US3814404A - Blast furnace and method of operating the same - Google Patents

Blast furnace and method of operating the same Download PDF

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US3814404A
US3814404A US00221900A US22190072A US3814404A US 3814404 A US3814404 A US 3814404A US 00221900 A US00221900 A US 00221900A US 22190072 A US22190072 A US 22190072A US 3814404 A US3814404 A US 3814404A
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zone
furnace
gas
gases
tuyeres
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H Claflin
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Kaiser Steel Corp
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Kaiser Steel Corp
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Priority to JP1211273A priority patent/JPS5544125B2/ja
Priority to US399260A priority patent/US3928023A/en
Priority to BE135964A priority patent/BE805223A/fr
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    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21B—MANUFACTURE OF IRON OR STEEL
    • C21B5/00—Making pig-iron in the blast furnace
    • C21B5/001—Injecting additional fuel or reducing agents
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P10/00—Technologies related to metal processing
    • Y02P10/20—Recycling

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  • ABSTRACT- A blast furnace of improved and more readily control- FUEL INJECTED lable operation which comprises three sets of tuyeres, i.'e.', the normal or primary tuyeres at the base or melting zone of the furnace, a second set disposed in the bosh or second zone, preferably above the middle thereof and below the mantel, and a third set of tuyeres disposed in a third zone above-the bosh zone and preferably just abovethe mantel.
  • the second and third tuyere sets are used to introduce reducing gas which mixes with that generated in the furnace to create, limit and control the second and third zones.
  • the furnace atmosphere and operation are controlled and temperatures regulated in each zone to improve permeability of the burden, rate and completion of the reduction and smelting of ore to hot metal and improved utilization of the burden coke by controlled introduction of increments of reducing gases into each of the second and third sets of tuyeres and thence to the furnace zones so formed.
  • Means of re-forming offtake stack gases and of generating reducing gas from a low cost source to provide reducing gases for such introduction are associated with the blast furnace in an advantageous embodiment.
  • a method of operation in reducing ores, for example iron ores, and a system for such operation with production of suitable reducing gases are also provided.
  • the invention relates to a method of controlling operation of a blast furnace by introducing reducing gas at two levels of such a furnace to form three controlled reaction zones, to improve the economy and effectiveness of the ore-reducing and smelting process.
  • This can be carried out in a system wherein a portion of the necessary reducing gas, containing carbon monoxide and hydrogen, is provided from outside the blast furnace by a converter which, among other things, can reform a portion of the blast furnace top gases as well as generate reducing gas in the process.
  • the modern blast furnace operator is searching for improved ways of advantageously controlling the blast furnace process.
  • the main effort has been to regulate the top and bottom inputs of the furnace in such a way as to reduce hot metal cost per ton, increase tons of metal, for example pig iron produced per hour, and make a uniformly satisfactory quality hot metal.
  • the present invention will make it possible to achieve these objectives by providing ways and means of creating and closely controlling three distinct zones within the furnace. Each such zone will perform its principal functions better than such furnace functions are presently performed and the operators ability to control what happens throughout the furnace will be substantially increased.
  • a major opportunity for reducing cost is by reducing the cost of the materials used to provide heat for the process and the reducing agent required to convert metal oxides such as iron oxide to the metal.
  • blast furnace coke is the most costly raw material used, and the supply of coking coal from which a suitable coke can be made is rapidly decreasing.
  • the various means previously known for reducing the coke requirements have included reducing blast furnace heat requirements by better burden preparation, e.g., by modifying the sizing or chemical composition thereof (a top input control), increasing the heat furnished by the blast and injecting materials into the furnace through the tuyeres or close above through auxiliary tuyeres (bottom input controls).
  • Thepresent invention by recognizing and providing a means of counteracting the conditions condu cive to irregular operations where they occur in the furnace provides a unique way of reducing the coke rate substantially before the troublesome conditions will reappear or the quality of the hot metal will become impaired.
  • the nature of the downward movement can be abnormal and portions of the burden may arrive at critical points in the furnace without being changed progressively in an orderly downward movement. Production may be lost or reduced, and variations in quality may occur.
  • the volume of the blast is reduced, often substantially.
  • the volume of blast introduced during the high volume blowing cycle plus that during the check period is less than couldhave been introduced at a steady lower blowing rate, the overall result is a reduction in the average tons of hot metal which can be produced per hour.
  • the amount of reducing gas generated from coke per ton of hot metal is reduced to the extent of the reduction in coke per ton of hot metal, increasing the likelihood that unreduced FeO will-reach a point low enough in the stack to melt before it can be reduced to iron. Then, when it is reduced to Fe, it tends to partially solidify, stopping up interstices.
