CA2024237A1 - Apparatus for producing quality steel directly from iron ores - Google Patents

Abstract

ABSTRACT OF THE INVENTION
The apparatus of the present invention is for producing quality steel directly from iron ores with reducing gas. The apparatus comprises three vessels: (1) a primary reduction vessel, (2) a reducing gas production vessel and (3) a secondary or final reduction vessel. (3) is a high temperature vessel having two hoppers at the top, one into which the partially reduced iron ores are introduced by a conveyor from the bottom of vessel (1), and the other for holding the iron ores and slag ingredients. Molten steel and slag floating on it collect in the bottom where they are held prior to batch withdrawal. Conduits are provided in the wall of vessel (3) (a) to withdraw molten steel and (b) to withdraw molten slag. A plurality of tuyers having arcuate ends are rotatably mounted in the wall above the molten slag layer for introducing (1) oxygen, (11) coke and (iii) reducing gas. By rotating the tuyers, the angle of introduction of the fluid ingredients can be changed to cause them to impinge on the surface of the slag and cause it to rotate clockwise or counterclockwise. The coke and oxygen react to form a reducing gas that rises countercurrent to descending partially reduced iron ores and slag ingredients and flows from the top of the high temperature vessel into the gas production vessel where waste heat is utilized to convert carbonaceous materials, steam and carbon dioxide into hot, strong reducing gas comprising hydrogen and carbon monoxide. Conduits are provided to conduct (1) this gas to (a) the primary and (b) the secondary reduction vessels and (2) sulfur and phosphorus vapors to recovery vessels.

Description

APPARATUS FOR PRODUCING OUALITY STEEL
~- DIRECTLY FROM IRON ORES
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The present invention relales to improved apparatus for producing quality steel directly ~rom iron ores which is more ~uel e~ficient and less expensive than apparatus now in use. More particularly, the apparatus of the invention is much less expensive than presently known equipment and makes possible the production o~ a given quanity of high quality steel using less luel, enables the cost o~ maintenance to be substantially ' , reduced, and requires tar less manpower. Moreover, the apparatus -produces steel o~ high c~uality because the level of impurities is readily controlled and desirable alloying ingredients can be added to d~sirable levels.

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BACKGROUND OF THE INVENnON
~' In conventional steel-making operations, iron oxide ores are reduced, to the metallic stage in a highly carbonaceous environment in a bl2st ','- furnace. This environment results in raising the carbon level in the hot '1 '' ~`r ~ metal bath ~ar above the desired level for quality steel and results in the production of silicon and indirectly contirbutes to the presence in the hot metal o~ higher percentages of other detrimental impurities :han! were ~' they reduced and mel~ed in an atmosphere relatively /ree o/ carbon.

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Because of the nature and operation of the blast furnace, virtually all of the phoshorus that enters the furnace in drawn of~ in solution in the hot metal as an impurity which, with present customary methods, is difficult and expensive to remove and results in losses of metals that must be oxidized in the slag bath ~o aid in the removal of this highly detrimental impurity. It also results at times in producing heats of steel use~ul only as scrap.
In conventional blast furnace operations, coke, iron ore and fluxing compounds are charged in the iop of the fumace in amounts which substantially fill the entire inner cavity. A blast o~ preheated air, which may be supplemented or enriched by oxygen and is introduced at the bottom of the furnace through tuyeres, suppons combustion of the coke in `
this region of the furnace, producin~ much heat energy and ultimately producing carbon monoxide which is the main reducing agent in the blast : :~
furnace operation. As the reducing gas reacts with the iron oxides, it produces carbon dioxide, melted iron or partially reduced iron oxides and ;releases some quantitiss of heat ener~y. ~;Where temperatures are sufficiently high, carbon may react directly with iron oxide to produce carbon dioxide and metallic iron. This carbon dioxide may react with the carbon to form more carbon monoxide. These two reactions absorb large quantities of energy and impart a cooling ~ ~
effect which soon lowers the temperature of the charge and blast, as the ~ ;
~as ascends up through the burden, below an effective reaction ',temperature. ~ ., The fluxing compound, usually calcium carbonate with or without manganese carbonate, absorbs large quantities of energy as it decomposes or calcines. Carbon dioxide is released in this decomposition which further reacts with the.free carbon absorbing much energy and carrying fuel away as carbon monoxide in the top gas. Undesirable impurities ~
including excessive carbon, phosphorus, silicon and sulfur remain in the . . .
metal which is drawn off at the bottom of the blast furnaces.

2024~37 Expensive equipment such as Bessemer converters, open hearth ~urnaces, and electric furnaces have been developed in which expensive operations, including basic oxygen processes, are carried out for the - -purpose of reducing these undesirable impurities to acceptable levels.
Each of these operations is expensive and has limitations as to ~he amounts of the various impurities it can economically remove and the quality and types of steel each can produce.
The Coke which is needed for the process is produced in the conventional coking process by destructive distillation of a blend of pulverized coal in an air-free refractory-lined oven. Heat from the firing chambers into the interior of the ovens is transferred through these refractory linings which are thick enough to result in low efficiency in the transfer of heat. As the distillation proceeds, the more volatile products are driven off first and the less volatile and heavy products remain, including a large portion of the free sulfur.
Temperatures reached in the coking process are sufficiently high to volatilize sulfur in the coal but because of its high density (eight times the density of air) most of it remains as a residue in the coke unless there is some means of propelling it from the heated coke in the oven.
Approximately 90% of the sulfur that enters the blast furnace comes trom the sulfur residue in the coke. Sulfur is a very difficult impurity to remove from molten iron or steel. The coking oven process is very ~ -inefficient an has been tolerated only because it can recover all the carbon and by products char~ed into it and it can utilize the abundant and excessive top gas produced in the blast furnace operation of reducing and melting viffln iron. However the over all fuel efficiency of the t~vo combined processes is still low and coke is expensive and a premium for both chemical use and the production of virgin cast iron.
To relieve this condition there have been several methods developed to produce virgin metallic iron direct from the ore without using pre-coked coal (D.R.I.). Some processes produce sponge iron; others produce a molten ~ cast iron.

2024~37 The one, sponge iron, supplements the demand for scrap iron;! the other supplements the demand tor blast furnace hot metal. Although these (D.R.I ) processes do eliminate the need of the coking process there still remains the need for secondary refining and the liquification of the sponge metallics. The process of this invention accomplishes all that the other D.R.I. processes accomplish plus it has the capability of ~;
re~ining the metallics to high qualities of molten steel. This is accomplished while recovering the energy in the high temperature gases required to melt and raise the steel to casting temperatures and eliminates the waste o~ fuel consumed while removing excessive carbon and accompanying impurities, resulting in a process that is tuel, ~ -facility, and labor efficient in the production of a relatively pure hot metal, that can be readily alloyed to desired specifications, ready for casting. A process which directly reduces steel (D.R.S.) trom iron ore with coal as the primary source fuel.

SUMMARY OF THE INVENTION

The apparatus of the invention has a number of important features. .
One of these features is the apparatus for producing quality steel directly from iron ore which comprises (1) means for reducing iron ores under conditions which produce an oxidizing molten metal bath, and (2) means for maintainin~ said bath as an oxidizing molten metal bath during moltdown of a heat of steel. The operations carried out in this apparatus result in eliminating excessive carbon, phosphorus, sulfur and stops the ; -production of silicon in the steel.
Another important feature is the apparatus for producing quality steel directly from iron ores which comprises (1) means for reducing iron ores under conditions which produce an oxidizing molten metal bath, (2) -- - ~ -means for introducing coke and oxygen above said molten metal bath, and (3) means for introducing superheated reducing gas into said molten metal to remove all oxygen from the bath. The operations carried out in this ~ ~ -apparatus result in the elimination of excessive impurities and give the heat of steel the ability to maintain proper chemical and physical characteristics.

