HYDROGENATION

RELATED APPLICATION DATA

[0001] This application claims the benefit of priority of U.S. Provisional Patent Application Serial No. 61/889,251, filed on October 10, 2013, and titled "Systems and Methods for Iron Ore Direct Reduction to Produce Steel Through Electromagnetic Induction and Hydrogenation," which is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

[0002] The present invention generally relates to the field of steelmaking. In particular, the present invention is directed to systems and methods for directly reducing iron ore to metallic iron and for producing steel through electromagnetic induction and hydrogenation.

BACKGROUND

[0003] The process of making steel typically involves the reduction of iron ore, which can be found in nature as magnetite (Fe ₃ 0 ₄ ), hematite (Fe ₂ 0 ₃ ), goethite (FeO(OH)) and limonite

(FeO(OH) n(H ₂ 0)), by producing a reduction gas, such as carbon monoxide (CO) from coal or methane (CH ₄ ), and combining the reduction gas with iron oxide(s) to form carbon monoxide (CO) or carbon dioxide (C0 ₂ ) and an intermediate product comprising metallic iron (Fe ⁺ ) and carbon (C). This intermediate product, which typically has a carbon concentration greater than 2.1% by weight, is often referred to as "pig iron." To transform such pig iron into steel, the carbon present in pig iron must be reduced to a concentration of less than about 2.1% by weight. To accomplish such a transformation from pig iron to steel, the pig iron is typically melted and exposed to oxygen, which reacts with the carbon in the melted pig iron to form CO and C0 ₂ . This reaction acts to remove carbon from the metallic iron and can reduce the concentration of carbon to less than 2.1%, thus forming steel.

[0004] A direct reduction process can be used to produce a material commonly referred to as "DRI" (direct-reduced iron), which is sometimes referred to as "sponge iron." This conventional direct reduction process aims to reduce the iron ore in order to produce iron. This process involves heating iron ore through combustion of CH ₄ (methane), which reacts with oxygen to form CO (carbon monoxide) or CO + H ₂ , which promotes reduction due to the presence of CO. The CO gas reduces the iron ore into metallic iron and carbon, namely, DRI, which also contains carbon in its composition.

[0005] Typically, steel production processes use carbon for two or more purposes. Often, carbon is used as fuel to heat iron oxide to the ignition point, at which time the CO reduces the iron oxide into metallic iron. Carbon is also often used in the form of CO in order to promote the reduction reaction of the iron oxide, thus producing metallic iron and carbon. Such reduction processes often generate large volumes of C0 ₂ and CO, but the resulting material typically still has more carbon-content than steel. Steel production requires further processing to remove more carbon from the metallic iron of pig iron, or DRI.

SUMMARY OF THE DISCLOSURE

[0006] In one implementation, the present disclosure is directed to a method of producing steel. The method includes providing at least one iron-oxide-rich agglomeration containing iron ore and having a reduction initiation temperature; inductively heating at least one iron-oxide-rich agglomeration to at least the reduction ignition temperature; and maintaining, via inductive heating, the at least one iron-oxide-rich agglomeration at least at the reduction ignition temperature so as to convert the at least one iron-oxide-rich agglomeration to a corresponding at least one metallic- iron- rich agglomeration.

[0007] In another implementation, the present disclosure is directed to a system for forming a metallic-iron-rich agglomeration. The system includes an agglomerating apparatus designed and configured to agglomerate an iron-oxide rich material into at least one iron-oxide-rich

agglomeration, the iron-oxide-rich material having a reduction-ignition-point temperature; an inductive heater designed and configured for inductively heating the at least one iron-oxide-rich agglomeration at least to the reduction-ignition-point temperature for an amount of time sufficient to produce a reduction reaction that reduces the iron-oxide rich material to metallic-iron-rich material so as to create a corresponding at least one metallic-iron-rich agglomeration; and a hydrogen-gas system in fluid communication with the inductive heater so as to provide hydrogen gas or a hydrogen-containing gas mixture to the inductive heater during the inductive heating of the at least one iron-oxide-rich agglomeration so as to hydrogenate the iron-oxide-rich material.

