Improved industrial reduction of bauxite and alumina to aluminum by hydrogen

Abstract

A reactor vessel that converts aluminum ores to aluminum is provided. The reactors uses hydrogen with bauxite and with alumina to convert to oxide and reduced metal, respectively, within one facility as opposed to traditional methods which might require at least three facilities. The process efficiently uses and recycles heat and materials to increase energy-efficiency and to self-sustain two out of three species needed for the conversion. Using electrolysis and hydrogen for operations, results in a process that generates no greenhouse gases.

Description

TITLEIMPROVED INDUSTRIAL REDUCTION OF BAUXITE AND ALUMINA TO ALUMINUM BY HYDROGENREFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of United States Provisional Serial No. 63 / 515,230 entitled Improved Industrial Reduction of Bauxite and Alumina to Aluminum by Hydrogen filed on July 24, 2023, the entire contents of which are incorporated by reference herein for all purposes.TECHNICAL FIELD

[0002] The present disclosure relates generally to systems, devices and methods for metal ore reduction. More specifically, the present disclosure describes systems and methods for converting aluminum ores to aluminum.BACKGROUND

[0003] The world's aluminum ores are converted to aluminum by a multitude of steps, in an industrial process that includes the Bayer process followed by roasting or calcining then application of the Hall-Heroult process. These methods require high temperatures, aggressive wet chemicals and significant electrical power to convert bauxite to alumina and then alumina to aluminum. Overall, these methods are energy-intensive, generate significant waste streams, use hazardous materials and result in high greenhouse gas emissions. For example, the Hall-Heroult process uses large quantities of electrical power to melt an electrolyte and to apply an electrochemical reduction between electrodes that results in carbon dioxide generation. Optimization has been explored to its limit and is currently at a stand-still using these methods.

[0004] The use of hydrogen has been considered for the reduction of alumina and for bauxite, but potentially successful methods rely on a very high-energy hydrogen plasma beam and do not scale well to generate a desired industrial production rate. Exploration using thermo-chemical methods requires extremely high temperatures and the conversion or reduction of alumina to aluminum, for example, is slow and also notamenable to scale-up to a desired production rate. A method combining thermal energy, chemical reactants and a catalytic material has been explored for converting alumina to aluminum using hydrogen and aluminum itself. This thermo-chemo-catalytic method not only shows potential to reduce alumina to aluminum using hydrogen but also the potential to be scaled to a desired industrial production rate. In addition, the method may have merit to converting bauxite to alumina and then to aluminum given the combination of thermal energy, chemical reactants and catalytic material has the potential to reduce bauxite constituents.

[0005] Even with potential successful conversion, the combination of heat, reactants, catalyst, and system materials in a thermo-chemo-catalytic process, has not been optimized to identify high heat transfer, high mass transfer, and maximum reduction or conversion rate conditions. It has also not been investigated to resolve the potential to scale-up to a desired industrial production rate by means of a properly configured process, vessel or reactor. In particular, for maximizing reaction rate, hydrogen, alumina and molten aluminum must be in contact sufficient for reaction to occur along with significant removal of the gaseous reaction product, water.

[0006] Thus, what is needed is a system and method to enhance reduction rate during metal ore reduction and within the ore reduction volume.SUMMARY

[0007] The present disclosure relates generally to systems, devices and methods for metal ore reduction. More specifically, the present disclosure describes systems and methods for converting aluminum ores to aluminum.

[0008] According to one example of the instant disclosure, a device and method that effectively converts or reduces bauxite to alumina using hydrogen in the presence of molten aluminum or an alloy which can be performed at a rate commensurate with a desired production scale is provided.

[0009] According to another example of the instant disclosure, a device and method that effectively converts or reduces alumina to aluminum using hydrogen in the presence of molten aluminum or an alloy which can be performed at a rate commensurate with a desired production scale is provided.

[0010] According to another example of the instant disclosure, a device and method that effectively converts or reduces bauxite to aluminum using hydrogen in the presence of molten aluminum or an alloy which can be performed at a rate commensurate with a desired production scale is provided.

[0011] According to one example of the instant disclosure, a device and method that effectively converts or reduces bauxite to alumina and to aluminum using hydrogen at elevated temperature, as a plasma, in the presence of molten aluminum or an alloy, or some combination thereof, which can be performed at a rate commensurate with a desired production scale is provided.

[0012] According to one example of the instant disclosure, a device and method that effectively converts or reduces alumina to aluminum using hydrogen at elevated temperature, as a plasma, in the presence of molten aluminum or an alloy or some combination thereof which can be performed at a rate commensurate with a desired production scale is provided

[0013] According to another example of the instant disclosure, a device and method that converts or reduces bauxite to alumina and aluminum plus, also, alumina to aluminum which reduces the amount of hazardous materials that might be employed or created relative to current industrial methods that use bauxite and alumina to produce aluminum is provided.

[0014] According to another example of the instant disclosure, a device and method that converts or reduces bauxite to alumina and aluminum plus, also, alumina to aluminum which decreases the areal or spatial footprint employed relative to current industrial methods that use bauxite and alumina to produce aluminum is provided.

[0015] According to another example of the instant disclosure, a device and method that converts or reduces bauxite to alumina and aluminum plus, also, alumina to aluminum which reduces the number of steps required from to start to finish relative to current industrial methods that use bauxite and alumina to produce aluminum is provided.

[0016] According to another example of the instant disclosure, a device and method that converts or reduces bauxite to alumina and aluminum plus, also, alumina to aluminum which reduces the energy required relative to current industrial methods that use bauxite and alumina to produce aluminum is provided.

[0017] According to another example of the instant disclosure, a device and method that converts or reduces bauxite to alumina and aluminum plus, also, alumina to aluminum which, by virtue of the reduction in the number of steps, the footprint and energy, or some combination thereof, decreases the greenhouse gases generated relative to current industrial methods that use bauxite and alumina to produce aluminum is provided.

[0018] According to another example of the instant disclosure, a device and method that converts or reduces bauxite to alumina and aluminum plus, also, alumina to aluminum, using hydrogen, which can be scaled to a desired production rate is provided.

[0019] In embodiments, a system for generating metal, particularly aluminum, from metal ores using hydrogen or other suitable reducing gases on a relevant industrial scale is provided. The system comprises an inlet flow portion configured to deliver one or more inlet streams comprising solid and gaseous components, wherein the solid and gaseous components comprises metal ore, metal catalytic species, reducing gases, and combustion gases, a reduction portion configured to accept the one or more inlet streams, wherein the reduction portion is configured to reduce an ore to a reduced metal, and wherein gaseous product species are created from a reduction reaction or from combustion to form reduction portion streams, an array of internal structures located in the reduction portion, and partially within the entrance section or exit section, wherein the array of internal structures are configured to, when the reduction streams or components contact them, form a reduced metal, a recycle feature to re-use catalytic species in the reduction portion, an exit section configured to accept the different mix of gaseous species and a solid species exiting the reduction portion, wherein the different mix gaseous species and the solid species comprises unreacted combustibles, reduction reactants, reduction and combustion products, solids, unreacted ore, partially reacted or reduced ore, catalytic materials or any combination thereof, wherein gaseous species are re-used in an integrated gas generator to re-supply reducing gases for reduction. Metal or reduced metal may also be part of the mix of species.

[0020] In embodiments, a method for generating metal, particularly aluminum, using hydrogen or other suitable reducing gases on a relevant industrial scale is provided. The method comprises delivering one or more inlet streams to an entrance portion, the inletstreams comprising solid and gaseous components, wherein the solid and gaseous components comprises metal ore, metal catalytic species, reducing gases, and combustion gases, accepting one or more of the inlet streams to a reduction portion wherein the reduction portion is configured to reduce an ore to a reduced metal, and wherein gaseous product species are created from a reduction reaction or from combustion to form reduction portion streams, an array of internal structures located in the reduction portion, and partially within the entrance section or exit section, wherein the array of internal structures are configured to, when the reduction streams or components contact them, form a reduced metal, a recycle feature to re-use catalytic species in the reduction portion, an exit section configured tllOo accept the different mix of gaseous species and a solid species exiting the reduction portion, wherein the different mix gaseous species and the solid species comprises unreacted combustibles, reduction reactants, reduction and combustion products, solids, unreacted ore, partially reacted or reduced ore, catalytic materials or any combination thereof, wherein gaseous species, notably water vapor, are re-used in an integrated gas generator to re-supply reducing gases for reduction.

[0021] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. The claimed subject matter is not limited to implementations that solve any or all disadvantages noted in the Background.BRIEF DESCRIPTION OF FIGURES

[0022] Aspects of the present disclosure are illustrated by way of example and are not limited by the accompanying figures for which like references indicate like elements.

[0023] FIG. 1 illustrates vertical lengthwise, side-views for an example integrated system, including a reactor, where hydrogen is generated and aluminum ores are converted to alumina or aluminum, according to an exemplary embodiment;

[0024] FIG. 2 illustrates vertical lengthwise, side-views for the example integrated system of FIG. 1, including the reactor, where hydrogen is generated and aluminum ores are converted to alumina or aluminum, according to an exemplary embodiment;

[0025] FIG. 3 illustrates vertical lengthwise, side-views for the example integrated system of FIG. 1, including the reactor, where hydrogen is generated and aluminum ores are converted to alumina or aluminum with all material flow streams identified, according to an exemplary embodiment;

[0026] FIG. 4 illustrates horizontal, top-down views for reactor internal plates, where reactant materials meet in the conversion of aluminum ores to alumina or aluminum, emphasizing the relative position of ports, nozzles or holes from plate-to-plate, according to an exemplary embodiment;

[0027] FIG. 5 illustrates special features at the bottom of the reactor according to an exemplary embodiment;DETAILED DESCRIPTION

[0028] Exemplary embodiments are discussed below with reference to the Figures.

[0029] In the descriptions above and in the claims, phrases such as "at least one of' or "one or more of' may occur followed by a conjunctive list of elements or features. The term "and / or" may also occur in a list of two or more elements or features. Unless otherwise implicitly or explicitly contradicted by the context in which it used, such a phrase is intended to mean any of the listed elements or features individually or any of the recited elements or features in combination with any of the other recited elements or features. For example, the phrases "at least one of A and B;" "one or more of A and B;" and "A and / or B" are each intended to mean "A alone, B alone, or A and B together." A similar interpretation is also intended for lists including three or more items. For example, the phrases "at least one of A, B, and C;" "one or more of A, B, and C;" and "A, B, and / or C" are each intended to mean "A alone, B alone, C alone, A and B together, A and C together, B and C together, or A and B and C together." Use of the term "based on," above and in the claims is intended to mean, "based at least in part on," such that an unrecited feature or element is also permissible.