  • Injections at the primary tuyeres such as steam, oil, coal tar, natural gas, crushed coal and crushed coke, are used to partially offset increased blast temperatures. Such injections. to varying degrees, reduce the flame temperature and also replace the reducing gas lost. The reducing gas generated from them, however, must, along with the gas generated from the remaining coke, push its way up through the critical bosh area in competition with an increased downward flow of slag and molten iron.
  • 0 blast enrichment such as the use of oxygen-enriched air, along with hydrocarbon injections at the primary tuyeres, can help to provide the high temperature heat requirements and can also make up fo the lesser volume of reducing gas as would be formed from the lesser amount of coke to be added in the burden. Such enrichment also reduces the volume of exit gas to the extent of the N from air replaced in the blast.
  • the adiabatic flame temperature at the primary tuyeres will increase if, to further decrease the total gas volume of inert N that must flow upward, more 0 is usedin the high temperature blast per ton of hot metal.
  • the burden charged at the top made up of metalbearing materials such as ore, sinter, pellets or the like, coke and fluxing materials, must be preheated as it moves down the stack, the metal sources must be reduced from the oxide to the metallic form and the slag and metal produced must be heated to required molten temperatures prior to withdrawal.
  • the molten temperature is so selected as to control the sulphur content of the metal.
  • the present invention departs from the prevailing concept of controlling the operation from the top and the bottom (what is charged at the top or what is blown in at the bottom through the primary tuyeres) and provides a means for creating three separate zones of activity where different functions will be performed in the most advantageous sequence. It also teaches the way they will be controlled to reduce undesirable overlapping and minimize the magnitude of conflicting activities.
  • This invention relates to a method of operating a blast furnace for the production of metals such as iron, nickel, copper, lead, etc.; and more particularly, it relates to such method wherein three zones of such furnace are controlled individually to provide more uniform operation thereof and to achieve advantageous ecological and economic results.
  • a primary, a secondary and a tertiary zone are provided in a blast furnace.
  • the primary zone which is that adjacent to the primary tuyeres, the flame temperatures attained or developed in front of each such tuyere are substantially higher than those normally developed in conventional blast furnace practice, and generally are over 1860C. for example.
  • the temperature in this zone or series of zones at the primary tuyeres is sufficient to bring the metal to casting temperature and to melt the slag so that these molten materials drop to the crucible at the base of the furnace and are drawn off in the usual manner.
  • the secondary or bosh zone is located adjacent to and extends above the primary zone, and the temperatures maintained in the secondary zone are below those in the primary zone.
  • the tertiary zone lies above the secondary zone and is a preheating, and reduction zone where metal oxide or oxides are reduced to form the corresponding metal.
  • the temperatures therein are close to but less than l000C., the highest temperature being found at the base of the zone or adjacent the second zone. These zones are disposed generally horizontally of the furnace.
  • a burden which consists essentially of, for instance, iron ore, coke and a flux such as limestone is prepared and charged in the usual way.
  • a set of conventional primary tuyeres is provided below the bosh and serves to introduce into the primary zones a blast of air or of oxygen-enriched air, heated as will be described, into the base of the furnace.
  • the auxiliary fuels commonly used in the operation of blast furnaces such as natural gas, powdered coke, powdered coal or fuel oil and combustion is carried out to bring the temperature in the primary zones to the desired level.
  • the primary zone extends from the mouth of therespective primary tuyere at least to the carbon grate formed in the bosh zone from the furnace burden coke.
  • the primary zone there will be generated all of the high temperature heat which is required to melt the metallic product and the slag and to provide other secondary zone heat requirements, and maximum practical adiabatic flame temperatures, e.g., of over 1800C., are obtained in these zones.
  • the adiabatic flame temperature is intended to mean the temperature at the hottest point of the flame.
  • these high temperatures can be obtained by using blasts of high temperatures and by incorporating a substantial amount of oxygen therein, e.g., from 25 percent to 100 percent oxygen, the remainder, if any, being air.
  • the highest available blast tempera tures and a large percentage of oxygen in the blast are used in consuming the coke and auxiliary fuels injected at the primary tuyeres. Injections will be controlled to make possible the flame temperatures required.
  • oxygen addition can be increased if less than percent is being added, to reduce the volume of gas moving upward by eliminating nitrogen.
