System and process for injecting dissociated fuel with metal oxide fines into a blast furnace

Abstract

An injection process and system for a smelting furnace is disclosed. The process comprises: providing a fuel gas; heating the fuel gas to dissociate the fuel gas into a particulate and a first reducing gas; providing an oxygen-containing stream; optionally providing metal oxide fines comprising oxide; reacting the oxygen and optionally oxide in the metal oxide fines with the particulate to produce a select amount of heat, a second reducing gas, and optionally a reduced metal and a molten slag; co-injecting the first reducing gas, the second reducing gas, and optionally the reduced metal and the molten slag into the smelting furnace as a process stream. One or more of the fuel gas, fines carrier gas, oxygen-containing gas, and the fines may be preheated; blast air is preheated.

Description

SYSTEM AND PROCESS FOR INJECTING DISSOCIATED FUEL WITH METAL OXIDE FINES INTO A BLAST FURNACEFIELD

[0001] The present disclosure relates to blast furnaces for smelting metals.BACKGROUND

[0002] Conventional approaches to providing fuels into a blast furnace for smelting metal ore comprise the delivery or charging of coke at the top of the blast furnace shaft along with the metal ore, and slag-forming constituents. Coke supplies fuel for heating and also provides a permeable bed to allow the reduction of metal oxides to hot metal. Unfortunately, coke and coal produce a large amount of carbon emissions which have negative environmental effects. To further heat the metal ore to casting temperature, a hot blast of air is typically introduced near the bottom of the furnace through tuyeres. Metal reduced from the ore collects in the lower part of the blast furnace and is drawn off in a casting process.

[0003] The reduction process in the blast furnace requires metal ore to be screened to prevent ore fines from clogging the permeable bed of coke and sized burden materials. This screening and removal of fines is to help control the pressure drop through the burden materials and to provide sufficient gas-to-solid contact for an efficient reduction process. Screened metal ore fines typically become waste material that is sent to landfill for disposal.

[0004] Sometimes, metal ore fines can be agglomerated or sintered together into larger particles so they may be charged into the top of blast furnace along with the regular metal ore feed.BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0005] FIG. 1 is a flow diagram of a process for injecting fuel with metal ore fines into a blast furnace as described herein.

[0006] FIG. 2 illustrates a schematic of a system for injecting a gaseous fuel and fines into a blast furnace according to the present disclosure.

[0007] FIG. 3 is a cross section view of a portion of a blast furnace with a system for injecting a gaseous fuel and metal ore fines in accordance with one embodiment.DETAILED DESCRIPTION

[0008] Described herein is a method, process and system for injecting alternate fuel comprising gaseous fuel and optionally metal ore fines into a blast furnace.

[0009] Conventional processes for smelting blast furnaces rely on high-conversion cost fuels such as coke which also result in carbon emissions. Injected fuels such as pulverized coal and natural gas may be provided into blast furnace tuyeres using injection lances to displace some of the coke to help reduce carbon emissions. However, use of such injected fuels in this manner must be limited due to their heating and dissociation energy requirements. Conventional processes also result in wasted metal ore in the form of fines that are produced as a result of material handling.

[0010] Though such fines may ultimately be used in the smelting process, the conventional method requires them to first be re-processed by sintering or briquetting or agglomeration to obtain material with a sufficiently large size for charging into the top of the blast furnace. Fines cannot be charged into the top of the furnaces directly since this can increase the pressure drop through the furnace and limit metal production within the furnace. Recycling of fines into larger agglomerants also imposes an additional step in the reduction process, reducing efficiency and increasing waste.

[0011] The present invention comprises a process and system for using an alternative fuel to coal or coke, and for handling metal oxide fines. In an embodiment, the invention comprises co-injecting into a blast furnace the alternative fuel, an oxygen-containing stream and, optionally metal oxide fines, via a blast air tuyere. The oxygen-containing stream may be blast air and / or oxygen gas from a non-blast air source. The process and system are to help reduce carbon emissions over conventional approaches while also consuming metal oxide fines without needing to further process into agglomerates.