Another feature of the apparatus of the invention is that the i means are provided to carry out the steps of reducing iron oxide under conditions which produce an oxidizing molten metal bath. The apparatus may comprise (a) means for first reducing iron ores under conditions which produce a carbonaceous molten meta! bath and (b) means in which said carbonaceous metal bath may be treated ~o change it ~o an oxidizing molten metal bath. A further feature of the apparatus of the invention is to provide means for converting waste heat in the gas flowing from a high temperature melt down vessel to chemical energy by introducing the gases into a vessel containing carbonaceous material, steam and carbon dioxide to convert them to hydrogen and carbon monoxide. The apparatus further comprises means for utilizing heat released trom the combustion of carbonaceous and hydrocarbon material with oxygen to generate reducing gas and form a melt of metal and slag. A further aspect of the apparatus is the means for limiting the temperature rise in the reducing gas formed -' by an endothermic reaction comprises means for introducing heat absorbing oxidizers into the carbonaceous and hydrocarbon material, and ~-thusly produce reducin~ gas and absorbing heat.
The apparatus further contemplates the means for blending heat-absorb;ng oxidizers in the melt down and primary gas generation zone and the secondary gas generation zone to moderate temperatures in the ~eneration zone and also in a vessel in which primary reduction of the ores is accomplished. The apparatus still further contemplates means for moderatin~ temperatures in a primary reduction vessel by introducin~
reactants such as carbon and hydrocarbons which react with partially oxidized reducing gases. This converts heat energy to chemical energy and revitalizes the reducing gases.
The invenUon also contemPIates means for cooling the reducing gases in a carbonaceous zone and means for introducing steam or carbon dioxide or a blend of both of them to convert heat energy from the -exothermic reaction to chemical energy in an endothermic reaction and ~ ~
thus prod,uce more reducing gas and lowering the temperature suitable for ~;
introduction into the primary reduction zone.
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A further aspect of the invention involves providing means ~or filtering the colloidal particles in the exhaust gases from the high temperature melt -down vessel by passing them through a layer of coke and coal while converting waste heat to chemical energy and coking the coal. An important advantage of the invention is the removal of sulphur from coke and coal by vaporizing and conveying it away with a superheated forced draft.
The apparatus of the invention further provides means for .
accomplishing the removal of phosphorus from the metallic bath by ;
maintaining an oxidizing metal bath which transfers the phosphorus from ;
the metal bath to a carbonizing slag bath. It also accomplishes the `:
removal of phosphorus from the slag bath by reducing it in a carbonaceous ~:
high-temperature atmosphere, conveyin~ the vapor out of the system with a reducing forced draft.
The apparatus still further contemplates means for introducing -partially reduced ores and slag ingredients into the upper part of a high- : ~
temperatùre melt down zone while coke or hydrocarbon fuel, oxygen, ~-steam, carbon dioxide, and recirculating gases are introduced into the lower region of said zone well below the point of introduction of the partially reduced ores and slag ingredients so that the reducing gases pass upwardly therethrough and thereby continues to reduce the partially ~ ~.
reduced ores to molten metal and forms a molten metallic and slag bath at -the bottom of the high temperature zone.
Finally, the apparatus contemplates means for introducing the reducing gases formed in the apparatus just stated partially into the ; ~
metallic and slag bath removing excessive oxygen therein and partially ::
above the slag layer. The apparatus of the invention combines the means for accomplishing the coking, blast furnace and open hearth operations in a single apparatus in which the combined effect of each of the phases compliments the others and produces hot metal relatively free of irnpurities in larger quantities and consumes less quantities of fuel. The reactants carbon dioxide and carbon or hydrocarbons are utilized to control excessive energy and produce highly concentrated reducing gas in ;:
the primary reduction vessel. What reactants are not utilized are discharged as à waste gas which does not remove other fuel potential ; :
with it. Among the advantages made possible by the present invention -over known apparatus are the following;
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Fuel consumption is reduced and the use of bituminous coal or other low quality fuels, which are more abundant and less expensive than anthracite coal, is made possible.
B. With only slight alterations, oil shale may be used as an alternate tuel and produce oil products.
C. A top gas may be produced which is high in thermal rating and may be used advantageously in other parts of the equipment as a heating gas.
D. Sintering plants are not needed because the apparatus can utilize finely divided ores. Finely divided ores not only augment the capacity of the furnace but they provide a greater surface for the reducing gas to work on and a smaller distance for the gases to penetrate to the center of the particles which escalates the reducin~ process.
E. The open hearth process and all other secondary refining furnaces are eliminated by the apparatus for directly reducing steel (D.R.S.).
F. The capacity of the furnace is augmented by the production of a highly concentrated reducing gas which can control the temperature ranges in various zones and, in particular, extend the reducing zone.
G. Reduces maintenance costs by providing less complex mechanical equipment and by conducting the processes therein so as not to deteriorate it, which results in less expense to maintain.
H, Reduces thermal losses by conducting the reduction in a smaller furnace and generates reducing gas by utilizing heat generated in the high temperature furnace of the melt down zone.
1. Balances the thermal reactions by the dynamic design and shape of the furnace and the nature of the reducing gas.
J. Reduces flu dust by reducing the volume of gas flowing through the furnace and filters the outflowing gas to reclaim what small panicles are entrained.
K, Eliminated the problem of banking furnaces and maintaining temperature in coke oven when not needed by having a dynamic charge which is adjusted easily or staned and stopped with ease, and cokins is accomplished by utilizing heat from the high tèmperature vessel. ~`
L. Eliminated heat loss from latent heat carried off by inert nitrogen gas in prior steel-making equipment which utilized air-supported combustion and reduction phases. ` - ~
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t~; Eliminated channeling of gas in the ~urnace by use o~ a dynamic -charge as opposed to the present stagnant burden through the more porous regions o~ which the gases pass with great speed.
N. Eliminates sulfur from the fuel by providing means for vaporizing and removing it by a high temperature forced draft.
O Eliminates the phosphorus by providing means to receive it in vapor `form atter reduction trorn the slag and condensing it in the by-product area.
P. Eliminates the production of iron nitrides by providing the means to use relatively pure oxygen rather than air.
Q. Eliminates the need for an extensive cooling system by providing means adapted for more efticient utilization and distribution ot the heat -~
in the high temperature area of the furnace. ~ -R. The apparatus produces a concentrated reducing gas which requires relatively small amounts of relatively pure oxygen.
S. The apparatus eliminates the need for pelletizing plants for concentrated ores although pelletized ores can also be used.
T. The apparatus reduces the amount of air pollution. ' -U. The apparatus oxydizes any pyrites that may occur in the ores used while the ores are bein~ preheated and sulfur in the ore is eliminated. `
V. Large savings in cost of refractories are realized because the ~ ~:
interior of the hi~h temperature vessel is continually being relined by the solid reactants as they enter the vessel, and the heat of their fusion absotbs ener~y, reducing the temperatures of the refractories lining below the melting point. ;~

