Process for reducing iron oxide to metallic sponge iron with liquid or solid fuels

Claim 2

IN AM ORE REDUCTION PROCESS WHEREIN IRON OXIDE PARTICULATES ARE FED INTO A FIRST END OF A REDUCTION FURNACE AND REMOVED AS SUBSTANTIALLY METALLIC IRON FROM THE OPPOSITE END OF SAID FURNACE AND A REDUCING GAS IS INTRODUCED AT AN INLET IN SAID FURNACE AND A REDUCING GAS IS INTRODUCED AT AN INLET IN SAID STREAM OF REACTED GAS FROM AN OUTLET IN SAID FURNACE ADJACENT SAID FIRST END, THE IMPROVEMENT COMPRISING THE STEPS OF: PRODUCING A STREAM OF REDUCING-TYPE GAS IN A LIQUID OR SOLID GASIFIER FACILITY; PASSING AT LEAST SAID STREAM OF REACTED GAS THROUGH A COOLERSCRUBBER FACILITY PASSING SAID STREAM OF REDUCING-TYPE GAS AND SAID STREAM OF COOLED AND CLEANSED REACTED GAS THROUGH A COOLERFACILITY TO PRODUCE A GAS MIXTURE COMPOSED PRINCIPALLY OF REDUCTANTS DEFINED AS CO AND H2 WITH RESIDUAL AMOUNTS OF OXIDANTS DEFINED AS H2O AND CO2 SAID H2O PREDOMINATING OVER SAID CO2; HEATING SAID GAS MIXTURE TO A PREDETERMINED TEMPERATURE TO REACT A PORTION OF SAID CO REDUCTANTS WITH A PORTION OF SAID H2O OXIDANTS TO PRODUCE A PREDETERMINED QUANTITY OF H2 AND CO2 WHICH TRANSFORMS SAID GAS MIXTURE INTO A REDUCING GAS HAVING PREDETERMINED COMPOSITIONS OF H2, CO, H2O AND CO2; AND TRANSFERRING SAID REDUCING GAS TO SAID INLET OF SAID FURNACE.

Claim 3

The process of claim 1 wherein said reducing gas of preferred gas composition is directly introduced into said gas inlet of said furnace without further heating of said gas.

Claim 4

The process of claim 2 further including the steps of: combining said streams upstream of said CO2 removal facility; adding a controlled amount of water vapor to said gas mixture after said mixture leaves said CO2 removal facility and prior to heating same; and holding said heated mixture a sufficient time within a reactor at said predetermined temperature to establish equilibrium of the CO and H2O reaction.

Claim 5

The process of claim 3 further including the steps of: operating said CO2 removal facility at a temperature which removes substantially all of said CO2 from the said gas mixture; and cooling said reducing gas of preferred gas composition to a desired furnace inlet temperature by bleeding a regulated amount of said gas mixture downstream of said CO2 removal facility and upstream of said heater and introducing same to said reducing gas of preferred composition downstream of said reactor.

Claim 6

The process of claim 3 wherein said predetermined temperature of said reducing gas leaving said reactor is within the range of 1,400*-1,600*F., said temperature of said reducing gas entering said furnace is within the range of 1,300*-1,500*F., and said reducing gas has a composition defined by reductant ratio of H2/CO within the range of 1.0 to 2.0/1 and a minimum redUctant to oxidant ratio of H2 + CO/H2O + CO2 of approximately 9/1.

Claim 7

A process for directly reducing iron ore to metallic iron comprising the steps of: charging iron oxide particulates through the top end of a vertical reduction furnace and removing same as substantially metallic iron from the bottom end of said furnace; introducing a reducing gas of preferred composition into said furnace through a gas inlet removed from said top end of said furnace and withdrawing same as reacted gas from an outlet in said furnace adjacent said top end of said furnace; passing said reacted gas through a cooler-scrubber facility; producing a supplemental stream of reducing-type gas in a liquid or solid gasifier facility; combining said reacted, cooled and cleansed gas with said supplemental stream of gas to produce a first gas mixture; passing said first gas mixture through a CO2 removal facility to produce a second gas mixture; adding a controlled amount of water vapor to said second gas mixture in a humidifier to produce a third gas mixture composed principally of reductants defined as CO and H2 with residual amounts of oxidants defined as H2O and CO2, said H2O predominating over said CO2; heating said third gas mixture to a first temperature; holding said third gas mixture for a predetermined time within a reactor to raise said third gas mixture to a second temperature and react to approximately equilibrium a portion of said CO reductants with a portion of said H2O oxidants to transform said third gas mixture into a reducing gas having predetermined compositions of H2, CO, H2O and CO2; and transferring said reducing gas to said inlet of said furnace.

Claim 8

A process for directly reducing iron ore to metallic iron comprising the steps of: charging iron oxide particulates through the top end of a vertical reduction furnace and removing same as substantially metallic iron from the bottom end of said furnace; introducing a reducing gas of preferred composition into said furnace through a gas inlet removed from said top end of said furnace and withdrawing same as reacted gas from an outlet in said furnace adjacent said top end of said furnace; passing said reacted gas through a cooler-scrubber facility; producing a supplemental stream of reducing-type gas in a liquid or solid gasifier facility; combining said reacted, cooled and cleansed gas with said supplemental stream of gas to produce a first gas mixture; passing said first gas mixture through a CO2 removal facility to produce a second gas mixture; adding a controlled amount of water vapor to said second gas mixture in a humidifier to produce a third gas mixture composed principally of reductants defined as CO and H2 with residual amounts of oxidants defined as H2O and CO2, said H2O predominating over said CO2; heating said third gas mixture to a first temperature; holding said third gas mixture for a predetermined time within a reactor to raise said third gas mixture to a second temperature and react to approximately equilibrium a portion of said CO reductants with a portion of said H2O oxidants to transform said third gas mixture into a reducing gas having predetermined compositions of H2, CO, H2O and CO2; and transferring said reducing gas to said inlet of said furnace.

Claim 9

The process of claim 6 further including the steps of: operating said CO2 removal facility at a temperature which substantially removes said CO2 oxidants from said first gas mixture; and controlling said second temperature by the heat supplied in said heater and water vapor supplied in said humidifier to approximately equal the desired temperature of said reducing gas at said furnace inlet.

Claim 10

The process of claim 7 wherein said predetermined temperature of said reducing gas leaving said reactor is within the range of 1,400*-1,600*F., said temperature of said reducing gas entering said furnace is within the range of 1,300*-1,500*F., and said reducing gas has a composition defined by reductant ratio of H2/CO within the range of 1.0 to 2.0/1 and a minimum reductant to oxidant ratio of H2 + CO/H2O + CO2 of approximately 9/1.