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International Patents: Red Mud Management and Valorization

Editor’s Note: Light Metal Age has repeatedly published articles on bauxite residue (red mud), including the highly informative February 2024 article by Alton Taberaeux that described some of the latest trends in red mud processing.1 This editorial and selection of patents on red mud valorization supplements this archive, as the field of coping with the red mud problem continues unabated. 

As global red mud management and valorization have become so important, the Red Mud Project was launched in January 2025. It is based at the Department of Materials Science at the University of Patras in Greece, and includes Aluminium of Greece, International Committee for Study of Bauxite, Alumina & Aluminium (ICSOBA), and the University of Patras as project partners. Since it was launched, the Red Mud Project has evolved to disseminate results among different research teams and industries by providing the latest news and an extensive scientific bibliography on red mud.2 

The pace of development on this subject within the metallurgical community continues to advance in 2025, with the 5th Bauxite Residue Valorization and Best Practices meeting, which will be held during the TMS 2025 Annual Meeting & Exhibition on March 23–27, 2025 in Las Vegas.3 

Some pertinent facts about management and valorization of highly alkaline (pH = 11-13) red mud are widely available and briefly summarized as follows:

  • The Bayer process for alkaline alumina extraction from bauxite ore was invented by Karl Josef Bayer in 1888. Today, more than 90% of the world’s alumina is produced using this process.
  • More than 229 bauxite mines are in operation globally, and the Bayer process for production of aluminum is used in about 80 active plants worldwide, resulting in the production of red mud as hazardous waste.
  • Approximately 1–1.5 tonnes of red mud are produced for every 1 tonne of alumina, with the global average being around 1.23 tonnes of red mud per tonne of alumina.
  • In 2023, global production of primary aluminum was estimated at 70.7 million tonnes, with over 142 million tonnes of alumina produced, resulting in approximately 170 million tonnes of red mud in the same year. As of 2023, red mud stockpiles have surpassed 4.6 billion tonnes and continues to expand annually.
  • Red mud disposal costs can account for around 2% of the price of alumina on average. For example, if the price of alumina is $439 per tonne, then cost of disposing of red mud would be about $9 per tonne.
  • Only a fraction of red mud has found some use or is valorized. The most common forms of use include cement manufacture, the extraction of raw materials (iron, titanium, and rare-earth elements), soil amelioration, etc. 

Valorization of red mud to create innovative products or applications obviously requires not only creative insights that lead to useful outcomes, but also lead to capital (CAPEX) and operational (OPEX) expenditures that provide reasonable profit over the cost of disposal. The low rate of red mud valorization is not sustainable, considering the vast accumulation of red mud worldwide and the projected increase in demand for bauxite projected alongside the significantly rising demand for primary aluminum. Taking account of the average global composition of red mud and the compositional value distribution (Figure 1), red mud presents various valorization opportunities. 

Figure 1. Global bauxite residues, showing the average composition (left) and compositional value distribution (right).4

Stricter environmental policies are pushing the envelope and, already, there are several emerging technologies and established enterprises that are devoted to profiting from extracting valuable material from red mud. For example, in North America, the Canadian company Geomega Resources, Inc. has developed a process for extracting valuable rare earths from red mud and has garnered $4 million in funding for a pilot plant for complete valorization of red mud with the aim of significantly reducing its volume.5 

The French company ib2 has developed and patented a process that transforms low-grade bauxite, including that found in red mud, into high-grade ore and thereby optimizing alumina production while significantly reducing the red mud footprint.6 

In Germany, scientists at the Max-Planck-Institute for Iron Research have developed a process for converting the iron oxide in red mud into iron using fossil-free hydrogen plasma (Ar-10%H2) ignited in an electric arc furnace without the need for prior treatment of the dry red mud input material (Figure 2).7 

Figure 2. Schematic of the H2 -plasma process developed at the Max-Planck-Institute to convert dry red mud into Fe metal (top) and an example of red mud powder transformed after 10 min of reduction with sample separation into oxide-rich powder for subsequent steel production (bottom).7

The pace of R&D  and inventive methods of red mud valorization continues to expand, as shown in the recent patents selected hereafter. The global perspective on red mud valorization is apparent in the range of patents assigned to foreign companies. As is LMA’s practice for this column, abstracts of these recently granted patents are presented in descending order of date of issue. U.S. patents are available on-line at: https://www.uspto.gov/patents/search. 

References

  1. Tabereaux, A., “Advances in Processing Alumina Refinery Bauxite Residue Waste,” Light Metal Age, February 2024, pp. 32–35.
  2. “Bibliography,” Red Mud Project.
  3. “Bauxite Residue Valorization and Best Practices,” TMS 2025.
  4. “Bauxite Residues Processing,” Geomega.
  5. “Geomega Announces Funding from SDTC, Quebec and Rio Tinto for a $4M Pilot Plant and Feasibility Study of Sustainable & Complete Valorization of Bauxite Residues,” Geomega, March 31, 2022.
  6. “Breakthrough French technology for the sustainable transformation of bauxite waste into high-quality alumina,” ib2.
  7. Jovičević-Klug, Matic, et al., “Green Steel from Red Mud through Climate-neutral Hydrogen Plasma Reduction,” Nature, Vol. 625, January 25, 2024. pp. 703–709.

