| A preliminary study has been made of the reduction by mixtures of CO and H₂ of natural hematite ore. Effects of gas composition, temperature, and gas flow rate on the reduction rate were studied. Preferable reduction performance was achieved with an elevated temperature, a H₂ rich gas mixture, and increased gas flow rate. Based on the preliminary work, a larger scale test in a low shaft vessel with ore burden and coke, into which an oxygen-steam blast was blown, has also been made to approach the physical chemical behavior to the practical operation. From the test, it was evaluated that shaft furnace for iron ore reduction could be shortened in its height than conventional blast furnace, since the temperature gradient in the shaft vessel was so steepened and bosh gas composition was much more powerful than that of blast furnace. A proposed sheet was attempted fox the ironmaking process with oxygen-steam blast, using cleaned top gas as an auxiliary fuel, excluding blast hot stove, causing decreased coke ratio and increased production. |
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