[0012] In an embodiment, the process comprises heating the fuel outside the smelting furnace to dissociate the fuel into a particulate and a first reducing gas. Heating of the fuel may commence prior to the fuel entering the tuyere. The fuel may be, for example, a carbon fuel such as pure carbon with a carrier gas or coal with a carrier gas, a hydrogen fuel, or a hydrocarbon fuel such as natural gas. The heating may also produce a residual methane. Depending on the fuel, the first reducing gas may be, for example, hydrogen gas (such as in the case of a hydrogen fuel), or methane, carbon monoxide, or another reducing gas (such as in the case of a carbon fuel or a hydrocarbon fuel). Heating the fuel provides sensible heat to the firstreducing gas, where the first reducing gas can reach a temperature of about l,000°C to about l,200°C.

[0013] Oxygen and optionally metal oxide fines (such as iron oxide fines) are provided and contacted with the particulate of the dissociated fuel. Oxides interacting with carbon result in an endothermic redox reaction where the metal oxide in the metal oxide fines (such as ferric oxide), is reduced by the carbon in the carbon particulate or carbon in the furnace resulting in smelting to produce a reduced metal (such as iron), molten slag and carbon monoxide. The carbon monoxide from this reaction forms a first portion of the second reducing gas. This reduction reaction may occur outside of the furnace, such as in the tuyere, and / or inside the furnace, such as in the raceway of the furnace. This reduction reaction may commence outside of the furnace and complete inside of the furnace.

[0014] Where particulate is not present, such as where the first reducing gas is hydrogen gas, the endothermic redox reaction may occur in the furnace where metal oxide fines can react with carbon that is already present.

[0015] Carbon monoxide is produced as a result of an exothermic reaction from a portion of the unreacted carbon from the particulate or from carbon in the furnace reacting with some of the oxygen, such as oxygen from the oxygen-containing stream (e.g. oxygen gas and / or oxygen present in the blast air). The carbon monoxide from this exothermic reaction forms a second portion of the second reducing gas. The exothermic nature of this reaction can bring both the first and second reducing gas to a higher temperature than the first heated fuel reducing gas, such as about 2,000°C. The oxygen in this exothermic reaction is consumed by the particulate outside the furnace, such as in a blowpipe connected to the furnace, in a tuyere or, alternatively, in the raceway inside the furnace, such as when no carbon is present outside the furnace.

[0016] Any unreacted metal oxide fines, the oxygen-containing stream, the first reducing gas, the second reducing gas, the reduced metal, and molten slag (each, a “feed stream”) may be coinjected into the smelting furnace as a process stream. The process stream may be injected into the furnace via a tuyere that is conventionally used to inject blast air into the furnace. The tuyere may be entirely re-purposed to only inject the process stream instead of blast air into the furnace. Alternatively, the tuyere may be adapted to inject the process stream together with blast air, or to inject blast air as the oxygen feed stream for the resulting process stream. Theprocess stream is injected at a first elevation. The reduced metal and molten slag may be emulsified upon entry into the furnace to be separated at a later time by gravity.

[0017] Following the injection, the first and second reducing gases may rise to a second elevation in the furnace that is higher than the first elevation, and such reducing gases may reduce other metal oxides in the furnace at the higher second elevation.

[0018] The process may be carried out absent the metal oxide fines for helping reduce carbon emissions over conventional approaches, such as those that use coke.

[0019] In certain operating modes, the number of adapted tuyeres that deliver the process stream may be a larger proportional or all of the tuyeres of the furnace. In such an operating mode, one or more of the feed streams for the process stream may be preheated prior to entering the tuyere to maintain the target raceway temperature and overall productivity of the furnace. The relative flow rates of blast air and oxygen gas can be adjusted to control raceway conditions.

[0020] Processes disclosed herein may commence in a blowpipe, and continue from the blowpipe, into a tuyere and finalize in the raceway of the furnace.