[0008] In still another implementation, the present disclosure is directed to a composition of matter, which includes an agglomeration that contains agglomerated metallic-iron material directly converted from agglomerated iron-oxide-rich material using an inductive-heating-and-hydrogenation process.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] For the purpose of illustrating the invention, the drawings show aspects of one or more embodiments of the invention. However, it should be understood that the present invention is not limited to the precise arrangements and instrumentalities shown in the drawings, wherein:

FIG. 1 is a flow diagram illustrating a method of directly reducing iron ore to metallic iron;

FIG. 2 is a flow diagram illustrating a method of preparing iron ore, for example, for use in the method of FIG. 1;

FIG. 3 is a diagram of a system for forming agglomerations of iron-oxide-rich material that can be used in the method of FIG. 1 ;

FIGS. 4 A to 4C illustrate an acoustic-cavitation duct that can be used as an acoustic-cavitation device of the system of FIG. 3, with FIG. 4A being an elevational view of the acoustic-cavitation duct, FIG. 4B being an enlarged isometric elevational view of one section of the acoustic-cavitation duct of FIG. 4A, and FIG. 4C being an enlarged end view of the duct section shown in FIG. 4A;

FIG. 5 is a diagram illustrating an exemplary converter system that directly converts iron-oxide-rich material to metallic iron in a batch-wise manner without a vacuum;

FIG. 6 is a diagram illustrating another exemplary converter system that directly converts iron- oxide-rich material to metallic iron in a generally continuous process under vacuum conditions;

FIG. 7 is a photograph of crude iron-ore pellets; and

FIG. 8 is a metallographic photograph (400x magnification) of a pellet made in accordance with aspects of the present disclosure.

The drawings are not necessarily to scale and may be illustrated by phantom lines, diagrammatic representations and fragmentary views. In certain instances, details that are not necessary for an understanding of the embodiments or that render other details difficult to perceive may have been omitted. DETAILED DESCRIPTION

[0010] Aspects of the present disclosure are directed to a steel production process that can reduce iron ore directly into metallic iron and steel, thus eliminating intermediate carbon-reduction processes typically required in conventional steelmaking, by bringing the ore to the reduction ignition point using electromagnetic induction heating. In an embodiment, a specific combination of power and frequency for an electromagnetic induction-heating field and a hydrogenation process that reduces the iron oxide to metallic iron and can be used to produce steel directly without generating any carbon oxides or contaminating the metallic iron with carbon. This process produces metallic iron without carbon in its composition; this process can be used to produce steel directly from iron ore without intermediate processes. A beneficial result is that the minimum scale for production using this process, when compared to an integrated steel mill plant, can be lower both in terms of manufacturing costs and investment costs. As such, significant barriers to market entrance can be reduced, as can the cost of steel production itself. By using this process, the labor force required to produce steel can also be reduced, and, accordingly, the product price can be minimized.

[0011] At a high level, aspects of the present disclosure are directed to systems and methods for implementing a direct iron-ore-to-metallic-iron production process. In an embodiment,

electromagnetic induction of a specific power and frequency is used to heat agglomerated iron ore to its reduction ignition point temperature (about 500 °C), then the heated ore is subjected to hydrogenation, which reduces the iron ore into carbon-free metallic iron. With the proper addition of carbon, such as via steel scrap and/or carbon fines, steel can be produced using the clean metallic iron and can then be directly used in steel-working processes and/or formed into plates, tubes, rebar, bars, strip, among other shapes.

[0012] Aspects of the present disclosure can be used to implement particularly environmentally friendly processes and/or particularly economically viable processes. Producing steel without using carbon raw materials as an energy source or carbonated reduction gases promotes the elimination of CO and C0 ₂ during the steel production process chain and minimizes carbon emissions. Direct reduction of iron ore into metallic iron using electromagnetic induction and hydrogenation produces metallic iron and, depending of the chemical compositions of the iron ore, potentially several hydrates, which are easily removed from the production process and have many uses in the chemical industry. When iron ore is processed according to aspects of the present disclosure, very few of its chemical components go to waste, and a significant reduction of environmental impact can be achieved when compared with existing metallic iron production. As mentioned, aspects of the present disclosure can also be used to decrease the minimum scale of production for steel mill plants when compared to integrated steel mills or electrical steel mills. The energy required to heat iron ore by applying electromagnetic induction can be lower than the energy demanded by carbon

combustion processes; as such, energy costs associated with steel production can be significantly reduced compared to carbon-energy based steel mill plants. This is so, at least in part, because electromagnetic fields produced according to aspects of the present disclosure do not have to overcome the resistance of the electric arc commonly found in electric steel mill plants.

