CA2024236A1 - Process of producing quality steel directly from iron ores - Google Patents

Abstract

ABSTRACT OF THE INVENTION
The present invention is a process of producing quality steel directly from iron ores with reducing gas. Preferable the iron ores are partially reduced in a primary reduction vessel by the reducing gas which is produced in a gas production vessel and the secondary reduction to molten steel takes place in a third, high temperature vessel into the top of which the partially reduced iron ores are introduced, preferably with slag ingredients, and in the bottom of which the molten steel, with a layer of slag floating on it, is held prior to batch withdrawal.
The molten steel bath may be carbonaceous or oxidizing as produced but if it is carbonaceous it must be converted to oxidizing before withdrawing steel, Into the high temperature vessel are introduced (a) superheated reducing gas into the molten steel bath, and (b) coke and oxygen above it which react to form a reducing gas that rises countercurrent to descending partially reduced iron ores and slag ingredients and flows from the tip of the high temperature vessel into the gas production vessel where waste heat is converted to chemical energy vessel in the presence of carbonaceous materials, steam and carbon dioxide. These materials by an exothermic reaction form a hot, strong reducing gas comprising hydrogen and carbon monoxide, (a) part of which may be used for he primary reduction and (b) part of which may used for the secondary reduction of the ores. Tiny particles in the withdrawn gas are removed when it passes through the carbonaceous material in the gas production vessel.
Sulfur and phosphorus present in starting materials are removed.

Description

202423~ ~

- PROCESS OF PRODUCING QU~LITY STEEL
DIRECTLY FROM IRON ORES

INTRODUCTION

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Th- pr-~ent lnventlon relates to an lmproved process of producln~ -qu-llty ~teel directly from tron ores whlch ls more fuel eSflclent and le~ expen~lve than ~ethods now ln use. More partlcularly, the process ~ ~ ;
of the lnventlon can be carrled out ln much less expenslve equlpment ~nd ~ekc~ po~lble the productlon of a glven quantlty of hlgh quallty ~teel u~lng le~ fuel, enablos the cost of maintenance to be ~ub~tantl-lly reduced, and requlres S-r less manpower. Moreover, the prooe~ produc-~ ~taal of hlgh qu-lity because the level of Impurlties reedlly conteolled nd desIrable alloylng lngredlents can be added i~
to de~ircble l-val~
; BACKGROUND OF THE INVENTION ` ~ ~
In c-nv-ntlon-l ~teel-m-klng operatlons, lron oxlde ores ~re .,"'!,",.'`,"'"'."''';
r~du~ced to tho met-lllc stage ln a hlghly carbonaceous env1ronment 1n a ~ -la~t iurn-ce. The envlronment results ln ralslne the carbon level ln ~`~
th-~hlot metal bath far above the deslred level for qualityusteel and -re~ults ln the production of slllcon and lndtrectly contelbutes to the ~ !
~i prc~once ln the`hot metal oi~ hlgher peecenta~es of other detrlmental purltlc~ than were they reduced snd melted ln an stmo~phere ;x~
rcl~tl~ely free of carbon ; , , ;

~--b Because of the nature and operation of the blast furnace, virtually all of the phoshorus that enters the turnace in drawn off 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 1hat must be oxidized in the sla~ bath to aid in the removal of this hi~hly detrimental impurity. It also results at times in producin~ heats of steel useful only as scrap.
In eonventional blast furnace operations, coke, iron ore and fluxin3 eompounds are ehar~ed in the top of the furnace in amounts which substantially fill the entire inner eavity. A blast of preheated air, which -may be supplemented or enriehed by oxy~en and is introduced at the bottom ot the furnaee throu~h tuyeres, supports eombustion of the coke in this re~ion of the furnace, producin~ much heat ener~y and ultimately producin~ earbon monoxide which is the main reducin~ a~ent in the blast furnaee operation. As the reducin~ ~as reacts with the iron oxides, it produees earbon dioxide, melted iron or partially redueed iron oxides and ;
releases some quantities of heat ener~y.
Where temperatures are suffieiently hi~h, earbon may reaet directly with iron oxide to produee earbon dioxide and metallie iron. This carbon dioxide may reaet with the earbon to form more carbon monoxide. These two reaetions absorb large quaritities of ener~y and impart a eoolin~
effeet whieh soon lowers the temperature of the ehar~e and blast, as the gas aseends up throu~h the burden, below an effective reaction temperature.
The fluxing eompound, usually ealeium earbonate with or without man~anese earbonate, absorbs lar~e quantities of ener~y as it deeomposes or ealeines. Carbon dioxide is released in this decomposition whieh further reaets with the free earbon absorbin~ mueh ener~y and earrying fuel away as earbon monoxide in the top ~as. Undesirable impurities ineludin~ exeessive earbon, phosphorus, silicon and sulfur remain in the metal whieh is drawn off at the bottom of the blast furnaces.

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Expensive equipment such as Bessemer converters, open hearth furnaces, and electric furnaces have been developed in which expensive operations, includin~ basic oxy~en processes, are carried out tor the purpose of reducin~ these undesirable impurities to acceptable levels.
Each of these operations is expensive and has limitations as to the 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 cokin~ process by destructive distillation of a blend of pulverized coal in an air-tree refractory-lined oven. Heat from the firing chambers into the interior of the ovens is transferred throu~h these retractory linin~s which are thick enou~h 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, includin~ a lar~e portion o~ the free sulfur.
Temperatures reached in the cokin~ process are sufficiently hi~h to volatilize sulfur in the coal but because of its hi~h density (ei~ht times the density ot air) most of it remains as a residue in the coke unless thero is some means of propellin~ it trom the heabd coke in the oven.
Approximately 90% ot the sulfur that enbrs the blast turnace comes ~-from the sulfur residue ;n 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 sbundant and excessive top ~as produced in the blast furnace operation of reducin~ and melting vir~in iron. However the over all fuel efficiency of the two combined processes is still low and coke is expensive and a premium for both chemical use and the production of vir~in cast iron.
To relieve this condition there have been several methods developed to produce vir~in metallic iron direct from the ore without usin~ pre~
coked coal (D.R.I.). Some processes produce spon~e iron; others produce a molten cast iron.

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~n2423~ :
The one, spon~e iron, supplements the demand for scrap iron; the other supplements the demand for blast turnace hot metal. Although these (D.R.I.) processes do eliminate the need of the cokin~ process, there still remains the need for secondary refinin~ and the liquification of the spon~e metallics. The process of this invention accomplishes all that the other D.R.I. processes accomplish plus it has the capability of refinin~ the metallics to hi~h qualities of molten steel. This is accompîished while recoverin~ the ener~y in the hi~h temperature gases required to melt and raise the steel to castin~ temperatures and eliminates the waste o~ tuel consumed while removin~ excessive carbon and accompanyin~ impurities, resultin~ in a process that is fuel, ;
facility, and labor efficient in the production of a relatively pure hot metal, that ean be readily alloyed to desired specifications, ready for eastin~. A process which directly reduces steel (D.R.S.) from iron ore with eoal as the primary source fuel.
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.' ' ',' SUMMARY OF THE INVENTION

The proeess ot the invention has a number of important features.
One of these features is the proeess of producin~ quality steel directly from Iron oro whieh eomprises (1) reducin~ iron ores under conditions whieh produee an oxidizing molten metal bath, and (2) maintainin~ said bath as an oxidi2in~ molten metal bath durin~ meltdown of a heat of steel.
These operations result in eliminating exeessive earbon, phosphorus, sulfur and stops the production of silieon in the steel.
Another important feature is the process of producin~ quality steel diroetly from iron ores which eomprises (1) reduein~ iron ores under oonditions whieh produee an oxidizing molten metal bath, (2) introducin~
coke and oxy~en above said molten metal bath, and (3) introducin~
superheated reducin~ ~as into said molten metal to remove all oxy~en from the bath. These operations result in the elimination of excessive impurities and ~ives the heat of steel the ability to maintain proper ehemieal and physical characteristies.