  • the higher gas temperatures in the primary zone will not cause the complications normally experienced because the smaller volume of gas will readily be reduced in temperature by introduction of reducing gas at a lower temperature at the secondary tuyeres.
  • the temperature of the upwardly moving gas (measured at several points), top gas composition, stack pressures and stock movement downward will all be monitored. The rapid changes they indicate should be made to achieve the production rate sought and are brought about largely by adjusting the gas temperature, volume, pressure, and composition at one or several tuyere inputs.
  • the reducing gas stream formed in front of the primary tuyeres is added to and modified as it moves up the stack by reudcing gas introduced into the second and third zones through their respective tuyeres.
  • the reducing gases react with the metal oxides to form CO and H 0 and the corresponding metals, for example, iron.
  • the second or secondary'zone will include the balance of the bosh area extending upward from adjacent the primary zones to just below the mantel, that is, the bosh area not in the primary zone. The temperature in this zone is slightly less than those in the primary zone.
  • the second set of tuyeres is disposed around the periphery of this zone in its upper portion and below the mantel.
  • the temperatures within the second zone generally will range from less than flame temperatures at the bottom of such zone to about 1000C. at the top of the zone.
  • the height of this zone will be limited by injection of reducing gas at a controlled temperature, which has been generated outside the furnace and which is introduced through the set of auxiliary or second set of tuyeres, located near the top of the zone.
  • the second zone there occurs melting of substantially all or at least a major portion of the reduced metal products, such as metallic iron and its metal impurities, and the slag-producing burden materials.
  • the coke forms a constantly renewed carbon grate through which molten material must flow downwardly and through which the gas which is generated in the primary tuyere zone must move upwardly.
  • the CO present therein is reduced to CO.
  • Some of the carbon of the coke is absorbed by the hot molten metal.
  • the reduction of the iron oxide to metallic iron is at least partially etfected and accomplished to a much greater degree in the third or tertiary zone, that is, in the preheating or preliminary reduction zone, than in the usual blast furnace operation. Therefore, there is less consumption of carbon in the bosh area than in the usual blast furnace operation.
  • the coke requirement is reduced further when oxygen additions are made at the primary tuyeres sufficient to reduce the amount of gas flow per ton of hot metal. The heat available at over lOC. is increased, resulting in an increased high temperature heat utilization per pound of coke consumed.
  • the volume of gas flowing upwardly through the most constricted portion of the carbon grate, that is, through the bosh area, per ton of hot metal is substantially reduced by the method of the present invention; and downward counterflow of molten metal and slag per ton of hot metal is also decreased because of the reduction in coke ash, inasmuch as less coke is consumed per ton of hot metal.
  • the generation of ash, if any, from injected hydrocarbon occurs in major part below the most constricted portion of the coke grate where the counterflow problem is minimal, so that this ash also poses less of a problem.
  • the third or tertiary zone is primarily a preheating and reduction zone where the burden is brought up to temperature and the reduction of iron oxide is substantially effected.
  • This zone extends from adjacent the top of the bosh or the mantel to the top of the column of burden and is formed by the reduction in temperature of the gas stream flowing upwardly from the second zone and by adding reducing gas to this gas stream through secondary tuyeres.
  • a set of auxiliary tuyeres that is, a third set of tuyeres, is disposed in the furnace stack wall, suitably just above the mantel.
  • Additional amounts of a reducing gas are introduced through this third set of tuyeres and provide CO and-H to effect reduction of the iron oxide of the burden.
  • a major portion of the metallic burden is reduced to fonn the corresponding metal and CO and H 0 where hydrogen is present, with no solution loss or substantial back reaction to CO and H respectively.
  • Suitable bustle pipes or other means to supply gases to the second and third sets of tuyeres are also provided in the conventional manner, or as desired.
  • a portion of the top gases issuing from the blast furnace are sent to a converter or to a converting zone where they are reduced for example advantageously by reaction with non-coking coal particles, to re-form CO and H by reaction of the carbon of the coal with the carbon dioxide and water vapor in the blast furnace gases.
  • the reformed reducing gas is'then recycled to the second and third zones to provide the' gaseous reducing agents described above.
  • Gases issuing from furnace zones other than the blast furnace zone described above, and containing substantial amounts of carbon dioxide, carbon monoxide, and water vapor can also be introduced into the gas converter wherein carbon monoxide and hydrogen are re-formed and the re-fonned and heated gas mixture recycled back to the indicated zone, or zones, of the blast furnace.