[0013] Aspects of the present disclosure allow for iron ore to be mixed with scrap (despite any contamination), scale, and/or other iron-rich materials prior to processing. Metallic materials, such as iron oxide material, mixed with the iron ore will respond to the electromagnetic field and reach the reduction temperature point. Any contaminants, when exposed to hydrogen or a hydrogen gas mixture, will react with the hydrogen and form hydrates that can easily be removed by a gas scrubbing system. Scrap metallic material processed according to aspects of the present disclosure will become steel. By controlling the amount of carbon, such as via steel scrap and/or carbon fines, included in the mixture, the carbon content of the end-product can be controlled to achieve a desired carbon content of the end-product steel. Because scrap, scale, and other generally iron-rich materials can be processed in this way, steel and iron can be recycled more efficiently. Exemplary

embodiments illustrating aspects of the present disclosure are described below in the context of several specific examples.

[0014] Referring now to the drawings, FIG. 1 illustrates an exemplary method 100 of reducing iron ore to steel. At step 105, iron ore, such as milled iron ore, is provided. At optional step 1 10 the iron ore can be cleaned and/or depolarized as needed or desired. Cleaning and/or depolarization can be performed, for example, using an acoustic cavitation process or other suitable process(es). At optional step 1 15, the iron ore can be mixed with any one or more other materials, such as shredded scrap steel and steel scale, among other generally iron-oxide-rich materials, to form an iron-ore mixture. It is noted that the size of any additional material added should not compromise the ability to agglomerate the material. At step 120, the iron ore from step 105 or step 1 10 or the iron-ore mixture from step 1 15 is agglomerated to form agglomerations, such as pellets and/or briquettes. At step 125, the agglomerated iron ore or iron-ore mixture is inductively heated, such as by subjecting the agglomerations to an electromagnetic field suitable for inductively heating the agglomerated iron ore or iron-ore mixture. In one example, the electromagnetic field is applied at a frequency from about 2 kHz to 12,000 kHz or higher, so as to inductively heat the agglomerated iron ore or iron-ore mixture to at least the reduction ignition temperature of the agglomerated material.

[0015] The electromagnetic induction field promotes the increase of the speed and vibration of the electrons of the oxide atoms. This increase of movement reflects the absorption of energy from the frequency of exposure of electromagnetic field. In this way, the material effectively heats itself as it is exposed to a field of one or more specific frequencies. Part of the heating is caused by the electrical resistance experienced by the electrons as they traverse the material. As those skilled in the art will readily appreciate, the power and frequency of the electromagnetic field may be adjusted according to the concentration of the iron ore and/or the particular chemical composition of iron oxide and any other added materials in the agglomerations. The agglomeration of the iron oxide ore or iron-ore mixture is important for the purposes of the inductive heating process, because if the iron oxide and/or the other added material(s) were to be used in powder form or otherwise non- agglomerated form, the non-agglomerated material would align with the electromagnetic field direction, and, thus, there would be significantly less of an increase in electron speed and vibration due to induction, which would likely result in the material not reaching its ignition point.

[0016] The agglomerations typically need to be heated to at least 500°C to reach the reduction ignition point. At this temperature, an electromagnetic induction device containing the

agglomerations, optionally operating under vacuum conditions, can be injected with hydrogen in a pure gas state or in a specific mixture. The vacuum can remove all of the atmospheric gases of the pellets and/or briquettes to promote a faster reduction reaction between the hydrogen gas or gas mixture and the iron oxide material and contaminants present, which become hydrates. The injection of hydrogen or hydrogen mixture can be initiated when the agglomerated material reaches its reduction ignition point. At the reduction ignition temperature, hydrogenation allows for hydrogen to come into contact with the oxygen of any oxides inside the pellets or briquettes, which then react with the hydrogen to form water and potentially several hydrates, depending on the amount of contaminated material present in the iron ore and/or in the mixture of iron ore, other iron oxide materials, and/or shredded steel scrap. The hydrogen promotes the reduction of the iron oxide into carbon-free metallic iron, i.e., steel. This is so because hydrogen and oxygen are strongly predisposed to form H ₂ 0, and as the iron oxide has its internal energy increased by electromagnetic induction, the iron-oxygen bonds will be weakened and the presence of hydrogen will promote the bonding of hydrogen to the oxygen, reducing the iron oxide into metallic iron and forming water as a byproduct of the reaction.