[0021] FIG. 1 depicts a flow diagram illustrating the process in accordance with embodiments of the present disclosure, and predominantly as described above.

[0022] FIG. 2 depicts an injection system 102 for a furnace 114 according to embodiments of the present disclosure. The system comprises a tuyere 112, a fuel heater 106, and a fuel gas feed pipe 104 for providing a fuel to the fuel heater 106 and the tuyere 112. The fuel heater 106 heats the fuel from fuel feed pipe 104 to dissociate the fuel. The fuel may be dissociated into hydrogen and carbon particulate, for example. The portion of the fuel feed pipe 104 positioned downstream from the fuel heater 106 for providing dissociated fuel to the tuyere 112 is the dissociated fuel feed pipe 116.

[0023] A fuel gas feed pipe 104 may be provided with a natural gas feed as the fuel. The system also comprises a metal oxide feed pipe 108 which may be provided with a metal oxide feed, such as iron ore. The system may comprise an oxygen feed pipe 110 which may be provided with an oxygen feed, such as oxygen gas. The fuel feed pipe 104, metal oxide feed pipe 108 and oxygen feed pipe 110, may be connected to provide for co-inj ection of the feeds into the furnace 114 through tuyere 112.

[0024] In an embodiment, a metal fines feed pipe (not shown) and the oxygen feed pipe 110 may be combined via separate injection systems to the dissociated fuel feed pipe 116 downstream from the fuel heater 106 to provide for co-inj ection of those additional feeds into the furnace 114 through tuyere 112.

[0025] In another embodiment, the metal fines feed and oxygen feed may be combined into a single feed pipe (not shown) which may be connected to the dissociated fuel feed pipe 116 downstream from the fuel heater 106 to provide for co-inj ection of the feeds into the furnace 114 through tuyere 112.

[0026] The fuel gas heater 106 may be an electric heater.

[0027] The fuel gas feed pipe 104 feeds fuel to the heater. The carbon particulate in the resulting dissociated heated fuel gas in the dissociated fuel feed pipe 116 reacts with the injected oxygen from the oxygen feed pipe 110 and the oxygen in the ore fines dispensed from the metal oxide feed pipe 108. This may generate the required heat to provide a tuyere raceway reaction zone with a reducing gas stream with normal flame temperature for the furnace process, for example, about 2000°C. The combined stream may then continue into the furnace where the reactions between the fuel, which may be dissociated (for example, natural gas dissociated into carbon particulate and hydrogen), carbon in the furnace (such as coke), fines, and oxygen continue to take place. The continued reactions may cause the ore fines to be smelted generating hot metal and slag which may accumulate into the hearth of the furnace, while at the same time providing a surplus reductant and energy in the form of hydrogen and carbon monoxide gases in the process.

[0028] In a blast or smelting furnace comprising a plurality of tuyeres, one or more tuyeres may be adapted / converted to inject into the furnace the dissociated fuel, oxygen and optionally metal oxides, in accordance with the present disclosure.

[0029] In some embodiments blast air may not flow through the adapted tuyere or converted tuyeres as the case may be such that the adopted / converted tuyeres are entirely dedicated to injecting the dissociated fuel, oxygen, and optionally metal oxides.

[0030] In some embodiments, blast air may flow through other tuyeres of the furnace that have not been so adapted / converted to comprise the present invention.

[0031] In embodiments where the tuyere is adapted to inject the process stream together with blast air, or to inject blast air as the oxygen-containing stream of the process stream, each adapted tuyere is implemented as a multi-passage assembly (e.g., concentric passages or amulti-lance arrangement) configured to separately deliver (i) dissociated fuel and / or fuel gas, (ii) metal oxide fines carried by a gas stream, and (iii) an oxygen-containing stream comprising oxygen gas, (iv) blast air via a blast air feed 118, or a combination thereof.

[0032] Check valves, flow-control valves, and temperature-controlled heaters can be positioned in the feed streams to set raceway adiabatic flame temperature and process stream penetration while maintaining furnace pressure.