  • an oxygen-enriched blast is advantageous not only in increasing flame temperatures in the primary tuyere zone but also in reducing the volume of gas which must move upwardly through the coke carbon grate located mainly in the adjacent portion of the secondary or bosh zone, that is, in the highest temperature portion of the second zone. To attain maximum production, it is necessary to reduce the gas volume/ton of hot metal through this area where upwardly moving gases must compete for interstitial space with the downward flowing molten material.
  • Another advantage of an oxygen-enriched blast is that the substitution of oxygen for air, or for part of the air, in the blast reduces the amount of water vapor introduced in the blast and thus saves the heat which would be consumed in effecting disassociation of the water vapor to hydrogen and oxygen.
  • Burden coke requirements can be reduced because the combination of the high blast temperatures useable and an oxygen enriched blast generates more high temperature BTUs per pound ofburden coke and injected fuel consumed. Also, some of the heat requirments are reduced, there is less steam to be disassociated, the
  • a particular advantage of this invention is an increase in the production rate when operating a blast furnace according to the method of this invention.
  • the production rate is increased, at least in part, as a result of reducing the volume of gas coming out of the primary tuyere zone per ton of hot metal and which must flow upwardly through the most congested portion of the furnace burden.
  • the system of the present invention has great advantages in that basic oxygen fumes which contain dusts, e.g., iron oxide dusts, of very fine particle size and which are thus difficult to collect and to dispose of without danger of water and air pollution can now be put to good uses.
  • dusts e.g., iron oxide dusts
  • they can be readily utilized as a source of metal and of utilizable oxygen as injections into the tuyeres of the gas converter.
  • roll scale can be utilized in such a converter
  • the top gases from the blast furnace itself can be recycled in a closed system as described herein, avoiding the exhaustion to the atmosphere or the dumping of the finer collected particles or sintering them in a sinter plant equipped with a baghouse that is costly to acquire and operate.
  • the system provided in this invention thus also enables economic disposition of these steel plant wastes and avoids substantial pollution of the environment.
  • FIG. 1 is a schematic vertical sectional view of a blast furnace and associated equipment according to the present invention which are suitable for carrying out the process of this invention.
  • FIG. 2 shows schematically a system suitable for carrying out the present invention, including a converter device.
  • FIG. 1 shows schematically a cross section of a modified blast furnace 45 having three sets of tuyeres, i.e., a primary or conventional set 21 disposed around the periphery of the furnace 45 in the hearth or melting zone, a secondary set 46 disposed similarly in the bosh zone and a third set 47 disposed in like manner just above mantel 48.
  • a primary or conventional set 21 disposed around the periphery of the furnace 45 in the hearth or melting zone
  • a secondary set 46 disposed similarly in the bosh zone
  • a third set 47 disposed in like manner just above mantel 48.
  • a gas converter 54 of any desired type where they are reacted with a carbonaceous reducing agent to reduce the CO and H content to CO and H respectively, and these re-formed reducing gases are now sent to a pair of manifold or bustle pipes 35, 36 to which are connected tuyere sets 46 and 47, respectively, so that the reducing gases can be injected into the furnace.
  • the temperature of the gases injected into tuyere set 46 is advantageously from about 900 to about I000C. so as to mix with and cool the gases moving upwardly from the first zone.
  • the temperature of the blended gas stream is close to 1000C. by the time it reaches the upper end of the second zone.
  • the gases withdrawn from converter 54 or another type of such device may require a cooling treatment, to attain the aforesaid object, before being injected into tuyere set 46 and can be cooled in any desired device (not shown) or by blending with unprocessed blast furnace top gas as shown in FIG. 2.
  • the gases injected into tuyere set 47 are advantageously at a temperature close to I000C. They provide a gas mixture with the upward-flowing furnace gases having a temperature close to but less than about I000C. and if necessary are also cooled before entering manifold 36 by being blended with blast furnace exit gas through gas line 52 as shown in FIG. 2.
  • Temperatures at two points in the second and third zones are suitably measured by conventional thermocouples 42 and 44, respectively,connected to suitable recording devices (not shown). That is to say, temperature sensing means are associated with each of the sets of auxiliary tuyeres and are disposed in the secondary and tertiary zones.
  • the schematically illustrated blast furnace 45 of FIG. 2 as in the case of the furnace 45 of FIG. 1 is provided with a primary set of tuyeres 21, a secondary set 46 and a tertiary set 47.
  • Each set of tuyeres is disposed around the periphery of the blast furnace forming a circle of each set in the usual manner, primary tuyere set 21 being disposed in the hottest or hearth zone of the furnace, secondary set 46 being disposed in the upper portion of the bosh zone and below the mantel 48, and tertiary set 47 being disposed just above the mantel and at the bottom of zone 3 of the furnace.