[0017] The water synthesis reaction is a strong exothermic reaction, reflecting the amount of energy and chemical affinity that the bond of hydrogen to oxygen presents. Contaminants present in the iron-oxide ore will typically react with the hydrogen, because contaminants are typically also bonded with oxygen. The presence of hydrogen at an appropriated ignition temperature will promote the formation of several hydrates and water from the contaminants, because the oxygen contained in the contaminants will combine with the hydrogen. This is why the reduction ignition point should be at least 500 °C, though it may need to be increased depending on the presence of other chemical compounds in the agglomerations, such as chemical compounds that require a higher reduction ignition point to promote the reaction between hydrogen and any oxides.

[0018] At step 130, inductive heating of the agglomerations is continued until the iron oxides in the agglomerations are converted to metallic iron. At optional step 135, the converted

agglomerations are melted and worked into any one or more desired shapes, such as plates, tubes, rebar, bars, strip, among others. It is noted that the hydrates may be captured by an air-cleaning system and can have posterior economical use in the chemical industry. Method 100 and/or any step(s) thereof can be implemented in a batch-wise or continuous-flow process.

[0019] FIG. 2 illustrates an exemplary method 200 for cleaning and/or depolarizing iron ore that can be used at optional step 110 of method 100 of FIG. 1. Referring to FIG. 2, at step 205 iron ore, such as milled iron ore, is received into method 200. At step 210, an iron-ore pulp is formed for use in a cleaning step. In one example and for a particular acoustic cavitation cleaning process (see below), water is added to the iron ore to produce an iron-ore pulp having about 15% to 50% solids content, by weight. In one particular example, the iron pulp has a 35% solids content, by weight. At step 215, the iron-ore pulp is subjected to an acoustic cavitation process to clean and/or depolarize the iron ore in the pulp to produce a slurry of cleaned/depolarized iron ore, removed contaminants, and water. The acoustic cavitation process may include moving the iron-ore pulp through an acoustic cavitation duct that is preferably capable of applying at least 7 kW/liter/minute of acoustic energy to the pulp to promote the release of earth contaminants by means of cavitation bubbles that explode over the ore surfaces and inside its micro cracks. These exploding cavitation bubbles promote the release of contaminants, increasing the purity of the iron ore. When the material comes from a magnetic concentration, such as magnetite, the material can also be submitted to acoustic cavitations to depolarize the material to allow for more effective use of electromagnetic field induction heating.

[0020] At step 220, the slurry output from the acoustic cavitation process is processed to increase the concentration of the cleaned/depolarized iron ore, separating the cleaned/depolarized iron ore from the contaminants. Step 220 may be performed using a gravimetric concentration process or other suitable concentrating process. . At step 225, the concentrated cleaned/depolarized iron ore is dewatered to reach a specific humidity according to the agglomeration process used later in the overall process (e.g., briquetting processes typically require completely dry material, while pelletization can tolerate higher moisture levels). Dewatering can be performed using any suitable process, such as by filtering, heating, or a combination of these. At this point, the dewatered, concentrated cleaned/depolarized iron ore can be further processed per method 100 of FIG. 1, such as by being used at optional step 115 or step 120.

