Editors Note: In a new life cycle assessment report available for download, the Aluminum Association states that, from 1991 to 2022, the energy and carbon impact of primary aluminum production in North America has declined by 49% while that of recycled aluminum production dropped by 60%. This 157 page report analyzed data from over 100 production facilities in the U.S. and Canada utilizing primary aluminum ingot and/or recycled aluminum ingot, all forms of wrought aluminum products, and die castings.1 The huge impact of recycled aluminum is immediately obvious in all of the numerous graphs and tables of quantitative research for primary and secondary aluminum presented in the report, which is apparent in the comparison of the global warming potential (GWP) calculated between the two (Figure 1).2
The huge advantage of secondary aluminum is often quoted by the industry, but the GWP is a carefully determined quantitative measure that the Aluminum Association and the International Aluminum Institute (IAI) agree upon and represents the environmental and economic basis of the “why” for recycling aluminum. In its world view, IAI data shows that ~75% of the ~1.5 billion tonnes of aluminum ever produced is still in productive use today, with North America having the highest aluminum recycling input rate or RIR (proportion of aluminum recycled scrap contained in the metal produced) of 57% compared with a global aluminum RIR of 32%.3
Although the GWP advantage so vividly portrayed in Figure 1 is the impetus for recycling aluminum, the processing steps or “how” to recycle aluminum in all of its wide range of applications is challenging, especially considering all of its useable methods for optimizing energy efficiency, percentage of recovery, and economic benefit. The recently granted U.S. patents selected below present novel ideas as to how this is done in various process steps: from collecting and sorting to meeting specifications for chemical composition and quality, efficient remelting, and the final application.
As is LMA’s practice for this column, the abstracts of the recently granted patents are presented in descending order of date of issue. Copies of all U.S. patents are available on-line at: www.uspto.gov/patents/search.
References
1. “The Environmental Footprint of Semi-Fabricated Aluminum Products in North America,” Aluminum Association, January 2022.
2. “Aluminum Carbon Footprint Cut in Half Over 30 Years,” Aluminum Association, January 2022.
3. “Aluminum Recycling,” IAI Factsheet.
— Joseph C. Benedyk, Editor
US12003002 — A POWER GENERATION APPARATUS AND POWER GENERATION METHOD — Kabushiki Kaisha Toyota Chuo Kenkyusho (Japan) — An object provides a power generation apparatus performing the purification of an Al alloy melt using scrap as raw material. A power generation apparatus includes: a container body with aluminum alloy melt and molten salt in a liquid junction with the aluminum alloy melt; an anode which is in contact with the aluminum alloy melt; and a cathode which is in contact with the molten salt. DC power is obtained from between the anode and the cathode by an anode reaction on the aluminum alloy melt side and a cathode reaction on the molten salt side. When the aluminum alloy melt and the molten salt are separated by a separator allowing ionic conduction between the aluminum alloy melt and molten salt, the power generation efficiency is enhanced. The amount of a reactant in the aluminum alloy melt is monitored by measuring the electrical quantity associated with the power generation.
US11964304 — SORTING BETWEEN METAL ALLOYS — Sortera Technologies, Inc. (USA) — A material sorting system sorts materials utilizing an x-ray fluorescence and/or a vision system that implements a machine learning system in order to identify or classify each of the materials, which are then sorted into separate groups based on such an identification or classification determining that the materials are composed of either wrought aluminum, extruded aluminum, or cast aluminum. The system is capable of sorting between cast aluminum alloys and also between wrought aluminum alloys.
US11939644 — METHOD FOR REGENERATING COPPER-CONTAINING ALUMINUM ALLOY FROM ALUMINUM ALLOY SCRAP — The Boeing Company (USA) — A method for regenerating different types of copper-containing aluminum alloys using aluminum alloy scrap from aeronautical industry includes detecting a chemical composition of said aluminum alloy scrap and optionally adding a suitable amount of a metal or alloy additive according to a composition requirement of a target aluminum-copper alloy, thereby obtaining a mixture of aluminum alloy scrap and metal or alloy additive; vacuum smelting the mixture of aluminum alloy scrap and metal or alloy additive in a vacuum furnace, wherein impurities are removed and an aluminum alloy solution is formed; filtering the aluminum alloy solution using a filter to obtain a melt comprising a target aluminum alloy composition; and casting the target aluminum alloy composition from said melt.
