Mastering technology of blast furnace iron smelting using pulverized-coal fuel in the PAO NLMK BF shop № 2

Abstract

Application of pulverized-coal fuel (PCF) for coke saving is strategic direction of energy costs decreasing for iron smelting in PAO NLMK blast furnaces, which allows to change the structure of coals supply to the plant and to decrease their summarized consumption. Stages of the technology mastering considered, including period of adjusting the PCF preparation and their supplying to the blast furnaces and at the stage of charging system selection and blast regime adjustment ensuring the maximum degree of CO utilization and the specified performance. Analysis of the dynamics of coke consumption and fuel additives showed that the consumption of total carbon fuel remained almost unchanged, despite the difference in the amount of carbon supplied with natural gas and with the PCF. Calculations made by the mathematical model showed that with an increase in the PCF consumption and a decrease in the consumption of natural gas, the replacement rate of coke with natural gas increased by an average of 0.09 kg of coke per 1 cubic meter of natural gas. As a result of the iron smelting technology mastering, in the PAO NLMK BF № 2 a specific coke consumption decrease reached by more than 80 kg/t of iron and natural gas consumption decrease by more than 60 m3/t of iron. The conditions were revealed for the blast furnaces to operate as with minimum coke consumption and with maximum intensity. The blast furnaces operation in the determined regime parameters allow to decrease the fuel costs for iron production.