Another feature of the present invention is that the step of reducing iron oxide under conditions which produce and oxidizin~ molten metal bath may be carried out in two operations: (a) first reducin~ iron ores under conditions which produce a carbonaceous molten metal bath and (b) treatin~ said carbonaceous metal bath to chan~e it to an oxidizin~ molten metal bath. A further feature of the process of the invention is to convert waste heat in the ~as flowin~ from a hi~h temperature me1t down vessel to ehemical ener~y by introducin~ the ~ases into a vessel containin~
earbonaeeous material, steam and earbon dioxide to eonvert them to hydro~en and earbon monoxide. The proeess turther eomprises utilizing heat released from the eombustion of earbonaeeous and hydrocarbon material with oxygen to ~enerate reducin~ ~as and form a melt of metal and sla~. A further aspeet of the invention is to limit the temperature rise in the redueing ~as formed by an endothermic reaetion by introducin~ ;
heat absorbin~ oxidizers into the earbonaeeous and hydroearbon material, produeing reduein~ gas and absorbin~ heat.
The proeess further eontemplates the proeess of blendin~ heat~
absorbin~ oxidizers in the melt down and primary ~as ~eneration zone and -the seeondary gas ~eneration zone to moderate temperatures in the ~eneration zone and also in a vessel in whieh primary reduetion of the ores is aeeomplished. The proeess still turther eontemplates moderatin~
temperatures in a primary reduetion vessel by introduein~ reaetants sueh ~ ~ -as earbon and hydroearbons whieh reaet with partially oxidized reducing ~ases. This eonverts heat energy to ehemieal energy and revitalizes the ~-redueing gases. ;
The invention also eontemplates eoolin~ the reduein~ gases in a earbonaeeous zone introdueing steam or earbon dioxide or a blend of both ~ ~;
of them to eonvert heat ~nergy from the exothermie reaetion to ehemieal ener~y in an endothermie reaetion and thus produee more reduein~ ~as and lowering the temperature suitable for introduction into the primary reduction zone.

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202423~ -A further aspect o~ the invention involves filterin~ the colloidal - -particles in the exhaust gases from the hi~h temperature melt down vessel by passing them through a layer of coke and coal while converting waste heat to chemical energy and cokin~ the coal. An important advanta~e of the invention is the removal of sulphur from coke and coal by vaporizin~ and conveyin~ it away with a superheated forced draft. ~ -The process of the invention further accomplishes the removal of phosphorus from the metallic bath by maintainin~ an oxidizin~ metal bath which transfers the phosphorus from the metal bath to a carbonizin~ slag -bath. It also accomplishes the removal of phosphorus from the slag bath by reducin~ it in a carbonaceous hi~h-temperature atmosphere, conveying the vapor out of the system with a reducing forced draft.
The process still further contemplates introducin~ partially reduced ores and sla~ in~redients into the upper part of a hi~h-temperature melt down zone while coke or hydrocarbon fuel, oxy~en, steam, carbon dioxide, and recirculating gases are introduced into the lower re~ion of said zone well below the point of introduction of the partially reduced ores and sla~
In~redients so that the reducing ~ases pass upwardly therethrou~h and thereby continues to reduce the partially reduced ores to molten metal and forms a molten metallic and sla~ bath at the bottom of the hi~h temperature zone.

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202~23~
Finally, the process contemplates introducin~ the reducin~ ~ases tormed in the process just stated partially into the metallic and sla~ bath removin~ excessive oxy~en therein and partially above the sla~ layer. The process o~ the invention combines the cokin~ blast furnace and open hearth operations in a sin~le apparatus in which the combined effect of each of the phases compliments the others and produces hot metal relatively free of impurities in lar~er quantities and consumes less quantities of fuel. The reactants carbon dioxide and carbon or hydrocarbons are utilized to control excessive ener~y and produce hi~hly concentrated reducin~ ~as in the primary reduction vessel. What reactants are not utilized are dischar~ed as a waste ~as which does not remove other fuel potential with it. Among the advanta~es made possible by the present invention over the known process are the tollowin~
A. Fuel consumption is reduced and the use of bituminous coal or other low quality fuels, which are more abundant and less expensive ~han anthracite coal, is made possible.
B. With only slight alterations, oil shale may be used as an alternate ;, fuel and produce oil products. ;
C. A top ~as may be produced which is high in thermal rating and may be used advantageously in other phases of the manufacturing process as a heating ~as.
D. Sintering plants are not needed because the process can utilize ~inely divided ores. Finely divided ores not only au~ment the capacity of tho furnace but they provide a greater surface for the reducing ~as to work on and a smaller distance for the gases to penetrate to the center of ~`
the particles which escalates the reducing process.
E. The open hearth process and all other secondary refining furnaces are eliminated by the direct process of reducing steel (D.R.S.).
~. The capacity of the furnace is au~mented by the production of a -~
hi~hly concentrated reducing ~as which can control the temperature ranges in various zones and, in particular, extend the reducing zone.
G. Reduces maintenance costs by utilizing less complex mechanical equipment and conducting the processes therein so as not to deteriorate it, which results in less expense to maintain.
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h. Reduces thermal losses by conducting the reduction in a smaller furnace and ~enerates reducin~ gas by utilizin~ heat ~enerated in the high temperature furnace of the melt down zone.
1. ~alances the thermal reactions by the dynamic design and shape of the furnace and the nature of the reducin~ ~as.
J. Reduces flu dust by reducin~ the volume of ~as flowin~ through the furnace and filters the outflowing gas to reclaim what small particles are entrained.
K. Eliminated the problem of bankin~ furnaces and maintaining temperature in coke oven when not needed by having a dynamic char~e which is adjusted easily or started and stopped with ease, and cokin~ is accomplished by utilizing heat from the high temperature vessel.
L. Eliminated heat loss from latent heat carried off by inert nitrogen ~as in prior steel processes in air-supported combustion and reduction phases.
M. Eliminated channeling of ~as in the furnace by use of a dynamic char~e as opposed to the present stagnant burden through the more porous re~lons of which the gases pass with great speed.
N. Eliminates sulfur from the fuel by vaporizing and removing it by means of a high temperature forced draft.
O Eliminates the phosphorus in vapor form after reduction from the slag and condensing it in the by product area.
P. Eliminates the production of iron nitrides by usin~ relatively pure oxygen rather than alr.
Q. ElTminates the need for an extensive cooling system by more efficient utilization and distribution of the heat in the high ternperature area of the furnace.
R. Produces a concentrated reducing gas which requires relatively small amounts of relatively pure oxygen.
S. Eliminates the need for pelletizing plants for concentrated ores ~ -althou~h pelletized ores can also be used.
T. Reduces the amount of air pollution.
U. Any pyrites that may occur in the ores used are oxidized while being preheated and sulfur in the ore is eliminated.