[0030] The subject matter described herein can be embodied in systems, apparatus, methods, and / or articles depending on the desired configuration. The implementations set forth in the foregoing description do not represent all implementations consistent with the subject matter described herein. Instead, they are merely embodiments consistent with aspects related to the described subject matter. Although a few variations have been described in detail above, other modifications or additions are possible. In particular, further features and / or variations can be provided in addition to those set forth herein. For example, the implementations described above can be directed to various combinations and sub-combinations of the disclosed features and / or combinations and sub combinations of several further features disclosed above. In addition, the logic flows depicted in the accompanying figures and / or described herein do not necessarily require the particular order shown, or sequential order, to achieve desirable results. Other implementations may be within the scope of the following claims.

[0031] The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope is, therefore, indicated by the appended claims rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.Exemplary Materials

[0032] Various metal ore types and oxides may be converted or reduced in the reactor system. For example, suitable metal ores may include, but are not limited to, bauxite ore forms such as gibbsite (AI(OH )3), boehmite (y-AIO(OH)) and diaspore (a-AIO(OH)). Suitable oxides may include, but are not limited to, alumina (AI2O3) of all types. Additionally, carbides, oxides, sulfides, carbonates, sulfates and phosphates of W, Ti, Fe, Cu, Cr, Co, Zn, Mn, Sn, Si, Ni, Sm, Mg, Li, Sc, Y, U, Th, various lanthanides, and rare-earths may be converted or reduced. Although the systems and methods described below are broadly applicable to any metal ore, for convenience, the examples below are described in the specific context of reducing aluminum ores or compounds, particularly AI(OH )3and / or AI2O3. Although the technology is described herein in certain examples in the context of treating aluminum ores or compounds, the technology is not so limited and is more broadly usable and adaptable to any metal ore.

[0033] In embodiments, metal ores provided to example reactor systems may be in powder or pellet form. Particles or pellets comprising example powders provided to reactors may have a nominal length or diameter between 10 to 2000 microns. In embodiments, reduced metal ore or partially reduced metal ore may be a powder with nominal particle length or diameter ranging from 5 to 1900 microns.

[0034] In embodiments, various gases may be provided to example reactor systems and are typically reductants. For instance, example gaseous species may comprise reductants or reactants such as hydrogen (H2). Other example gases for combustion, used for heating, may include hydrogen (H2), carbon monoxide (CO), methane (CH4), natural gas, hydrocarbons, alcohols and / or ketones, as well as air and oxygen (O2).

[0035] In embodiments, molten metals may be provided to or created within example reactor systems. Molten species include aluminum and aluminum mixed or alloyed with various proportions of titanium, iron, magnesium, manganese, zinc, silicon, carbon, nickel and copper.

[0036] In embodiments, outlet streams provided by reactor systems may comprise solids and gaseous streams, which may comprise conversion or reduction products, unreacted reductants or gaseous reactants, unreacted solids, and / or unreacted combustibles and combustion products. Example unreacted reductant or gaseous species may comprise hydrogen (H2). Example reduction products may comprise aluminum (Al), various oxidation states of aluminum, AI2O3, H2O, and combinations thereof. Example reduction products may also comprise aluminum or aluminum-based compounds alloyed or combined with various proportions of Ti, Fe, Mg, Mn, Zn, Si, C, Ni or Cu. Example unreacted solids may comprise bauxite ores and / or AI2O3and / or the same alloyed or combined with Ti, Fe, Mg, Mn, Zn, Si, C, Ni or Cu. Example combustion products may comprise CO2, H2O, nitrogen (N2) and NOX. Example unreacted combustibles or combustion required species may comprise H2, CO, O2, CH4, other hydrocarbons, alcohols, ketones, and combinations thereof.

[0037] In embodiments, one or more materials may be used within or upon internal structures or walls that are compatible with all the materials and operating conditions used in the reaction, reduction or conversion to alumina or aluminum. These comprisesteel (various types), titania, zirconia, silica, aluminum nitride, SiC, C as well as Ti, W, Mo, and Ni, including their oxides and alloys thereof.

[0038] In embodiments, the generation of hydrogen may occur by electrolysis of water, steam-methane reforming, thermal or thermo-catalytic decomposition of water or hydrocarbons and / or water-gas shifting. The description herein emphasizes water electrolysis, however, other methods may be used. Materials used in the hydrogen generating methods may include a wide range of catalysts and / or electrode materials including but not limited to Pt, Pd, Rh, Os, Re, Nb, Fe, Ni, alumina, silica, titania, zirconia, yttria stabilized zirconia (with or without Ni or Sc), lanthanum strontium manganite yttria stabilized zirconia, bismuth oxide, lead oxide, Ni-cermets, niobates (with or without Mn, Ti or Fe), molybdenum sulfide, cerium compounds and alloys, Ni compounds and alloys and may contain carbon.

[0039] In embodiments, the internal structures may be cylindrical, tubular, rectangular, square, flat (as in a plate), solid, porous, contain penetrations or perforations or be meshed. The use of the term pipe may be interchanged with tube or vice versa.

[0040] In embodiments, the terms aluminum ore, molten ore and melt are used. Aluminum ore refers to bauxite, alumina or other aluminum compounds. Molten ore refers to the matrix of embedded aluminum ore (usually as a solid) in melted aluminum or other aluminum alloy or metal or metal alloy. Melt refers to the metal catalyst molten phase at any point in the process. Towards the end of the process, this is actually the product form which is primarily molten aluminum, aluminum alloy or metal or metal alloy, although a small amount of unreacted aluminum ore may still be present.Example Reactor Systems

[0041] In embodiments, the complete system may comprise entrance portions, conversion or reduction portions, feed handling and delivery components, structures for hydrogen generation, heating components, and exit portions. Various operating conditions and example configurations are discussed below.

[0042] In the example configurations, the following example materials are primarily discussed: ore: Bauxite or AI2O3(examples of possible aluminum ores or forms) reductants: H2solid reduction or conversion products: Al or AI2O3gaseous reduction products: H2O combustion reactants: H2O2(if air is used, then also N2) combustion products: H2O (if air is used, possibly NOx) hydrogen generating species: H2O

[0043] As mentioned above, this system and method may be adapted to any metal ore and is not solely applicable to aluminum ores or forms. In examples where ores and forms other than those that are aluminum-based are treated, this chemistry and these example materials may differ from these shown here.

[0044] Example configurations may use combustion for heat delivery, which may be full oxidation or partial oxidation of hydrocarbons. Combustion may also be hydrogen or carbon monoxide (CO) combustion.

[0045] Example configurations may use inductive, microwave, or resistive methods for heat delivery or various combinations thereof.

[0046] These and other examples will be explained in more detail below with respect to FIG. 1 through FIG. 5.

[0047] Referring now to FIG. 1, a reactor system 100 is shown. The reactor system comprises reactor 101 embodiments that comprise internal features that are configured so that alumina and hydrogen are, respectively, embedded within and dissolved within an aluminum melt to facilitate contact of hydrogen with alumina at an aluminum melt interface to enhance the rate of reaction between hydrogen and alumina.

[0048] In embodiments, water vapor generated by reactions within reactor 101 that convert alumina to aluminum is recycled and used to regenerate the hydrogen. This reduces the externally supplied feed requirement for generating hydrogen.

[0049] In embodiments, heat content which would otherwise be wasted, is used to reduce the required externally supplied energy for generating hydrogen from the water vapor.

[0050] With reference to FIGS. 1-3, exemplary vertical lengthwise side-views of an integrated system which includes the vessel or reactor 101, its internal structures and the associated features (for example, other unit operations and equipment) which generate and process hydrogen, according to an example. The depiction of theintegrated system and its associated streams has been split into three figures. As a result, FIG. 1 - FIG. 3 may be used simultaneously in the description of certain features and functions. Vessel 101 may be anywhere from 5 ft to 60 ft tall and 3 ft to 30 ft in diameter.

[0051] Aluminum ores (for example bauxite or alumina) enter through reactor ore inlet 106 into hopper 108. In embodiments, these materials are delivered in a batch-wise method to reactor 101. In embodiments, once the hopper 108 is full, valves (not all shown) isolate the hopper 108 atmosphere. In embodiments, vacuum pump 240 is configured to evacuate the atmosphere inside hopper 108 through hopper vacuum pipe 128 to a vacuum less than approximately 600 torr.

[0052] In embodiments, once the hopper 108 has been evacuated, hydrogen is back-filled into the hopper 108 to a pressure from approximately 1 atm to 20 atm through hopper hydrogen feed pipe 126 using compressor 237. The source of the hydrogen will be described in more detail below.

[0053] In embodiments, heater 105 heats the hopper 108 up to 650 °C. In embodiments, heating may be by combustion. In embodiments, heating may be by microwave, induction, or resistive methods (which may require electrical power). In embodiments, heating may be accomplished by a combination of these or other suitable methods.

[0054] In embodiments, heating may be by hydrogen combustion, which may utilize hydrogen generated at electrolyzer 102. Hydrogen exits electrolyzer 102 via electrolyzer hydrogen pipe 114 as electrolyzer hydrogen stream 321. Electrolyzer hydrogen stream 321 is split into hydrogen stream 330 and heater hydrogen feed stream 336. Heater hydrogen feed stream 336 is directed by pump or compressor 243 to heater 105. Oxygen is also generated by the electrolyzer 102, and may be used for heat generation by its combustion with hydrogen. Oxygen exits the electrolyzer 102 at electrolyzer oxygen pipe 122 as electrolyzer oxygen stream 322. Stream 336 in pipe 130 can be comprised of hydrogen stream 322 from the electrolyzer 102, hydrogen stream 329 from the separator 104, oxygen stream 322 from the electrolyzer 102 or a combination, as needed for combustion heating in heater 105. Oxygen at stream 322 can also be deployed for other tasks either inside or outside the process via exit pipe 337.

[0055] In embodiments, water vapor required as a feed for electrolyzer 102 for the generation of hydrogen may be provided by recycling the combustion exhaust stream335 from heater 105. In embodiments, instead of being sent to the atmosphere, the captured exhaust stream 335 flows through exhaust pipe 129 and is pumped or compressed by pump or compressor 242 to the electrolyzer inlet pipe 121.