[0033] FIG. 3 depicts an injection system 202 according to embodiments of the present disclosure.

[0034] A fuel heater 206 fed by fuel feed pipe 204 heats and dissociates the fuel contained therein. The dissociated fuel is directed by the dissociated fuel feed pipe 216 portion of the fuel feed pipe, which directs the dissociated fuel to the furnace tuyere 212. For example, the fuel may be natural gas, and the dissociated fuel may comprise carbon particulate and hydrogen and may have some residual methane. The fuel feed pipe 204 may be separate from a tuyere blowpipe assembly or bustle pipe 218.

[0035] A combined metal fines and oxygen feed may be directed by a combined metal fines and oxygen feed pipe 210 and dispensed via an oxygen outlet to the dissociated fuel feed pipe. The combined metal fines and oxygen feed may then be injected into the furnace 214 via tuyere 212.

[0036] In some embodiments, dissociated fuel feed pipe 216 may be fed to the tuyere 212 from the floor of the furnace 214, not from the mid or top portions of the furnace 214.

[0037] In some embodiments, the combined metal fines and oxygen feed may be injected into the furnace 214 by a lance (not shown).

[0038] In embodiments where the tuyere is adapted to inject the process stream together with blast air, and / or to inject blast air as the oxygen-containing stream, the blast air may be injected into the furnace 214 from a tuyere blowpipe assembly or bustle pipe 218 via tuyere 212.

[0039] Starting Materials, Burden Loading and Maintenance of Blast Furnace Pressure

[0040] Systems, methods, and process herein described use a fuel, and a metal oxide or metal oxide fines, such as iron oxide or iron oxide fines, as starting materials.

[0041] The fuel may be a hydrogen fuel such as pure hydrogen, a carbon fuel such as pure carbon, or a hydrocarbon fuel such as natural gas, coal, coke or other suitable hydrocarbon fuel where solid fuels will be transported by a carrier gas to generate a fuel gas.

[0042] The fuel is contained in a fuel feed pipe 104 and fed into a fuel heater 106 where the fuel is heated outside the blast furnace to a selected temperature, for example, from about l,000°C to about l,200°C.

[0043] Where hydrocarbons are present in the fuel, such as where the fuel is natural gas, carbon with a carrier gas, or coal with a carrier gas, heating the hydrocarbon fuel results in dissociation of the fuel to form a hydrogen reducing gas (a first reducing gas) by pyrolysis. The hydrogen reducing gas and carbon particulate are collectively referred to herein as a dissociated fuel and are fed into a dissociated fuel feed pipe 116 downstream from the fuel heater 106.Carbon with a carrier gas, which is heated in the fuel heater 106 is also considered herein to be a dissociated fuel. The dissociated fuel feed pipe 116 may be considered a portion of the fuel feed pipe 104. The dissociation fuel is fed into the blast furnace in a dissociated fuel stream.

[0044] Metal oxide fines comprising oxide groups are combined with the dissociated fuel.This may occur via a metal oxide feed pipe 108 where the metal oxide or metal oxide fines are fed into the dissociated fuel feed pipe 116 in a metal oxide stream. The combination of metal oxide fines and dissociated fuel fed into the blast furnace is referred to as a process stream.

[0045] The process stream may be provided into a tuyere 112 via the dissociated fuel feed pipe 116.

[0046] Where hydrocarbons are not present in the fuel, such as where the fuel is a hydrogen fuel, the first reducing gas is fed into the dissociated fuel feed pipe 116 downstream from the fuel heater 106 and fed into the blast furnace. Metal oxide fines comprising oxide groups already present in the furnace, such as in the form of coke, contact the first reducing gas in the blast furnace.

[0047] An additional material provided may be oxygen. As used herein, oxygen can comprise blast air, an oxygen gas stream separate from a blast air source, or combinations thereof.Oxygen may be combined with the hydrogen reducing gas, carbon from particulate and metal oxide or metal oxide fines in the process stream via an oxygen feed pipe 110 connected to the fuel feed pipe 116 before being fed into the tuyere 112. The molar ratio of metal oxide or metal oxide fines to oxygen may range from about 1 to about 1 and from about 2 to about 1 to and may be adjusted for controlling the injection flame temperature of the furnace or other reasons.