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202 423 ~ ~
V. Lar~e savin~s in cost of refractories are realized because the interior of the hi~h temperature vessel is continually bein~ relined by the solid reactants as they enter the vessel, and the heat of their fusion ~:
absorbs ener~y, reducin~ the temperatures of the refractories linin~
below the meltin~ point.
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~ ' BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described and illustrated in conjunction with the drawin~ in which~
fi~. 1 is a vertical schematic sectional view of the apparatus of the ~:
invention; : .',' ., Fi~. 2 Is a partial vertical sectional view of the high temperature vessel in which tinal reduction and melt down takes place showin~ an~ular direction of introduction of gas; : -Fig. 3 is a cross sectional view on the line 3--3 of Fig. 2;
Fio, 4 is a partial vertical section of the lower end of said vessel showing the shape of a nozzle partly in lon~itudinal section for introducing the ~as Into the vessel throu~h a tuyer0 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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` ^ 202~236 1.. DETAILED DESCRIPTION OF THE PROCESS OF THE INVENTION

The preferred process of the invention comprises the steps of (1) preheatin~ finely divided iron ore with tailin~s of a reduction ~as; (2) destructive distillation of powdered coal and convertin~ it to powdered coke; (3 ) ~eneratin~ a reducin~ ~as trom the powdered coke in the primary or the secondary iaeneration vessels (4) subjectin~ the preheated ore to .
primary reduction by said reducing gas; (5) admixin~ the pre-reduced ore with fluxinia compounds ~n. the top o~ the hi~h temperature vessel. (6) inject powdered coke into the bottom o~ high temperature vessel with conveyin~ recirculated r~ducina ~as; (7) blowin~ oxyaen into said coke and ~as (a) to produce a hi~h temperature zone by oxidizin~ 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 ~enerated ~ases (c~ to form a sla~; (8) poolin~ the molten metal under the slaia to refine it and achievinia sufficiently hiiah temperatures for tapping and casting the steel; (9) separately removing sla~ and refined molten metal;
(10) (a) withdrawino aaseous products trom the hi~h temperature zone, (b) 6eparating the gaseous products from any entrained dust particles, (c) -.
Introduein~ a portion ot the ~aseous products into the destructive . .~
di~tillation chamber of the carbonaceous vessel, and (d) admixina the dust ~ -:
particles with the coke after coking; (11) introducin~ the remainder of the ~aseous products from the hi~h temperature vessel to the secondary ~as ~eneration ehambers of the carbonaceous vessel and conditionin~ it for use in (a) primary reduetion vessel (b) reuse in the hi~h temperature vessel (c) or for storage; (12) disehar~in~ waste iaas from the primary reduction zone; and (13) dischari~ing coal gas from the carbonaceous vessel to the by-product recovery facilities.

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The apparatus in which th~ process is carried out comprises means in which each step of the process may be carried out includin~ (A) a primary reduction vessel; (B) a carbonaceous vessel for destructive distillation of coal and secondary reducin~ ~ases ~eneration; (C) a high temperature vessel, which has several functions, (I), for the primary reducin~ ~as ~eneration, (Il) for final reducin~ pre-reduced ores, (Ill), to melt the materials, (IV), to refine the material, and (V) to heat molten metal to tappin~ and eastin~ temperature; (D) means for the diversion of ~ases flowin~ from the hi~h temperature vessel ~30 to the secondary ~as ~eneration ehamber 90 or to the cokin~ zone 78 (E) means for conducting primarily reduced ore trom the primary reduction vessel to the hopper at the top of the high temperature vessel, mixing it with ealeium and man~anese oxides or car~onates and introducin~ the mixture into the high temperature vessel; (F) means for withdrawin~ ~as from the hi~h temperature vessel, separating any entrained particles in it (G) means for subjecting eoal to destructive distillation with the waste heat from the hi~h temperature vessel and conveying the by-produets away for proeessin~ (H) means for ~eneratin~ a reduein~ ~as from the waste ~as and waste heat emitted from the hi~h temperature vessel in the carbonaceous vessel (I) means for eireulatin~ ~as withdrawn from the secondary ~as ~eneration zone, (i) to the primary reduetion zone, (ii) to the bottom of the -high temperature melt down and ~as generation zone, (iii) or for storage;
U) means for introdueing fuel ( i.e. eoke or hydrocarbons) from the earbonaeeous vessel with a eonveying recireulatin~ gas into the bottom -~
zone of the high temperature vessel; (k) means for withdrawing Qas from the primary reduetion vessel, and (L) means for preheating ores prior to ~ r subjeetin~ them to reduetion.
Referrin~ now more partieularly to Fig. 1 of the drawin~s, reterenee ~`
number 10 represents a primary ore reduetion vessel, 70 a cokin~ vessel for the destruetive distillation of eoal and a seeondary reducin~ ~as ~eneration and 130 a hi~h temperature vessel for primary ~as ~eneration, -the tinal reduction, the meltdown of eontingencies and refinin~ and ' eonditioning the heat for eastin~

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The primary ore reduction vessel 10 comprises an upri~ht casin~ 11 havin~ a hopper 12 at the top to receive powdered ore. The hopper 12 includes funnel-shaped bottom wall 14 with a central outlet 16 at the upper end of a short passage 17 leadin~ to a preheatin~ zone 18. The passage 17 must have some means of preservin~ a pressure differential between zone 18 and the atmosphere.
The pressure preservin~ means may be provided by any suitable mechanism, e.~., a conventional ~as lock as illustrated, a fluidized system for conveying finely divided ore into hopper 12, and the like. Where the passage is provided with a ~as lock, it may comprise an independently movable upper bell 13 closable a~ainst a suitable seal at the bottom of passa~e 17, an invened frustoconical chamber 19 havin~ its upper periphery secured to a wall 20 slopin~ down from passa~e 17 and its lower end formin~ a seal with a lower bell 15 closable a~ainst the mouth of chamber 19. Bell 13 has a hollow operatin~ rod 13a connected to it.
Bell 15 has an operatin~ rod 15a connected to it which passes up throu~h hollow rod 13a.
Each operatin~ rod extends upwardly far enou~h for an operator or mechanism to move the bells up and down. In use, the upper bell is lowered to permit material enterin~ the vessel 10 to fill the chamber 19, raised to close the inlet into it, the lower bell is lowered to permit the material in chamber 19 to flow into the zone 18, and then the lower bell is raised a~ainst its seat. Where a fluidized system is used, it would be similar to the fluidized system for vessel 152, as described hereafter.
Ore particles flowin~ throu~h chamber 19 enter the preheating zone 18 in which said upper wall 20 slopes downwardly to wal' 11 to which it is secured. The enterin~ particles fall into a centrally located distributin~
means 22 in the form of an upper inverted cone and a series of spaced inverted 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.