[0056] In embodiments, heater 105 is manufactured from ceramic-type materials such as alumina or a material like silicon carbide (SiC) if internal temperatures above approximately 900 °C are used. In embodiments, if temperatures below approximately 1200 °C are used in heater 105, the materials of its construction may be stainless steel; Ni, Al, Ti, W, or Cu alloys; or other alloy materials such as Inconel, Incoloy or Hastelloy.

[0057] In embodiments, once the hopper 108 and its contents are both at or below approximately 650 torr and at or above approximately 100 °C, the contents are charged or released into enclosed zone 228. Then, hopper 108 is isolated from the rest of the reactor using hopper isolation valves 127.

[0058] In embodiments, once the hopper 108 and its contents are both at or below approximately 650 torr and at or above approximately 100 °C, the contents are backfilled with hydrogen (or reductant) from pipe 126 from 1 to 20 atm. Then, hopper 108 is isolated from pipe 126 (using valves).

[0059] In embodiments, once the hopper 108 is back-filled with hydrogen from approximately 1 to 20 atm, the contents are charged or released into enclosed zone 228. Then, hopper 108 is isolated from the rest of the reactor using hopper isolation valves 127.

[0060] In embodiments, at start-up of the process, Al particles are mixed with the bauxite or alumina (aluminum ore) particles fed at reactor ore inlet 106 to hopper 108. In embodiments, the ratio of Al to aluminum ore may be approximately 3 moles to 60 moles of aluminum to aluminum ore. In embodiments, once the reactor 101 is operating at steady state, the Al feed mixed with the aluminum ore is sourced (recycled) from the reactor bottom 234 via an atmosphere isolated lift mechanism 109 (for example, a screw auger, conveyor, or other appropriate lift); in embodiments, where recycled Al is used, fresh Al may no longer need to be mixed with the aluminum ore at reactor ore inlet 106. More description regarding the mechanism by which the Al is generated and reaches reactor bottom 234 will be provided below in this section.

[0061] In embodiments, the recycled Al material transported by lift mechanism 109 is fed to enclosed zone 228. In embodiments, the recycled Al is transported by lift mechanism109 to enclosed zone 228 in a batch-wise method. In embodiments, the recycled Al is transported by lift mechanism 109 to enclosed zone 228 after a charge or load from hopper 108 is first provided to enclosed zone 228. In embodiments, once the recycled Al is fed into enclosed zone 228, lift mechanism 109 is isolated from enclosed zone 228 by valves. In this manner, the recycled Al is primarily on top of or above the aluminum ore (bauxite or alumina) within the enclosed zone 228.

[0062] In embodiments, heating, via heater 105 continues to heat enclosed zone 228 and its contents until reaching at the Al melting point of approximately 660 °C or greater. The result is a hydrogen-charged mix of solid alumina or bauxite particles embedded in an aluminum melt.

[0063] In embodiments, molten ore drips, as described in more detail below, from enclosed zone 228 to reaction zone 110 through inlet perforated plate 229, from reaction zone110 to reaction zone 111 through perforated plate 230, from reaction zone 111 to reaction zone 112 through perforated plate 231, from reaction zone 112 to reaction zone 113 through perforated plate 232, and from reaction zone 113 to condensation and gas expulsion zone 132 through perforated plate 233.

[0064] In embodiments, at the bottom of enclosed zone 228 is an inlet perforated plate 229 through which the reactor feed stream 312 may drip into the reaction zone 110. The rate of transport from enclosed zone 228 into reaction zone 110 is dependent on several features of the perforations in inlet perforated plate 229.

[0065] In embodiments, inlet perforated plate 229 and / or perforated plates 230, 231, 232, 233 may contain anywhere from approximately 4 to 100 ports, holes, nozzles, penetrations, or perforations (which will be called "holes 402" from this point forward, refer to FIG. 4).

[0066] In embodiments, the thickness of the inlet perforated plate is approximately 1 / 16 in. to 1 / 2 in. The holes 402 may be chamfered at top or bottom, may be frustoconical in shape, may be cylindrical in shape, may have sides which are at angles from approximately 5 degrees to 65 degrees, or may be rounded at the top or bottom or both. The inside diameter of each hole 402 may be from approximately 1 / 32 in. to 1 / 2 in. The top side of the holes 402 may also be surrounded by one or more features, such as a circular wall (which may be approximately 1 / 32 in. to 1 / 16 in. in width and approximately 1 / 32 in. to 1 / 2 in. high). The properties of the holes 402 or of featuresaround the holes may be the same for each hole in the perforated plate, may be all unique to each hole in the perforated plate, or may be the same for some holes and different for other holes throughout the perforated plate. In embodiments, each perforated plate successively lower in the vertical arrangement of reaction zones may include fewer holes 402 in it than the one above it.

[0067] In embodiments, each perforated plate successively lower in the vertical arrangement of reaction zones may include the same number of holes 402 in it than the one above it. In embodiments, each perforated plate successively lower in the vertical arrangement of reaction zones may include more holes 402 in it than the one above it. In embodiments, each perforated plate successively lower in the vertical arrangement of reaction zones may include at least 5% more holes in it than the one above it.

[0068] In embodiments, the layers of molten ore on the perforated plates (which contain solid alumina particles) are relatively thin; the layers may be between 1 / 32 in. and 1 / 2 in. thick. This may facilitate the escape of water vapor product from the layer relative to thicker configurations.

[0069] In embodiments, the number, shape, and distribution of holes 402 affects the rate at which reactor feed drips or transports downward into the next reaction zone. This rate may also be impacted by the surface tension and viscosity of the reactor feed and the differential pressure across the plate. The presence of walls around holes may also impact this rate.

[0070] In embodiments, the more holes 402 in a plate, the faster the production rate of aluminum. In embodiments, the smaller diameter the holes 402, the slower the production rate. In embodiments, the higher surface tension reactor feed, the slower the production rate. In embodiments, the higher viscosity reactor feed, the slower the production rate. In embodiments, the lower the pressure on the underside of the plate or the higher the pressure on the top side of the plate (or the higher the pressure differential between the top and undersides of the plate), the higher the production rate. In embodiments, the presence of walls around the holes 402, the slower the production rate during an initial time, until the wall is breached.

[0071] In embodiments, the perforated plates may be comprised of ceramic-type materials such as alumina or a material such as SiC. In embodiments, the plates may be comprised of stainless steel, N i-a Hoys, Al-alloys, C, Ti, W and Mo.

[0072] In embodiments, stainless steel, Ni-alloys, Al-alloys, C, Ti W, Mo, ceramic-type materials, alumina, SiC, and / or other suitable high-temperature materials may be utilized for fabrication of the reactor 101 walls, pipes, and other features.

[0073] In embodiments, the reactor feed drips or transports into reaction zone 110 which has a perforated plate 230 at the bottom (which is also the top of reaction zone 111). The holes or perforated plate 230 may have similar or dissimilar features to the holes of inlet perforated plate 229. In embodiments, reaction zone 110 is heated via heater 105.

[0074] In embodiments, the molten ore next drips or otherwise flows through perforated plate 230 into reaction zone 111. In embodiments, reaction zone 111 has a hole-filled plate 231 at the bottom (which is also the top of reaction zone 112). The holes may have similar or dissimilar features to the holes at plate 230. In embodiments, perforated plate 231 may include more holes than perforated plate 230. In embodiments, reaction zone 111 is heated via heater 105.

[0075] In embodiments, gaseous exit process pipe 115 exits reaction zone 111 and enters hydrogen separation device 104. Hydrogen separation device 104 can be isolated from reaction zone 111 by a valve on gaseous exit process pipe 115. The valve on gaseous exit process pipe 115 can also be a flow control valve to control flow from reactor zone 111 into hydrogen separation device 104. The transport of gasses from reactor zone 111 via gaseous exit process pipe 115 to hydrogen separation device 104 may be by a driving force provided by compressor 237 and / or pump or compressor 238.

[0076] The location of gaseous exit process pipe 115 may be in one or more reaction zones and may be located anywhere, but preferably reactions zones 111 and 112, or up or down, along the reaction zone assembly. The purpose of this process pipe is to facilitate the decrease in water vapor content in reaction zones.

[0077] In embodiments, there is a space around the reaction zones and within the outer shell of the overall vessel but above the solidifying and gas expulsion zone 132 that is used to minimize heat loss in the reaction zones. In embodiments, this space is a reactor upper portion 241 and is defined at an outer perimeter by reactor shell 245, is defined at an inner perimeter by reactor zone walls 247, at an upper surface by reactor upper surface 249, and at a lower surface by separation plate 239. In embodiments, reactor upper portion 241 may include one or more of: layers of refractory material, one or more insulating materials, a vacuum below approximately 650 torr, or a gas backfill upto 2 atm. In embodiments, the atmosphere in reactor upper portion 241 may be comprised of N2 or Ar. N2 and Ar are lower thermal conductivity gases than air (an insulative property) and are not combustible or flammable (including them may be a safety feature).

[0078] The conversion reaction, for example for conversion of alumina by hydrogen, generates water. In embodiments, the concentration of water inside reaction zone 111 may be reduced. The partial evacuation of the water vapor laden atmosphere from reaction zone 111 to hydrogen separation device 104 via gaseous exit pipe 115 is applied so that water may be removed from that stream. Excess hydrogen may also be removed in this atmosphere. To recover the excess hydrogen, hydrogen separation device 104 separates hydrogen and water vapor. This may be required if the electrolyzer 102 does not perform well at splitting water in the presence of hydrogen. Alternatively, hydrogen separation device 104 may not be needed if electrolyzer 102 performs well in the presence of hydrogen.

[0079] In embodiments, hydrogen separation device 104 includes a membrane assembly for separating hydrogen and water vapor and may be a diffusion membrane of the type using Pd, Pd-Cu, Pd-Ag, Pd-Ni or of a type using V or Nb and their alloys. In embodiments, hydrogen separation device 104 may be of a type using polymers where hydrogen diffuses through the membrane to a shell side where it enters hydrogen separation exit pipe 119 and the water vapor (in embodiments, containing residual hydrogen) flows out of hydrogen separation device 104 via hydrogen separation water pipe 120.

[0080] In embodiments, hydrogen separation device 104 may be a zeolite or molecular sieve filled bed or set of beds where the zeolite or molecular sieve trap water and allow hydrogen to exit via hydrogen separation exit pipe 119. In such examples, water vapor trapped on the zeolite or molecular sieve may be periodically desorbed (for example, by decreasing operating pressure or increasing operating temperature). Desorbed water may flow out of hydrogen separation device via hydrogen separation water pipe 120.