US11932923 — STRUCTURAL DIE CAST ALUMINUM ALLOYS — Ohio State Innovation Foundation (USA) — There is a need to improve methods of recycling aluminum which afford alloys suitable for use in applications where high performance is needed. Of all impurity elements, iron is considered the most detrimental, and its deleterious effect on the mechanical properties of Al—Si alloys is well known to the aluminum casting industry. Provided herein are aluminum alloys and methods of making them that comprise aluminum, silicon, iron, and manganese. Iron can be present in the aluminum alloy in a concentration greater than or equal to 0.3% by weight, based on the total weight of the aluminum alloy. In some embodiments, the iron is present in an amount ranging from 0.3% by weight to 1% by weight, based on the total weight of the aluminum alloy. The manganese can be present in amount effective to suppress (or even eliminate) the formation of a β-Al5FeSi phase during casting of the aluminum alloy. In some embodiments, the manganese can be present in an amount ranging from 0.1% by weight to 1.3% by weight, based on the total weight of the aluminum alloy. In some embodiments, iron and manganese can be present in a ratio of 1:1 or less.
US11904362 — METHOD AND DEVICE FOR ANALYSING AND/OR SORTING SCRAP METAL — Hydro Aluminium Recycling Deutschland GmbH (Germany) — The disclosure relates to a method for the analysis and/or sorting of scrap metal, more particularly of scrap aluminum, in which a quantity of scrap metal, more particularly aluminum scrap, in the form of a scrap bundle or a group of scrap bundles is provided, in which method the scrap bundle or the group of scrap bundles is irradiated by at least one neutron source, the gamma radiation emitted by the scrap bundle or by the group of scrap bundles is captured by at least one detector, and composition information relating to the composition of the scrap bundle or the group of scrap bundles is determined on the basis of the gamma radiation captured by the at least one detector. The disclosure further relates to a device for analyzing and/or sorting scrap metal.
US11904283 — VOLATILES CAPTURE EDUCATOR SYSTEM — GPRE IP LLC (USA) — This invention relates principally to a metal furnace or kiln, and more particularly to an educator system for a coated aluminum scrap melting furnace that collects organic and particulate volatiles off-gassing from aluminum scrap located in the furnace’s coated scrap hearth (i.e., de-lacquering) chamber and directs those volatiles into the melt zone (i.e., heating) chamber of the furnace to provide additional process burn fuel and reduce the quantity of waste exhaust pollutants. A volatiles consuming educator system for coated scrap metal furnaces with separate de-lacquering and melt chamber is described. Motive gas is forced through an inlet into a mixing chamber in a direction opposite a suction port, creating a Venturi that draws gases from the de-lacquering chamber through the mixing chamber. The motive gas and the drawn gases mix and are forced through a discharge port, ignited, and injected into the melt chamber to help heat the melt chamber. A computer monitors process conditions and controls a regulator that adjusts the motive gas flow in response to those conditions.
US11852336 — METHOD AND BURNER FOR HEATING A FURNACE FOR METAL PROCESSING — Messer Industries USA, Inc. (USA) — A method for heating an aluminum recycling furnace (40) used for metal processing by combusting a fuel in the furnace (40) by supplying an oxidizing gas through an oxidizing gas supply line (20) into the furnace (40) and by supplying a fuel through a fuel supply line (30) into the furnace (40), wherein the oxidizing gas is supplied in form of a central oxidizing gas flow (24) together with a first shroud gas flow (25), and/or the fuel is supplied in form of a central fuel flow (34) together with a second shroud gas flow (35), and to a corresponding burner (10).