The openings between the truncated cones permit ~asses (I) to flow -- ~ -outwardly into and upwardly throu~h the preheating zone in eontact with ``
the free surfaces 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 eonduct hot ~as from a source to be deseribed into the same spaee and into the powdered ore. Pipe 34 preferably is provided with a valve 35 to eontrol the flow of the hot gas through it. Preheated ore partieles flowing from the preheating zone 18 through outlet 26 enter a primary reduction zone 36 of whieh the upper wall preferably is the bottom wall 24 of the preheating zone. The strueture provides a passageway between the upper wall 24 and upper -~
surfaee of the partieles introdueed into ehamber 36 through outlet 26. A
~as outlet pipe 37 is provided whieh eommunieates with this passageway through wall 11 to withdraw gases therefrom. The gaseous diseharge throu~h eonduit 37 will be largely earbon dioxide and water vapor with a small pereenbge of earbon monoxide and hydrogen. Gas inlet pipe 34 reeeives the ~ases it supplies to preheating zone 18 from outlet pipe 37 and these gases have both labnt heat and redueing ~ases that are of "signifieant value as a fuel when oxidized with air from inlet pipe 32. ;
Gases flowin~ out of zone 36 through eonduit 37 whieh are not diverted ; `-into pipe 34 may either be used as alternate fuels or stored for future use. ~ ~i The lower wall 38 of zone 36 is a downwardly sloping helix of spaoed, eontraetin~ turns of a metal ribbon. -This strueture forms a funnel shaped, eontraeting bottom wall.',.,'J~' ,,'"
havin~ a eentral outlet 40. Near the midpoint of zone 36 is a distributing means 42 whieh is similar in strueture and funetion to distributing means 22. The easing 11 is provided with a eooling agent inlet pipe 44a, the inner end of whieh terminates under the distributing means 42. ;;

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- 2~24~6 A further primary reduction zone 46 is provided below zone 36 into which the ore particles flow throu~h outlet 40 onto a distributin~ means -48 similar in structure and function to distributing means 22. The upper ~ -wall o' zone 46 preferably is the lower wall 38 of zone 36 and its bottom wall is a helix 50 similar 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 eonduit 58 whose function will be described hereinafter.
Casin~ 11 is preferably provided with additional coolin~ agent inlet pipes 44b, 44c, and 44d. Pipe 44b terminates in the passa~eway under the bottom wall 38 and above the upper level of partieles in zone 46. Pipe 44c terminates in the open spaee under distributin~ means 48. Pipe 44d terminates in the spaee between the bottom helix 50 and bottom wall 54.
Coolin~ agent inlet pipes 44a, 44b, 44e and 44d may have a eommon manifold (not shown) eonneeted to a souree of eooling agent, if desired, or they may be individually supplied with one or more eoolin~ agents from one or more sourees thereof. Casing 11 has an inlet openin~ 64 into the spaee between the bottom helix 50 and bottom wall 54 for a eonduit 118 having a valve 68a, 68b, and 121b therein for a purpose deseribed hereinafter. The ores introdueed at the top of vessel 10, after treatment in it, are disehar~ed through eonduit 58.
Means must be provided at this outlet to preserve the pressure differential between the inside of vessel 10 and the atmosphere, just as ~-means must be provided for passa~e 17, as deseribed above. Here again a eonventional gas loek may be provided as illustrated sehematieally but preferably a fluidized eonveying system is provided by a feed serew 58a to move ore partieles from outlet openin~ 56 to a downward duet 58b where they are fluidized by a jet of gas from a venturi 58e and thereby eaused to flow through eonduit 58d into hopper 152 whieh is later deserlbed in detail. The fluidizin~ gas whieh eonveys the ore particles from outlet 56 into hopper 152 is returned from the hopper 152 by eonduit 58e with the aid of pump P to venturi 58e. The fluidized system will also maintain the proper pressure in vessel 10 when the pressure in vessel 130 ;;
is lower or higher than the pressure in vessel 10. The ves~el 70 eomprises an upright easin~ 71 having a hopper 72 with a funnal-shaped bottom wall 74 at the upper end thereof to reeeive powdered eoal.

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While any coal may be used, one advanta~e o~ the present invention is the low ~rade 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 havin~ parts like those for hopper 12, or a fluidized system to supply the finely divided materials, somewhat fluidized 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 casin~ 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 flowin~ through outlet 76 into zone 78 fall upon a centrally located diverter 81 similar in structure and function to 22, 42,~ ~ `
and 48 in casin~ 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 dividin~ wall 86 in the ;
casin~ to which its outer periphery is connected. It is provided with a central outlet opening 88 ali~ned with openin~ 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 ~as inlet by means of a spaced under wall 86b for a purpose later described. The material flowin~
out of he first Intermediate zone 88a enters a second intermediate zone -;
a8b in which there is ~ distributor 81b, a helix 82b, and a double bottom ;~
wall 86c and 86d, all similar in structure to the parts of the first ;
interrnediate zone 88a. ~

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The mat~rial flowin~ out of the second intermediate channel 88b flows into a lower zon~ 90 and onto a distributin~ 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 openin~ 96. Helix 94 is spaced somewhat above the bottom wall 98 of casing 71 which pr~ferably is funnel-shaped with and outlet opening 100 connected to a conduit 102 havin~ 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 dischar~es into line 120, as more fully described hereinafter.
A coal ~as 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 ~as 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 therethrou~h.
The central openinps in helix 82a and helix 82b are smaller in diameter than the central openin~s in plates 86a and 86b of the first intermediate zone 88a and the plates 86a and 86b of the second intermediate zone 88b so that the stream of particles flowing 1rom the first intermediate zone 88a into the second intermediate zone 88b and trom the second intermediate zone 88b into the lower zone 90 leaves a space between it and the periphery ot the central openings in which 86b and 86d for ~as to flow upwardly from zone 90 into zone 88b and trom zone 88b into zone 88a. The lower plates 86b and 86d extend somewhat further Inwardly than upper plates 86a and 86c so that gas tlowing through the space between them flows only upwardly into the zone above .
it.

202423~ ~
The object of the structure in the lower zones of vessel 70 just described is (1) to permit the hot ~asses 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 reactin~ 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 8Bb or line 110 as a conveying and reducing sas to vessel 130. (2) to permit introduction of C02 and/or steam into the hot rising ~ases 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 further introduction of C02 and/or steam into the partially cooled -~-~
~ases from zone 88b flowing into zone 88a and from it throu~h 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 b~fore being stored if desired, permittin~ further coolin~ (not shown).
In the event that the gas tlowing through conduit 118 from the second intermediate zone 88b is at a higher temperature than desired, it may be physirally 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 ~as from the first intermediate zone 88a withdrawn by pump 114a through conduit 110a and introduced into passageway 118, through passageway 120b controlled by valve 68a.
The apparatus enables an operator to have full control over the temperature of the gas entering the bottom of vessel 10 by the simple expedient of opening valves and operating pumps. If desired, temperature probes (not shown) may be used with meters (not shown) to electrically ; ;-rnonitor 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 tG supply steam from a sultable source (not shown) into the combustion zone in hi~h temperature vessel 130. Line 122 has a valve 126 therein to control the flow of steam into v~ssel 130.

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A line 124 also communicates with vessel 130 by way of line 120 to permit introduction into vessel 130 of fluxin~ and purifyin~ in~redients from a suitable source (not shown). Line 120 has a valve 128 in it in advance of the inlet into it of the dischar~e from the ball mill 105. Valve 128 enables the flow 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 ~as leavin~ secondary ~as ~eneration 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 hi~h temperature vessel 130, to the primary reduction zone 46 in vessel 10, or for storage in stora~e unit 121 to ~ive (1) ~ases flowin~ throu~h va~ve 128 conveys fuel and assists in the process of full reduction and melt down at relatively hi~h temperatures in vessel 130, (2) blendin~ a tempered reducin~ ~as with ~as comin~ from chambers 88a and 88b for primary reduction of ores at optimum temperatures in zone 46 of vessel 10, (3) continuation of process in vessel 10 when vessel 130 is batchin~ out.
Recirculatin~ ~as flowin~ throu~h conduit 110 from chamber 90 and outlet ~as of vessel 70 ~enerated in vessels 130 and 70 in excess of the quantity drawn off throu~h 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 emined throu~h line 106 and may also be drawn off throu~h line 120a under control of valve 6B for storaQe in tank 121 for further use, as described. Gas flowin~ through valve 128 passes th-ou~h 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 throu~h lines 122 and 124, as described.