[0081] In embodiments, hydrogen exiting hydrogen separation device 104 via hydrogen separation exit pipe 119 may flow via hopper hydrogen feed pipe 126 to charge hopper108 with hydrogen. In embodiments, hydrogen exiting hydrogen separation device 104via hydrogen separation exit pipe 119 may be mixed with hydrogen exiting electrolyzer 102 in electrolyzer hydrogen pipe 114 and may flow through hydrogen process pipe 123.

[0082] In embodiments, the molten ore next drips or flows into reaction zone 112 through perforated plate 231. Reaction zone 112 may include perforated plate 232 at the bottom (which is also the top of reaction zone 113). The holes of perforated plate 232 may have similar or dissimilar features to the holes of perforated plate 231. In embodiments, perforated plate 232 may include more holes than perforated plate 231. In embodiments, reaction zone 112 is heated via heater 105.

[0083] In embodiments, annular pipe 131 concentrically surrounds heater 105. In embodiments, annular pipe 131 transports hydrogen into reaction zone 112. In embodiments, this hydrogen is at a pressure approximately from 1 to 20 atm. In embodiments, this hydrogen is added into reaction zone 112 at a ratio of approximately 3 to 60 moles of hydrogen per mole of alumina (or bauxite). The annular pipe 131 and the hydrogen it contains is heated by heater 105.

[0084] In embodiments, annular pipe 131 transports hydrogen into reaction zone 112 as a plasma. The conditions are applied at or near the exit of 131, using devices upon or within 131, to generate a hydrogen plasma.

[0085] In embodiments, when combustion is used as the source of heat, the hydrogen is pre-heated by the heater 105. Exhaust gases from the combustion heat the hydrogen as the exhaust transports downward through heater 105 and the hydrogen transports upward within annular pipe 131. In embodiments, when electrical power methods are used as the source of heat, heat may be applied intermittently or continuously along at least a portion of the length of heater 105 to achieve heating goals. In embodiments, the hydrogen within annular pipe 131 is heated to at least a temperature above the melting point of aluminum when it enters reaction zone 112.

[0086] In embodiments, a distribution plate 125 distributes the hydrogen exiting annular pipe 131 below perforated plate 231 and throughout reaction zone 112. Distribution plate 125 may be conical or flat and may be solid or contain perforations.

[0087] In embodiments, the molten ore drips or flows into reaction zone 113 which has perforated plate 233 at the bottom (which is also the top of the condensation and gas expulsion zone 132). The holes may have similar or dissimilar features to the holes atperforation plate 232. In embodiments, perforated plate 233 may include more holes than perforated plate 232. In embodiments, reaction zone 113 is heated via heater 105.

[0088] In embodiments, the molten ore drips or flows into condensation and gas expulsion zone 132. A separation plate 239 provide a separation between this zone and the reactor upper portion 241 in which the reaction zone assemblies are located.

[0089] In embodiments, when the molten ore enters the gas expulsion zone 132, it is fully converted (or nearly fully converted) to reactor product (for example, alumina to Al). In embodiments, the molten ore may contain dissolved hydrogen and entrapped water vapor. This is depicted in FIG. 3 as a droplet 319 moving downward.

[0090] The droplets pass downward through the gas expulsion zone 132 to the reactor bottom 234, a container for product particles, where they are liquid droplets in the gas expulsion zone 132 and starting to solidify just before or upon entry into or within the reactor bottom 234. Simultaneously, hydrogen and water vapor escape and are evolved from the droplets into process pipe 116. This is actually shown above a droplet moving upward in FIG. 3 as 320.

[0091] In embodiments, either one or both of pump or compressor 235, 238 provide a driving force to remove gases from gas expulsion zone 132. In embodiments, this driving force creates a sub-atmospheric vacuum within condensation and gas expulsion zone 132. This vacuum may promote diffusion and permeation of gases out of the droplets. In embodiments, the droplets will be sufficiently gas-free by the time they reach the bottom 234 so that they may be used in subsequent part manufacturing steps.

[0092] In embodiments, additional gas exit locations (in addition to combined exit process pipe 116), may be included aroundgas expulsion zone 132. In embodiments, inclusion of additional gas exit locations may contribute to effective evacuation of this zone and may contribute a driving force for water vapor and hydrogen to evolve from, desorb, or escape from the falling droplets 319.

[0093] In embodiments, perforated plate 233 is at the bottom of the lowest reaction zone (reaction zone 113 as depicted) and at the top of gas expulsion zone 132. In embodiments, perforated plate 233 includes small diameter holes on the order of approximately 1 / 32 in. to 3 / 8 in. to generate small droplet sizes. In embodiments, the smaller droplet sizes generated may have lower mass transfer limitations to help speedup the evolution of entrained gases from the droplet 319 into the condensation and gas expulsion zone 132 as they fall to the bottom of the reactor.

[0094] In embodiments, smaller droplet sizes cool more quickly than larger droplets. In embodiments, cooler droplets lead to more efficient or more complete gas expulsion so long as the droplets remain liquid. However, cooler droplets will solidify faster. An optimal droplet size will promote maximum gas expulsion before solidification, which must occur before reaching the reactor bottom. In embodiments, the droplet size may be affected by the range of possible operating temperatures. In embodiments, an optimum droplet size may be formed from the perforated plate approximately 233 hole size range provided.

[0095] In embodiments, the holes of perforated plate 233 may include walls surrounding them at their perimeter on their top side. In embodiments, the walls may be from approximately 1 / 32 in. to 1 / 4 in. high and approximately 1 / 32 in. to 1 / 8 in. thick to holdup molten ore from the most recent delivered feed batch, providing additional residence time in the reaction zone 113 to complete reactions and to evolve gases (including water vapor), before falling through the holes of perforated plate 233 into the condensation and gas expulsion zone 132. An optimal hole wall height range is desired to promote the residence time and melt layer thickness on the plate, given the range of possible operating temperatures. In embodiments, an optimal hole wall height may maximize the reaction from aluminum ore to Al. In embodiments, an optimal hole wall height may maximize the desorption or expulsion of water vapor from the molten ore before dropping into the gas expulsion zone 132.

[0096] For perforated plates (for example, perforated plates 229, 230, 231, 232) above the bottom-most location (for example, perforated plate 233), approximately 1% - 10% of all holes on the plate may include relatively higher walls around them. In embodiments, the walls may be higher than the surface of the remaining holes or walls around such holes by approximately 1 / 32 in. to 1 / 8 in. to facilitate the transport of gaseous species from a lower reaction zone into a higher reaction zone. In embodiments, molten ore will drop out of each reaction zone to the reaction zone below through holes with shorter height walls (or, in embodiments, no walls) surrounding them, leaving the higher wall holes open for gas transport.

[0097] In embodiments, perforated plates such as 229, 230, 231 and 232 may also have plate floor which are membranes, meshes or sieves, where molten ore may slowly transit downward through pores, or not at all, while gases transit upward through pores.

[0098] In embodiments, hydrogen separation device 103 is a device with all the same attributes and possible configurations as hydrogen separation device 104. Hydrogen and water vapor are separated. Hydrogen may exit hydrogen separation device 103 via hydrogen separation exit pipe 118 and water vapor (which may contain residual hydrogen) may exit hydrogen separation device 103 via hydrogen separation water pipe 117.

[0099] In embodiments, the gases exiting hydrogen separation device 104 in hydrogen separation water pipe 120 and the gases exiting hydrogen separation device 103 in hydrogen separation water pipe 117 are mixed at electrolyzer inlet pipe 121. In embodiments, the gases of electrolyzer inlet pipe enter the electrolyzer 102 (in embodiments, with pump or compressor 238 providing the driving force to move such gases and to elevate pressure as may be desired for electrolyzer performance).

[0100] In embodiments, hydrogen exiting hydrogen separation device 103 via hydrogen separation exit pipe 118 may be mixed with hydrogen in hydrogen process pipe 123 and flow toward the reactor in hydrogen process pipe 124.

[0101] In embodiments, pump or compressor 236 may provide the driving force to transport hydrogen into the reactor 101 via annular pipe 131.

[0102] In embodiments, solid product Al particles (i.e. solidified droplets) exit reactor 101 at reactor product exit 107 in FIG. 1 (also shown as reactor product exit 503 in FIG. 5). In embodiments, solid product particles exit the reactor 101 continuously. In embodiments, solid product particles exit the reactor 101 in batches.

[0103] Referring now to FIG. 5, a product hopper 504 may be located at the bottom of the reactor or below the reactor. In embodiments, product hopper 504 may have similar features to hopper 108, for example, product hopper 504 may be configured so that it can be evacuated through product hopper exit pipe 505 by vacuum pump or compressor 506. In embodiments, solid product Al particles may pass through reactor product exit pipe 107, 503 into product hopper 504 at the rate at which they are generated (from alumina) inside the reactor 101. Allowing the particles to flow directly from the reactor 101 to the product hopper 504 minimizes the time the particles spend inside of reactor101 and protects the product particles from oxidation. In embodiments, this may also contribute to continued evolution of gases from the particles. In embodiments, the product particles may be transferred to a storage container. In embodiments, the storage container may be evacuated or may contain a nitrogen atmosphere to maintain its oxygen-free condition and to prevent oxidation.

[0104] In embodiments, the electrolyzer 102 may leverage the temperature of the water vapor or gases of electrolyzer inlet pipe 121 entering the electrolyzer. In embodiments, the temperature of these inlet gases may be from 200 °C to 1000 °C. In embodiments, the pressure of the gases entering the electrolyzer 102 may be from 1 atm to 20 atm. In embodiments, the water vapor contained in the stream of electrolyzer inlet pipe 121 has properties of steam. In embodiments, the electrolyzer is a high-temperature device. In embodiments, water vapor has been created by the reduction of bauxite or alumina with hydrogen in reactor 101 and / or by the combustion of hydrogen for heat generation in heater 105; these recycled water vapor sources may be used to feed the electrolyzer 102.

[0105] In embodiments, oxygen is generated in the electrolyzer 102. The oxygen may exit electrolyzer 102 at electrolyzer oxygen pipe 122. In embodiments, the oxygen can be delivered to pipe 130 and used for combustion heating (for example, in heater 105), thus eliminating or reducing the need to supply oxygen from external sources. In embodiments, the oxygen generated may be in excess of the amount required for all operations of system 100, 200, 300.

[0106] In embodiments, a sub-quantity of the Al product particles may be used / recycled as a melt in enclosed zone 228 (as discussed above). In embodiments, the recycled Al product particles are transported upward via lift mechanism 109 to be re-delivered into enclosed zone 228, where they join the hydrogen charge and alumina (aluminum ore) particles which are delivered into enclosed zone 228 from hopper 108.