[0048] The combination of metal oxide fines with the dissociated fuel may reduce the need to load burden materials through the top of the blast furnace, for example via a charge hopper.The loading of burden materials, such as sinter or briquetted metal oxides may reduce the needfor pre-processing steps as any charged metal oxide fines needs to be agglomerated. If fines are directly fed to the top of the furnace, they reduce the permeability of the blast furnace burden, increasing the pressure drop across the furnace bed, thereby making the furnace inefficient.

[0049] Exothermic Reaction Heating the Blast Furnace

[0050] The combination of carbon from the carbon particulate contained in the process stream and / or carbon in the furnace with oxygen results in an exothermic reaction yielding carbon monoxide. The oxygen may be provided via the oxygen feed pipe 110, via a blast air feed 118, and / or oxides in the metal oxide or metal oxide fines. Heat energy resulting from this reaction may be used to heat and / or maintain or adjust the temperature of the blast furnace. Adjustments may be made to the molar ratios of the carbon and carbon particulate and oxygen to control the amount of heat produced.

[0051] The typical operating temperature of a blast furnace may range from 1600°C to about 2500°C, for example, about 2000°C. At such temperatures, water vapor is unstable in the presence of carbon. Therefore, the use of electrolysis of water to yield a hydrogen reducing gas is not desirable and is unsuitable as the reaction is significantly endothermic. Accordingly, the processes, methods, and systems defined herein are free or substantially free of water.

[0052] The sensible energy resulting from the reaction of the carbon particulate and oxygen may be introduced into the blast furnace via tuyere 112.

[0053] The temperature of the blast furnace may be further adjusted by injecting blast air through a separate tuyere into the blast furnace.

[0054] Formation of Second Reducing Gas and Reduction of Metal Oxide

[0055] Following the exothermic reaction yielded from the reaction of carbon particulate and / or carbon in the furnace with oxygen, any carbon dioxide formed further reacts with the carbon particulate in the furnace to yield carbon monoxide. The resulting carbon monoxide from the process stream acts as a second reducing gas in the overall blast furnace process and reduces metal oxides higher in the furnace to yield molten metal, slag and carbon dioxide. The molten metal and slag may accumulate in the hearth of the blast furnace and be removed from the furnace by known methods.

[0056] The direct injection of metal oxide or metal oxide fines into the furnace obviates the requirement of any sintering, briquetting or other agglomeration technique prior to smelting. Additionally, the injection of metal oxide fines into the furnace via the process stream toprovide improved gas-to-solid contact for an efficient reduction process and a reduction of waste to landfill.

[0057] Co-Injection of Burden Materials and Injection Velocity

[0058] Injection velocity at the dissociated fuel feed pipe 104, metal oxide feed pipe 108 and oxygen feed pipe 110, blast air feed 118, or combined metal fines and oxygen feed may be adjusted to change the smelting characteristics of the process stream. Selection of a particular injection velocity through the tuyeres may help prevent clogging of portions of the system by particulate or other materials.

[0059] Reduction of the metal oxide in the metal oxide fines producing, in part, reduced metal and molten slag may occur outside of the furnace 114, such as in the blowpipe or tuyere 112, and / or inside the furnace 114, such as in the raceway of the furnace 114. For example, the reduction reaction of the metal oxide in the metal oxide fines may commence outside of the furnace 114 and be completed inside of the furnace 114. In some embodiments, the reduced metal and molten slag resulting from the reduction of the metal oxide in the metal oxide fines may be entrained as droplets or emulsified upon entry into the furnace 114, such as in the raceway, to be separated at a later time by gravity.

[0060] Injection velocity may be further selected to facilitate the blowing of carbon particulate into the furnace and / or combustion characteristics of the process stream.