; , ' , ~ , BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described and illustrated in conjunction with thedrawing in which:
Fig. 1 is a vertical schematic sectional view of the apparatus of the invention;
Fig. 2 is a partial vertical sectional view of the high temperature vessel in which final reduction and melt down takes place showing angular direction of introduction of gas;
Fig. 3 is a cross sectional view on the line 3--3 of Fig. 2;
Fig. 4 is a partial vertical section of the lower end of said vessel showing the shape of a nozzle partly in longitudinal section for introducing the gas into the vessel through a tuyere at various angles produced by rotation of the nozzle, and;
Fig. 5 is a sectional detailed view of alteration in apparatus for process of implementing oil shale as a fuel.
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2Q24237 ~ ~
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DETAILED DESCRIP~ION OF THE APPARATUS OF THE INVENTION
, The preferred apparatus of the invention comprises means ~or carrying out the steps of (1) preheating finely divided iron ore with ~:
tailings of a reduction gas; (2) destructive distillation of powdered coal :
and convertin~ it to powdered coke; (3 ) generating a reducing gas from the powdered coke in the primary or the secondary generation vessels (4) subjecting the preheated ore to primary reduction by said reducing gas; (5) ;
admixing the pre-reduced ore with fluxing compounds in the top of the high : ~:
temperature vessel (6) inject powdered coke into the bottom of high ~::
temperature vessel with conveying recirculated reducing gas; (7) blowing ~.
oxygen into said coke and gas (a) to produce a hi~h temperature zone by ~ -oxidizing coke to carbon monoxide and carbon dioxide (b) to melt and :
reduce the partially pre-reduced ore to molten metal with the heat of :~
reaction of the generated gases (c) to form a slag; (8) pooling the molten metal under the slag to refine it and achieving sufficiently high .
temperatures for tappin~ and casting the steel; (9) separately removing slag and re~ined molten metal; (10) (a) withdrawing gaseous products from the high temperature zone, (b) separatin~ the gaseous products from any entrained dust particles, (c) Introducing a portion of the gaseous products into the destructive distillation chamber of the carbonaceous vessel, and (d) admixing the dust particles with the coke after cokins;
(11) introducing the remainder of the gaseous products from the high tempetature vessel to the secondary gas ~eneration chambers of the carbonaceous vessel and conditioning it for use in (a) primary reduction -:
vessel (b) reuse in the hi~h temperature vessel (c) or for storage; (12) ~:dischar~in~ waste ~as from the primary reduction zone; and ~13) discharging coal ~as from the carbonaceous vessel to the by-product recover~ facilities.
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~ 1, .'' ~' 2Q2~237 The apparatus comprises means in which each step of the process may be carried out including (A) a primary reduction vessel; (B) a carbonaceous vessel for destructive distillation of coal and secondary reducing gases generalion; (C) a high temperature vessel, which has several functions, (!), for the primary reducing gas generation, (Il) for final reducing pre-reduced ores, (Ill), to melt the materials, (IV), to refine the material, and' (V) to heat molten metal to tapping and casting `
temperature; (D) means for the diversion of gases flowing from the high temperature vessel 130 to the secondary gas generation chamber 90 or to the cokin~ zone 78 (E) means for conducting primarily reduced ore from the - ~
primary reduction vessel to the hopper at the top o~ the high temperature ''-~;
vessel, mixin~ it with calcium and man~anese oxides or carbonates and introducing the mixture into the high temperature vessel; (F) means~ for . ' withdrawin~ ~as from the hi~h temperatur~ vessel, separating any entrained particles in it (G) means tor subjectin~ coal to destructive ' distillation with the waste heat from the hi~h temperature vessel and conveyin~ the by-products away for processing (H) means for ~eneratin~ a ' ' "' reducing gas from the waste gas and waste heat emitted from the hi~h i '" ' "
temperature vessel in the carbonaceous vessel (I) means for circulating `' gas withdrawn from the secondary gas ~eneration zone, (i) to the primary reduction zone, (ii) to the bottom of the high temperature melt down and '~'~h' `
gas~generation zone, (iii) or for storage; U) means for introducin~ fuel ( i.e. , ooke or hydrocarbons) from the carbonaceous vessel with a conveyin~
recirculating ~as into the bottom zone of the high temperature vessel; (k) "~
means tor~ withdrawino gas trom the primary reduction vessel, and (L) i~
means~ for preheatin~ ores prior to subjecting them to reduction.
Referring now more pàrticularly to Fi~. 1 ot the drawings, reference 'i'',' ; `number 10 represents a primary ore reduction vessel, 70 a coking vessel ~; '` ,"
t or the destructive distillation~ of' coal and a secondary reducing ~as '':'a~
oen~ration and 130 a high temperature vessel for primary~as ~eneration, the final reduction, the meltdown of con!in~encies and,refining and ,~ ;,,'J,~ ,i,,;,."
M; ~ ; conditioning the heat for casting~

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The primary ore reduction vessel 10 comprises an upright casing 11 ~:
havin~ a hopper 12 at the top to receive powdered ore. The hopper 12 incl udes funnel-shaped bottom wall 14 with a central outlet 16 at the upper end of a short passage 17 leading to a preheating zone 18. The passa~e 17 must have some means of preserving a pressure differential between zone 18 and the atmosphere.
The pressure preservin~ means may be provided by any suitable me~:hanism, e.g., a conventional gas lock as illustrated, a fluidized system tor ~onveyin~ finely divided ore into hopper 12, and the like. Where the pas~a~e is provided with a gas lock, it may comprise an independently movable upper bell 13 closable against a suitable seal at the bottom of pas~a~e 17, an inverted frustoconical chamber 19 havin~ its upper per;phery secured to a wall 20 slopin~ down from passage 17 and its low~r end lormin~ a seal with a lower bell 15 closable against the mouth of chamber. 19. Bell 13 has a hollow operating rod 13a connected to it.
Bell 15 has an operating rod 15a connected to it which passes up through hollow rod 1 3a. ..
Each operatin~ rod extends upwardly far enough for an operator or mechanism to move the bells up and down. In use, the upper bell is low~red to permit matetial entering the vessel 10 to fill the chamber 19, rais~d to close the inlet into it, the lower bell is lowered to permit the ~ .
mat~tial in chamber 19 to flow into the zone 18, and then the lower bell is raised against its seat. Where a fluidized system is used, it would be sim~lar to the fluidized system for vessel 152, as descri~ed hereafter. ~.
Ors puticles tlowin~ through chamber 19 enter the preheatin~ zone 18 in which said upper wall 20 slope6 downwardly to wall 11 to which it is s-c4rod. Tho enterin~ particles fall into a centrally located distributing mea~s 22 in the form of an upper inverted cone and a series of spaced inv~lted truncated cones of increasin~ diameter to direct the downwardly moving ore particles outwardly toward the casing 11 and onto a funnel-shaped bottom wall 24 with a central outlet 26. :

, 2Q2~237 The openings between the truncated cones permit gasses (I) to flow outwardly into and upwardly through the preheating zone in contact with the free sur~aces of ore particles (Il) into the free space formed above the upper level of ore particles by the casing 11 and the wall 20 and (Ill) out ~-into a waste gas conduit 28 connected to a flue (not shown). A valve 30 is preferably provided in conduit 28 to control the flow of gases through it.
An air inlet pipe 32 is provided in casing 11 to conduct air into the space formed by the inverted truncated cones from which it flows into the powdered ore surrounding the distributing means 22. A gas inlet pipe 34 :
is also provided in casing 11 to conduct hot gas from a source to be described into the same space and into the powdered ore. Pipe 34 preterably is provided with a valve 35 to control the flow o~ the hot gas through it. Preheated ore particles flowing from the preheating zcne 18 through outlet 26 enter a primary reduction zone 36 of which the upper ~-wall preferably is the bottom wall 24 of the preheating zone. The structure provides a passageway between the upper wall 24 and upper surface of the par~icles introduced into chamber 36 through outlet 26. A ~;
gas outlet pipe 37 is provided which communicates with this passageway through wall 11 to withdraw gases therefrom. The gaseous discharge through conduit 37 will be largely carbon dioxide and water vapor with a 1 small percentage of carbon monoxide and hydrogen. Gas inlet pipe 34 ~-receives the ~ases it supplies to preheating zone 18 from outlet pipe 37 - ~. Y.
and these gases have both latent heat and reducing gases that are of :
significant value as a fuel when oxidized with air from inlet pipe 32.
Gases flowin~ out of zone 36 through conduit 37 which are not diverted ~;
into pipe 34 ma~ either; be used as alternate fuels or stored for future use.
The lower wall 38 of zone 36 is a downwardly sloping helix of spaced, contracting turns of a metal ribbon.
This structure forms a funnel shaped, contracting bottom wall -- .
having a central outlet 4û. Near the midpoint of zone 36 is a distributing ;means 42 which is similar in structure and function to distributing means .;
22. The casing 11 is provided with a cooling agent inlet pipe 44a, the ~;
inner end of which terminates under the distributing means 42. ~:
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202~237 A further primary reduction zone 46 is provided below zone 36 into :.
which the ore particles flow through outlet 40 onto a distributing means . :
48 similar in structure and function to distributing means 22. The upper wall ot zone 46 preferably is the lower wall 38 of zone 36 and its bottom wall is a helix 50 ~imilar in structure to helix 38 and which has a central outlet opening 52. Helix 50 is spaced somewhat above the bottom, funnel-shaped wall 54 of the casing 11 which has an outlet opening 56 connected to one end of a conduit 58 whose function will be described hereinafter. .
Casing 11 is preferably provided with additional cooling agent inlet pipes 44b, 44c, and 44d. Pipe 44b terminates in the passageway under the bottom wall 38 and above the upper level of particles in zone 46. Pipe 44c .
terminates in the open space under distributing means 48. Pipe 44d -.
terminates in the space between the bottom helix 5û and bottom wall 54.
Cooling agent inlet pipes 44a, 44b, 44c and 44d may have a common manifold (not shown) connected to a source of cooling agent, if desired, or . .
they may be individually supplied with one or more cooling agents from one or more sources thereof. Casin~ 11 has an inlet opening 64 into the space between the bottom helix 50 and bottom wall 54 for a conduit 118 having a valve 68a, 68b, and 121b therein for a purpose described ::
hereinafter. The ores introduced at the top of vessel 10, after treatment in it, are discharged through conduit 68.
.. Means must be provided at this outlet to preserve the pressure ditferential between the inside of vessel 10 and the atmosphere, just as means mùst be provided for passage 17, as described above. Here again a conventional gas lock may be provided as illustrated schematically but preferably a fluidize.d conveying system is provided by a feed screw 58a to move ore particles from outlet openin~ 56 to a downward duct 58b where they are fluidized by a jet of gas from a venturi 58c and thereby caused to flow through conduit 58d into hopper 152 which is later described in detail~ The fluidizing gas which conveys the ore particles from outlet 56 into hopper 152 is returned from the hopper 152 by conduit , . i 58e with the aid of pump P to venturi 58c. The fluidized system will a!so maintain the proper pressure in vessel 10 when the pressure in vessel ~30 ~ ;
is lower or higher than the pressure in vessel ~0. The vessel 70 comprises a~ upri~ht casing 71 having a hopper 72 with a funnel-shaped .
bottom wall 74 at the upper end thereof to receive powdered coal. .

