BLAST-FURNACE SMELTING METHOD Russian patent published in 2019 - IPC C21B5/00 

FIELD: metallurgy.

SUBSTANCE: invention relates to blast-furnace smelting. Ore material and coke are periodically loaded into blast furnace, composition and amount of ore materials and coke is controlled, additional fuel flow blown through tuyeres into furnace hearth, blow, chemical composition of furnace gas and melting products, temperature of cast iron, actual carbon content in cast iron. At that, saturated content of carbon in cast iron of each outlet is determined. Ratio of actual content of carbon in cast iron to saturated is maintained in interval (C_a/C_m) 0.92–0.98 by controlling natural gas flow rate. With reduction of ratio C_a/C_m below 0.92 natural gas flow rate is increased by 2.0–10.0 m³/t of cast iron for each 0.01 reduction of said ratio while maintaining oxygen content in blowing. When ratio (C_a/C_m) is increased more than 0.98 natural gas flow is reduced by 0.2–2.0 m³/t of cast iron for each 0.01 increase in said ratio while maintaining oxygen content in blowing.

EFFECT: improvement of filtration processes of melting products through coke nozzle and saving of reference fuel.

1 cl, 2 tbl, 1 dwg