[0061] Injection velocity may be further selected proportional to the momentum of the metal fines dispensed from the metal oxide outlet 108 and the penetration of the process stream into the furnaces.

[0062] For example, injection velocity of the combined stream from the dissociated gas feed pipe 104, metal oxide feed pipe 108 and oxygen feed pipe 110 or combined metal fines and oxygen feed though the injection nozzle or tuyere 212 may be about 200 meters per second.

[0063] Concurrent Blast Air and Process Stream Injection Through Adapted Tuyeres

[0064] In some embodiments, blast air is co-injected into the furnace through at least a subset of the same adapted tuyeres that deliver the process stream described herein. The blast air and the process stream may be provided at the same time through the same tuyere. As used herein, the oxygen source for the process stream can include oxygen gas, blast air, or combinations thereof.

[0065] This configuration can be helpful when a significant number, such as a majority or all, of the tuyeres are adapted to inject the process stream — e.g., in operating modes where the available fuel gas supply to the furnace is limited or the amount of fines to be injected needs to be increased — such that using only a small subset of adapted tuyeres to provide the process stream would not satisfy the furnace heat and mass balances. This concurrent blast air and process stream injection through adapted tuyeres may be necessary to ensure the furnace process requirements are met.

[0066] To maintain blast furnace operating conditions under such constraints, blast air is routed through those adapted tuyeres concurrently with the process stream.

[0067] In such configurations, one or more feed streams of the process stream — such as the fuel gas (e.g., dissociated fuel), the fines carrier gas, and / or the oxygen-containing gas — may be preheated before mixing and / or entry into the tuyere. Normally, only the fuel gas is preheated, but the fines carrier gas, local oxygen enrichment, and even the fines themselves may be preheated as well. Blast air is preheated according to conventional practice. The process stream may therefore be a combination of heated and unheated feed streams.

[0068] Flow rates of blast air, oxygen-containing gas, fuel gas, and fines are controlled to achieve the target raceway temperature and penetration while preserving overall furnace pressure and gas-flow distribution. As used herein, the oxygen source for the process stream can include oxygen gas, blast air, or combinations thereof.

[0069] Other Applications

[0070] In some applications, for example, in the recovery operation of a blast furnace, the systems and processes described herein may be practiced without the addition of metal oxide fines as a burden material.

[0071] In such applications, the above-described systems and processes may be practiced with fuel gas and oxygen alone.

[0072] Where particulate is not present, such as where the fuel is hydrogen gas, the endothermic redox reaction may occur in the furnace where metal oxide fines comprising carbon are already present in for form of coke, for example.

Claims

AMENDED CLAIMS received by the International Bureau on April 2, 2026 (02.04.2026)Claims

1. An injection process for a smelting furnace comprising: providing a fuel gas; heating the fuel gas to dissociate the fuel gas into a particulate and a first reducing gas; providing metal oxide fines comprising oxide; providing an oxygen-containing stream; reacting the oxide in the metal oxide fines with the particulate and the oxygen from the oxygen-containing stream to produce a select amount of heat, a second reducing gas, a reduced metal, and a molten slag; co-injecting the first reducing gas, the second reducing gas, the reduced metal and the molten slag into the smelting furnace as a process stream.

2. The injection process of claim 1, wherein the process stream is injected at a first elevation within the smelting furnace, and further comprising reacting other metal oxides in the smelting furnace at a second elevation with the first and second reducing gases to produce additional reduced metal and additional molten slag, wherein the second elevation is higher than the first elevation.

3. The injection process of claim 1, wherein the particulate comprises carbon.

4. The injection process of claim 1, wherein the fuel gas comprises natural gas.

5. The injection process of claim 1, wherein the first reducing gas is heated to about 2000°C.

6. The injection process of claim 1, wherein the second reducing gas has a temperature of about 2000°C.

7. The injection process of claim 1, wherein the molar ratio of the metal oxide fines to the oxygen from the oxygen-containing stream is from about 1: about 1 to about 2: about 1.