2~24237 ;~
While any coal may be used, one advantage o~ the present inY/ention is the low grade or bituminous coal, which is much cheaper than anthracite, may be use satisfactorily. The bottom wall 74 of hopper 72 ~
has a central outlet passage 76 leading to a coking zone 78. The passage ~ ~:
76, like passage 17, must have some means to preserve a pressure differential between zone 78 and the atmosphere. This pressure preserving means may be provided by any suitable structure, e.g., a gas lack as schematically illustrated having parts like those for hopper 12, or ~-;
a fluidized system to supply the finely divided materials, somewhat ~luidized system supply the finely divided materials, somewhat like parts 58, 58a, and 58b. The upper wall of zone 78 preferably is an inverted ; -frustoconical wall 80 connected at its outer periphery with casing 71 and ~;
at its inner periphery to the outlet 76 somewhat above its lower end to ;
provide an essentially free space or flow channel immediately below it. ~;
Particles flowing through outlet 76 into zone 78 ~all upon a centrally located diverter 81 similar in structure and function to 22, 42, ~ ~
and 48 in casing 11. The bottom wall of zone 78 is a helix 82, similar in ; ;
structure and function to helix 38 in vessel 10. It has an outlet opening :
84 and is spaced somewhat above a funnel-shaped dividing wall 86 in the casing to which its outer periphery is connected. It is provided with a ~ :
central outlet opening 88 aligned with opening 84 to permit flow of particles from zone 78 into a first intermediate zone 88a in which there ;
is a distributor 81a, a helix 82a, and a funnel-shaped bottom wall 86a. ~-~
Preferable the bottom wall 86a serves also as a gas inlet by means of a ~ ~ n spaced under wall 86b for a purpose later described. The material flowing out of he first intermediate zone 88a enters a second intermediate zone 88b in which there is a distributor 81b, a helix 82b, and a double bottom wall 86c and 86d, all similar in structure to the parts of the first intermediate zone 88a. ~:
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2Q2~237 The material flowing out of the second intermediate channel 88b flows into a lower zone 90 and onto a distributing means 92 of similar structure to distributing means 22. The bottom wall of zone 90 is a helix 94, similar in structure and function to helix 50 in vessel 10. and it has an outlet opening 96. Helix 94 is spaced somewhat above the bottom wall 98 of casing 71 which preferably is funne!-shaped with and outlet opening 10û connected to a conduit ~02 having a mechanical feed 104 therein for a purpose to be described hereinafter. Conduit 102 connects outlet 100 to the inlet of a ball mill 105 which discharges into line 120, as more fully described hereinafter.
A coal gas outlet line 106 communicates through the upper wall 80 with the space in coking zone 78 between wall 80 and the upper surface of the powdered coal. Its purpose is to permit coal gas to pass through casing 71 to the exterior and to conduct it to a by-product recovery means ~not shown). Line 106 preferably is provided with a valve 108 to control flow of gas therethrough.
The central openings in helix 82a and helix 82b are smaller in diameter than the central openings in plates 86a and 86b of the first intetmediate zone 88a and the plates 86a and 86b of the second intermediate zone 8Bb so that the stream o~ particles flowing from the first intermediate zone 88a into the second intermediate zone 88b and from the second intermediate zone 88b into the lower zone 90 leaves a space between it and the periphery of the central openings in which 86b and 86d for gas to flow upwardly from zone 90 into zone 88b and from ~
zone 88b into` zone 88a. The lower plates 86b and 86d extend somewhat ~ ~ .
further inwardly than upper plates 86a and 86c so that gas flowing throu~h the space between them flows only upwardly into the zone above it.

2 0 2 ~ 2 3 7 The object of the structure in the lower zones o~ vessel 70 Just described is (1) to permit the hot gasses introduced into zone 90 from the high temperature vessel 130 to react with the portions of CO2 and H20 contained therein and somewhat cool them chemically by reacting with the coke or hydrocarbons and regenerating these portions of CO2 and H20 to CO and H2; then allowing these gasses to be withdrawn to zone 88b or line 110 as a conveying and reducing gas to vessel 130. (2) to permit ~ ~;
introduction of C02 and/or steam into the hot rising gases from zone 90 to cool it chemically by reacting with the coke or hydrocarbons to an intermediate temperature before being withdrawn from zone 88b through conduit 110b by means of fan 114b and introduced through passage 118, valve 68b into the lower part of vessel 10 as described above, and (3) to permit funher introduction of C02 and/or steam into the partially cooled gases from zone 88b flowing into zone 88a and from it through conduit ~- ~
110a by means of pump 114a to cool these gases as cool as can be ~ -achieved by chemical means for storage in vessel 121. Gases may also be -scrubbed with water before being stored if desired, permitting further , --cooling (not shown). ;`
In the event that the gas flowing through conduit 118 from the second intermediate zone 88b is at a hi9het temperature than desired, it ~ -may be physically cooled to a desired temperature by blendin~ it (1) in : `
conduit 118 with gas stored in 121 which flows through passage 121a and ~ ` ~
valve 121b by means of pump 114c, and (2) with gas from the first ~ ~-intermediate zone 88a withdrawn by pump 114a through conduit 110a and ' ~ -introduced into passa~eway 118, throu~h passageway 120b controlled by ~;
valve 68a.
The apparatus enables an operator to have full control over the ~
temperature of the ~as enterin~ the bottom of vessel 10 by the simple ~;
expedient of opening valves and operatins pumps. If desired, temperature ~ `
probes (not snown) may be used with meters (not shown) to electrically monitor temperatures in various strategic locations. Operations may also ~;
be automated by programmable controls (not shown). A line 122 communicates with vessel 130 by way of line 120 to supply steam from a ~ ~;
suitable scurce (not shown) into the combustion zone in high ~emperature vessel 130. Line 122 has a valve 12~ therein to control the flow of steam into ~essel 130. ,;
, '.''..'' "
' "' ';

2~4237 A line 124 also communicates with vessel 130 by way o~ line 120 to permit introduction into vessel 130 of fluxing and purifying ingredients trom a suitable source (not shown). Line 120 has a valve 128 in it in advance of the inlet into it of the discharge trom the ball mill 105. Valve 128 enables the tlow of gas from chamber 90 in vessel 70 into vessel 130 to be controlled. Valves 128, 68a and 68b, and 68 control the divisions of the gas leaving secondary gas generation chambers 90, 88a, and 88b in vessel 70 into proper portions which flow, respectively, to the combustion and melt down zone in the bottom of the high temperature vessel 130, to the primary reduction zone 46 in vessel 10, or for storage in storage unit 121 to give (1) gases flowing through valve 128 conveys fuel and assists in the process of full reduction and melt down at relatively high temperatures in vessel 130, (2) blending a tempered reducing gas with gas coming from chambers 88a and 88b ~or primary reduction of ores at optimum temperaSures in zone 46 of vessel 10, (3) : ~
continuation of process in vessel 1û when vessel 130 is batching out. ~ ~-Recirculating gas flowing through conduit 110 from chamber 90 and outlet gas of vessel 70 generated in vessels 130 and 70 in excess of the -quantity drawn off through conduit 110a, 110b, and 118 which flows to zone 46 of vessel 10, is conducted into upper destructive distillation zone 78 of carbonaceous vessel and emitted through line 106 and may also be drawn off through line 120a under control of valve 68 for storage in tank 121 for further use, as described. Gas flowing through valve 128 passes through a venturi 128a where it fluidizes the fine particles from ball mill 105 and delivers; them to vessel 130 throu~h line 120, with any supplemental materials introduced through lines 122 and 124, as described.