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~2~3~
Vessel 10 preferably operates continuously while vessel 70 operates semicontinuously and 130 operates semicontinuous and batch-wise. Gas flows from vessel 130 into vessel 70 throu~h openin~ 172 by way of lines 156, 158, and 170. This flow may be stopped or retarded when vessel 130 is dischar~in~ sla~ or steel. Stora~e tank 121 may at that time be caused to dischar~e ~as stored in it throu~h line 121a and control valve 121b into line 118 and through it into vessel 10. The ~as flowin~ into vessel 10 trom cooler zone 88a through lines 110a. pump 114a, lines 120b, valve 68a and line 118, and from 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 hi~her than desired, it may also be blended with the proper amount of cooler ~as from tank 121 supplied to line 118 throu~h line 121a and control valve 121b.
An oxy~en supply line 132 is connected at one end to a suitable oxy~en 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 ot oxy~en into the combustion zone just above the `
molten metal bath in vessel 130. -A slag outlet notch 142 at the level of a sla~ layer tormed 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 tormed in the ;~
bonom of vessel 130, on which the sla~ layer floats, permits purified hot metal to be drawn off as desired from openin~ 142 is also opened and closed in customary tashion.
The upper end 146 of vessel 130 is secured to an inlet pipe 148 a considerable distance above its lower end to provide a tree-tlow outlet passa~e at the top of vessel 130 as fine material flows throu~h a common - :~line 1~0 from hopper 152 for partially reduced iron ore, e.~., Fe, FeO, and from hopper 154 for sla~ in~redients, e.g. calcium oxide or carbonate with or without man~anese 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 tluidized conveyin3 system and screw feedin~ of material for each hopper as illustrated for hopper 152.

19 ' ~:.
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.2.~;~3~ :
An outlet line 156 communicates at one end with the ~low channel at the top ot the hi~h temperature vessel 13û and at the other end tan~entially with the side wall 158 of a cyclone separator 160 havin~ 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 ~as outlet from separator 160 Solid particles separated by centrifu~al force from the swirlin~ ~ases removed form vessel 130 in cyclone separator 160 fall to the bottom and are conducted by a funnel-shaped bottom wall 164 into an outlet pipe 170, which is connected at its other end to vessel 70 through an openin~ 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 ~as flows from the separator 160 throu~h line 166 into the flow channel in vessel 70 between wall 94 and wall 98 throu~h an openin~ 176 in wall ~1 Dampers 174 and 178 control ~-the division of flow of the ~as into upper or lower zones of vessel 70 Gases dischar~ing from vessel 130 are divided by valve 178 and valve 174 Gases communicatin~ with zone 78 will coke the coal by destructive distillation and ~ases communicatin~ with zone 90, will be re~enerated, and chemically cooled and will continue to the hi~h bmperature vessel 130 or conducted to tho primary reduction vessel, or stored in vessel 121 ;~
for lat~r us- in the primary reducin~ zone ~;
Th- v ss-l 10 is for partially reducin~ the iron ores, the vessel 70 b tor destructive distillation of coal to produce coke and to recovering wast heat from the hi~h temperature vessel in the production of a ; ~ `
r ducin~ ~as, the hi~h temperature vessel 130 is for final reduction, m-ltin~ and purifyin~ the metalics These operations are joined into a `
u nihry combination by the interconnecting pipin~ capable of carrying out the ~process of the invention and achieving the numerous advantages and ~ ~-b nefit described above It represents the best emDodiment of the apparatus of the invention presently known but, as those skilled in the art - ~;
wlll understand, variations and modifications thereof may be made ;~ -;
without departin~ from thei scope of the apparatus aspect of the invention - ~;
as defined in the claims below ; ~
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The process of the invention comprises the combination of steps or operations of (A) destructively distillin~ coal to form coke a by-product gas and a reducing ~as, (B) partially reducin~ fine iron ores with said reducin~ ~as, (C) introducin~ said partially reduced ores into a hi~h temperature zone with said coke, oxy~en, steam, and recirculated ~as to complete the reduction of the iron ores to metal in molten condition, (D) purifyin~ the molten metal with a slag comprisin~ calcium oxide with or without manganese oxide; and (E) removing molten purified metal and slag separately or to~ether trom the hi~h temperature zone. The process is preferably carried out continuously, although it may be carried out semicontinuously or batchwise, in the secondary reduction hi~h temperature zone, if desired. Other process modifications and variations may be made, as those skilled in !he art will reco~nize and understand, without departin~ from the scope of the invention as hereinafter defined.
Referrin~ now to Fig. 2, and Fi~. 3, the vessel 130 has a lower bowl-shaped end 180 comprising an inverted frustoconical wall 181 having a plurality of tuyeres 182, 182a, and 182b therein and a bottom reservoir 184 where molten metal and sla~ may flow. The tuyeres 182, 182a, 182b may vary in declination and inclination from horizontal to a downward slope toward the interior of the vessel, as seen in Fi~s. 2, 3, and 4. Fi~. 3 shows that the fluid flow may also be at an an~le tan~ent to the vertical axis V - V of Fi~.2. Fi~. 3 shows three (3) tuyeres 182, and three (3) ;
tuyeNs 182a, and three (3) tuyeres 182b. Tuyeres 182 serve to introduce oxy~en into vessel 130, Tuyeres 182a and 182b serve to introduce (fuel), coke, steam and reducin~ ~as. but more or less may be provided, if desired.
The jets of ~as enterin~ the tuyeres 182, 182a, 182b as seen in Fi~. 3, serve to impart a clockwise or counter clockwise rotation, to the ~ases and the liquid contents of the vessel.

~24~
Fig. 4 illustrates the preferred structure of a rotatable nozzle 186 for introducin~ ~as through tuyeres 182, 182a, and 182b into the hi~h temperature vessel at various angles. The inner end 188 of nozzle 186 is sli~htly arcuated so that the direction of flow of jet of ~as flowin~
through it can be changed by rotating the nozzle, as illustrated by the lines extending outwardly at different angles from the end f !he nozzle.
A gear 190 symbolically depicts a turnin~ mechanism for the nozzle. This simple means makes adjustment of the directions of the jet of gas into the bottom of the hi~h temperature vessel very easy and has the ~reat advantages of enablin~ an operator to control the process carried out in the vessel 130. An alternative control of the directional flow of the ~as may be obtained by the installation of multiple tuyeres of fixed but different angles and by select;vely controllin~ the flow of ~as into selected tuyeres to ~ive the optimum an~le of introduction of ~as for a given process.
In earrying out the method aspect of the invention in the apparatus thus described, the partially reduced iron ore is introduced into the hi~h temperature vessel 130 through inlet tube 148, which may be provided with helieally-shaped fins (not shown) to impart a swirlin~ motion to the partieles, eausin~ them to travel outwardly by eentrifugal force as they --leave the tube 148. The partieles are allowed to fall freely in -eountereurrent relation to the upwardly flowing vortex of swirling eoneentrated redueing ~as at high temperature which has been generated -~
from the hi~h temperature eombustion of the fuels and oxygen introduced from lines 120 and 132 through the tuyeres 182, 182a and 182b from ; ~ -nozzles 186 as deseribed above. The falling partieles are somewhat bouyed up by the risin~ gas whieh decreases their rate of descent. ~;