8. The injection process of claim 7, further comprising adjusting the molar ratio of metal oxide fines to oxygen for controlling the injection flame temperature of the furnace.

9. The injection process of claim 1, wherein the metal oxide fines comprise iron oxide fines.

10. The injection process of claim 1, wherein the reacting the oxide in the metal oxide fines with the particulate and the oxygen occurs outside or inside the smelting furnace.

11. The injection process of claim 1, wherein the process stream is coinjected into the smelting furnace through a tuyere.

12. The injection process of claim 11, wherein the tuyere is free of blast air.

13. The injection process of claim 11, wherein the reacting the oxide in the metal oxide fines with the particulate and the oxygen occurs in the tuyere or in a raceway of the smelting furnace.

14. The injection process of claim 1, wherein the heating the fuel gas comprises pyrolysis of the fuel gas.

15. The injection process of claim 1, wherein the heating the fuel gas occurs outside the smelting furnace.

16. The injection process of claim 1, further comprising selecting a velocity of the co-injecting of the first reducing gas, the second reducing gas, the reduced metal and the molten slag proportional to a desired momentum of the process stream into the furnace.

17. The injection process of claim 1, wherein the co-injecting the first reducing gas, the second reducing gas, the reduced metal and the molten slag occurs at a rate of at about 200 m / s.

18. The injection process of claim 1, further comprising providing blast air and further co-injecting the first reducing gas, the second reducing gas, the reduced metal and the molten slag into the smelting furnace as the process stream with the blast air.

19. The injection process of claim 1, wherein the oxygen-containing stream comprises oxygen gas, blast air, or a combination thereof.

20. The injection process of claim 18, wherein the oxygen-containing stream is the blast air.

21. The injection process of claim 18, wherein the co-injecting the blast air comprises co-injecting the oxygen-containing stream through the same adapted tuyere concurrently with the process stream

22. The injection process of claim 18, wherein the smelting furnace comprises a plurality of tuyeres and a significant number of the tuyeres co-inject the process stream and the blast air into the furnace.

23. The injection process of claim 22, wherein one or more of the fuel gas, a fines carrier gas, the oxygen-containing gas, and the metal oxides fines are pre-heated prior to being provided to the smelting furnace.

24. A process for smelting metal in a blast furnace comprising: providing a metal oxide; providing coke;providing blast air through a first tuyere into the furnace; heating a fuel gas; providing into the furnace the heated fuel gas, metal oxide fines comprising metal oxide fines, and an oxygen-containing stream through a second tuyere, the heated fuel as a first reducing gas; reducing the metal oxide in the metal oxide fines with carbon to form a process stream comprising molten metal, molten slag, a heated first reducing gas, a second CO reducing gas, and a select amount of heat; smelting the metal oxide fines with carbon or hydrogen to produce a molten metal and slag at a first elevation; and reducing other metal oxides at a second higher elevation in the furnace to produce additional molten metal and slag and to produce carbon dioxide.

25. The process of claim 24, wherein the first reducing gas is the hydrogen.

26. The process of claim 24, further comprising selecting an injection velocity of the process stream in proportion to a desired penetration of the process stream into the furnace.

27. The process of claim 26, wherein the injection velocity is about 200 m / s.

28. The process of claim 24, wherein heating the fuel gas occurs outside the furnace.

29. The process of claim 24, wherein the reducing the metal oxide in the metal oxide fines with carbon to form the process stream occurs in the tuyere or in a raceway of the smelting furnace.

30. The process of claim 24, wherein the second tuyere and the first tuyere are the same tuyere.

31. The process of claim 24, wherein the oxygen-containing stream comprises oxygen gas, blast air, or a combination thereof.

32. An injection process for a smelting furnace comprising: providing a fuel gas; heating the fuel gas to provide a reducing gas; co-injecting the reducing gas, and an oxygen-containing stream into the furnace, wherein the heating the fuel gas occurs outside the smelting furnace.