US11835295 — MELT FURNACE HEADER GATE SYSTEM — GPRE IP, LLC (USA) — In various metal recycling systems, the furnace comprises multiple compartments or chambers to accommodate serial steps in the recycle process. For example, for aluminum scrap that is coated with paints and various other surface materials, it is typical to remove such coatings from the scrap aluminum before the aluminum is actually melted. A metal furnace header gate system haying a recirculation port in the furnace, a hot gas generator, a gas blower, and a furnace door. The door has an embedded gas manifold and outlet ports that each connect the manifold to a directional nozzle. The blower draws exhaust from the recirculation port into the hot gas generator, which generates additional exhaust and mixes the exhaust gases together. The blower forces this exhaust mixture into the manifold, through the nozzles, and into the furnace. A computer controls the blower and the hot gas generator to regulate the system.
US11823125 — METHOD AND SYSTEM FOR PROCESSING ALUMINUM ALLOY RIMS USING RIM SERIAL NUMBERS — House of Metals Company Limited (Canada) — The described embodiments relate to the field of processing aluminum alloy rims and to the use of aluminum alloy rim serial numbers during the course of processing and or recycling. A method for processing aluminum alloy rims including: providing a feed of a plurality of aluminum alloy rims of different compositions, each aluminum alloy rim having a serial number distinguishing that aluminum alloy rim from other aluminum alloy rims; storing in a non-transient computer-readable memory, a plurality of aluminum alloy rim categories; dividing the feed of aluminum alloy rims into a plurality of batches of aluminum alloy rims by, for each rim in the feed of aluminum alloy rims, scanning that aluminum alloy rim to determine the serial number of that aluminum alloy rim; based on the serial number, determining, from amongst the plurality of aluminum alloy rim categories, an aluminum alloy rim category for that aluminum alloy rim, wherein each batch of aluminum alloy rims in the plurality of batches of aluminum alloy rims corresponds to a category in the plurality of aluminum alloy rim categories.
US11821055 — ARTICLES AND METHODS FOR PROCESSING SCRAP ALUMINUM — Massachusetts Institute of Technology (USA) — Aluminum can be recycled by separating and sorting the aluminum and reusing the metal in various applications. However, it may also be reacted, for example, with water in order to obtain useful products, such as thermal energy, hydrogen gas, and useful aluminum products such as aluminum oxyhydroxide, aluminum hydroxide, and aluminum oxide. Articles and methods for processing aluminum are generally described. The aluminum can include compositions of gallium and/or indium such that the aluminum is activated to react with water. In one aspect, an article comprising at least one layer with a first surface and a second surface opposite the first surface is described, wherein the at least one layer comprises aluminum and at least one selected from the group of gallium and indium, and wherein the at least one layer comprises one or more bends such that the at least one or more layers forms a non-planar surface.
US11795528 — ALUMINUM ALLOY MATERIAL AND METHOD FOR MANUFACTURING THE SAME — Toyota Jidosha Kabushiki Kaisha (Japan) — To manufacture an aluminum alloy material for die-casting at low-price, it is considered to use an aluminum scrap as a raw material; however, low priced aluminum scrap contains a large amount of magnesium (Mg), zinc (Zn), and iron (Fe) that possibly cause a reduction of the tensile strength or the elongation ratio of the aluminum alloy. Provided is an aluminum alloy material for die-casting that allows being manufactured at low-price and has a high strength property and a sufficient elongation property as an aluminum alloy, and a method for manufacturing the same. An aluminum alloy material for die-casting contains Si: 9.6 mass % to 12 mass %, Cu: 1.5 mass % to 3.5 mass %, Mg: more than 0.3 mass % to 1.6 mass %, Zn: 0.01 mass % to 3.5 mass %, Mn: 0.01 mass % to 0.7 mass %, Fe: 0.01 mass % to 1.3 mass %, and Al and inevitable impurities: balance when the aluminum alloy material for die-casting as a whole is 100 mass %, and a mass ratio of Fe to Mn (Fe/Mn) is 4.4 or less.
