Comprehensive Mathematical Model of Full Oxygen Blast Furnace and its Solution

Abstract

A comprehensive mathematical model of full blast furnace with top gas recycling was established. The model consists of the calculation equations for gas composition of four zones (hearth, belly, lower shaft. top) in the blast furnace, the thermo-chemical balance model, the energy balance model of hot stand-by zone of the blast furnace and the shaft efficiency model. By using the model, the new process was calculated. The results show that coke rate and coal rate of the new process are both 200 kg/thm, fuel rate is decreased by 22.8% compared with that of conventional blast furnace. In addition, theoretical combustion temperature decreases with increasing hearth-recycle gas quantity. Increasing of hearth-recycle gas quantity by 10 m3/thm decreases theoretical combustion temperature by 10.0 K. 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 could also be studied with this model.