33. The injection process of claim 32, wherein the fuel gas comprises carbon; wherein the heating the fuel gas dissociates the fuel gas into a particulate and a first reducing gas;and further providing metal oxide fines comprising oxide; providing the oxygen-containing stream; reacting the oxide in the metal oxide fines with the particulate and oxygen in the oxygen-containing stream to produce a select amount of heat, a second reducing gas, a reduced metal, and a molten slag; and co-injecting the first reducing gas, the second reducing gas, the reduced metal and the molten slag into the smelting furnace as a process stream.

34. The injection process of claim 33, wherein the process stream is injected at a first elevation within the smelting furnace, and further comprising reacting other metal oxides in the smelting furnace at a second elevation with the first and second reducing gases to produce additional reduced metal and additional molten slag, wherein the second elevation is higher than the first elevation.

35. The injection process of claim 33, wherein the process stream is coinjected into the furnace through a tuyere.

36. The injection process of claim 32, further comprising a molar ratio of reducing gas to oxygen gas from about 1 : about 1 to about 1 : about 2.

37. The injection process of claim 32 further comprising selecting an injection velocity of the reducing gas, and an oxygen gas into the smelting furnace.

38. The injection process of claim 38, wherein the injection velocity is about 200 m / s.

39. The injection process of claim 32 further comprising co-injecting blast air with the reducing gas into the furnace.

40. The injection process of claim 32, further comprising providing metal oxide fines and co-injecting the metal oxide fines with the reducing gas and the oxygen-containing stream into the furnace.

41. An injection system for a smelting furnace, comprising: a tuyere for injecting materials into the smelting furnace; a fuel heater for heating a fuel to produce a heated fuel gas; a heated fuel gas feed pipe connected to the fuel heater from providing fuel to the heater; a dissociated fuel feed pipe connecting the fuel heater to the tuyere for providing the heated fuel gas to the tuyere; a metal oxide feed pipe fluidly connected to the dissociated fuel feed pipe for dispensing metal oxide fines into the dissociated fuel feed pipe; andan oxygen-containing stream feed pipe fluidly connected to the dissociated fuel feed pipe for providing oxygen gas into the dissociated fuel feed pipe.

42. The injection system of claim 41, wherein the oxygen-containing stream feed pipe is fluidly connected to the dissociated fuel feed pipe or to the tuyere, the oxygen-containing stream feed pipe configured to deliver the oxygen gas, preheated blast air, or combinations thereof to the dissociated fuel feed pipe or to the tuyere.

43. The injection system of claim 41, further comprising one or more control valves located in one or more of the heated fuel gas feed pipe, the dissociated fuel feed pipe, the metal oxide feed pipe, and the oxygen-containing stream feed pipe, each of the one or more control valves configured to regulate flow rates to achieve a target temperature and / or penetration into a raceway of the furnace while maintaining furnace pressure.

44. The injection system of claim 41 wherein the tuyere is configured to inject the oxygen gas into the furnace with the heated fuel gas and the metal oxide fines.

45. The injection system of claim 41, wherein the fuel heater is located outside of the smelting furnace.

46. The injection system of claim 41, further comprising a blast air feed fluidly connected to the tuyere for dispensing blast air to the tuyere.

47. The injection system of claim 41, wherein the tuyere comprises a plurality of passages or a multi-lance assembly configured to separately dispense (i) the heated fuel gas, (ii) the metal oxide fines, and (iii) the oxygen gas, blast air, or a combination thereof into the smelting furnace.

48. The injection system of claim 42, further comprising one or more of:(i) a fines carrier gas heater configured to preheat a gas conveying the metal oxide fines,(ii) an oxygen-containing stream heater configured to preheat the oxygen gas and / or locally oxygen-enriched blast air, and(iii) a metal oxide fines preheater.

49. The injection system of claim 41, wherein the tuyere comprises a multipassage or multi-lance assembly configured to separately deliver (i) the heated fuel gas and / or dissociated fuel, (ii) the metal oxide fines carried by a gas stream, and (iii) the oxygen-containing stream, and to optionally co-inject preheated blast air through the same tuyere.

Images