US11788178 — METHODS OF MAKING HIGHLY-FORMABLE ALUMINUM ALLOYS AND ALUMINUM ALLOY PRODUCTS THEREOF — Novelis Inc. (USA) — Provided herein are highly-formable aluminum alloys and methods of making such alloys. The method of preparing aluminum alloys described herein can include a low final cold reduction step and/or an optional inter-annealing step to produce randomly distributed crystallographic texture components that produce an isotropic aluminum alloy product exhibiting improved formability and deep drawability. The methods described herein result in aluminum alloy microstructures having a balance of alpha fibers and beta fibers that promote improved formability of aluminum alloy sheets. The resulting improvements in quality allow for shaping processes with reduced defect rates. The aluminum alloys for use in the casting step can be a primary material produced from raw materials (e.g., purified aluminum and additional alloying elements). In some further examples, the aluminum alloys for use in the casting step can be a recycled material, produced at least in part by aluminum scrap and optionally in combination with a primary material. In some cases, aluminum alloys for use in the casting step can contain at least about 40% of recycled content. For example, the aluminum alloy for use in the casting step can contain at least about 45%, at least about 50%, at least about 60%, at least about 70%, at least about 80%, at least about 90%, or at least about 95% of recycled content.
US11767575 — VORTEX SCRAP METAL INJECTOR — GPRE IP, LLC — For aluminum scrap that is coated with paints and various other surface materials, it is typical to remove such coatings from the scrap aluminum before the aluminum is actually melted. It is desirable to have an apparatus or system for a scrap metal delacquering and a melt furnace that provides for the controllable in situ injection of additional metals into the furnace’s melt flow to improve the efficiency of and control over the system. As will become evident in this disclosure, the present invention provides such benefits over the existing art. A vortex injection system for a metal recycling furnace, a delacquering chamber, and a melt chamber, and a molten metal flow channel running through each chamber. The system diverts a portion of the molten metal flow through a vortex bowl, after which that portion of the molten metal flow is then returned to the main molten metal flow. The vortex bowl has an insertion port through which scrap metal and other materials may be controllably injected into the molten metal flow.
US11761056 — SYSTEMS AND METHODS FOR RECYCLING WASTE METAL PIECES USING SHOT BLASTING AND SHOT REMOVAL — House Of Metals Company Limited (Canada) — A method and system of recycling aluminum alloy wheels, the method and system comprising (a) providing a feed of aluminum alloy wheels of a particular alloy; (b) fragmenting the aluminum alloy wheels into a plurality of fragments (c) shot blasting the plurality of fragments to clean non-aluminum contaminants off the plurality of fragments; (d) separating the plurality of fragments from the plurality of shot by moving a mixture of the plurality of fragments and the plurality of shot adjacent a dividing surface; and (e) providing the remaining plurality of fragments for use in manufacturing at least one component made from aluminum alloy.
US11760655 — METHOD FOR RECYCLING IRON AND ALUMINUM IN NICKEL-COBALT-MANGANESE SOLUTION — Hunan Brunp Recycling Technology Co., Ltd., Guangdong Brunp Recycling Technology Co., Ltd., and Hunan Brunp Vehicles Recycling Co., Ltd. (China) — The present invention relates to the field of spent battery recovery technologies, and specifically, to a method for recycling iron and aluminum during nickel-cobalt-manganese solution recovery.The method comprises the following steps: leaching a battery powder and removing copper therefrom to obtain a copper-removed solution, and adjusting the pH value in stages to remove iron and aluminum, so as to obtain a goethite slag and an iron-aluminum slag separately; mixing the iron-aluminum slag with an alkali liquor, and heating and stirring same to obtain an aluminum-containing solution and alkaline slag; and heating and stirring the aluminum-containing solution, introducing carbon dioxide thereto and controlling the pH value to obtain aluminum hydroxide and an aluminum-removed solution.