  • Primary tuyeres 21 are provided with a conventional bustle pipe 14 which feeds to the tuyeres a hot blast, preferably substantially hotter than normal practices and wherein the blast can be air of oxygen-enriched air, for instance.
  • each individual tuyere in the secondary set of tuyeres 46 is disposed vertically directly above a corresponding tuyere in the primary set of tuyeres 21; and each tuyere in the tertiary set 47 is disposed in offset fashion above and on a vertical line suitably midway between, corresponding tuyeres in the secondary set 46, in order to provide the best distribution of the reducing gases into and through the descending burden of the furnace.
  • the base of the blast furnace 45 in each of FIGS. 1 and 2 is provided with an iron notch 24, where molten iron is tapped at intervals, and with a slag notch 25 disposed a suitable distance above iron notch 24 in the conventional manner, so that slag can be withdrawn as desired from such notch 25.
  • blast furnace 45 The upper portion of blast furnace 45 is not completely shown. Thefurnace will be fed using equipment modern enough to keep the furnace continuously charged in the conventional pattern at the higher operating rates which will be attainable by use of the instant invention. Any desired amount of the furnace gases thereof, exiting through downcomer 27 are passed through a conduit 28 to a gas converter 54 which in the embodiment of FIG. 2 is in the form of a modified blast furnace. Converter 54 is provided with primary tuyeres 38 to introduce heated air or oxygen-enriched air into the converter and also with a conventional bustle pipe 20.
  • Solid carbonaceous reducing agents such as noncoking coal and limestone flux, are added at the upper portion 31 of the converter; and the gas from the blast furnace downcomer 27 and containing CO and H 0 to be converted back to CO and H is introduced into the converter through a suitable manifold or bustle pipe 37 usually after mixing BOP gas and converter top gas and thence through an injection system which is a part of the primary tuyere assembly 38 at the base of the converter.
  • the incoming gas is passed upwardly through the bed of hot coal and the CO and H 0 content is reduced to form the desired CO and H while at the same time any metal oxide present is reduced to form the corresponding metal.
  • bustle pipe 37 via mixer 29 take-off gas from a basic oxygen process (BOP) steel furnace.
  • BOP basic oxygen process
  • basic oxygen process furnace gas contains CO but is very rich in CO and it is introduced hot and without cleaning into the converter.
  • the basic oxygen furnace gas also contains micron size iron oxide fume particles which are ordinarily difficult to collect or process.
  • the CO content can be readily utilized in the system of this invention, and the CO converted to CO.
  • the iron content will also be readily recovered by the above-noted reduction procedure.
  • the re-formed reduction gas from the converter is taken off at the side of the converter above the bosh and mantel thereof and conducted to bustle pipes 35 and 36 from which it is fed into the secondary and tertiary sets of blast furnace tuyeres 46 and 47 respectively.
  • the reformed gases to be delivered to the blast furnace are taken 011 above the mantel 39 at which point they are at about the desired temperature and suitable for introduction into the blast furnace 45. If it is desired to use a portion of the re-formed gas for other purposes, it can be taken off at the top of converter 54.
  • the temperature of the up-moving gas streams in the blast furnace 45 will be such as to produce a burden-gas heat interchange which will substantially limit the conversion of CO to CO and H to H and CO by reaction with the coke to zones one and two in the primary tuyere and bosh areas.
  • This is effected by maintaining the coke above zone two below the temperature at which such reactions will occur, with their attendant loss of coke and by maintaining a sufficient reducing gas supply at an adequate top pressure to satisfy the metallic oxide reduction requirements mainly in zone three.
  • lt is also advantageous to prevent all portions of the burden in the tertiary zone from attaining temperatures at which the metallic oxides, for example, iron oxides, are prematurely melted.
  • the tertiary set of tuyeres is used effectively to introduce the additional volume of heated reducing gas required to help reduce the major portion of the metallic oxide burden in zone three.
  • the furnace is charged with an admixture of metallic oxide, which can be in the form of ore, pellets or sinter, limestone and coke. This is done according to usual practice in this art except that the amounts of limestone and coke will be reduced.
  • the hot blast is introduced into the tuyeres 21 in the primary zone and reducing gases are introduced into the secondary tuyeres and tertiary tuyeres 47,-all as described above.
  • reducing gases are introduced into the secondary tuyeres and tertiary tuyeres 47,-all as described above.