202~237 Vessel 10 prelerably operates continuously while vessel 7~ !
operates semicontinuously and 130 operates semicontinuous and batch-wise Gas flows trom vessel 130 into vessel 70 through opening 172 by ;
way o~ lines 156, 158, and 170. This flow may be stopped or retarded when vessel 130 is discharging slag or steel. Storage tank 121 may at that time be caused to discharge gas stored in it through line 121a and control valve 121b into line 118 and through it into vessel 10. The gas flowing into vessel 10 from cooler zone 88a through lines 110a. pump 114a, lines 120b, valve 68a and line 118, and ~rom intermediate zone 88b, line 110b, pump 114b and line 118 into zone 46 can usually be blended to the desired temperature, but if the temperature should be higher than desired, it may also be blended with the proper amount o~ cooler gas from `~ -tank 121 supplied to line 118 through line 121a and control valve 121b. -An oxygen supply line 132 is connected at one end to a suitable oxygen supply (not shown) and at the other end to the combustion zone in , ~:
the interior of vessel 130. Line 132 is provided with a valve 134 to control the rate of flow of oxygen into the combustion zone just above the molten metal bath in vessel 130.
A slag outlet notch 142 at the level of a slag layer formed in vessel 130 permits slag to be drawn off as desired, and is opened and closed in customary methods.
A steel outlet notch 144 at the level of molten metal formed in the ~ `
bottom of vessel 130, on which the slag layer floats, permits purified hot `~
metal to be drawn off as desired from opening 142 is also opened and :`
closed in customiry fashion.
The upper end 146 of vessel 130 is secured to an inlet pipe 148 a considerable distance above its lower end to provide a free-flow outlet passa~e at the top of vessel 130 as fine material flows through a common line 150 from hopper 152 for partially reduced iron ore, e.g., Fe, FeO, and ~, from hopper 154 for slag ingredients, e.g. calcium oxide or carbonate with ,~
or without manganese oxide or carbonate, into vessel 130. The feed from each of hoppers 152 and 154 preferably is at a controlled rate. Means to provide such feed may compromise a fluidized conveying system and .:
screw feeding of material for each hopper as illustrated for hopper 152. "~

.
.... ...
: ; .'''' ..
19 , ~,'.,,~

:., :'.- -:~ ~

An outlet line 156 communicates at one end with the flow channel at -the top of the high temperature vessel 130 and at the other end tangentially with the side wall 158 of a cyclone separator 160 having a top wall 162 and a conical bottom wall 164. The wall 164 is connected to a gas line 166 a considerable distance below its upper end 168 which serves as the gas outlet from separator 160. Solid particles separated by centrifugal force from the swirling gases removed form vessel 130 in cyclone separator 160 fall to the bottom and are conducted by a Sunnel-shaped bottom wall 164 into an outlet pipe 170, which is connected at its other end to vessel 70 through an opening 172 in wall 71, and from it into the flow channel between lower walls 82 and 86 at the bottom of zone 78 in vessel 70. The solid particle-free gas flows from the separator 160 throu~h line 166 into the flow channel in vessel 70 between wall 94 and wall 98 through an opening 176 in wall 71. Dampers 174 and 178 control the division of flow of the gas into upper or lower zones of vessel 70.
Gases discharging from vessel 130 are divi~ed by valve 178 and valve 174.
Gases communicating with zone 78 will coke the coal by destructive -~
distillation and gases communicating with zone 90, will be regenerated, -~
and chemically cooled and will continue to the high temperature vessel 130 or conducted to the primary reduction vessel, or stored in vessel 121 for later use in the primary reducin~ zone.
The vessel 10 is tor partially reducing the iron ores, the vessel 70 is for destructive distillation of coal to produce coke and to recovering waste heat from the hi~h temperature vessel in the production of a ~;
r0ducin~ gas, the high; temperature vessel 130 is for ~inal reduction, melting and puri~ying the metalics. These operations are joined into a unitary combination by the interconnecting piping capable of carrying out the process o~ the invention and achieving the numerous advantages and benefits described above. It represents the best embGdiment of the apparatus o~ the invention presently known but, as those skilled in the art will understand, variations and modifications thereof may be made without departing from the scope o~ the apparatus aspect of the invention as de~ined in the claims below.
~, . .

202~237 The apparatus o~ the invention comprises means ~or combining the `
steps or operations ol (A) destructively distilling coal to form coke, a by- -product gas and a reducing gas, (B) partially reducing ~ine iron ores with said reducing gas, (C) introducing said partially reduced ores into a high temperature zone with said cohe, oxygen, steam, and recirculated gas to complete the reduction of the iron ores to metal in molten condition, (D) purilying the molten metal with a slag comprising calcium oxide with or without manganese oxide, and (E) removing mol~en puri~ied metal and slag separately or together ~rom the high ternperature zone. The apparatus is adapted to carryins out the process continuously, although it may be carried out semicontinuously or batchwise, in the secondary reduction high temperature zone, if desired. Other apparatus modifications and variations may be made, as those skilled in the art will recognize and understand, without departing ~rom the scope o~ the invention as hereina~ter defined. .
Referring now to Fig. 2, and Fig. 3, the vessel 130 has a lower bowl-shaped end 180 comprising an inverted ~rustoconical wall 181 having a plurality ot tuyeres 182, 182a, and 182b therein and a bottom reservoir 184 where molten metal and slag may ~low. The tuyeres 182, 1B2a, 182b ';",,~'!';
may vary in declination and inclination ~rom horizontal to a downwarci siope toward the interior of the vessel, as seen in Fi~s. 2, 3, and 4. Fig. 3 shows that the fluid 11OW may also be at an anQle tangent to the vertical ;;axis V - V o~ Fig.2. Fig. 3 shows three (3) tuyeres 182, and three (3) tuyeres 182a, and three (3) tuyeres 182b. Tuyeres 182 serve to introduce : -oxygen into vessel 130. Tuyeres 182a and 182b serve to introduce (~uel), coke, steam and reducing gas, but more or less may be provided, if desired.
The jets o~ gas entering the tuyeres 182, 182a, 182b as seen in Fig. 3, serve to impart a clockwise or counter clockwise rotation, to the gases and the liquid contents of the vessel.
. , .' .-~'~

21 ~, ` 2~24237 Fig. 4 illustrates the preferred structure of a rotatable nozzle 186 for introducing gas through tuyeres 182, 182a, and 182b into the high temperature vessel at various angles. The inner end 188 of nozzle 186 is slightly arcuated so that the direction o~ flow of jet of gas flowing through it can be changed by rotating the nozzle, as illustrated by the lines extending outwardly at different angles from the end of the nozzle.
A gear 190 symbolically depicts a turning mechanism for the nozzle. This simple means makes adjustment of the directions of the jet of gas into the bottom of the high temperature vessel very easy and has the great advantages of enabling an operator to control the process carried out in the vessel 130. An alternative control of the directional flow of the gas may be obtained by the installation of multiple tuyeres ot fixed but different angles and by selectively controlling the flow of gas into selected tuyeres to give the optimum angle of introduction of gas for a given process.
In carrying out the method aspect of the invention in the apparatus thus described, the partially reduced iron ore is introduced into the high temperature vessel 130 through inlet tube 148, which may be provided with helically-shaped fins (not shown) to impart a swirling motion to the particles, causing them to travel outwardly by centrifugal force as they leave the tube 148~ The particles are allowed to fall freely in countercurrent relation to the upwardly flowing vortex of swirling concentrated reducing gas at high temperature which has been generated trom the high temperature combustion of the fuels and oxygen introduced from lines 120 and 132 through the tuyeres 182, 182a and 182b from nozzles 186 as described above. The falling particles are somewhat bouyed up by the rising gas which decreases their rate of descent.
.
',~ ,, . , ''' ` - 202~237 The swirling m~tion imparted to the descending particles by the tins and swirling vortex of reduci~g gases throws them against the re~ractory lining of vessel 130 where t~ey ~orm a lining blanhet over the re~ractories and between the intense heat ~rom the combustion zone. This counterllow movement of particles and gases causes the gases at their highest temperature and concentration to react with the hottest and most nearly reduced iron oxides in the lower part o~ vessel 130 to ef~ect almost complete reduction t~ereol to metal in molten state which then collects in reservoir 1B4 while the rising gases at suitable temperature and concentration to react with the lower temperature and more highly oxidized fallirig particles. 'J'~
The metal layer ~ormed by further reduction of iron ores to iron is so controlled as to contain some iron oxides as an oxygen carrylng agent to obstruct the production of silicon and assures the removal of excessive carbon and what traces of FeS that may remain and the phosphorus as described later, this condition pefsists almost up to time of draw-off to assure their rernoval. The final deoxidizing of iron oxide before tapping is ~ ~;
accomplished by increasin~ the flow of carbon monoxide, and causing it to impinge and pierce into the metal layer ~rom tuyeres 182b while retarding or stopping the iron oxides Irom ~lowing into high temperature vessel 130.
At this time oxygen will be injected into the high temperature vessel tt~rough tuyeres 182 directed above the molten bath. Recirculating gas and carbonaceous fuel will be injected into the vessel above the oxygen through tuyeres 182a and below the oxygen through tuyeres 182b.
The oxygen and fuel ratio may be adjusted to oxidize the fuel to ~orm concentrated carbon monoxide gas or concentrated carbon dioxide, depending on the intensity of the heat and the volume ot the gas desired while raising the bath to desired tapping temperature. Carbonaceous materials may be added to the nnetal bath by means of tuyeres 182a and 182b to give desired carbon level to heat of steel prior to tapping. ~.
.. "

' ' .