US11740024 — MELTING AND/OR STIRRING OF MOLTEN METALS — Altek Europe Limited (Great Britain) — The present invention has amongst its potential aims to provide apparatus for stirring and methods of stirring which generate better flow patterns for drawing non-melted metal into molten metal and/or for mixing non-molten metal with molten metal, e.g., in the recycling of aluminum. The method comprising: providing apparatus including an electromagnetic mover adjacent a part of the container, wherein the electromagnetic mover has a primary motion axis, the primary motion axis being aligned along the direction of the maximum linear force generated by the electromagnetic stirrer; applying a current to the electromagnetic mover such that changes in magnetic field configuration cause movement of the molten metal within the container; wherein the primary motion axis is inclined relative to the vertical in two different planes; or wherein the longitudinal axis is inclined relative to the vertical in two different planes. The method and apparatus are designed to generate a plurality of different flow zones within the container and/or larger container, the different flow zones differing from one another in terms of their position in the container and/or larger container and/or the different flow zones differing from one another in terms of the relative flow velocities and/or the different flow zones differing from one another in terms of the relative directions of flow.
US11740022 — FURNACE CONTROLLER AND METHOD OF OPERATING A FURNACE — Air Products and Chemicals, Inc. (USA) — There is a significant amount of variability in remelting secondary aluminum, from charge material, to furnace condition, through to operations. These sources of variability can introduce a significant amount of uncertainty into the process, leading to a large spread in performance results. A control scheme for a furnace can use real-time and historical data to model performance and determine relationships between different data and performance parameters for use in correcting suboptimal performance of the furnace in real-time. Operational parameters can be logged throughout the cycle for all cycles for a period of time in order to establish a baseline. These data can then be used to calculate the performance of the process. A regression analysis can be carried out in order to determine which parameters affect different aspects of performance. These relationships can then be used to predict performance during a single cycle in real-time and provide closed or open loop feedback to control furnace operation to result in enhanced performance.
US11705222 — METHOD OF REDUCING GREENHOUSE GAS EMISSIONS FROM RECYCLING ALUMINUM ALLOY WHEELS — House of Metals Company Limited (Canada) — A method of recycling aluminum alloy wheels, the method may comprise (a) providing a feed of aluminum alloy wheels; (b) fragmenting the aluminum alloy wheels into a plurality of fragments; (c) shot blasting the plurality of fragments to at least partly remove at least one contaminant material; (d) storing at least one recognition criterion and at least one carbon factor; (e) for each fragment of a representative sample of fragments, determining, for each contaminant material, a contaminant material concentration estimate for that fragment; (f) operating a data processor to either approve or reject the plurality of fragments, based on an aggregate carbon emission calculation being based on the contaminant material concentration estimate and the carbon factor. When the plurality of fragments is approved, they may be provided to a downstream recycling process. When the plurality of fragments is rejected, they may be further shot blasted
US11660762 — WASTE SORTING ROBOT — MP Zenrobotics OY (Finland) — A waste sorting robot can include a manipulator comprising a suction gripper for interacting with one or more waste objects to be sorted within a working area, and wherein the manipulator is moveable within the working area. There is a controller configured to send control instructions to the manipulator. At least one pressure sensor is in fluid communication with the suction gripper and configured to generate a pressure signal in dependence on a fluid pressure in the suction gripper. The controller is configured to receive the pressure signal and to determine manipulator instructions in dependence on the pressure signal.
US11631909 — METHODS AND SYSTEMS FOR SCALABLE DIRECT RECYCLING OF BATTERIES — Li Industries, Inc. (USA) — During battery production, wrought aluminum and cathode materials typically take up around half and 10% to 14%, respectively, of the cradle-to-gate energy consumption or greenhouse gas (GHG) emission. Recycling aluminum and cathode material can therefore significantly reduce the energy consumption and GHG emission of battery production. A method includes processing at least one Li-ion battery into a plurality of core sections. Each core section in the plurality of core sections includes an anode section, a cathode section including a cathode material, a separator section disposed between the anode section and the cathode section, and an electrolyte. The method also includes disposing the plurality of core sections into a solvent to produce a mixture of cathode materials from the plurality of core sections. The solvent and the electrolyte form an ionic conductive medium, and the mixture of the cathode materials is characterized by a substantially homogeneous distribution of an active element in the cathode material.
