Comprehensive mathematical model of top gas recycling-oxygen blast furnaces

A comprehensive mathematical model was established to develop a new iron-making process for a top gas recycling and oxygen blast furnace.The model consists of the calculation equations for gas composition of each area in the blast furnace,the thermal equilibrium model on the top skip area of the blast furnace,the thermo-chemical balance model,and the stack efficiency model.Operating parameters for the new iron-making process were calculated with the model.The results show that the coke rate and the coal rate of the new iron-making process are both 200 kg·t^-1,and in comparison with a traditional blast furnace,the fuel ratio decreases by 22.9%.In addition,the tuyere circulation gas quantity has great influence on the theoretical combustion temperature.When the tuyere circulation gas quantity increases by 10m³·t^-1,the theoretical combustion temperature decreases by 17.6K.Furthermore,the model could be applied to calculate the operating parameters when the raw materials and fuel conditions are different,and the change laws of operating parameters under the same raw materials and fuel conditions also could be studied with this model.