[0021] FIG. 3 graphically illustrates various steps of method 200 of FIG. 2, as well as several other steps, using particular processing equipment for performing these steps. Element numeral 300 identifies raw milled iron ore prior to processing. Element numeral 302 illustrates a magnetic separator that can be used prior to performing step 205 of method 200 of FIG. 2 for separating particles of magnetic iron ore 304 to be processed from non-magnetic particles 306 in raw milled iron ore 300. Iron ore 304 is then provided to a mixer 308 that mixes the iron ore with water (not illustrated) to make an iron-ore pulp 310 (see step 210 of FIG. 2). As noted above, mixer 308 and/or any supporting apparatus may be calibrated so that iron-ore pulp 310 has a solids content of about 35%, with the remaining 65% being the mixing water. From mixer 308, iron-ore pulp 310 is provided to an acoustic cavitation device 312, which in this example is a vertically oriented duct, with the pulp being pumped upwardly through the duct from the device's lower end 312 A. As noted above, subjecting the particles in iron-ore pulp 310 to acoustic cavitations works to clean and/or depolarize the iron ore particles. Generally, the acoustic cavitations separate contaminants from iron ore particles, including removing contaminants from the surface of the iron ore particles and from within micro-cracks in the iron ore particles. The output of acoustic cavitation device 312 is a slurry 314 containing cleaned and/or depolarized iron ore particles, the removed contaminants, and the mixing water.

[0022] FIGS. 4 A to 4C illustrate an exemplary acoustic cavitation duct 400 that can be used, for example, as cavitation device 312 of FIG. 3. Referring to FIGS. 4 A to 4C, exemplary cavitation duct 400 (FIG. 4A) shown is designed and configured to process an about 15%-solids iron-ore pulp to an about 50%-solids iron-ore pulp composed of thick iron-oxide rich material and water at the rate of 10 m ³ /hour. In the particular example of FIGS. 4 A to 4C, the percentage of solids in the iron-ore pulp is about 35%, by weight. This should be kept in mind when reading the following description of cavitation duct 400 to understand that other embodiments can have different configurations, dimensions, etc., especially when designed for other processing rates and/or other solids-content percentages.

[0023] Acoustic cavitation duct 400 includes an inlet 404 and an outlet 408. When installed, duct 400 is oriented vertically with inlet 404 at the lower end and outlet 408 at the upper end. It is noted that it is preferred, but not absolutely necessary, that duct 400 be oriented vertically or inclined, rather than horizontally, since a horizontal orientation could cause precipitation of solids within the duct. Having inlet 404 at the lower end also helps in controlling the time that the iron-ore pulp is exposed to the acoustic cavitation action. In this example, acoustic cavitation duct 400 is 5 meters long in the direction of flow between inlet 404 and outlet 408, and is made up of five identical 1 -meter-long segments 400(1) to 400(5) secured to each other via flanged and bolted connections 412(1) to 412(4). Inlet 404 and outlet 408 are similarly secured to acoustic cavitation duct 400 via flanged and bolted connections 416(1) and 416(2). As seen best in FIGS. 4B and 4C, acoustic cavitation duct 400 defines an internal passageway 420 having a rectangular transverse cross-sectional shape of approximately 70 mm x 32 mm in size.

[0024] As seen in FIG. 4B, each acoustic cavitation duct segment 400(1) to 400(5) includes eleven ultrasonic transducers spaced evenly along that segment, with six transducers 424(1) to 424(6) on one side of that segment and five transducers 428(1) to 428(5) on the other side.

Transducers 424(1) to 424(6) and 428(1) to 428(5) provide acoustic emissions of compression and decompression waves that promote cavitation within the iron-ore pulp as it flows continuously through duct 400. This action not only cleans binder fines and other surficial matter from the particles in the iron-ore slurry, but it also renders unnecessary conventional static residence times and conventional agitators.

[0025] In this example, ultrasonic transducers 424(1) to 424(6) and 428(1) to 428(5) are each piezoelectric transducers, with transducers 424(1) to 424(6) being 50 W, 25 kHz transducers and transducers 428(1) to 428(5) being 50 W, 40 kHz transducers. Thus, entire acoustic cavitation duct 400 made up of the five like segments 400(1) to 400(5) has a total of 55 ultrasonic transducers 424(1) to 424(6) and 428(1) to 428(5), with 30 of the transducers being 50 W, 25 kHz transducers and 25 of the transducers being 50 W, 40 kHz transducers. Transducers 424(1) to 424(6) and 428(1) to 428(5) are powered in groups of five by eleven 250 W power supplies 432(1) to 432(11).