  • it will frequently be desirable to make changes which will result in either a maximum tons of hot metal per operating hour rate, a desired tons per hour operating rate, or a lowest hot metal cost per ton operating rate.
  • the most economic blowing rate will be lower than the rate required to obtain highest production and, accordingly, various adjustments are made in the blowing rate, depending on the production rate desired. Other changes, such as in the amount of added oxygen or the temperature of the hot blast, are also made as desired.
  • the functions are then monitored in such a manner that minor burden fluctuations and trends leading to furnace malfunction are immediately detected and the indicated suitable adjustments required immediately made.
  • continuous monitoring measurements will be made usually including those of top pressure, top temperature, top gas composition, top gas flow, bottom pressure, slag temperature, and hot metal, burden, and blast air analyses. For example, low slag temperatures may indicate that there is danger that the sulphur con tent of the hot metal is becoming excessive.
  • higher amounts of oxygen may indicate that there is danger that the sulphur con tent of the hot metal is becoming excessive.
  • thermocouple placed therein and the temperature is recorded in the usual manner.
  • Raw materials are delivered to the top of the furnace 45 according to good modern practice, except that the quantity of coke and limestone required per ton of feed is less.
  • the amount of coke per ton of hot metal can be reduced by at least 20 percent, and that of limestone by at least 25 percent.
  • the increase in the operating rate will offset these gains and put a full load on the raw material delivery system.
  • Fuel in the form of crushed c'oal, coke or coal tar is also introduced into thehearth zone of the furnace at 15 by a conventional injection system.
  • Most of the high temperature heat, i.e., about 1000C. is utilized in the second zone adjoining the primary or tuyere combustion zone.
  • the size, i.e., the height, of this secondary zone is determined or controlled by the addition of reducing gases injected through secondary tuyeres 46. Such gases will blend with the higher temperature gases from the primary zone reducing their temperature as required to attain zone control.
  • reducing gases that are fed to the blast furnace 45 through auxiliary tuyeres are generated in a gas converter 54, which is designed in the form of a modified blast furnace, as also indicated and described in part above.
  • a portion of the top gases from blast furnace 45 areconducted by main or pipe 28 to a gas mixer.29 where they may be blended with gases which have issued from a hooded BOP furnace 53, wherein steel is being made by the well-known oxygen process, andstored in a holder 57.
  • Another portion of the blast furnace top gases is sent to a cleaning system by conduit 51 and thence to storage; and a third portion, if and as needed to control the temperature of reducing gas being injected, goes by conduit 52 to be mixed with reducing gases entering the blast'furnace through the secondary and tertiary tuyere sets 46 and 47.
  • the oxygen steel and blast furnace top gases in admixture contain H O, C0, C0 and very finely divided iron oxide, e.g., one micron size particles, and the admixture is injected into the gas converter 54 in the manner described above.
  • the oxygen-enriched air blast from a turbo-blower 55 is suitably heated in the gas converter stove 56 fired by blast furnace gas from storage unit and is then conducted to bustle pipe 20 and primary tuyeres '38.
  • Oxygen steel furnace gas and fumes from holder 57 can also be injected by the system that works in conjunction with the primary tuyeres receiving the hot blast.
  • Molten metal e.g.
  • Corrections in furnace operation can be effected manually, semi-automatically or automatically, and a process computer can be employed.
  • a correction can be effected, for example, by changing the temperature or amount of gas injected at the secondary tuyeres, or by like changes in the re-formed gas injected at the tertiary tuyeres.
  • changes in composition and other characteristics of the furnace gases can be more precisely and continuously measured and changes in furnace operation made accordingly. Changes in gas temperatures, pressures and compositions and volumes can be monitored by appropriate devices installed at crucial points in the system and furnace, recorded and followed to effect the required changes.
  • Method of reducing iron ores to form metallic iron comprising:
  • Method of operating a blast furnace to form metallic iron comprising:
  • gaseous reducing agent consists essentially of an admixture of CO and H 7.
  • a portion of said gases withdrawn from the top of said furnace are reacted with a carbonaceous reducing agent to re-form carbon monoxide andv hydrogen and said re-formed gases are recycled to said zones as said gaseous reducing agent.