[0107] In embodiments, gases in the gas space within the reaction zones 110, 111, 112, 113, do not directly pass from one zone into another. In embodiments, pressure differentials between zones may not substantially affect the previous or subsequent zones because the holes may be filled with a liquid layer which may act as a barrier to such gas flow. In embodiments, hydrogen enters reaction zone 112 via annular pipe 131 and may generate gas flow pathways through open or liquid-filled holes in perforated plate 231,whereby reaction zone 111 may receive a charge of gaseous hydrogen as hydrogen flows through the holes or perforated plate 231. In embodiments, hydrogen permeation in the aluminum melt is high, and the movement of aluminum melt from one reaction zone to a subsequent reaction zone is a possible pathway for hydrogen mobility from one reaction zone to another. In embodiments, this may occur by diffusion or by actual transport via gas bubbling through a liquid layer.

[0108] In embodiments, one or more pipes penetrate one or more reaction zones for the purpose of removing gaseous atmosphere over the melt to assist with reducing water vapor concentration of and total content over the melt. In embodiments, this may provide a driving force for water vapor to evolve from the melt, which is desired for promoting the reduction or conversion reaction. An example of such a stream is gaseous exit process pipe 115, which is shown in FIG. 1. In embodiments, the removed gases flow through gaseous exit process pipe 115 and are transported to a membrane system external to the reduction vessel (for example, hydrogen separation device 104), to separate water vapor from hydrogen.

[0109] In embodiments, a zeolite or molecular sieve bed is provided within a pipe (for example, gaseous exit process pipe 115 and / or combined exit process pipe 116) to selectively remove water from the gaseous stream flowing through it. In embodiments, the hydrogen-rich exit from the bed may be recycled back into the reaction zone or to feed the top of the reactor. In embodiments, the bed, valves, and pumps are located outside of the reduction vessel. In some example, periodically, the bed may be isolated from the reaction zone pipe feeding it (for example, gaseous exit process pipe 115 and / or combined exit process pipe 116) by closing a valve and may be regenerated by removing the water vapor. In embodiments, regeneration may be by heating or by evacuation with a pump. Evacuated water vapor may be sent to the hydrogen generating system. In the figures, an electrolyzer 102 is shown for hydrogen generation. Once regenerated, the bed may be re-exposed to its associated reaction zone(s) (for example, isolation valves may be opened). In embodiments, utilization of such a bed as described herein, which may actively remove water vapor from the reactor atmosphere, is expected to contribute to driving the desorption of water vapor from the molten ore inside of its associated reaction zone.

[0110] FIG. 4 represents the relative arrangement of holes 402 in the perforated plates 229, 230, 231, 232 and 233. In embodiments, no hole 402 in any plate is vertically aligned with the hole 402 in the perforated plate below it or above it, so that the reactor feed drip / molten ore drip may encounter the subsequent perforated plate and not fall straight through multiple holes 402, providing additional residence time for the material inside the reaction zone before transporting through the hole 402. In embodiments, the holes 402 are arranged so that a molten ore droplet falling from one plate onto another plate is a maximum distance from each plate hole providing additional residence time for the material inside the reaction zone before transporting through the hole 402 to the next plate below.

[0111] Reaction zones 110, 111, 112 and 113 represent only one arrangement of reaction zones with their (bottom) perforated plates 230, 231, 232 and 233, respectively. In embodiments, there may be from 4 to 12 reaction zones in a single reactor 101. The reaction zones may cylindrical or box-like in shape, or may have any other suitable cross- sectional shape. They may have a surface area at the bottom of each reaction zone between 0.5 square feet and 10 square feet. In embodiments, the bottom surface area of each reaction zone, successively lower in the vertical arrangement of reaction zones, will have more surface area than the reaction zone immediately above it. In embodiments, the combined hole surface area for successively lower perforated plates throughout the vertical arrangement of reaction zones may be greater than or less than the combined hold surface area of the perforated plate(s) above it.

[0112] In embodiments, the height from the top perforated plate of a reaction zone to the bottom perforated plate may be from 1 inch to 4 feet. In embodiments, the height from the top perforated plate of a reaction zone to the bottom perforated plate may be the same or different throughout the vertical arrangement of reaction zones. In embodiments, the higher the height of a reaction zone, the greater the potential for a molten ore drip to splash upon its impact on a perforated plate. In embodiments, a splash may benefit the evolution of water vapor product from the drip (which may contribute to maintaining the forward reaction). However, in embodiments, a splash may increase the likelihood for solid alumina powder to potentially segregate to the top of the Al melt, which may cause a portion of the alumina to be no longer in contact with hydrogen within the melt. In embodiments, the lower the height of a reaction zone, thehigher the potential for a molten ore drip to settle onto the top of the melt layer, which may contribute to alumina remaining inside that melt layer and in contact with hydrogen within the melt.

[0113] In embodiments, reactor 101 may include one or more heaters. In embodiments, reactor 101 may include between 1 to 12 heaters. The heater 105 as described above may be representative of any heaters included in reactor 101. The heaters, such as heater 105, may be cylindrical, square, or rectangular. The heaters, such as heater 105, may be hollow or solid. If the heaters are solid, they may comprise resistive heating elements. If the heaters are hollow, they may be heated by combustion, and an internal burner array may generate a flame anywhere vertically along the heater pipe. In embodiments, the heaters may include internal or externally attached induction or microwave heating components. In embodiments, the outside diameter of the heater ranges from 1 in. to 1 ft In embodiments, the inside diameter ranges from 0 in. to 8 in.

[0114] In embodiments, heater 105 may operate with an internal temperature range of 600 °C to 1950 °C. In embodiments, heater 105 may operate with an internal pressure range of 1 atm to 20 atm. In embodiments, the highest internal temperatures of heater 105 are in the top two-thirds of the reaction zones. In embodiments, reaction zone temperatures and materials range from 660.3 °C to 1850 °C. In embodiments, all perforated plates and a portion of their liquid layers on top are in physical contact with the heater 105 and / or annular pipe 131. In embodiments, additional features such as fins (horizontal, vertical, both, solid or porous), foams, or foils may be applied around the heater 105 to facilitate heat transfer to gases inside the reaction zones. A horizontal fin representation is shown by FIG. 4 in a reaction zone attached to the heater 105 as fins 434. In embodiments, molten ore may drip onto these features (for example, fins 434) which may facilitate the expulsion of water vapor from the drip. In embodiments, the temperature on the surfaces of these features is above the melting point of aluminum, which ensures that the molten ore continues to drip further down onto the perforated plate below.

[0115] Referring to FIG. 5, in embodiments, reactor 101 includes a deformation device 502. Deformation device 502 may be a plate, which may be heated in some embodiments. Deformation device 502 may deform liquid droplets 319 as they strike the plate, thus opening up surface area that promotes the evolution of gases from the liquid droplet319. If heated, the deformation device 502 temperature may be at least 10 degrees above the melting temperature of aluminum, in embodiments.

[0116] In embodiments, the process and apparatus as described herein may be modular. In embodiments, any reaction zones and / or perforated plates may be replaced or switched out with alternative designs. In embodiments, reaction zones and / or perforated plates may be removed or added. In embodiments, replacement, switching, removal, or addition may be performed as frequently or as infrequently as needed to support the conversion or reduction given the desired production rate, composition of the feed material, and quality of the Al product.Example Methods of Operation

[0117] Example methods of operating a reactor may be applied to example reactor configurations shown in FIG. 1 through FIG. 5 as discussed above. References below to specific portions of certain reactors are made for convenience only and are without limitation. Broadly, example reactors may comprise a reaction, reduction or conversion portion; an entrance / inlet portion; plates and tubes for delivery and handling of feed; plates and tubes or pipes for delivery of heat; internal structures which facilitate reduction or conversion; external structures which generate and handle hydrogen for reduction or conversion; and an exit portion.

[0118] In embodiments, a method may include providing solids and a gaseous stream to an inlet of the reduction portion, resulting in reduction or conversion of a metal compound, which may be an ore, to reduced metal. In embodiments, the reactions which may occur inside the reaction, reduction or conversion section include metal compound conversion or reduction, combustion, and / or partial oxidation. Reduction or conversion of alumina is shown below as an example, but other metal compound types, or other ore types, are possible. In embodiments, the temperature at which reduction or conversion occurs inside reduction or conversion reactor 101 may be between ~660 °C and 1850 °C and the pressure between 1 and 20 atm. for alumina:AI2O3 + 3H2 2AI + 3H2O; AI2O3 is solid, Al is liquid, and water is steam the state of molecular hydrogen within an aluminum melt is:H2+ Al(melt) -> 2H + Al(melt) the reaction of hydrogen (in the Al melt), therefore, with alumina is:AI2O3+ 3 H2+ Al(melt) AI2O3+ 6H + Al(melt)(from alumina) + 3 H2O + Al(melt)

[0119] In an ore example, bauxite including specific Fe, Al, Ti and Si components, is reduced or converted to a metal in a less oxidized state or to a completely reduced metal. This also include intermediates between bauxite and alumina such as, for example, alumina hydrate.

[0120] In embodiments, combustion for heating may be by hydrogen or by natural gas (in embodiments, as complete oxidation and in embodiments as partial oxidation) or by CO. If air is used for combustion, nitrogen and / or NOx may be present on the product side of the reaction expressions. for combustion: te)

[0121] In embodiments, the reaction for the reduction or conversion of alumina to aluminum, without the presence of a melt, does not proceed rapidly and only proceeds measurably at very high temperature, over approximately 1750 °C.

[0122] In order for the reaction to proceed more rapidly and at lower temperature, the alumina and hydrogen should be co-located within an aluminum melt. More importantly, hydrogen and alumina should be in proximity to each other at the interface of aluminum with alumina. One reason for the rate increase is that hydrogen dissolved in or adsorbed upon Al is observed to be in an atomic state, which is more reactive than the molecular state. Hydrogen, among gases, has a high solubility in liquid aluminum.

[0123] In embodiments, the features, 110-113, in reactor 101 are configured to facilitate the co-location of alumina and hydrogen in an aluminum melt to ensure the reaction proceeds rapidly and potentially at lower temperature.

[0124] In embodiments, the features, 110-113, in reactor 101 are configured and applied to facilitate the co-location of hydrogen at the alumina and aluminum interface.