[0026] Those skilled in the art will readily appreciate that acoustic cavitation duct 400 shown is merely one example, and that many other configurations are possible. Design considerations for designing a continuous-flow acoustic cavitation device include the composition of the iron-ore pulp at issue, the flow rate of the slurry, the applied power of the ultrasound, the residence time of the slurry in the acoustic cavitation duct, and the processing rate required, among others. It appears that the power should be greater than 7W/s and that the residence time should be at least about

2.5 seconds for most commercial applications. Alternative configurations of acoustic cavitation devices can have passageways that differ in size, transverse cross-sectional shape, length, straightness, etc. Alternative configurations can also have different numbers of transducers and different transducer locations and arrangement. Those skilled in the art will be able to design, make, and use acoustic cavitation devices that provide the desired/necessary cleaning function without undue experimentation.

[0027] Referring again to FIG. 3, after being submitted to acoustic cavitation in acoustic cavitation duct 312, slurry 314 is provided to one or more concentrators 316, such as a gravimetric concentrator, that remove the contaminants and concentrate the cleaned iron ore to create an ore concentrate 318. Iron ore concentrate 318 is provided to dewatering equipment 320 for removing the water and lowering the moisture content of the ore concentrate to create a dried ore concentrate 322. Dewatering equipment 320 may include one or more heating dryers 324 and/or one or more filtering devices 326, such as a press filter, a vacuum filter, or other filter type, or any combination of these, among other device(s). As noted above, the moisture level within dried ore concentrate 322 is typically determined by the process by which the dried ore concentrate will be agglomerated. In this connection, dried ore concentrate 322 is provided to agglomeration equipment 328, such as one or more briquetting machines 330 and/or one or more pelletizers 332, among others, that

agglomerate dried ore concentrate 322 into agglomerated iron ore 334, such as briquettes 334A and pellets 334B. Agglomerated iron ore 334 is then ready for further processing, such as at inductive heating step 125 of method 100 of FIG. 1. [0028] FIG. 5 depicts an exemplary converter system 500 for converting iron-ore-rich agglomerations 504, for example, briquettes 504A and/or pellets 504B, into metallic-iron-rich agglomerations 508, here, briquettes 508A and/or pellets 508B, via an inductive-heating process, such as can occur in steps 125 and 130 of method 100 of FIG. 1. Agglomerations 504 may be prepared in any suitable manner, such as via method 200 of FIG. 2. In the embodiment shown, system 500 is configured for processing agglomerations 504 in batches without a vacuum.

System 500 of FIG. 5 includes an electromagnet-field applicator 512 that subjects iron-oxide-rich agglomerations, such as agglomerations 504, to electromagnetic energy to inductively heat the agglomerations in the manner and for the steel-conversion purposes noted above. As those skilled in the art will readily appreciate, electromagnetic-field applicator 512 can be any one or more suitable devices or piece(s) of equipment for subjecting iron-oxide-rich agglomerations to electromagnetic fields that convert the iron-oxide-rich agglomerations into metallic-iron-rich agglomerations 508.

[0029] In the example shown, electromagnetic-field applicator 512 includes an electromagnetic- field tunnel 516 and an electromagnetic-field generator 520. Electromagnetic-field tunnel 516 receives the iron-oxide-rich agglomerations, such as agglomerations 504, on a batch-by-batch basis, and electromagnetic-field generator generates an electromagnetic field, here represented by flux arrows 524, and is located so that the agglomerations within the tunnel are inductively heated by the generated field. It is noted that briquettes, such as briquettes 504A produced by the pressure of a briquetting machine typically tend to behave more predictably in the presence of the electromagnetic field because the material is more compact than with the pellets, and this compactness can reduce the potential for the agglomerated material to align with the direction 528 of power flow of

electromagnetic field 524. Direction 528 of electromagnetic field 524 is not as important as the power and the frequency of the field, parameters of which are described above.

[0030] In this embodiment, converter system 500 includes a reservoir 532 of hydrogen or hydrogen mixture that is controllably released into electromagnetic field tunnel 516 during the inductive-heating process to promote reduction of the iron ore and/or other materials within the agglomerations within the tunnel. Converter system 500 also includes byproduct-processing equipment 536 for processing byproducts generated during the reduction process. In this example, byproduct-processing equipment 536 includes a water-quenching and/or cleaning device 540, a pipe 544 for expelling water vapor, and a reservoir 548 for collecting any byproduct hydrates for recycling and/or sale and/or further processing, as desired. [0031] It is noted that while system 500 is designed and configured to perform the inductive heating without a vacuum, those skilled in the art will readily understand that this system can be modified for inductively heating the agglomerations within a vacuum. For example, the ends of electromagnetic-field tunnel 516 can be sealed with suitable vacuum closures (not shown), such that after a batch of iron-ore-rich agglomerations are located within the tunnel, the tunnel can be sealed and evacuated to a suitable vacuum level prior to, contemporaneous with, or otherwise in