US11543184 — ADJUSTABLE KILN FLIGHT FOR ROTARY KILN DECOATER AND ASSOCIATED METHOD — Novelis Inc. (USA) — During metal recycling, such as recycling aluminum (including aluminum alloys), organic coatings, such as paints, lacquers, and the like must be removed with a decoating process to prevent violent gas evolution during recycling processing. As part of the decoating process, the metal scrap is mixed in a decoating kiln with kiln flights within the kiln to lift up and then drop the scrap to distribute the metal scrap within the kiln for heat exchange with the hot gas and to make the scrap advance. Disclosed are adjustable kiln flights for rotary kilns and associated methods. The kiln flight includes a base configured to be secured to a rotary kiln surface of a rotary kiln. In some aspects, the kiln flight includes a flight body rotatably supported on the base such that an angular orientation of the flight body is adjustable. In various examples, the kiln flight includes a height adjuster movably supported relative to the base such that a height of the kiln flight is adjustable. A method of controlling a rotary kiln with the adjustable kiln flight includes supporting a kiln flight on a base that is secured to an inner kiln surface of a rotary kiln and adjusting at least one of the angular orientation of the kiln flight or the height of the kiln flight.
US11535022 — METHOD AND APPARATUS FOR RECYCLING PACKAGING MATERIAL — Saperatec GmbH (Germany) — A method for recycling of packaging material is disclosed. The packaging material comprises a multilayer material (10) comprising a metal layer (30) such as aluminum and at least one polymer layer (20, 40). The method comprises placing the packaging material in a vat (310) comprising a separation fluid (330) to produce a mixture of metal shreds from the metal layer (30), plastic shreds from the polymer layer (20, 40) and residual components. The separation fluid comprises a mixture comprising a mixture of water, a short-chained carboxylic acid, phosphoric acid and an alkali metal hydroxide solution.
US11509000 — PROCESS FOR THE RECOVERY OF CATHODE MATERIALS IN THE RECYCLING OF BATTERIES BY REMOVING ALUMINUM AND IRON — Northvolt AB (Sweden) — A first aspect of the present disclosure is a process for removal of aluminum and iron in the recycling of rechargeable batteries, preferably rechargeable lithium ion batteries. A process for removal of aluminum and iron in the recycling of rechargeable batteries comprising providing a leachate from black mass, adding phosphoric acid (H3PO4) to said leachate and adjusting the pH to form iron phosphate (FePO4) and aluminum phosphate (AlPO4), precipitating and removing the formed FePO4 and AlPO4, and forming a filtrate for further recovery of cathode metals, mainly Ni, Mn, and Co metals and lithium.
US11441206 — SYSTEM AND METHOD OF OPERATING A BATCH MELTING FURNACE — Air Products and Chemicals, Inc. (USA) — A system and method of controlling a secondary aluminum melting process in a melting furnace, including determining at least one furnace parameter characterizing a melting furnace, adding a charge containing solid metal into the melting furnace, detecting at least one charge parameter characterizing the charge, firing a burner into the melting furnace to provide heat to melt the charge, and exhausting burner combustion products from the furnace, detecting at least one process parameter characterizing progress of melting the charge, calculating a furnace efficiency based on the at least one furnace parameter, calculating a predicted process pour readiness time based on the at least one charge parameter, the at least one process parameter, and the furnace efficiency, and controlling the metal melting process based on the predicted process pour readiness time.
US11358217 — METHOD FOR MELTING SOLID METAL — Molten Metal Equipment Innovations, LLC (USA) — A scrap melting system and method includes a vessel that is configured to retain molten metal and a raised surface about the level of molten metal in the vessel. Solid metal is placed on the raised surface and molten metal from the vessel is moved upward from the vessel and across the raised surface to melt at least some of the solid metal. The molten metal is preferably raised from the vessel to the raised surface by a molten metal pumping device or system. The molten metal moves from the raised surface and into a vessel or launder.