[0125] In the conversion of alumina to aluminum by hydrogen, water vapor is generated. In embodiments, the reactor 101 and its components are configured to provide routes for this product to be evolved from the melt. The presence of water vapor suppresses the forward reaction to aluminum. In embodiments, reducing the quantity and concentration of water vapor in the atmosphere within a reaction zone may be achieved by active evacuation. In embodiments, a thin Al melt layer which contains the alumina and hydrogen may decrease hindrance to mass transport of the water vapor within the melt layer to its top surface, where it can rapidly desorb or evolve. In embodiments, a high hydrogen to alumina molar ratio in the atmosphere over the thin melt layer may be maintained with active delivery of hydrogen into a reaction zone and nearby reaction zones. Both the decrease in water vapor concentration and sustained high concentration of hydrogen keep the forward rate as high as possible.

[0126] Gaseous content in the solid aluminum product is undesired. In embodiments, the aluminum product gaseous hydrogen content is significantly decrease or eliminated in the by allowing droplets to pass through the gas expulsion zone, which can deform, and are exposed to a low absolute pressure (which may be a vacuum) and a low partial pressure of hydrogen such that gases are driven to evolve from the droplets, decreasing their concentration in the product, once it solidifies.

[0127] In embodiments, alumina to aluminum conversion in the presence of hydrogen in an aluminum melt results in at approximately least 50% of the alumina being converted or reduced to aluminum in 24 hours at 1200 °C and at least 1 atm with hydrogen passing over the top of a reactant feed sample and a molar ratio of Al to alumina of at least 20. In embodiments, this conversion percentage can be increased by removing more of the water vapor product from the melt, increasing the temperature, increasing the pressure and ensuring hydrogen saturation of the melt by passing hydrogen under and through the reactant feed, molten ore or melt on a perforated plate.

[0128] In embodiments, hydrogen and an Al melt may be used to convert bauxite to alumina. The generated alumina may then be converted to aluminum in the same reactor. A product of such reactions may be water vapor. In embodiments, the bauxite (reactant) and alumina (intermediate product) are both in the solid phase, and so thebauxite may be delivered to the process as a fine powder to increase the reactive surface area for conversion to alumina by hydrogen within the Al melt. In embodiments, the water vapor formed is in the form of steam.

[0129] In embodiments, bauxite powder or particles may be processed and reduced by hydrogen using the same steps outlined in the method for processing and reducing alumina powder or particles by hydrogen. In embodiments, the resulting product will contain other constituents (detailed below) which may require separation later. In addition, fresh Al may be required for melt creation, because the recycled Al may contain some of the bauxite constituents, which may additively build up within the recycled streams over the time the reactor runs.

[0130] Bauxite is comprised primarily of the following compounds: gibbsite (AI(O H )3), boehmite (y-AIO(OH)), diaspore (a-AIO(OH)), goethite (FeO(OH)), hematite (Fe2O3), kaolinite (AI2Si2O5(OH)4), silica (SiO2), anatase (TiO2) and ilmenite (FeTiO3). The approximate weight percent of the Al containing species is from about 40 to 45%, of the Fe-containing species is from approximately 25% to 30%, and of the Ti-containing and Si- containing species are from approximately 3% to 5% each.

[0131] In traditional ore reduction processes, some of these compounds are separated from the aluminum ore in the Bayer process, which uses alkaline materials and generates a waste product called red mud. The red mud is often treated as a waste material but there are constituents in it which can be harvested by other methods. In the method described here, this waste is not generated.

[0132] Referring again to the systems of FIG. 1 - FIG. 5, exposure of bauxite to molecular hydrogen at temperatures in the 450 °C to 750 °C range and a pressure of at least 1 atm will convert or reduce the Fe containing species within bauxite to pure iron. In embodiments of the current method and device, the Fe containing species within bauxite will be exposed to: temperatures ranging from 660 °C up to 1600 °C; at least 1 atm of pressure; molecular hydrogen (in the gas space); and atomic hydrogen (formed in the Al melt), which is more reactive than the molecular hydrogen. Therefore, in some embodiments, the Fe containing species may be fully reduced. Equations are shown below:Goethite: 3H2+ 2FeO(OH) -> 2Fe + 4H2OHematite: 3H2+ Fe2C>3 -> 2Fe + 3H2O

[0133] In embodiments, the Fe-containing species may be reduced by molecular hydrogen at the conditions stated relative to the Al, Ti, and Si containing species and so the Fe- containing species will be reduced first, before the other species. In high-temperature reactor conditions and an excess of molecular hydrogen, with its presence in the atomic state, the Al containing species in the bauxite will reduce to alumina and then to aluminum.

[0134] Full reduction of the titania and also silica may be difficult in molecular hydrogen even at very high temperatures. In embodiments, high-temperature reactor conditions and an excess of molecular hydrogen, with its presence in the atomic state, may accomplish some conversion or reduction of these species. In embodiments, generation of aluminum from bauxite may be accomplished before there is significant reduction of titania or silica. Therefore, Ti and Si may be present in the melt as oxides.

[0135] The melt, in the form of droplets, solidifies by the time it reaches the reactor 101 vessel exit at 234. These solid lumps, particles, pellets or beads are the final product, which will contain Fe, Al, and oxidized forms of titanium and silicon and possibly a small amount of unreacted aluminum ore. In embodiments, the oxidized species may be entrained but not alloyed with the other species, Fe and Al. In embodiments, Fe and Al may form one or more alloys. In embodiments, throughout the process, the concentration of Al represents over 80 (and most likely over 90) weight percent of the melt total. In embodiments, according to the phase diagram for Fe and Al, at this range of Al concentrations, the two species will not be alloyed. Instead, Fe will be entrained in Al. In embodiments, as a result of the presence of Fe and the other oxides in the droplets, a follow-on separating process may be required to purify the Al.

[0136] Referring again to the systems of FIG. 1 - FIG. 5, many of the methods described below are described in the context of conversion of alumina to Al, using alumina as the raw material (the raw ore). However, in accordance with the principles of this disclosure, alumina may be interchanged with bauxite and / or other aluminum oresunless described otherwise. If bauxite is used, the bauxite will first convert to alumina, and the alumina will then convert to aluminum.

[0137] Referring now to FIG. 1 and FIG. 3, in embodiments, three materials are needed for the process: hydrogen, alumina (aluminum ore), and aluminum. Hydrogen may be obtained by water electrolysis (for example, from electrolyzer 102, which may be supplied with water from external sources at start-up). Hydrogen is needed in excess for the conversion of alumina to aluminum relative to stoichiometry. Once at steady-state, excess hydrogen may be recovered and recycled, and excess hydrogen is no longer needed from the electrolyzer 102, just the stoichiometric requirement. Once at steady state, the water needed for the electrolyzer 102 to generate hydrogen for the process comes from water vapor in electrolyzer inlet stream 325, which is a combination of water streams 323, 324. Water streams 323, 324 are the outlets of hydrogen separation devices 103, 104, which separate most of the excess hydrogen from the water vapor that were both present in combined reactor exit stream 309 and reactor exit stream 310.

[0138] In embodiments, water vapor may be generated by the conversion or reduction of alumina by hydrogen and is present within reaction zone 111 and within gas expulsion zone 132. Combined reactor exit stream 309 and reactor exit stream 310 may be recovered from these zones. In embodiments, one or more streams represented by reactor exit stream 310 remove atmosphere from one or more of reaction zones 110, 111, 112, 113 to suppress the amount of water vapor that may build up in the reaction zones 110, 111, 112, 113. In embodiments, one or more streams represented by combined reactor exit stream 309 removes atmosphere from gas expulsion zone 132 to facilitate the expulsion of the hydrogen and water vapor from the Al droplet product while it transports downward, eventually solidifying.

[0139] With the use of hydrogen separation devices 103, 104, substantially pure or pure hydrogen streams may be obtained at hydrogen streams 326, 327 while water vapor with residual hydrogen flows as water streams 323, 324 towards the electrolyzer 102. In embodiments, the hydrogen in hydrogen stream 326 may be used to charge the initial alumina feed stream 301 and / or to combine with the electrolyzer hydrogen stream 321. The hydrogen stream 327 may be combined with hydrogen stream 334 which may include contents of electrolyzer hydrogen stream 321 and / or hydrogen stream 329.Hydrogen streams 326, 327 and electrolyzer hydrogen stream 321 may flow together to form hydrogen feed stream 302, which is the hydrogen feed to the annular pipe 131. In embodiments, electrolyzer 102 may be configured so as to be able to process excess hydrogen input within its water or steam input stream; in such a situation, hydrogen separation devices 103, 104 may not be necessary.

[0140] In embodiments, water vapor may also be recovered from the exhaust exiting heater 105 via exhaust pipe 129 (as captured exhaust stream 335) which may be sent to the electrolyzer 102 to generate hydrogen and oxygen for combustion. In this manner, externally supplied water may not be necessary for generating hydrogen necessary for combustion.

[0141] If the combustion process uses another combustible such as natural gas, then water can still be used from the exhaust. However, a separating device may be required to split other exhaust components from stream 335 with a high concentration water vapor stream, exiting the separator, sent to electrolyzer 102.

[0142] It is recognized that electrolyzers, such as electrolyzer 102, may require water in excess of the amounts specifically required for the needs of any reaction and combustion in order to operate effectively. This excess water may be recycled to the electrolyzer 102 to maintain its operation but it is not used to generate hydrogen (and oxygen). Water may be hot, saturated liquid, 2-phase, saturated vapor or steam.

[0143] The electrolyzer 102 also generates oxygen as electrolyzer oxygen stream 322, which can be used for combustion by delivering in stream 336 and using as the oxidizer in combustion stream 303, in embodiments.

[0144] The electrochemical expressions for electrolyzer operation are shown here.Electrolysis of water vapor:

[0145] In embodiments, the temperature of the water vapor (steam) and hydrogen containing streams (water streams 323, 324; hydrogen streams 326, 327) may range from 200 °C to 800 °C. In embodiments, these streams may contain heat which can berecycled and used to boost process feed temperatures. In embodiments, this heat may also be used to reduce the external power input requirement for the electrolyzer 102, which may be an energy-efficiency enhancement of the process. If hydrogen separation devices 103, 104 are not used in embodiments, the temperature of the electrolyzer inlet stream 325 entering the electrolyzer 102 may be as high as 1000 °C. In embodiments, the use of a high-temperature electrolyzer (such as a solid-oxide electrolyzer) with these high feed and entrance temperatures may provide a long-term energy savings benefit to the aluminum generating process relative to operating an electrolyzer at lower temperatures. In embodiments, this could result in at least 20% less energy required relative to operation of the electrolyzer at 25 °C (about room temperature).

