FIELD: metallurgy. SUBSTANCE: method involves providing oxygen enrichment of first in-going gas flow introduced into furnace by utilizing oxygen-enriched gas flow from second in-going gas flow, in which first in-going gas flow is pressurized and heated before being introduced into furnace; separating second in-going gas flow by means of ion transfer module comprising ion transfer membrane having inlet side and outlet side, to produce oxygen-depleted gas flow at membrane inlet side and oxygen- enriched gas flow at membrane outlet side; introducing flow of pure gaseous oxygen or flow of oxygen-enriched gas into first in-going gas flow in any position before first in-going gas flow is introduced into furnace. EFFECT: increased efficiency in producing oxygen for enrichment of gas blasted into furnace. 10 cl, 8 dwg, 5 tbl