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The swirlin~ motion imparted to the descending particles by the fins and swirlin~ vortex of reducin~ gases throws them a~ainst the refractory ~;
linin~ of vessel 130 where they form a linin~ blanket over the refractories and between the intense heat from the combustion ~one. This counterflow movement of particles and ~ases causes the gases at their hi~hest temperature and concentration to react with the hottest and most nearly reduced iron o~ides in the lower part of vessel 130 to effect almost complete reduction thereof to metal in molten state which then eollects in reservoir 184 while the rising gases at suitable temperature and eoneentration to react with the lower temperature and more hi~hly oxidized falling particles.
The metal layer formed by further reduction of iron ores to iron is so controlled as to contain some iron oxides as an oxy~en earryin~ agent to obstruct the production of silieon and assures the removal of excessive earbon and what traees of FeS that may remain and the phosphorus as described later, this condition persists almost up to time of draw-off to assure their removal. The final deoxidizing of iron oxide before tapping is aeeomplished by increasin~ the flow of earbon monoxide, and eausing it to impinge and pieree into the metal layer from tuyeres 182b while retarding or stoppin~ the iron oxides from flowin~ into hi~h temperature vessel 130.
At this time oxy~en will be injeeted into the high temperature vessel through tuyeres 182 direeted above the molten bath. Recireulatin~
~as and earbonaeeous fuel will be injeeted into the vessel above the oxy~en throu~h tuyeres 182a and below the oxygen through tuyeres 182b.
The oxy~en and fuel ratio may be adjusted to oxidize the fuel to form eoneent~ated earbon monoxide ~as or eoneentrated earbon dioxide, depending on the intensity of the heat and the volume of the gas desired whlle raisin~ the bath to desired tapping temperature. Carbonaeeous materials may be added to the metal bath by means of tuyeres 182a and 182b to ~ive desired earbon level to heat of steel prior to tapping. `-:, , 2~2~236 It is preferred to oxidize the tuel favorin~ carbon dioxide at this period to obtain a hi~h ratio of ener~y to the volume of ~as ~enerated in the hi~h temperature vessel. The object is to deoxidize the heat of steel while raisin~ the carbon to the desired carbon levels and the temperature to optimum tappin~ temperature. Excessive heat energy can be recovered in this phase by injectin~ carbonaceous material at an elevated position above the combustion zone (not shown) producin~ an endothermic reaction with the products of combustion, or the combusted ~ases can be conducted to the destructive distillation zone (78) and secondary ~as ~eneration zone (90, 88b, and 88a) in vessel 70 where heat ener~y can be utilized for destructive distillation of coal and r~coverin~ and convertin~ heat ener~y to chemical energy (described later). However, it is desirable for the recirculating gas injected into the bath o~ steel to be nearly 100% carbon monoxide and heated to temperatures o~ 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 oxy~en to carbon monoxide and elevate this reducing ~as 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 tlow upwardly through coke in the lower secondary gas ;~~eneration chambers 90, 88b,and 88i of vessel 70 where the latent heat in the gases furnishes sufficient ener~y 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 læ, 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 conditlons as desired in the various zones in th~ vessel 130.

:'. '~' ;.
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24 ` ~`.

.-The gases introduced throu~h tuyeres 182, 182a, and 1~2b are of ~our types, viz. oxy~en, 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 10û% effective reducin~ agent, carbon monoxide and hydro~en. The followin~ equations illustrate how different effects may be realized in the lower combustion zone by the proper application of these gases: (1) Oxy~en when reduced by carbon fuel to form carbon monoxide releases heat ener~y accordin~ to the equation O2 + 2C --->
2CO I 53,600 calories. (2) Carbon dioxide when reduced by carbon fuel to form earbon monoxide absorbs ener~y accordin~ to the equation C02 + C --->
2CO - 40,700 calories. (3) Steam reduced by carbon to form hydro~en ~as and earbon monoxide absorbs ener~y according to the equation H20 + C ---, H2 + CO - 27,000 calories.
Reactions whieh take place in the upper reaction zone of vessel 130 are illustrated by these equations: (4) Reduction of iron oxide by carbon monoxide releases energy aceordin~ to the equation CO ~ FeO ~ Fe ~ C02 +
2,340 ealories. (S) Reduetion of iron oxide by hydrogen absorbs energy aeeordin~ to the equation FeO I H2 Fe ~ H20 - 7874 calories.
When it is desired to inerease the temperature simultaneously in the -lower eombustion and tusion zone and in the upper reduetion zone, exygen is inereased with enough carbon fuel (coke) to reduce all the oxygen to carbon monoxide. In the lower zone, it takes place aeeording to equation (1) and in the upper zone aeeordin~ to equation (4).
When it is desired to deerease the temperature in the lower combustion zone and inerease the temperature in the upper reduetion zone, carbon dioxide (or the regenerated gas from ehamber 90) is increased with suffieient carbon present to reduee it to earbon monoxide. In the lower zone this takes plaee aeeording to equation (2) and in the upper zone aceording to equation (4).
When it is desired to deerease the temperature in both upper and lower zones, steam is inereased with sufficient carbon present to reduce it to hydrogen and carbon monoxide. In the lower zone this takes place aerording to equation (3) and in the upper zone aeeording to equations (4) and (5) with a net effeet of ^5,530 ealories. The produets of reaetion and the energy of these same reaetions are earried over into vessel 10 atter being revitalized in vessel 70, whieh reaetions in the upper zone of vessel 130 somewhat ereates a shadow effeet to the reactions tollowing in vessel 10.
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These equations show that the temperature can be re~ulated in the lower combustion zone and in the upper reduction zone to a degree while maintainin~ full flow of concentrated reduction gases.
In the event that the primary reduction o~ the ores takes place faster in vessel 10, than the melt down proceeds in vessel 130, the 100%
effective reducin~ gas ~enerated, as explained, could be moderated as a reducin~ gas and intensified as a heatin~ medium in varyin~ degrees by decreasin~ the amount of carbon that follows the oxy~en so that the sases generated could approach 100% carbon dioxide; in this way the rate of the processes of reduction and meltin~ proceedin~ in vessels 10 and 130 can ~;
be balanced.
This procedure could also be used when supplementing shredded or sponge metalics when desirin~ 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 followin~ equations: i (5) O2 1 2C ~ 2CO ~53,600 calories ~ .';;
(6) O2 ~ C ~ CO2 ~94,400 calories By decreasin~ the amount of carbon tollowin~ a given amount of oxygen in equation (5) to equation (6? the volume of the combustible products decreases by 50/O and the amount of heat released increases by 176%. These equations show that the intensity o~ heat can be increased up to 352% by decreasin~ the carbon to oxygen ratio. ; `
The excessive ener~y released by increasin~ the oxygen to carbon ~ :~
ratio in vessel 130 to augment the meltin~ of the metalics, will be recovered in carbonaceous vessel 70, illustrated in the following equation:
(7) C02 ~C ~ 2CO - 40,800 calories.
The ener~y released in reaction (5) is equal to the net ener~y o~
reaction, in reactions (6) and (7). By increasin~ the heat intensity in `~
~quation (6) a lar~er portion of the ener~y can be utilized for meltin~ the ;
metalics and what excessive energy remains will be recovered in the lower chambers of the carbonaceous vessel 70. These equations show that the temperature can further be regulated in the lower combustion zone by extending and converting the upper reduction zone to a meltdown zone - ~`
whil~ maintaining full flow of concentrated reducin~ gases leaving the ~ -carbonacsous vessel 70. ~ -,.: -.
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202~2~
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As these reducing ~ases flow upwardly countercurrent to the descendin~ iron oxides, much of these gases will be oxidized to carbon dioxide and steam so that the ~aseous dischar~e throu~h conduit 156 will be partly carbon dioxide and steam, with a ~reater portion of carbon monoxide and hydrogen. The dischar~e temperature will usually be in the ran~e of 180ûo F to 3000O F. The ~aseous dischar~e 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 ~as ~eneration zones 90, 88b, and 88a, while a portion of the ~ases are passed throu~h the coke and then a portion is recycled to the vessel 130 as described above, and a portion continues to the primary reducin~ vessel ~0. The proportion of the ~ases that enters vessel 70 throu~h lines 166 and 170 is controlled by dampers or butterfly valves 174 and 178 which may, if desired, be manipulated so that the tlow may be restricted. This makes it possible to direct the flow of the dischar~ed gases to the upper chamber 78 and the lower chambers 90, 88b, and 88a of vessel 70 in desired vary;ng amounts while maintaining a hi~her pressure in vessel 130.
All regenerated gases tlow through the lower chambers 90, 88b, and 88a ot vessel 70 after which part may be returned to the high temperature vessel 130 throu~h conduit 120 and part may be diverted to the primary reduction vessel 10 by conduit 110b, blower 114b and conduit 118. The fluidized ~olid particles from 96, 100, 102, and 104 ~low almost as pure fluid throu~h 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 ~ases from hi~h temperature vessel 130 by re~eneratin~ a reducing ~as in converting hea~ -ener~y to chemical ener~y, (2) moderates the temperature of the reducin~
gases suitable for introduction into primary reduction vessel, (3 ) prepares a ~as useful for moderating temperatures in the combustion ~one, (4) chemically cools excessive temperatures in preparing the reducin~ ~as for use in vessel 10 or for storage, and (5) it lowers the temperature of the sases so they are useful for conveying solid fuels into the high temperature vessel 130, as described.

