate, ox ygen rate and the export energy. Further, it is shown that in the combinati on of the COREX+DRI-unit, the maximum metallization of sponge iron depends on the type of coal used in the corex process.