  • a system for reducing iron ores to form metallic iron and gaseous products of reduction including carbon dioxide and water comprising a modified blast furnace including a primary set of tuyeres disposed in the 16 hearth zone of said furnace, a secondary set of tuyeres disposed around the upper portion of the bosh zone of said furnace and a tertiary set of tuyeres disposed around the upper portion of said furnace near the base of its reducing zone, means for introducing a gaseous reducing agent into said secondary and said tertiary sets of tuyeres, means for separately withdrawing top gases, molten iron products and molten slag from said blast furnace, a gas converter having means to hold a bed of hot solid carbonaceous reducing agent and means to draw off molten materials from said converter, means for withdrawing a portion of the gaseous products of reduction from said blast furnace and for conducting said products to said converter for direct contact with said carbonaceous reducing agent, means for withdrawing gases from said gas converter and means
  • a system as in claim 8 including means to conduct gases from said gas converter to each tuyere of said secondary and said tertiary sets of tuyeres.

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US00221900A 1972-01-31 1972-01-31 Blast furnace and method of operating the same Expired - Lifetime US3814404A (en)

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Application Number Priority Date Filing Date Title
US00221900A US3814404A (en) 1972-01-31 1972-01-31 Blast furnace and method of operating the same
JP1211273A JPS5544125B2 (fr) 1972-01-31 1973-01-31
US399260A US3928023A (en) 1972-01-31 1973-09-20 Method of treating off gases from iron processes
BE135964A BE805223A (fr) 1972-01-31 1973-09-24 Haut fourneau et procede d'exploitation de celui-ci

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Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3904398A (en) * 1972-08-22 1975-09-09 Centre Rech Metallurgique Manufacturing pig iron in a blast furnace
US3955963A (en) * 1973-05-18 1976-05-11 Centre De Recherches Metallurgigues-Centrum Voor Research In De Metallurgie Method of reducing ore
US4198228A (en) * 1975-10-24 1980-04-15 Jordan Robert K Carbonaceous fines in an oxygen-blown blast furnace
WO1981002584A1 (fr) * 1980-03-11 1981-09-17 R Jordan Poussieres fines de carbone dans un haut fourneau alimente en oxygene
WO1981003668A1 (fr) * 1980-06-12 1981-12-24 H Claflin Haut fourneau universel ameliore a controle de zone et procede de production de metal, de gaz et de laitiers chauds
US4309024A (en) * 1977-07-18 1982-01-05 Modern Equipment Company Cupola with auxiliary gas generator
US4529440A (en) * 1978-07-21 1985-07-16 Jordan Robert K Chemicals from coal
US4844737A (en) * 1986-12-27 1989-07-04 Nippon Kokan Kabushiki Kaisha Method for operating a blast furnance by blowing pulverized coal
US4917727A (en) * 1985-07-26 1990-04-17 Nippon Kokan Kabushiki Kaisha Method of operating a blast furnace
US6030430A (en) * 1998-07-24 2000-02-29 Material Conversions, Inc. Blast furnace with narrowed top section and method of using
US6432533B1 (en) * 1996-03-15 2002-08-13 Kabushiki Kaisha Kobe Seiko Sho Metallic iron containing slag
US6464928B1 (en) * 1998-01-29 2002-10-15 Airproducts And Chemicals Inc Gas regulation system for blast furnace
US6506231B2 (en) 1996-03-15 2003-01-14 Kabushiki Kaisha Kobe Seiko Sho Method and apparatus for making metallic iron
US20110272868A1 (en) * 2009-01-05 2011-11-10 Paul Wurth Refractory & Engineering Gmbh Bustle pipe arrangement
US8808616B2 (en) 2009-01-05 2014-08-19 Paul Wurth Refractory & Engineering Gmbh Bustle pipe arrangement
US10526670B2 (en) * 2013-06-14 2020-01-07 CCP Technology GmbH Blast furnace and method for operating a blast furnace
WO2022058770A1 (fr) * 2020-09-15 2022-03-24 Arcelormittal Haut fourneau pour la production de fer

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6010114U (ja) * 1983-06-30 1985-01-24 リンナイ株式会社 五徳
JPS6297408U (fr) * 1985-12-09 1987-06-22

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US81775A (en) * 1868-09-01 Alexander hamar
US2420398A (en) * 1943-12-20 1947-05-13 Kinney Eng Inc S P Method of operating blast furnaces