2Q2~2~
The pressure in vessel 130 is maintained several times hi~her than the pressure in vessel 70, e.~. 2 or 3 atmospheres in vessel 130 and 1 atmosphere in vessel 70.
The withdrawn ~ases that flow through conduit 170 into upper chamber 78 of vessel 70 serves several functions:
(1) Removal ot excess waste ~aseous products generated in the high temperature vessel, i.e. sulfur dioxide, carbon dioxide, steam, and phosphorus.
(2) Utilizin~ the latent heat contained in said waste sases 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 ~ases through the coal to remove su!fur contained in it. Sulfur is in a solid state up to a temperature ot 262 F., a liquid from that temperature to 832 F., and ;~ ~ ~
above that vaporizes successively as S8, S4, S2, and S which have ;
molecular wei~hts of 256.66, 128.25, 64.14, and 32.07 grams/mole respectively. The ~ases at hi~h temperature and hi~h flow vaporize the sulfur residue and carries it out of the coking system into the by-products ;
recovery means. Sulfur is also removed as hydro~en sulfide from this zone. Sulfur is thus removed from the fuel before contacting the ferrous products and contaminatin~ them.

(5) Removal of the suspended solids (dust particles) in the sub-micron ;
size ran~e by absorption in and filtration through 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.

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REMOVAL OF PHOSPHORUS ::

Phosphorus exists in the reduced metal layer as a dissolved chemical iron-phosphorus bond. To remove it from solution, it is oxidized, which is readily accomplished because of the presence of iron oxide in the slightly oxidized reduced metal layer and the phosphorus pentoxide floats 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 2730O 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 driving chemical action in the metal and slag layers is exactly opposite to conditions in other customary refining methods for the 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 oxidi~ed 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.

.
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2~2~3~ ~ ~
REMOVAL OF SULFIJR

The primary reduction vessel 10 has a plurality of different zones through which finely divided iron ores or concentrates flow Irom the feed hopper 12 throu~h inlet ~6. The upper zone in chamber 18 is a preheat zone which uses latent heat and tuel left in the gases from the reduction reaction lower down in vessel 10. Air or oxygen may be supplied to this zone throu~h pipe 32 in sufficient quantities to completely oxodize any tuel remainin~ in the ~ases and utilize heat of combustion as well as latent heat in the preheatin~ operation. The preheatin~ operation oxidizes the sulfides in the ore to sulfur oxides (S02) and removes it form the iron - -oxides in the ~ases that flow from the vessel throu~h conduit 28. This removes that portion of the sulfur in the ore enterin~ the system that would otherwise enter the molten metal from the ores used. What volatile sulfur or sulfides are in the fuel are remove as explained before in the functions of upper chamber 78. Any residue of sulfides remainin~ in the fuel are oxides to sulfur dioxide in the combustion chamber of vessel 130, as the fuel and oxy~en burn. What sulfur may find its way to the molten bath will be removed easily from the sli~htly oxidWn~ metal bath as iron oxides carry oxy~en to the sulfides and removes the sulfur as an oxide. -Gases ~enerated in seeondary ~eneration vessel 70 and in the hi~h temperature primary ~eneration vessel 130 are introduced into its lower ehamber 46 of vessel 10 by means of conduits 156, 166, 11Oa, 11ûb, 118, `and 66, are used to reduce the iron oxides of the ore in vessel 10 between partition 24 and bottom wall 54, sometimes referred to as the primary reduetion zones. The ~ases from vessel 70 are usually at a desired temperature and they have a relatively hiph content of carbon monoxide with some portions of hydro~en. As these ~asses reduce the iron oxides in ~-the ore, heat is produced which may cause the temperature to rise hi~h enough 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 reaetion of carbon monoxide reducin~ FeO with the endothermic reaction of hydro~en with iron oxide.
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Gaseous hydrocarbons and/or other coolin~ medium, includin~ coke or coal, may be introduced through pipes 44a, 44b, 44c, and 44d to further keep the temperature throu~hout the primary reduclion zone at optimum levels. Where coke or coal is included in the coolin~ 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 reducin~ the ores. Reactions that may occur in vessel 10 include the followin~:
A. Reduction with CO which are all exothermic: (i) Fe203+ CO ---> 2FeO +
CO2 + 38,260 calories.(ii) Fe304 ~ CO ~ 3 FeO + C02 + 15,660 calories .(iii) FeO + CO ~ Fe + C02 + 2, 340 calories. B. Reductions with reagents causin~ endothermic reactions: (iv) Fe304+ C --~ 3 FeO + CO -44,540 calories. (v) 4 FeO + 2 CH4 - > 4 Fe + 2 C02 + 4H2 - 61,986 calories. (vi) 2 FeO + 2C - ~ 2 Fe + 2CO - 34,200 calories. (vii) CO2 + C ---~ 2 CO ~ 40,700 calories. (viii) FeO + H2 ---, Fe H20 - 7,874 calories.
In carryin~ out the present process it is advisable to carry out the combustion reactions that produce much heat, i.e., the reaction of oxy~en with carbon tuel and reduction of iron oxide by carbon monoxide in the hi~h 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.~., 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 dischar~ed 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 hi~h temperature meltdown reduction vessel 130 to which the partially reduced ores are transferred by conduit 58d, which may be a skip, conveyor belt, au~er, pneumatic (fluidized) eonveyor, elevator, or the like, into hopper 152 from which the material flows into vessel 130 throu~h line 150 and inlet pipe 148. If desired, iron particles from other sources and spon~e iron may be added at the hopper 1~2 or an alternate hopper.

.~ ;. ... . - . . . . . . ~ , ... . ; .... .

