Study of smelting reduction iron coupled with pulverized coal gasification to produce high-concentration syngas

Abstract

The iron and steel manufacturing industry is a vital industry for a nation's economy. The traditional smelting reduction ironmaking process has the disadvantages of high consumption of lump coal and coke as well as low space utilization rate. This study proposes a smelting reduction ironmaking process coupled with pulverized coal gasification on the upper part of a smelting furnace. The proposed process is then used to prepare high-concentration reducing gas for ironmaking, and an Ouye gasifier is developed. The characteristics of multiphase turbulent reaction flow and gasification performance in an Ouye gasifier is analyzed through numerical simulation and the results are in good agreement with the industrial operational data. The results of the industrial operation show that coke consumption, total fuel, and oxygen decreases with the increase in the mass ratio of injected pulverized coal to smelting. When the coal injection ratio is 200 kg/t, coke consumption is reduced by approximately 30%, total fuel consumption is reduced by approximately 12%, total oxygen consumption is reduced by approximately 6%, and effective gas concentration at the outlet of the entrained flow bed is up to 84%. A high-quality reducing gas greatly promotes the reduction of iron oxide in the shaft furnace, reduces the reduction load of the smelting bed, and reduces coke consumption, total fuel, and oxygen. Thus, high-quality reducing gas improves the energy utilization rate of the ironmaking process. Both theoretical research and industrial practice show that smelting reduction ironmaking coupled with pulverized coal gasification produces high-quality and low-cost reducing gas and syngas for the metallurgical-chemical polygeneration system.