Effect of coal powder mass‐energy conversion efficiency on oxygen coal ironmaking and parameter optimization

Abstract

AbstractA new process of prereduction of rotary kiln‐oxygen coal combustion and melting ironmaking was developed. The core is to realize the conversion of mass and energy of pulverized coal through high‐density injection of pulverized coal and high‐density combustion in the molten pool to provide the required energy for the ironmaking process. By calculating the combined energy values of working conditions under different metallization rates (η), gas oxidation degrees (α) and blast oxygen content (μ), the pulverized coal consumption, exergy income, exergy expenditure, four gas exergy values, and process of the process system under different working conditions were analyzed. Exergy using efficiency, quantitatively evaluated the interaction between the mass‐energy conversion efficiency of coal powder and process parameters and used orthogonal analysis to determine the combination of working conditions with the highest energy utilization rate. The results show that increasing the metallization rate, gas oxidation degree, and blasting oxygen content will change the exergy value, and the exergy utilization efficiency will increase with the increase of metallization rate, gas oxidation degree, and blast oxygen content, but the various parts exergy the value does not reach the optimum with the increase of the process operating parameters. After comparing and analyzing the overall working conditions, it can be known that when the charge metallization rate is 70%, the melting furnace gas oxidation degree is 12% and the blast oxygen content is 98%, the rotary kiln‐oxygen coal combustion melting furnace has the best operating conditions and the highest energy utilization efficiency. A mathematical relationship model including metallization rate, gas oxidation degree, blast oxygen content, and process exergy utilization efficiency was established: y = η × 0.1908+α × 0.467227383+μ × 0.137069+0.522508.