2024236 ~-ln vessel 130 the reduction to metal in the molten state is accomplished, impurities are removed as described and the desired carbon and oxy~en content are established and hi~h enou~h metal temp~ratures are attained prior to batch tapping. Any desired alloying ingredients may be added before tappin~ or thereafter in the ladle (not shown) into which the molten metal may be caused to flow from vessel 130. By adding the alloying in~redients at this stage of the process, excellent control of the percentage thereof in the final alloy is assured. Any necessary final adjustments of earbon eontent may be made just prior to tappin~ or at the time alloying in~redients are added in the ladle. -~-While eoal has been deseribed as the preferred form of fuel, oil shale ean be used by makin~ sli~ht modifications in the apparatus. In ~eneral oil shale in ~ranular form is fed through vessel 70 in the same manner as coal.
In the upper part above 86, hydrocarbons are distilled from the shale and exit ~hrough duct 106 under eontrol 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 hydroearbons exitin~ throu~h duct 106 -may be returned to vessel 70 as deseribed below. If more hydroearbons are produeed than needed as fuels in the proeess, they may be refined in much the same manner as erude oil and be sold in eommeree.
Beeause the oil shale residue does not have any eombustible material '' in It when the hydrocarbons have been distilled off, it is neeessary to add eombustible material to the residue ~1) in zone 88a throu~h the spaee between plates 86a and 86b, (2) in zone 88b throu~h the spaee between plates 86e and 86d, and (3) in zone 90 throu~h duet 127. The oil sh~ie ~ ~
residue exitin~ from the midpoint of vessel 70, instead of bein~ sent to ~ -vessel 130 is disposed of in any suitable manner, as deseribed above, as it has not further value as a fuel in the proeess of the invention. However the residue may, to some extent, be utilized as a fluxin~ eompound as needed.
The hyqrocarbons distilled from the shale will be substituted for eoke and feed into line 120 by suitable means (not shown). The quality steel produeed by the proeess of the invention may be worked up into usable shapes and forms in the mannar eustomarily performed on quality steels produeed by -other methods known to the art.

Claims (5)

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

2. The process of producing quality steel directly from iron ore which comprises:
A. reducing iron ore under conditions which produce an oxidizing molten steel bath, B. introducing superheated reducing gas into said molten steel bath, C. introducing coke and oxygen above said molten steel bath, and D. withdrawing quality steel from said molten steel bath.

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

4. The process of producing quality steel directly form iron ore in which iron ore is partially reduced in a zone, then finally reduced in a high temperature zone in which carbonaceous material is oxidized which comprises:
A. 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 and carbon monoxide, and B. withdrawing quality steel from said high temperature zone.

5. The process of producing quality steel directly from iron ore which comprises:
A. forming a molten steel bath and floating slag layer from iron ore and slag ingredients by utilizing heat released from the combustion of carbonaceous fuel with oxygen to generate reducing gases, and B. withdrawing quality molten steel and slag.
7. The process of producing quality steel directly from iron ore which comprises:
A. partially reducing iron ore in a primary reduction zone, B. completely reducing said partially reduced iron ore in a secondary reduction and melt down zone, C. generating reducing gases in a separate zone;

D. 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. withdrawing quality steel from said melt down zone.
8. The process of producing quality steel directly from iron ore which comprises:
A. partially reducing iron ore in a primary reduction zone, B. generating reduction gases in a reduction zone and utilizing them to effect said partial reduction and partially oxidizing said gases, C. introducing carbonaceous material from the group consisting of carbon and hydrocarbon into said partially a oxidized gases which react therewith to convert heat energy into chemical energy and revitalize said reducing gases, and D. withdrawing quality steel.
9. The process of producing quality steel directly from iron ore which comprises:
A. producing reducing gases in a carbonaceous zone by an exothermic reaction;
B. introducing material from the group consisting of steam and carbon dioxide into said reducing gases to convert heat energy produced by said exothermic reaction to chemical energy which produces more reducing gases;
C. reducing iron ore to molten steel with said reducing gases; and D. withdrawing quality steel.

10. The process of producing quality steel directly from iron ore which comprises:
A. reducing iron ore under conditions which produce an oxidizing molten steel bath and gases to be exhausted which contain colloidal particles, B. filtering said colloidal particles from said exhaust gases by passing them 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. withdrawing quality steel form said steel bath.
11. The process of coking coal which contains sulfur in a generation zone which comprises:
A. vaporizing sulfur, and B. conveying it from the generation zone by a superheated forced draft.
12. The process 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 reducing it in a carbonaceous high temperature atmosphere and conveying it out of the system with a reducing forced draft.
13. The process of producing quality steel directly from iron ores which comprises:
A. partially reducing iron ores, B. introducing said partially reduced iron ores with slag ingredients into the upper part of a high temperature zone, and C. introducing powdered coke, oxygen, steam and carbon dioxide into said high temperature zone at a level well below the level of introduction of said partially reduced ores and slag ingredients to produce reducing gases which flow upwardly through downwardly moving partially reduced iron ore and form a molten steel bath at the bottom of said zones with a molten layer of slag floating one it.
14. The process as set forth in claim 13 in which the reducing gases formed in the process are recirculated and introduced partially into said molten steel bath and slag layer and partially above the slag layer.
15. The process of producing quality steel directly from iron ores which comprises, in combination, the operations of:
A. producing reducing gas and coke from coal, B. partially reducing iron ores with said reducing gas, C. subjecting said partially reduced iron ores with slag ingredients, said coke and oxygen to high temperature in a zone to form a reducing gas to reduce said iron ores to metal in the molten state having a carbon content characteristic of steel, to form a slag floating on the molten steel to purify it and to attain a temperature in the molten steel bath sufficiently high for taping and casting, and D. removing molten steel and slag from the high temperature zone.
16. The process as set forth in claim 15 in which operation B is carried out semicontinuously.

17. The process as set forth in claim 15 in which operation A is carried out semicontinuously.
18. The process as set forth in claim 15 in which operation C is carried out semicontinuously.
19. The process as set forth in claim 15 in which the partially reduced ores and slag ingredients are introduced into the upper part of the high temperature zone and the coke and oxygen are introduced into the lower part of said zone.
20. The process as set forth in claim 19 in which reducing gases are formed in step A are introduced partially into the slag and partially into the molten steel.
21. The process of producing quality steel directly from iron ores which comprises, in combination, the operations of:
A. producing reducing gas and coke from coal, B. partially reducing iron ores with said reducing gas, C. subjecting said partially reduced iron ores with slag ingredients, said coke, oxygen, recirculating gas and steam to high temperatures in a zone to form a reducing gas to reduce said iron ores to metal in the molten state and to form a carbonaceous slag floating on the molten metal which contains phosphorus, D. oxidizing phosphorus present to phosphorus pentoxide and permitting it to rise to the carbonaceous slag layer, E. maintaining the carbonaceous slag layer at a temperature sufficient to reduce the phosphorus pentoxide to elemental phosphorus, F. vaporizing the elemental phosphorus.

G. removing the vapors from the reaction zone, and H. recovering the phosphorus from the vapors.
22. The process of producing quality steel from iron ores containing sulfides which comprises, in combination, the operations of:
A. producing reducing gas and coke from coal, B. partially reducing iron ores in a primary reduction zone with said reducing gas, C. oxidizing sulfides present in the ores in the primary reduction zone to sulfur oxides and removing them from the iron ores in the gases that flow from said zone, D. subjecting said partially reduced iron ores with slag ingredients, said coke, oxygen, recirculating gas and steam to high temperatures in a zone to form a reducing gas to reduce said iron ores to metal in the molten state as steel and to form a slag floating on the molten steel to purify it, and E. removing molten steel and slag from the high temperature zone.