US11345980 — RECYCLED ALUMINUM ALLOYS FROM MANUFACTURING SCRAP WITH COSMETIC APPEAL — Apple Inc. (USA) — Conventional recycling of manufacturing chip scrap (e.g. 6063 Al) is generally associated with downgraded quality. There remains a need for developing alloys and processes for recycling manufacturing scrap to improve the cosmetic appeal of the recycled aluminum alloys. The disclosure provides an aluminum alloy may include iron (Fe) of at least 0.10 wt %, silicon (Si) of at least 0.35 wt %, and magnesium (Mg) of at least 0.45 wt %, manganese (Mn) in amount of at least 0.005 wt %, and additional elements, the remaining wt % being Al and incidental impurities. In another aspect, a recycled 6000 series aluminum alloy may include iron (Fe) from 0.10 to 0.50 wt %, silicon (Si) from 0.35 to 0.80 wt %, and magnesium (Mg) from 0.45 to 0.95 wt %, manganese (Mn) in amount of 0.005-0.090 wt %, the remaining wt % being Al and incidental impurities, wherein the recycled aluminum alloy has the same cosmetic appeal as a virgin Al 6063 alloy.
US11332380 — METHOD FOR ALUMINUM-ENHANCED DEALKALIZATION OF RED MUD AND SEPARATION AND RECOVERY OF ALUMINUM AND IRON — Kunming University of Science and Technology (China) — The present invention discloses a method for aluminum-enhanced dealkalization of red mud and separation and recovery of aluminum and iron. The method includes: dissolving red mud in water, introducing excessive SO2, introducing O2 for aeration, and refluxing part of alkaline leachate after filtering; when pH of a red mud mixture decreases to below 3, washing and filtering the red mud mixture, adding NaOH to acidic leachate to adjust its pH to a strongly alkaline level, aging and filtering the leachate, treating filter residue to recover Fe2O3, and refluxing part of alkaline leachate after filtering to the red mud mixture; and adjusting pH of the remaining alkaline leachate after filtering to a weakly acidic level, and conducting filtering to recover aluminum.
US11311915 — AUTOMATED AERO ALUMINUM SCRAP SORTING SYSTEM BASED ON LASER INDUCED BREAKDOWN (LIBS) TECHNIQUE — The Boeing Company (USA) — A fully automatic online aero aluminum sorting and recovery system based on LIBS (Laser Induced Breakdown Spectroscopy) technology, which belongs to the field of aero aluminum sorting and recovery technology, and is suitable for online sorting, detection and recovery of large batch of aero aluminum. The fully automatic online aero aluminum sorting system based on LIBS technology provided in the present invention consists of six portions: a sample feeding unit (1), a surface treatment unit (2), a material positioning unit (3), a LIBS analysis and detection unit (4), a transfer unit (5) and a sorting and recovery unit (6). The system according to the invention can be used to realize the automatic online detection, sorting and recovery of aero aluminum, and the system does not have requirements on the surface condition of the recovered aero aluminum samples. The sorting accuracy rate is greater than 90% and the sorting rate is not less than 1 block per second.
US11040352 — SYSTEM FOR MELTING ALUMINUM AND RECYCLING BLACK DROSS — DS Liquid Co., Ltd. (Korea) — The present invention relates to a system for melting aluminum and recycling black dross, including an aluminum melting furnace responsible for melting aluminum scraps in molten aluminum and a black dross recycling device responsible for recycling black dross generated when the aluminum scraps are melted in the molten aluminum. The aluminum melting furnace includes a heating chamber provided with heating units responsible for heating the molten aluminum; and a melting chamber provided with an eddy unit responsible for generating an eddy descending in a spiral in the molten aluminum, a flux supply unit responsible for adding a flux to the eddy, and a raw material supply unit responsible for adding the aluminum scraps to the eddy, wherein, in the eddy unit, black dross formed when inclusions contained in the molten aluminum are captured by the flux is repeatedly descended and floated in the molten aluminum through the eddy, so that the black dross is collected into a spherical shape to form spherical black dross, and the black dross recycling device is responsible for recycling the spherical black dross.