`; ~

. ,:.

23 ~ ~

202~237 ., .
It is preferred to oxidize the fuel favoring carbon dioxide at this period to obtain a high ratio of energy to the volume of gas generated in the high temperature vessel. The object is to deoxidize the heat of steel while raising the carbon to the desired carbon levels and the temperature to optimum tapping temperature. Excessive heat energy can be recovered in this phase by injecting carbonaceous material at an elevated position above the combustion zone (not shown) producing an endothermic reaction with the products of combustion, or the combusted gases can be conducted to the destructive distillation zone (78) and secondary gas generation zone (90, 88b, and 88a) in vessel 70 where heat energy can be utilized for destructive distillation of coal and recovering and converting heat energy to chemical energy (described later). However, it is desirable for the recirculating gas injected into the bath ot steel to be nearly 100% carbon monoxide and heated to temperatures of near desired bath temperature or above. Oxygen and carbonaceous fuel can be injected into the line that feeds tuyeres 182b in the amounts to convert oxygen to carbon monoxide and elevate this reducing gas to desired temperature and deoxidize the metal bath without chilling it.
The gases withdrawn at the top of vessel 130 through conduit 156 are caused to flow upwardly through coke in the lower secondary gas generation chambers 90, 88b,and 88a of vessel 70 where the latent heat in the gases furnishes sufficient energy to convert all or part of the carbon dioxide therein to carbon monoxide. A portion thereof of the gas in zone 90 is then returned to the high temperature vessel 130 through line 110, ' pump 114, line 116, venturi 128a and line 120, along with steam, if desired, is introduced through line 122, and pulverized coke from mill 105 which is fluidized thereby, and calcium oxide, if desired, through line 124.
The carbon (coke), carbon dioxide, carbon monoxide, water and oxygen introduced into vessel 130 are controlled as to percentages contained and as to direction and flow so as to regulate the chemical reactions and temperature conditions as desired in the various zones in the vessel 130.
. . . .

2~2~237 The gases introduced through tuyeres 182, 182a, and 182b are of tour ,, types, viz. oxygen, steam, carbon monoxide and carbon dioxide. A sufficient amount of fuel is provided in the vessel to convert the oxygen present as such, or in the compounds, near 100% effective reducing agent, carbon monoxide and hydrogen. The following equations illustrate how different effects may be realized in the lower combustion zone by the proper -;~
application of these gases: (1) Oxygen when reduced by carbon fuel to form carbon monoxide releases heat energy according to the equation O2 + 2C ---> ~:
2CO + 53,600 calories. ~2) Carbon dioxide when reduced by carbon fuel to -form carbon monoxide absorbs energy according to the equation CO2 + C ---> . - ~-2CO - 40,700 calories. (3) Steam reduced by carbon to form hydrogen gas :
and carbon monoxide absorbs energy according to the equation H20 ~ C ---> H2 - . :::
CO - 27,000 calories.
Reactions which take place in the upper reaction zone of vessel 130 are -illustrated by these equations: (4) Reduction of iron oxide by carDon monoxide releases ener~y according to the equation CO + FeO ---> Fe ~ C02 +
2,340 calories. (5) Reduction of iron oxide by hydrogen absorbs energy according to the equation FeO +H2 ---~ Fe + H20 - 7874 calories.
When it is desired to increase the temperature simultaneously in the :
lower combustion and fusion zone and in the upper reduction zone, oxygen is . ~ ~
increased with enough carbon fuel (coke) to reduce all the oxygen to carbon `:monoxide. In the lower zone, it takes place according to equation (1) and in the upper zone according to equation (4).
When it is desired to decrease the temperature in the lower combustion zone and increase the temperature in the upper reduction zone, carbon dioxide .
(or the regenerated ~as frcm chamber 90) is increased with sufficient carbon present to reduce it to carbon monoxide. In the lower zone this takes place according to equation (2) and in the upper zone according to equation (4).
When it is desired to decrease the temperature in both upper and lower .- -~tones, steam is increased with sufficient carbon present to reduce it to --hydrogen and carbon monoxide. In the lower zone this takes place according to equation (3) and in the upper zone according to equations (4) and!(5) with a net effect of -5,530 calories. The products of reaction and the energy of these same reactions are carried over into vessel 10 after being revitalized in vessel 70, which reactions in the upper zone of vessel 130 somewhat creates a shadow effect to the reactions following in vessel 10. :
.

...:

, - .

2~24237 These equations show that the temperature can be regulated in the lower combustion zone and in the upper reduction zone to a degree while maintaining full flow of concentrated reduction gases.
In the event that the primary reduction of the ores takes place faster in vessel 10, than the melt down proceeds in vessel 130, the 100%
effective reducing gas generated, as explained, could be moderated as a reducing gas and intensified as a heating medium in varying degrees by decreasing the amount of carbon that follows the oxygen so that the gases generated could approach 100% carbon dioxide; in this way the rate of the processes of reduction and melting proceeding in vessels 10 and 130 can be balanced.
This procedure could also be used when supplementing shredded or sponge metalics when desiring to increase production or decrease the portion of the pre-reduced iron ores. The heat released with a given amount of oxygen and varying amounts of carbon to produce 100% carbon monoxide to 100% carbon dioxide is illustrated in the following equations:
(5) O2 ~ 2C ~ 2CO ~53,600 calories (6) O2 + C ~ CO2 ~94,400 calories By decreasing the amount of carbon following a given amount of oxygen in equation (5) to equation (6) the volume of the combustible products decreases by 50% and the amount of heat released increases by 176%. These equations show that the intensity of heat can be increased up to 352% by decreasing the carbon to oxygen ratio.
The excessive energy released by increasing the oxygen to carbon ratio in vessel 130 to augment the melting of the metalics, will be recovered in carbonaceous vessel 70, illustrated in the following equation~
(7j C02 ~C ~ 2CO - 40,800 calories.
The energy released in reaction (5) is equal to the net energy o~
reaction, in reactions (6) and (7). By increasing the heat intensity in ~quation (6) a larger portion of the energy can be utilized for melting the metalics and what excessive energy remains will be recovered in the ~i lower chambers of the carbonaceous vessel 70. These equations show that the temperature can further be regulated in the lower combustion zone by ;
xtending and converting the upper reduction zone to a meltdown zone while maintaining full flow of concentrated reducing gases leaving the carbonaceous vessel 70.

26 ~;

': ~ "' ,: - ~...

; As these reducing gases flow upwardly countercurrent to the -descending iron oxides, much of these gases will be oxidized to carbon dioxide and steam so that the gaseous discharge through conduit 156 will be partly carbon dioxide and steam, with a greater portion of carbon monoxide and hydrogen. The discharge temperature will usually be in the range of 1800 F to 3000O F. The gaseous discharge will entrain some solid particles which are separated out in the cyclone separator 158 and continue to vessel 70 to the destructive distillation zone 78 or the secondary gas generation zones 90, 88b, and 88a, while a portion of the gases are passed through the coke and then a portion is recycled to the vessel 130 as described above, and a portion continues to the primary reducing vessel 10. The proportion of the gases that enters vessel 70 through lines 166 and 170 is controlled by dampers or butterfly valves 174 and 1?8 which may, if desired, be manipulated so that the flow may--ue restricted. This makes it possible to direct the flow of the discharged gases to the upper chamber 78 and the lower chambers 90, 88b, and 88a of ;
vessel 70 in desired varying amounts while maintaining a higher pressure in vessel 130.
All regenerated ~ases flow through the lower chambers 90, 88b, and 88a of vessel 70 after which part may be returned to the high temperature vesse) 130 through conduit 120 and part may be diverted to the primary reduction vessel 10 by conduit 110b, blower 114b and conduit 118. The ` - -tluidized solid particles from 96, 100, 102, and 104 flow almost as pure fluid through conduit 120 and tuyere 182a and 182b.
The lower chambers 90, 88b, and 88a in vessel 70 serves several purposes: (1) recovers the latent heat of waste gases from high temperature vessel 130 by regenerating a reducing gas in converting heat energy to chemical energy, (2) moderates the temperature of the reducing gases suitable for introduction into primary reduction vessel, (3 ) prepares a ~as useful for moderating temperatures in the combustion zone, (4) chemically cools excessive temperatures in preparing the reducing gas for use in vessel 10 or for storage, and (5) it lowers the temperature of the gases so they are useful for conveying solid fuels into the high tempetature vessel 130, as described.
~ .