US2598735A (en) * 1948-07-16 1952-06-03 Hydrocarbon Research Inc Iron oxide reduction
US2811435A (en) * 1956-03-26 1957-10-29 British Oxygen Co Ltd Treatment of fumes in steelmaking operations
US2837419A (en) * 1957-02-15 1958-06-03 Texaco Development Corp Reduction of metal oxides
US2952533A (en) * 1956-02-21 1960-09-13 Cuscoleca Otwin Method of operating a furnace in which the material treated is reduced
US3197305A (en) * 1962-01-15 1965-07-27 Colorado Fuel & Iron Corp Iron blast furnace fuel injection
US3458307A (en) * 1967-03-07 1969-07-29 Armco Steel Corp Method of blast furnace reduction of iron ores

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Publication number Priority date Publication date Assignee Title
US81775A (en) * 1868-09-01 Alexander hamar
US2420398A (en) * 1943-12-20 1947-05-13 Kinney Eng Inc S P Method of operating blast furnaces
US2598735A (en) * 1948-07-16 1952-06-03 Hydrocarbon Research Inc Iron oxide reduction
US2952533A (en) * 1956-02-21 1960-09-13 Cuscoleca Otwin Method of operating a furnace in which the material treated is reduced
US2811435A (en) * 1956-03-26 1957-10-29 British Oxygen Co Ltd Treatment of fumes in steelmaking operations
US2837419A (en) * 1957-02-15 1958-06-03 Texaco Development Corp Reduction of metal oxides
US3197305A (en) * 1962-01-15 1965-07-27 Colorado Fuel & Iron Corp Iron blast furnace fuel injection
US3458307A (en) * 1967-03-07 1969-07-29 Armco Steel Corp Method of blast furnace reduction of iron ores

Cited By (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3904398A (en) * 1972-08-22 1975-09-09 Centre Rech Metallurgique Manufacturing pig iron in a blast furnace
US3955963A (en) * 1973-05-18 1976-05-11 Centre De Recherches Metallurgigues-Centrum Voor Research In De Metallurgie Method of reducing ore
US4198228A (en) * 1975-10-24 1980-04-15 Jordan Robert K Carbonaceous fines in an oxygen-blown blast furnace
US4309024A (en) * 1977-07-18 1982-01-05 Modern Equipment Company Cupola with auxiliary gas generator
US4529440A (en) * 1978-07-21 1985-07-16 Jordan Robert K Chemicals from coal
WO1981002584A1 (fr) * 1980-03-11 1981-09-17 R Jordan Poussieres fines de carbone dans un haut fourneau alimente en oxygene
WO1981003668A1 (fr) * 1980-06-12 1981-12-24 H Claflin Haut fourneau universel ameliore a controle de zone et procede de production de metal, de gaz et de laitiers chauds
US4381938A (en) * 1980-06-12 1983-05-03 Claflin H Bruce Multi-purpose zone controlled blast furnace and method of producing hot metal, gases and slags
US4917727A (en) * 1985-07-26 1990-04-17 Nippon Kokan Kabushiki Kaisha Method of operating a blast furnace
US4844737A (en) * 1986-12-27 1989-07-04 Nippon Kokan Kabushiki Kaisha Method for operating a blast furnance by blowing pulverized coal
US7938883B2 (en) 1996-03-15 2011-05-10 Kabushiki Kaisha Kobe Seiko Sho Method and apparatus for making metallic iron
US6432533B1 (en) * 1996-03-15 2002-08-13 Kabushiki Kaisha Kobe Seiko Sho Metallic iron containing slag
US6506231B2 (en) 1996-03-15 2003-01-14 Kabushiki Kaisha Kobe Seiko Sho Method and apparatus for making metallic iron
US20090025511A1 (en) * 1996-03-15 2009-01-29 Kabushiki Kaisha Kobe Seiko Sho Method and apparatus for making metallic iron
US6464928B1 (en) * 1998-01-29 2002-10-15 Airproducts And Chemicals Inc Gas regulation system for blast furnace
US6030430A (en) * 1998-07-24 2000-02-29 Material Conversions, Inc. Blast furnace with narrowed top section and method of using
US20110272868A1 (en) * 2009-01-05 2011-11-10 Paul Wurth Refractory & Engineering Gmbh Bustle pipe arrangement
US8808616B2 (en) 2009-01-05 2014-08-19 Paul Wurth Refractory & Engineering Gmbh Bustle pipe arrangement
US9028743B2 (en) * 2009-01-05 2015-05-12 Paul Wurth Refractory & Engineering Gmbh Bustle pipe arrangement
US10526670B2 (en) * 2013-06-14 2020-01-07 CCP Technology GmbH Blast furnace and method for operating a blast furnace
WO2022058770A1 (fr) * 2020-09-15 2022-03-24 Arcelormittal Haut fourneau pour la production de fer

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JPS5544125B2 (fr) 1980-11-11
JPS4888012A (fr) 1973-11-19
BE805223A (fr) 1974-01-16

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