[0146] In embodiments, hydrogen generation may be done by other methods. In embodiments, thermolytic or thermo-catalytic decomposition of hydrocarbons may be deployed, which may result in water vapor generated in the alumina conversion being an effluent stream from the reactor system. In embodiments, hydrogen may be generated by steam-methane reforming of hydrocarbons, which may leverage the use of steam or water vapor generated in the alumina conversion (recycling of all or part of the generated water vapor in the system). Stream-methane reforming generates carbon monoxide and carbon dioxide, which may require separation from the hydrogen before application, although CO may reduce oxide materials In embodiments, dry reforming of hydrocarbons may be used to generate hydrogen; this requires carbon dioxide (which is not anticipated as a product of reactor 101, however, another process may supply the carbon dioxide as a way to reduce greenhouse gas emissions). In embodiments, dry reforming generates carbon monoxide, which may require separation from the hydrogen before application, although CO may reduce oxide materials. In embodiments, water-gas shifting can be used to generate hydrogen. Steam orwater vapor generated in the alumina conversion may be recycled for this application. Water- gas shifting requires carbon monoxide (which is not anticipated as a product of reactor 101, however, another process may supply the carbon monoxide as a way to ultimately reduce greenhouse gas emissions from processes that might otherwise use the CO in a manner that converts it to carbon dioxide). In embodiments, water-gas shifting generates carbon dioxide, which might require separation from the hydrogen before application.

[0147] Equations relating to some of these non-electrolysis methods of generating hydrogen in the process are shown here.SMR (steam-methane reforming): ne reforming or dry reforming):WGS (water-gas shifting): CO + H2O CO2+ H2Decomposition: CH4^ C + 2H2

[0148] In embodiments, hydrogen may be delivered as stream 315 from annular pipe 131 into reactor zone 112 where it is dispersed and distributed by distribution plate 125 as dispersed hydrogen 318. The dispersed hydrogen 318 may permeate and dissolves into the Al melt as it travels up and down through the reaction zones 110, 111, 112, 113. In embodiments, dispersed hydrogen 318 may also channel alongside walls or within liquid layers as it travels up and down through the reaction zones 110, 111, 112, 113.

[0149] As described above, in embodiments, at or above the top of the reactor 101 is a hopper 108, followed by a mixing area (zone 228 which can be isolated from 108 and 109 and is referred to as enclosed 228) below it and a reaction zone 110 below enclosed zone 228. In embodiments, hopper 108 and enclosed zone 228 may be controlled such that adsorbed or absorbed water may be removed from feed materials (Al, alumina hydrate and aluminum ores (alumina, bauxite, or other ores), for example). In embodiments, hopper 108 and enclosed zone 228 may be controlled such that water, which is associated with chemical structure, may be dissociated from feed materials (Al, alumina hydrate and aluminum ores (alumina, bauxite, or other ores), for example). In embodiments, a combination of controlled heating, purging (for example, with gases or combinations of gases such as hydrogen or nitrogen), and evacuating (for example, to below 650 torr) removes or dissociates water from the feed materials and also removes water from the gas space within zone 228.

[0150] In embodiments, alumina is a required material which may be required to be in the form of a powder or particles. In embodiments, alumina is delivered into hopper 108 asinitial alumina feed stream 301, and the hopper 108 is evacuated (evacuation stream 333) and its contents are heated. In embodiments, heating comes from combustion or electrical sources which are denoted as combustion stream 303. The heating may drive adsorbed and / or absorbed moisture from the alumina (aluminum ore) and to pre-heat it before encountering aluminum particles.

[0151] At start-up, aluminum powder or particles may need to be mixed with alumina in excess until the required amount is achieved. This amount may be provided by recycling of aluminum from the bottom of the reactor. Once sufficient recycled aluminum is available, only alumina (aluminum ore) is needed in initial alumina feed stream 301.

[0152] Once the evacuated pressure and elevated temperature of the alumina (aluminum ore) are achieved, hopper 108 is filled with hydrogen and then fed as hopper exit stream 305 into enclosed zone 228.

[0153] In embodiments, aluminum is required. Aluminum may be introduced along with alumina (aluminum ore) in initial alumina feed stream 301until the overall needed amount as a catalyst is achieved. After that point, aluminum may be introduced only as lift aluminum feed stream 304 via lift mechanism 109. This is catalytically needed aluminum which may have been sourced from a melt which cooled into particles as it dropped through the gas expulsion zone 132 into the reactor bottom 234 where it was picked up and lifted in lift mechanism 109 and delivered into enclosed zone 228. A small portion of unreacted aluminum ore may be present in this material. The catalytic (recycled) aluminum may be delivered after the alumina with hydrogen charge is released into enclosed zone 228. Subsequent heating via pipe 105 may melt the aluminum and may create a mix of dissolved hydrogen, gaseous hydrogen, melted Al, and alumina particles that drips down or flows through inlet perforated plate 229 into the reaction zone 110.

[0154] The action of molten ore droplets falling through the reaction zone atmosphere onto a perforated plate may open up melt surface area which enhances hydrogen permeation into the droplet. This may also be true when a droplet strikes a surface, because it may deform or break up into smaller droplets. The same principles may apply for the desorption of both water vapor and hydrogen, as the liquid droplet falls through the gas expulsion zone, both in the case where it falls without hitting a surface and when it does hit a surface or perforated plate.

[0155] In embodiments, the recovery and recycle of the excess aluminum for the melt portion of the reactor feed may result in the self-sustaining supply of this material. In embodiments, no externally required material is needed.

[0156] In embodiments, the rate of production may be increased and / or the operating temperature and / or pressure may be decreased, for the same Al production rate, by using an aluminum alloy melt (for example, if the desired Al product requires the presence of one or more other metal constituents).

[0157] The above-described process of holding-up molten ore (melt) in a reaction zone and then dripping to the one below occurs from reaction zone 110 to reaction zone 111, from reaction zone 111 to reaction zone 112, from reaction zone 112 to reaction zone 113, and from reaction zone 113 to as expulsion zone 132. These are represented by reactor feed stream 312; hold-up drip streams 313, 314 and 316; and lower hold-up drip stream 317, respectively. Hydrogen may be fed into reaction zone 112 as hydrogen feed stream 315 and dispersed as dispersed hydrogen 318 to keep the hydrogen concentration elevated throughout the reaction zones. The atmosphere in reaction zone 111 may be actively removed as reactor exit stream 310 at a specified rate to reduce the water vapor quantity and water vapor concentration in this and nearby reaction zones.

[0158] Lower hold-up drip stream 317 stream moves downward, in the gas expulsion zone 132, as liquid droplets or particles indicated as droplet 319. In embodiments, the zone atmosphere may be evacuated through combined reactor exit stream 309 to drive gases out of the droplets 319. In embodiments, a sub-atmospheric pressure is achieved in the gas expulsion zone 132. Towards the bottom of the gas expulsion zone 132, the liquid droplets 319 solidify (shown as solid droplets 332 or particles) which collect in reactor bottom 234. Excess aluminum particles stream 308 is recycled to the top of reactor 101 and introduced again as lift aluminum feed stream 304. Aluminum product stream 307 represents the aluminum product stream resulting from the conversion of alumina (aluminum ore) to aluminum by hydrogen reduction. Exhaust stream 306 represents the combustion exhaust stream.

[0159] A small portion of unreacted aluminum ore may be present in product stream 307 but this is easily separable as the aluminum can be melted leaving a solid phase of aluminum ore for removal by physical separation methods.

[0160] In embodiments, heating is accomplished via heater 105. In embodiments, to increase efficiency, heating may be done at a level to generate temperatures required in the reaction zones, but in the gas expulsion zone 132, there may be no active heating. In embodiments, hydrogen entering as hydrogen feed stream 302 and exiting as hydrogen feed stream 315 is pre-heated by combustion exhaust or conducted heat down the pipe wall. In embodiments, no active heating is done in gas expulsion zone 132 to further enable the liquid droplets to cool and solidify.

[0161] In embodiments, the temperature of droplets 319 exiting the bottom of perforated plate 233 as lower hold-up drip stream 317 may range from approximately 675 °C to 1750 °C.

[0162] In embodiments, the hydrogen exiting its pre-heated delivery tube can also be converted to a plasma, substantially increasing its permeability into the melt and reactivity with any bauxite, alumina or their reduction or conversion reaction intermediates. There are known device types, which may be placed at or near the exit of the hydrogen delivery pipe, for converting hydrogen from a molecular state to a plasma or atomic state. In embodiments, pre-heating of the hydrogen within the delivery pipe, prior to exit, may reduce the energy required to convert to a plasma.

[0163] Referring to FIG. 5, in embodiments, aluminum product stream 307 flows through reactor product exit pipe 107 / 503 into product hopper 504. Product hopper 504 may be isolated and evacuated by vacuum pump or compressor 506 through product hopper exit pipe 505. Product aluminum may be recovered from product hopper 504 as aluminum product 508.

[0164] In embodiments, the rate of production of aluminum from alumina in the dimensions and operating conditions described is estimated to be at least 50 kg / day. Increasing the production rate may be achieved by inclusion of one or more of the following: additional reaction zones (i.e., more than the four described here), higher diameter reaction zones, more distributed heating sources within reaction zones, operation at the higher end of the design temperature range, operation at the higher end of the design pressure range, or by placing partial or complete reactor systems in parallel.

[0165] An example of how a production rate for Al might be achieved, e.g., from alumina is shown below. For example, if 25 kg / hr of aluminum product is desired (926 mols / hr),the following may be required or may result: 463 mols / hr of alumina feed (47 kg / hr), 1389 mols of reaction hydrogen (for example, from electrolysis) (3 kg / hr), Hydrogen overall may be delivered at a 10:1 molar ratio (4630 mols / hr or 9 kg / hr). This may result in 6 kg / hr of excess hydrogen (in embodiments, which may be recycled or combusted). An amount of hydrogen for combustion heating may be determined. Aluminum melt may be maintained at a 10:1 molar ratio (4630 mols / hr or 125 kg / hr). The perforated plates may hold an average total of about 750 kg of Al melt (with entrained hydrogen and alumina). 150 kg / hr aluminum lands at the bottom as solid beads with 125 kg / hr of aluminum recycled from the bottom of the process to be re-mixed at the top, and 25 kg / hr of aluminum may be harvested as product.