synchronicity with initiating the inductive heating. As another alternative, electromagnetic-field tunnel 516 may be replaced with a chamber (not shown) having a single opening or set of openings for loading and unloading the chamber with, respectively, iron-oxide-rich agglomerations and metallic-iron-rich agglomerations. Such a chamber can be a vacuum chamber that is operated at vacuum pressures, if desired.

[0032] FIG. 6 illustrates another exemplary converter system 600 made in accordance with the present invention. In this embodiment, converter system 600, in contrast to batch-wise and non- vacuum converter system 500 of FIG. 5, is both a continuous-flow system and a vacuum-based system. Converter system 600 is designed and configured to convert iron-oxide-rich

agglomerations 604, for example, briquettes 604A and/or pellets 604B, into corresponding metallic- iron-rich agglomerations 608, here, briquettes 608A and/or pellets 608B, via an inductive-heating process, such as can occur in steps 125 and 130 of method 100 of FIG. 1. In the example shown, converter system 600 includes a self-feeding continuous processor 612 having multiple stages 612(1) to 612(4) that are isolatable from one another and the ambient environment by valves 616(1) to 616(4). Stage 612(1) comprises a feed bin that receives and holds iron-oxide-rich

agglomerations 604 for period feeding to the next stage, i.e., stage 612(2), of continuous

processor 612 by appropriate operation of valve 616(1). Second stage 612(2) of continuous processor 612 comprises a first vacuum bin that is placed into a state of vacuum relative to ambient conditions surrounding the continuous processor using one or more vacuum pumps 620.

[0033] Stage 612(3) comprises an induction heater that includes a vacuum chamber 614 and one or more electromagnetic-field generators 624 that generate one or more electromagnetic fields selected to heat the agglomerations located within the vacuum chamber. Vacuum chamber 614 includes an inlet 614A and an outlet 614B and is under vacuum for improved conversion efficiencies as noted above. In this embodiment, converter system 600 includes a reservoir 62.8 of hydrogen or hydrogen mixture that is controllably released into vacuum chamber 614 during the inductive- heating process to promote reduction of the iron ore and/or other materials within the agglomerations within the vacuum chamber. Converter system 600 also includes byproduct-processing

equipment 632 for processing byproducts generated during the reduction process. In this example, byproduct-processing equipment 632 includes a water-quenching and/or cleaning device 636, a pipe 640 for expelling water vapor, and a reservoir 644 for collecting any byproduct hydrates for recycling and/or sale and/or further processing, as desired.

[0034] Stage 612(4) of continuous processor comprises a second vacuum bin for receiving the converted, metallic-iron-rich agglomerations from vacuum chamber 614 of induction heater 612(3). Second vacuum bin 616(4) is placed into a state of vacuum relative to ambient conditions surrounding the continuous processor using one or more vacuum pumps 648.

[0035] As those skilled in the art will readily understand, vacuum bin 612(2) is filled by opening valve 616(1) when valve 616(2) is closed. Once vacuum bin 612(2) is filled to a desired level, valve 616(1) is closed, and vacuum pump(s) 620 operated to create a vacuum within the vacuum bin.

[0036] To convert iron-oxide-rich agglomerations 604 to metallic-iron-rich agglomerations 608, converter system 600 of FIG. 6 may be operated as follows. Initially, to place vacuum chamber 614 of induction heater 612(3) into a vacuum state, valves 616(2) and 616(4) are closed, valve 616(3) is opened, and vacuum pump(s) 648 is/are operated to evacuate air from both the induction heater and second vacuum bin 612(4). Once induction heater 612(3) is at an appropriate vacuum pressure, valve 616(3) may be closed to prepare the induction heater for receiving iron-oxide-rich

agglomerations for conversion.

