Abstract A blast furnace of improved and more readily controllable operation which comprises three sets of tuyeres, i.e., the normal or primary tuyeres at the base or melting zone of the furnace, a second set disposed in the bosh or second zone, preferably above the middle thereof and below the mantel, and a third set of tuyeres disposed in a third zone above the bosh zone and preferably just above the mantel. The second and third tuyere sets are used to introduce reducing gas which mixes with that generated in the furnace to create, limit and control the second and third zones. The furnace atmosphere and operation are controlled and temperatures regulated in each zone to improve permeability of the burden, rate and completion of the reduction and smelting of ore to hot metal and improved utilization of the burden coke by controlled introduction of increments of reducing gases into each of the second and third sets of tuyeres and thence to the furnace zones so formed. Means of re-forming offtake stack gases and of generating reducing gas from a low cost source to provide reducing gases for such introduction are associated with the blast furnace in an advantageous embodiment. A method of operation in reducing ores, for example iron ores, and a system for such operation with production of suitable reducing gases are also provided.
THE METHOD OF TREATING OFF GASES FROM IRON PROCESSES WHICH COMPRISES ESTABLISHING A BED OF HOT SOLID CARBONACEOUS REDUCING AGENT IN A REFORMER, ADDING AN OXIDIZING GAS TO SAID REFORMER TO MAINTAIN SAID SOLID CARBONACEOUS FUEL AS A HOT BED, CONDUCTING SAID OFF GASES CONTAINING CO2 AND FINE IRON OXIDE PARTICLES TO SAID REFORMER WITHOUT AN INTERMEDIATE STEP THAT REMOVES SAID FINE PARTICLES, AND INTRODUCING SAID OFF GASES INTO THE LOWER PORTION OF SAID HOT BED OF CARBONACEOUS SOLID REDUCING AGENT, WHEREBY IRON OXIDE IS REDUCED TO METALLIC IRON AND CO2 IS CONVERTED TO CO, WITHDRAWING MOLTEN IRON FROM
Claim 2
Independent Claim
99 words
THE METHOD OF TREATING OFF GASES FROM IRON PROCESSES WHICH COMPRISES ESTABLISHING A BED OF HOT SOLID CARBONACEOUS REDUCING AGENT IN A REFORMER, ADDING AN OXIDIZING GAS TO SAID REFORMER TO MAINTAIN SAID SOLID CARBONACEOUS FUEL AS A HOT BED, CONDUCTING SAID OFF GASES CONTAINING CO2 AND FINE IRON OXIDE PARTICLES TO SAID REFORMER WITHOUT AN INTERMEDIATE STEP THAT REMOVES SAID FINE PARTICLES, AND INTRODUCING SAID OFF GASES INTO THE LOWER PORTION OF SAID HOT BED OF CARBONACEOUS SOLID REDUCING AGENT, WHEREBY IRON OXIDE IS REDUCED TO METALLIC IRON AND CO2 IS CONVERTED TO CO, WITHDRAWING MOLTEN IRON FROM
Claim 3
Dependent Claim
13 words
The method of claim 1 wherein coal is employed in said conversion furnace.
Claim 4
Dependent Claim
14 words
The method of claim 1 wherein roll scale is employed in said conversion furnace.
Claim 5
Dependent Claim
19 words
The method of claim 1 wherein off-gases from a basic oxygen steel furnace are conducted to said conversion furnace.
Claim 6
Dependent Claim
14 words
The Method of claim 1 wherein said hot carbonaceous bed also contains a flux.
Claim 7
Dependent Claim
15 words
The method of claim 1 wherein said carbonaceous bed is a bed of non-coking coal.