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US 5,234,490 AGranted
Operating a blast furnace using dried top gas
AssigneeArmco Inc.
InventorDavid M. Kundrat
Life of this patent
Estimating the term…
Abstract
Method of producing pig iron in a blast furnace. At least a portion of a top gas from a blast furnace is collected, dried and then heated to an elevated temperature preferably in the range of 900.degree.-1000.degree. C. An oxygen-enriched hydrogenaceous fuel is introduced into the furnace bosh and the heated dried top gas is introduced into the lower half of the furnace stack above the furnace bosh at a point above which the coke in the furnace is not reactive.
Claims21
A method of operating a blast furnace, comprising:
- introducing into the top of the furnace a charge containing metal oxide, coke and flux,
- collecting a top gas CO, H.sub.2, carbon dioxide and water from the furnace,
- increasing the reducing potential of said collected top gas by removing water but without removing carbon dioxide from at least a portion of said collected top gas thereby forming a dried top gas, heating said dried top gas to form a heated dried top gas,
- introducing said heated dried top gas into the lower half of the stack of the furnace at a position above which said coke is not reactive and
- introducing an oxygen-containing gas and a hydrogenaceous fuel into the bosh of the furnace whereby said metal oxide is reduced to a molten metal using said heated dried top gas.
2 more elements
A method of operating a blast furnace, comprising:
- introducing into the top of the furnace a charge containing metal oxide, coke and flux,
- collecting a top gas CO, H.sub.2, carbon dioxide and water from the furnace,
- increasing the reducing potential of said collected top gas by removing water but without removing carbon dioxide from at least a portion of said collected top gas to .ltoreq.3 vol. % thereby forming a dried top gas, heating said dried top gas, to form a heated dried top gas
- introducing said heated dried top gas into the lower half of the stack of the furnace at a position wherein the temperature of said coke is <1000.degree. C., introducing an oxygen-containing gas and a hydrogenaceous fuel into the bosh of the furnace,
- said oxygen-containing gas containing at least 70 vol. % oxygen with the balance being essentially nitrogen and
- said hydrogenaceous fuel having a molar ratio of carbon:hydrogen less than about 2.5 whereby said metal oxide is reduced to a molten metal using said heated dried top gas.
3 more elements
A method of operating a blast furnace, comprising:
- introducing into the top of the furnace a charge containing iron ore, coke and flux,
- collecting a top gas CO, H.sub.2, carbon dioxide and water from the furnace,
- increasing the reducing potential of said collected top gas by removing water but without removing carbon dioxide from at least a portion of said collected top gas to .ltoreq.3 vol. % thereby forming a dried top gas,
- said dried top gas containing CO, CO.sub.2, H.sub.2 and H.sub.2 O,
- heating said dried top gas to form a heated dried top gas to a temperature between 900.degree.-1000.degree. C., the ratio of said (CO+H.sub.2)/(CO.sub.2 +H.sub.2 O) in said heated dried top gas being .gtoreq.1.5 wherein said ratio is indicative of said reducing potential of said heated dried top gas,
- introducing said heated dried top gas into the lower half of the stack of the furnace at a position wherein the temperature of said coke is 950.degree.-1000.degree. C., introducing an oxygen-containing gas and a hydrogenaceous fuel into the bosh of the furnace,
- said oxygen-containing gas containing 70-90 vol. % oxygen, balance essentially nitrogen,
- said hydrogenaceous fuel having a molar ratio of carbon:hydrogen in the range of 0.5-2.5,
- said oxygen-containing gas and said hydrogenaceous fuel being at ambient temperature and
- the physical RAFT of the furnace being between 1750.degree.-2100.degree. C. wherein said iron ore is reduced to molten iron using said heated dried top gas.
7 more elements
Dependencies are inferred from the claim text.