27 : ~

2~
The pressure in vessel 130 is maintained several times higher than the pressure in vessel 70, e g. 2 or 3 atmospheres in vessel 130 and 1 atmosphere in vessel 70.
The withdrawn gases that flow through conduit 170 into upper chamber 78 of vessel 70 serves several functions:
(1) Removal of excess waste gaseous products generated in the high temperature vessel, i.e. sulfur dioxide, carbon dioxide, steam, and phosphorus .
(2) Utilizing the latent heat contained in said waste gases for the destructive distillation of coal or oil shale, (3) Removal of volatile by-products (4) Maintain a high rate of flow of the high temperature gases through the coal to remove sulfur contained in it. Sulfur is in a solid state up to a temperature of 262~ F., a liquid from that temperature to 832~ F., and a~ove that vaporizes successively as S8, S4, S2, and S which have molecular weights of 256.66, 128.26, 64.14, and 32.07 grams/mole respectively. The gases at high temperature and high flow vaporize the sulfur residue and carries it out of the coking system into the by-products recovery means. Sulfur is also removed as hydrogen sulfide from this ;
zone, Sulfur is thus removed trom the fuel before contacting the ferrous products and con~aminating them.
(S) Removal ot the suspended solids (dust particles) in the sub-micron size range by absorption in and filtration throu~h the coke. ;
(6) Reduces the phosphorus pentoxide to free elemental phosphorus vapor so that it is removed from vessel 70 to the by-products recovery -system.
~, , ....

;, ~ ,.,;
~.: "

,'. .: :-:, .... . ..

21~2~23~
REMOVAL OF PHOSPHORUS

Phosphorus exists in the reduced metal layer as a dissolved --chemical iron-phosphorus bond. To remove it trom solution, it is oxidized, which is readily accomplished because o~ the presence ol iron oxide in the ~` ;
slightly oxidized reduced metal layer and the phosphorus pentoxide ~loats l-to the top of the metal bath and becomes part of the slag layer. The slag bath is maintained predominantly acidic during the initial phase. In the slag layer the phosphorus material is reduced to elemental phosphorus by a layer of coke injected on the top of the slag layer. This occurs at temperatures above 2730 F. Phosphorus is a vapor above 516 F., and flows up through vessel 130 and out through conduit 156 with the rising gases to the cyclone separator 158. There most of what may have oxidized into phosphorus pentoxide, from contact with the descending partially reduced iron oxides, as it ascends through vessel 130 will precipitate into fine particles which leaves the separator by conduit 170 to flow into the upper chamber of vessel 70 where it is reduced again to elemental phosphorus due to the high temperature and carbonaceous atmosphere maintained there and passes upwardly through the porous carbonaceous material to conduit 106 and through it to the by-products recovery system. The drivin~ chemical action in the metal and slag layers is exactly opposite to conditions in other customary refining methods for tho removal of phosphorus where the metal layer is highly carbonaceous and the slag layer oxidizing, which carbon in the metal tends to reduce the phosphorus pentoxide which can then react and bond to the iron in the metal bath. In the process of the invention, on the contrary, phosphorus is oxidized and driven out of the metal layer into the slag layer by a slightly oxidizing metal bath as phosphorus pentoxide. Here it is reduced and removed from the carbonaceous slag layer and emitted as elemental phosphorus.

~`' '`' ''.~'.''' 2~2~37 REMOVAL OF SULFUR

. .
The primary reduction vessel 10 has a plurality of different zones through which finely divided iron ores or concentrates flow from the feed hopper 12 through inlet 16. The upper zone in chamber 18 is a preheat zone which uses latent heat and tuel lett in the gases from the reduction reaction lower down in vessel 10. Air or oxygen may be supplied to this zone through pipe 32 in sutficient quantities to completely oxodize any fuel remaining in the gases and utilize heat ot combustion as well as latent heat in the preheating operation. The preheating operation oxidizes the sulfides in the ore to sulfur oxides (S02) and removes it form the iron oxides in the gases that flow from the vessel through conduit 28. This removes that portion of the sulfur in the ore entering the system that would otherwise enter the molten metal from the ores used. What volatile ~ ~ i sulfur or sulfides are in the fuel are remove as explained before in the tunctions of upper chamber 78. Any residue of sultides remaining in the fuel are oxides to sultur dioxide in the combustion chamber ot vessel 130, as the fuel and oxy~en burn. What sultur may find its way to the molten bath will be removed easily trom the slightly oxidizing metal bath as iron oxidos carry oxygen to the sulfides and removes the sulfur as an oxide.
Gases~generated in secondary generation vessel 70 and in the high temperature primary generation vessel 13~ are introduced into its lower chamber 46 of vessel 10 by means of conduits 156, 166, 110a, 110b, 118, ;
and 66, aro used to reduce the iron oxides of the ore in vessel 10 between partlt;on 24 and bottom wall 64, sometimes referred to as the prirnary reductlon zones. Tho gases from vessel 70 are usually at a desired temperature and they have a relatively high content of carbon monoxide wlth some portions of hydrogen. As these gasses reduce the iron oxides in the ore, heat is produced which may cause the temperature to rise high -i~nou~h to make the solid particles sticky. To avoid this undesirable condition, portions of water vapor or steam can be blended with carbon dioxide in vessels 130 and 70 to balance somewhat the exothermic . ...~ ... ~
reaction of carbon monoxide reducing FeO with the endothermic reaction i~
of hydrogen with iron oxide~
,,, , ,:
:

., ~' ' " ~;~ ' .

2Q24~7 Gaseous hydrocarbons and/or other cooling medium, including coke or coal, may be introduced through pipes 44a, 44b, 44c, and 44d to ~urther keep the temperatur~ throughout the primary reduction zone at optimum levels. Where coke or coal is included in the cooling medium, carbon dioxide is produced in the reduction reaction and it may be reduced to carbon monozide by reaction with the carbon present, which creates a chemical coolin~ action. This carbon monoxide assists in reducing the ores. Reactions that may occur in vessel 10 include the following:
A. Reduction with CO which are all exothermic: (i) Fe203 + CO ---> 2FeO +
C02 + 38,260 calories.(ii) Fe304 + CO ---~ 3 FeO + CO2 + 15,660 calories .(iii) FeO + CO ~ Fe + C02 + 2, 340 calories. B. Reductions with reagents causing endothermic reactions: (iv) Fe304 + C ---> 3 FeO + CO -44,540 calories. (v) 4 FeO ~ 2 CH4 ---> 4 Fe + 2 CO2 + 4H2 - 61,986 calories. (vi) 2 FeO + ~C ---> 2 Fe 1 2CO - 34,200 calories. (vii) C02 + C ---> 2 CO - 40,700 calories. (viii) FeO + H2 ---> Fe H20 - 7,874 calories. -In carrying out the process in the equipment described herein, it is ;
advisable to carry out the combustion reac~ions that produce much heat, i.e., the reaction of oxy~en with carbon fuel and reduction of iron oxide by carbon .
monoxide in the high temperature melt down and final reduction vessel 130, the reactions that absorb lar~e quantities of heat set forth above in the vessel 70, i.e., while those carried out in the primary reduction vessel 10 are controlled to maintain relatively constant temperature, e.g., about 1600 F., or below the sticky temperature at which the particles become sticky, thereby enabling them to remain fluidized. It is desirable that the ores discharged from vessel 10 are only partially reduced there, e.g., to the Fe and FeO sta~e. The final reduction then takes place in the high temperature meltdown reduction vessel 130 to which the partially reduced ores are transferred by conduit 58d, which may be a skip, conveyor belt, auger, pneumatic (fluidized) conveyor, elevator, or the like, into hopper 152 from which the material flows into vessel 130 through line 150 and inlet pipe 148. If desired, iron particles from other sources and sponge iron rnay be added at the hopper 152 or an alternate hopper.

