| 摘要 |
PROBLEM TO BE SOLVED: To make iron effectively utilizing waste gas in a blast furnace by mixing oxygen which is obtd. by fractioning the air at extra-low temp., and the air to produce a specific composition of the air for blast furnace, fractioning strengthened blast furnace gas that CO in the blast furnace gas obtd. by burning together with hydrocarbon fuel is removed as CO2 by steam, at the extra-low temp. and directly reduction- acting the obtd. hydrogen with iron ore. SOLUTION: The oxygen separated from the air with the extra-low temp. fraction is mixed with the air to produce the air for blast furnace composed of mainly nitrogen and oxygen having 22-50 mol.% mixed with the air. The supplied air 1 is introduced into an extra-low temp. air separating plant 101 to produce the oxygen 6. The oxygen 6 is mixed with the air from the flowing 7 to produce the air 8 for blast furnace. The high temp. air 10 for blast furnace heated with a hot stove 103, together with the hydrocarbon fuel of coal, oil, natural gas, etc. are introduced into the blast furnace 104, and then the oxygen in the air 10 for blast furnace is reacted with the hydrocarbon fuel to produce reduction gas, and the iron ore is changed into the iron during raising in the furnace. |
