Method and apparatus for manufacturing sponge iron
AssigneeSKF Steel Engineering Aktiebolag
InventorSven Santen
Life of this patent
Estimating the term…
Abstract
Disclosed are a method and apparatus for manufacturing sponge iron by the continuous reduction of iron oxides in a shaft utilizing recirculation gases. Reaction gas is removed from the shaft furnace, substantially cleaned of all CO.sub.2 and H.sub.2 O, and then divided into at least two flow portions one of which is passed to a gas generator comprising a plasma burner. A reducing agent such as pit coal is injected together with an oxidant into the hot gas from the plasma burner so as to form a gas mixture comprised primarily of CO and H.sub.2, which gas mixture is then mixed with the other flow portion of the cleaned reaction gas in such proportion that the temperature of the resulting reduction gas is suitable for the reduction of iron oxides in the shaft furnace.
Claims19
A method of manufacturing sponge iron by the continuous reduction of iron oxides in a shaft furnace comprising the steps of:
- (1) removing the reaction gas from a shaft furnace;
- (2) removing from said reaction gas substantially all CO.sub.2 and H.sub.2 O;
- (3) dividing the reaction gas into at least two flow portions;
- (4) passing one of said flow portions to a gas generator comprising a plasma burner and means for injecting solid reducing agent and oxidant, and heating said reaction gas by said plasma burner and injecting into the heated gas solid reducing agent and oxidant so as to form an intermediate gas mixture comprised primarily of CO and H.sub.2 ;
- (5) maintaining said intermediate gas mixture at a temperature such that ash contained within the solid reducing agent forms a slag;
- (6) mixing said intermediate gas with at least one of said other flow portions in such proportion that the temperature of the resulting reduction gas is suitable for the reduction of iron oxides in a shaft furnace;
- (7) injecting said reduction gas into the lower portion of a shaft furnace and passing said reduction gas upwardly through said shaft furnace so as to reduce iron oxides contained in said furnace;
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- (8) removing from said furnace the reduced iron.
Apparatus for the manufacture of sponge iron by the continuous reduction of iron oxides comprising:
- (1) a shaft furnace for the reaction of iron oxides by a reduction gas comprised primarily of CO and H.sub.2 ;
- (2) means connected to the upper portion of the shaft furnace for removing reaction gas from the furnace;
- (3) cleaning means for the removal of CO.sub.2 from said reaction gas;
- (4) means for separating the cleaned reaction gas into at least two flow portions;
- (5) a gas generator for receiving at least one of said flow portions, said gas generator comprising a plasma burner and means for injecting solid reducing agent and oxidant into the gas heated by said plasma burner thereby to produce an intermediate gas mixture comprised primarily of CO and H.sub.2 ;
- (6) mixing means for the controlled mixing of said intermediate gas mixture with at least one of the other flow portions of the reaction gas thereby to obtain a reduction gas;
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- (7) means for injecting said reduction gas into the lower portion of the shaft furnace.
Dependencies are inferred from the claim text.