[0037] With valve 616(1) closed, feed bin 612(1) containing a suitable amount of iron-oxide- rich agglomerations (not shown), and valve 616(2) closed, valve 616(1) is opened to allow at least some of the agglomerations to flow from the feed bin into first vacuum bin 612(2). Once the desired amount of iron-oxide-rich agglomerations are contained in first vacuum bin 612(2), valve 616(1) is closed and vacuum pump(s) 620 is/are operated to evacuate air from within the first vacuum bin. Typically, the vacuum pressure created within first vacuum bin 612(2) is substantially the same as the vacuum pressure already existing within vacuum chamber 614. [0038] When the vacuum pressures within first vacuum bin 612(2) and vacuum chamber 614 are at the desired levels, valve 616(2) is opened to allow the agglomerate to flow from the first vacuum bin into the vacuum chamber via opening 614A, and once all of the agglomerations from the first vacuum bin have been transferred to the vacuum chamber, valve 616(2) is closed for the induction-heating process to start. At any point after valve 616(2) has been closed, first vacuum bin 612(2) can be reloaded by reopening valve 616(1). In conjunction with reloading first vacuum bin 612(2), the first vacuum bin is returned to ambient pressure, such as by virtue of opening valve 616(1) and/or by other means, such as by reversing vacuum pump(s) 620.

[0039] With iron-oxide-rich agglomerations now within evacuated vacuum chamber 614, electromagnetic-field generator(s) 624 can be energized to inductively heat the agglomerations. When the agglomerated material reaches its ignition point, hydrogen or a hydrogen mix may be injected into induction heater from reservoir 628 to assist with the conversion reactions. Induction heating continues until all or substantially all of the iron-oxide-rich agglomerations are converted into metallic-iron-rich agglomerations. Byproducts of the conversion reactions are drawn out of vacuum chamber 614 and processed by byproduct-processing equipment 632. Once the conversion from iron-oxide-rich agglomerations to metallic-iron-rich agglomerations has occurred within vacuum chamber 614, valve 616(3) is opened to allow the metallic-iron-rich agglomerations to move from the vacuum chamber to second vacuum bin 612(4) via outlet 614B. Once all of the metallic- iron-rich agglomerations from vacuum chamber 614 are in second vacuum bin 612(4), valve 616(3) is typically closed to maintain the vacuum within the induction heater during emptying of the metallic-iron-rich agglomerations from second vacuum bin 612(4). In this embodiment, as soon as or after valve 616(3) is closed, valve 616(4) is opened to allow the metallic-iron-rich converted agglomerations to flow out of second vacuum bin 612(4) as agglomerations 608. In conjunction with emptying second vacuum bin 612(4), the second vacuum bin is returned to ambient pressure, such as by virtue of the opening of valve 616(4) and/or by other means, such as by reversing vacuum pump(s) 648. At any point after second vacuum bin 612(4) has emptied, valve 616(4) is closed and air from the second vacuum bin is again evacuated to create a vacuum that typically is equal to or substantially equal to the vacuum in vacuum chamber.

[0040] As those skilled in the art will readily appreciate, converter system 600 can be operated in a nearly continuous manner by properly coordinating the opening and closing of valves 616(1) to 616(4) and the operating of vacuum pumps 620, 648 maintain as continuous a process as possible, while ensuring that feed bin 612(1) remains full enough to fill first vacuum bin 612(2) each time its filling is desired. The control of valves 616(1) to 616(2), vacuum pumps 620, 648, electromagnetic- field generator(s) 624, and any other equipment necessary to make converter system 600 function can be performed manually by one or more operators, automatically via an automated control system (not shown), or by a combination of automated and manual control. Those skilled in the art will understand how to control the various aspects of converter system 600 upon understanding this entire disclosure by adopting techniques and equipment known in the art from other technical fields.

[0041] FIG. 7 is a photograph of crude iron ore pellets and FIG. 8 is a metallographic image (400x magnification) of a pellet made in accordance with aspects of the present disclosure.

Particularly, FIG. 8 is metallographic assay after direct reducing to metallic iron showing the metallic-iron structure formed by the process.

[0042] Exemplary embodiments have been disclosed above and illustrated in the accompanying drawings. It will be understood by those skilled in the art that various changes, omissions and additions may be made to that which is specifically disclosed herein without departing from the spirit and scope of the present invention.