31 ::

2~2~7 In vessel 130 the reduction to metal in the molten state is accomplished, impurities are removed as described and the desired carbon and oxygen content are established and high enough metal temperatures are attained prior to batch tapping. Any desired alloying ingredients may be added before tapping or thereafter in the ladle (not shown) into which the molten metal may be caused to flow from vessel 130. By adding the alloying ingredients at this stage of the process, excellent control of the percentage thereof in the final alloy is assured. Any necessary final adjustments of carbon content may.be made just prior to tapping or at the tirne alloying ingredients are added in the ladle.
While coal has been described as the preferred form of fuel, oil shale can be used by making slight modifications in the apparatus. In general oil shale in granular form is fed through vessel 70 in ~he same manner as coal.
In the upper part above 86, hydrocarbons are distilled from 2he shale and exit through duct 106 under control of valve 108. If all the hydrocarbon material has not been distilled off in this upper zone, the balance will be distilled off in zone 88a. Some of the hydrocarbons exiting through duct 106 `may be returned to vessel 70 as described below. If more hydrocarbons are ~.
produced than needed as fuels in the process, they may be refined in much ;the same manner as crude oil and be sold in commerce.
Because the oil shale residue does not have any combustible material in it when the hydrocarbons have been distilled off, it is necessary to provide means to add combustible material to the residue (1) in zone 88a ~ ~
throu~h the space between plates 86a and 86b, (2) in zone 88b through the ; ;:
space between plates 86c and 86d, and ~3) in zone 90 throu~h duct 127. The oil shale residue exiting from the midpoint of vessel 70, instead of being ;
sent to vessel 130 is disposed of in any suitable manner, as described above, as it has no further value as a fuel for use in the apparatus of the invention.
However the residue may, to some extent, be utilized as a fluxing compound ~ -as needed. The hydrocarbons distilled from the shale will be substituted for coke and feed into line 120 by suitable means (not shown). The quality steel producedHn the apparatus of the invention may be worked up into usable , shapes and forms in the manner customarily performed on quality steels produced by other methods known to the art. ~:
Having thus described and illustrated the apparatus of the invention, ~ ~

32 :

:"~ ;:''."

Claims (20)

1. Apparatus for producing quality steel directly from iron ore which comprises:
A. means for reducing iron ore under conditions which produce an oxidizing molten steel bath, B. means for maintaining said bath as an oxidizing molten steel bath during melt down and reduction of a heat of steel, and C. means for withdrawing quality steel from said molten steel bath.

2. Apparatus for producing quality steel directly from iron ores which comprises:
A. means for reducing iron ores under conditions which produce an oxidizing molten steel bath, B. means for introducing superheated reducing gas into said molten steel bath, C. means for introducing coke and oxygen above said molten steel bath, and D. means for withdrawing quality steel from said molten metal bath.

3. Apparatus for producing quality steel directly from iron ores which comprises:
A. means for first reducing iron ores under conditions which produce a carbonaceous molten steel bath, B. means for treating said carbonaceous molten steel bath to change it into an oxidizing molten steel bath, C. means for maintaining said bath as an oxidizing molten steel bath during continued melt down of a heat of steel, and D. means for withdrawing quality steel from s aid molten steel bath.

4. Apparatus for producing quality steel directly form iron ores in which iron ores are partially reduced in a zone, then finally reduced in a high temperatue zone in which carbonaceous material is oxidized which comprises:
A. means for converting waste heat in gases flowing from the high temperature zone into chemical energy by introducing said gases into a vessel containing carbonaceous materials, steam and carbon dioxide to convert the steam and carbon dioxide to hydrogen ant carbon monoxide, and B. means for withdrawing quality steel from said high temperature zone.

5. Apparatus for producing quality steel directly from iron ore which comprises:
A. means for producing a molten steel bath and a floating slag layer from iron ore and slag ingredients by utilizing heat released from the combustion of carbonaceous material with oxygen to generate reducing gases, and B.means for withdrawing quality molten steel and slag.

6. Apparatus for producing quality steel directly from iron ores as set forth in claim 5 which further comprises means for limiting the rise of temperature by introducing heat absorbing oxidizers into said gases.

7. Apparatus for producing quality steel directly from iron ores which comprises:

A. means for partially reducing iron ores in a preliminary reduction zone, B. means for completely reducing said partially reduced iron ores in a secondary reduction and melt down zone, C. means for generating reducing gases in a separate zone, D. means for blending heat-absorbing oxidizers in the gases in the melt down zone and in the reducing zone to moderate the temperature in both zones and stabilize moderation in the primary reduction zone, and E. means for withdrawing quality steed from said mellt down zone.

8. Apparatus for producing quality steel directly from iron ores which comprises:
A. means for partially reducing iron ores in a primary reduction zone, B. means for generating reducing gases in a reduction zone and utilizing them to effect said partial reduction and partially oxidize said gases, and C. means for introducing carbonaceous material selected from the group consisting of carbon and hydrocarbon into said partially oxidized gases which react therewith to convert heat energy into chemical energy and revitalize said reducing gases.

9. Apparatus for producing quality steel directly from iron ores which comprises:
A. means for producing reducing gases in a carbonaceous zone by an exothermic reaction, B. means for introducing material from the group consisting of steam and carbon dioxide into said reducing gases to convert heat energy produced in said exothermic reaction to chemical energy in an exothermic reaction which produces more reducing gases, C. means for reducing iron ore to molten steel with said reducing gases, and D. means for withdrawing quality steel from said molten steel.

10. Apparatus for producing quality steel directly from iron ores which comprises:
A. means for reducing iron ore under conditions which produce an oxidizing molten steel bath and gases to be exhausted which contain colloidal particles, B. means for filtering said colloidal particles from said exhaust gases by passing them up through a layer of coke and coal particles while converting heat energy in said exhaust gases to chemical energy and coking said coal, and C. means for withdrawing quality steel from said steel bath.

11. Apparatus for producing quality steel directly from iron ores which comprises:
A. means for vaporizing sulfur in a coking zone, and B. means for convoying it from the coking zone by a superheaed forced draft.

12. Apparatus as set forth in claim 5 in which phosphorus in said molten steel bath is removed into the slag layer while said molten steel bath is oxidizing and the phosphorus in said slag layer is removed by means which reduce it in a carbonaceous high temperature atmosphere and convey it out of the system with a reducing forced draft.

13. Apparatus for producing quality steel directly from iron ores which comprises in combination:
(A) a high temperature vessel adapted to hold a bath of molten steel, (B) means for producing partially reduced iron ores;
(C) means for introducing partially reduced ores with flux ingredients, steam, oxygen and coke into said high temperature vessel above said metal bath (i) to reduce said iron ores to metal in the molten state to form said molten steel bath and (ii) to form a molten slag floating on said molten steel bath to control the carbon and impurity content thereof; and (D) means for removing molten steel and slag from said vessel.

14. The apparatus as set forth in claim 13 in which means are provided for operation operation A continuously.

15. The apparatus as set forth in claim 13 in which the means for introducing said partially reduced iron ores, flux ingredients, steam, oxygen and coke into the vessel introduces the partially reduced ores and the flux ingredients at the top of the vessel and the steam, oxygen and coke at the bottom thereof above said molten steel bath.

16. The apparatus as set forth in claim 15 which includes means rotatable between two fixed points for introducing the oxygen at different selected angles with respect to a horizontal plane and a vertical plane through the axis of the vessel.

17. The apparatus as set forth in claim 16 in which said means for introducing oxygen compmrises a rotatable nozzle having an arcute end and means for notating the nozzle.

18. The apparatus as set forth in claim 13 which includes means for withdrawing and centrifuging gases from the upper end of said high temperature vessel to separate solid particles from gases, means for introducing the separated solid particles into at least partially destructively distilled powdered coal, means for producing reducing gases, and means for introducing the centrifuged gases into said means for producing reducing gases.

19. Apparatus as set forth lo claim 18 which includes means for withdrawing reducing gas from said means for producing it, introducing part of it into said means for partially reducing iron ores, another part of it into the high temperature zone, and the balance, if any, into storage.

20. Apparatus as set forth in claim 19 which includes means for introducing part of the reducing gas entering the high temperature vessel with the molten slag and the molten steel and another part above the molten slag, and means for controlling the proportion of the gas introduced into (1) the means for partially reducing iron ores, (ii) said high temerature zone, and (iii) into storage.