[0166] In embodiments, it may take at least 4 hours for an aluminum atom (starting as alumina or aluminum ore) to pass through the reaction zones and into the gas expulsion zone; this may be one example of the required residence time for reduction given the operating conditions listed above. In embodiments, it may take between approximately 0.5 hours and 15 hours for an aluminum atom (starting as alumina or aluminum ore) to pass through the reaction zones and into the gas expulsion zone.

[0167] In embodiments, on the perforated plates, new alumina may be held-up longer on the plates than old alumina by allowing liquid droplets to fall from the upper to lower plate, into the lower plate melt, such that the new droplets land at the furthest possible distance from a plate hole. In embodiments, the droplet may cause a splash, may penetrate into the melt, and / or may then be covered by splashed material, ensuring the droplet is immersed in the drop location where it may encounter hydrogen under high reactivity conditions for sufficient residence time before migrating or being agitated toward a hole. In embodiments, vibration may be applied to agitate the melt and assist with contact between hydrogen, alumina and aluminum and to assist with expulsion of water vapor product and to assist with moving melt through a hole.

[0168] In embodiments, the method of droplet transfer does not necessarily result in homogenous residence times. In embodiments, regardless, aluminum atoms in alumina within the reactor 101 should experience a residence time within approximately + / - 25% of each other.

[0169] In embodiments, the rate of production of aluminum from bauxite in the dimensions and operating conditions described is estimated to be at least 25 kg / day. Inembodiments, the rate of production of aluminum from alumina in the dimensions and operating conditions described is estimated at least 50 kg / day. Increasing the production rate may be achievable by inclusion of one or more of the following: more reaction zones, higher diameter reaction zones, more distributed heating sources within reaction zones, operation at the higher end of the design temperature range, operation at the higher end of the design pressure range, or by placing complete or partial reactor systems in parallel.

[0170] It is recognized that bauxite contains other metal ores within it, as described above. In embodiments, these other ores may be converted to their oxide form or their metallic form. If the described system and method is used to process bauxite, these other materials may be present along with the product aluminum. In embodiments, an additional method may be used to separate them. In embodiments, this separation may be done by applying a follow-on reduction process which may use reductants, temperatures, and pressures to selectively reduce the different ores (to oxide or metal) and to selectively generate a product stream with solids and liquids which can be separated by known methods.

[0171] The method described here, in embodiments, to convert alumina (aluminum ores) to aluminum, may heat feed materials and may use electricity to run an electrolysis process to generate hydrogen. In embodiments, the described process may require less than 50% of the energy needed in the traditional method to generate aluminum from alumina

[0172] The traditional method of converting alumina to aluminum requires multiple systems. In embodiments, the method described here for converting alumina to aluminum is performed in a single system.

[0173] At least two facilities are required in the traditional method for converting alumina to aluminum, roasting and calcining, followed by the Hall-Heroult process, and one of those facilities requires a significant electrical power footprint. In embodiments, the method described here requires one (in embodiments, substantially vertical) facility. As a result, the footprint of the method described here may be at least 10% lower than the footprint of the traditional method.

[0174] Because less energy may be required to run the process in the method described here relative to the traditional method for converting alumina to aluminum, the operating cost may be at least 5% lower.

[0175] Because less hardware, fewer operations, and / or a smaller footprint (at least 5% smaller footprint) may be required to run the process in the method described here relative to the traditional method for converting alumina to aluminum, and the capital cost may be at least 5% lower.

[0176] Greenhouse and environmentally harmful gases are generated by the traditional method of making aluminum from alumina. These include carbon dioxide, fluorinated methane, and ethane. In embodiments, the method described may not generate any greenhouse gases. In embodiments, no fluorinated compounds or any halogencontaining compounds are used.

[0177] The traditional method of producing alumina from bauxite uses hazardous wet chemicals and generates a chemical waste stream. In embodiments, the method described here uses no wet chemicals and does not generate a waste stream. In embodiments, as described above, some of the bauxite constituents may still be present in the form of an oxide or reduced metal which may require a heated reduction method for later separation.

[0178] Referring again to the systems of FIG. 1 - FIG. 5, in the process disclosed herein, the electrical energy required to generate sufficient hydrogen, by electrolysis, to produce 1 kg of Al, by the reaction of the hydrogen with alumina, may be below 6 kWh per kg of Al. In embodiments, this electrical energy may be as low as or lower than 4.2 kWh per kg of produced Al. In embodiments, excess hydrogen may be provided to the reactor to prevent the conversion reaction from proceeding in the reverse. In embodiments, once a forward reaction is achieved at or after reactor start-up, excess hydrogen streams may be recycled to feed the reactor or contribute to heat by combustion.

[0179] In embodiments, a hydrocarbon may be used for heat, which may reduce the energy input required to operate the electrolyzer 102 because less hydrogen output would then be required.

[0180] In embodiments, the process disclosed herein may require at least 5% less energy per kg of Al generated than the traditional method of using electrolysis to generate alumina.

[0181] For the purposes of this application, terms such as "upper," "lower," "upward," and "downward" are intended to be descriptive with reference to and in relation to the orientation shown in the Figures for clarity, but the examples as practiced and included in the scope of the claims may include examples where the systems and devices are in a different orientation.

[0182] In another emboidment A method for generating metals, at an industrial scale, from their ores, the method comprising, at oen step, delivering one or more inlet streams comprising solid and gaseous components, wherein the solid and gaseous components comprise metal ore, reducing gases, catalytic materials and combustion gases.

[0183] At another step, accepting one or more of the inlet streams to a reduction portion wherein the reduction portion is configured to reduce an ore to a reduced metal, wherein gaseous product species are created from a reduction reaction or from combustion to form reduction portion streams.

[0184] At antoher step, forming a different mix of gas of gaseous, liquid and solid species, wherein at least a portion of the different mix comprises a reducing species comprising at least hydrogen, wherein at least a portion of the different mix of liquid species comprises catalytic species comprising a metal, wherein at least a portion of the different mix of solid species contains an aluminum ore; accepting one or more of the outlet streams to a recycle section wherein the gaseous streams are processed to recycle unreacted reductant and to use reduction product species to regenerate reducing species, wherein the solid species are recycled to provide catalytic material to facilitate reduction of aluminum ores in the reduction portion.

[0185] At another step, accepting the different mix of gaseous and solid species at an exit section, wherein the different mix gaseous species and the solid species comprise unreacted combustibles, reduction reactants, reduction and combustion products, solid products, solid catalysts, unreacted ore, partially reacted or reduced ore or any combination thereof.

[0186] As should be appreciated, the various aspects described with respect to the figures herein are not intended to limit the technology to the particular aspects described. Accordingly, additional configurations can be used to practice the technology herein and / or some aspects described can be excluded without departing from the methods and systems disclosed herein.

[0187] Similarly, where operations of a process are disclosed, those operations are described for purposes of illustrating the present technology and are not intended to limit the disclosure to a particular sequence of operations. For example, the operations can be performed in differing order, two or more operations can be performed concurrently, additional operations can be performed, and disclosed operations can be excluded without departing from the present disclosure. Further, each operation can be accomplished via one or more sub-operations. The disclosed processes can be repeated.

Claims

CLAIMS1. A system for generating metals from their ores, the system comprising an inlet configured to accept a flow portion and to deliver one or more inlet streams comprising solid and gaseous components, wherein the solid and gaseous components comprise metal ore, reducing gases, catalytic materials and combustion gases a reactor comprising a reduction portion wherein the reduction portion is configured to accept the one or more inlet streams and comprises a plurality of reaction zones, wherein the reduction portion is configured to reduce an ore to a reduced metal, and wherein gaseous product species are created from a reduction reaction or from combustion to form reduction portion streams; an array of internal structures located in the reduction portion, and partially within the entrance section or exit section, wherein the array of internal structures comprise a different mix of gaseous, liquid and solid species, wherein at least a portion of the different mix of gaseous species comprises reducing species comprising at least hydrogen, wherein at least a portion of the different mix of liquid species comprises catalytic species comprising a metal, wherein at least a portion of the different mix of solid species contains an aluminum ore; a recycle portion configured to accept one or more gaseous and solid outlet stream; wherein the gaseous streams are processed to recycle unreacted reductant and to use reduction product species to regenerate reducing species, wherein the solid species are recycled to provide catalytic material to facilitate reduction of aluminum ores in the reduction portion; an exit section configured to accept the different mix of gaseous species and solid species exiting the reduction portion, wherein the different mix gaseous species and the solid species comprise unreacted combustibles, reduction reactants, reduction and combustion products, solid products, solid catalysts, unreacted ore, partially reacted or reduced ore or any combination thereof.

2. The system of claim 1 wherein aluminum is generated from aluminum ores, such as bauxite or alumina, using molecular hydrogen at temperatures ranging from the melting point of aluminum to 1850 °C.

3. The system of claim 1 wherein other metal ores found in aluminum ore, such as Fe ore, are reduced to Fe using molecular hydrogen, simultaneous aluminum generation.

4. The system of claim 1 wherein an array of reactor internal structures forms a mixture of aluminum ore, reducing gas, such as hydrogen, and a liquid catalytic metal that ensures contact between alumina and hydrogen at an interface of alumina and the catalytic metal.

5. The system of claim 1 where the liquid catalytic metal may be Al or Al mixed or alloyed with Fe, Cu, Ni orTi6. A method for generating metals, at an industrial scale, from their ores, the method comprising: delivering one or more inlet streams comprising solid and gaseous components, wherein the solid and gaseous components comprise metal ore, reducing gases, catalytic materials and combustion gases; accepting one or more of the inlet streams to a reduction portion wherein the reduction portion is configured to reduce an ore to a reduced metal, wherein gaseous product species are created from a reduction reaction or from combustion to form reduction portion stream; forming a different mix of gas of gaseous, liquid and solid species, wherein at least a portion of the different mix comprises a reducing species comprising at least hydrogen, wherein at least a portion of the different mix of liquid species comprises catalytic species comprising a metal, wherein at least a portion of the different mix of solid species contains an aluminum ore; accepting one or more of the outlet streams to a recycle section wherein the gaseous streams are processed to recycle unreacted reductant and to use reduction product species to regenerate reducing species, wherein the solid species are recycled to provide catalytic material to facilitate reduction of aluminum ores in the reduction portion; accepting the different mix of gaseous and solid species at an exit section, wherein the different mix gaseous species and the solid species comprise unreacted combustibles, reduction reactants, reduction and combustion products, solid products, solid catalysts, unreacted ore, partially reacted or reduced ore or any combinatio thereof

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