Further Reading

Additional research and articles on red mud management and valorization that may be of interest to readers are as follows: 

— Joseph C. Benedyk, Editor

US12172929 — RED MUD UTILIZATION METHOD BASED ON CO-PROCESSING OF INDUSTRIAL EXHAUST GAS, SEWAGE TREATMENT AND ENVIRONMENT-FRIENDLY AND HIGH PERFORMANCE CIVIL FUNCTIONAL MATERIAL — Shandong University (China) — A red mud utilization method based on co-processing of industrial exhaust gas, sewage treatment and an environment-friendly and high-performance civil functional material, belongs to the technical field of environmental science and cementitious material preparation, and relates to a preparation process of a solid waste-based cementitious material, specifically including the steps: preparing an environment-friendly and high-performance red mud-based civil functional material by using slag obtained after sewage treatment with red mud and other solid wastes in physical and chemical activation and high-temperature calcination methods. The compressive strength of a solid waste-based cementitious material prepared by using the method can reach 29 MPa, the leaching quantity (lower than 3.0 ppm) of toxic elements such as heavy metals is far lower than the national standard requirement, and a solid waste-based cementitious material with great performance can be prepared.

 

US12172905 — METHODS OF EXTRACTION OF PRODUCTS FROM TITANIUM-BEARING MATERIALS — Avertana Limited (New Zealand) — The invention relates to processes for the extraction of products from titanium-bearing materials and more particularly, although not exclusively, extracting titanium dioxide and/or one or more other products from iron making slag. In one embodiment, the titanium-bearing material is red mud and comprises from at least approximately 5% to at least approximately 25% w/w titanium dioxide. In one embodiment, the red mud comprises approximately 5% to approximately 35% titanium dioxide. In certain embodiments, the red mud comprises approximately 5%, 10%, 15%, 20% or 25% titanium dioxide.

 

US12162000 — HYDROGEN PRODUCTION BY RED MUD-SUPPORTED NICKEL-BASED CATALYSTS AND METHODS OF PREPARATION THEREOF — King Fahd University of Petroleum and Minerals (Saudi Arabia) — A method for generating hydrogen (H2) includes introducing a H2-containing feed gas stream into a reactor containing a red mud-supported nickel (Ni-SRM) catalyst including Ni-SRM catalyst particles. The method further includes passing the H2-containing feed gas stream through the reactor to contact the H2-containing feed gas stream with the Ni-SRM catalyst particles at a temperature of 500°C to 700°C to form an activated Ni-SRM catalyst and terminating the introducing the H2-containing feed gas stream. The method further includes introducing and passing CH4-containing feed gas stream through the reactor to contact the CH4-containing feed gas stream with the activated Ni-SRM catalyst at a temperature of 600°C to 1000°C thereby converting at least a portion of the CH4 to carbon and H2.

 

US12146044 — RED MUD-BASED COMPOSITE ASPHALT ANTI-AGING AGENT, AND PREPARATION METHOD THEREFOR AND USE THEREOF — Shandong University (China) — The present invention relates to the technical field of road engineering construction and relates to a red mud-based composite asphalt anti-aging agent, and a preparation method therefor and use thereof. The red mud-based composite asphalt anti-aging agent consists of the following raw materials in parts by weight: 100 parts of red mud, 20-40 parts of a nano material, 10 parts of a cationic surfactant and 1 part of a silane coupling agent. The cationic surfactant is hexadecyl trimethyl ammonium bromide or octadecyl trimethyl ammonium bromide. The red mud-based composite anti-aging agent prepared by the present invention is added into asphalt to prepare a modified asphalt mortar to remarkably improve the anti-aging ability of the asphalt and realize the functional comprehensive utilization of the red mud. The problem that the addition of the red mud may lead to insufficient water stability of an asphalt mixture at present is solved.

 

US12145856 — PURIFICATION OF ORES USING BORONIC ACID-FUNCTIONAL COMPOUNDS — Ecolab USA Inc. (USA) — Described herein is a method of adding one or more boronic acid functional compounds to a mineral ore to result in a treated mineral ore. Where the mineral ore is a bauxite ore, and the ore is subsequently processed according to the Bayer process to obtain alumina, adding a boronic acid functional compound to the bauxite ore or a Bayer product followed by processing the treated bauxite ore or treated Bayer product using one or more processes associated with the Bayer process results in an increased yield of alumina product, increased alumina content (purity) in the alumina product obtained, or both when compared to the same bauxite ore or Bayer product subjected to the same process(es) but in the absence of a boronic acid functional compound.

 

US12134574 — OAE SYSTEM WITH CONTROLLED ACID NEUTRALIZATION — Ebb Carbon, Inc. (USA) — Acid byproduct from an OAE (Ocean Alkalinity Enhancement) system is mixed with an aqueous alkaline fluid such as obtained from bauxite residue or red mud under conditions that maintain the mixture at or above a target pH level at which the rate of acid neutralization is maximized and the release of CO2 into the atmosphere is prevented. A neutralization controller utilizes sensor data to monitor the mixture’s pH level and to control the rate at which acid byproduct is added (e.g., by a dosing pump) to the mixture. A reaction tank and an optional circulation line and in-line mixer are utilized to perform the mixing process. An optional agitator mechanism is provided to stir the mixture in the reaction tank, and to optionally move sensors and/or injectors along circular paths through the mixture. Optional fixed sensors and/or injectors are located in designated spaced-apart regions inside the reaction tank. The mixture is treated using optional flocculation and grit processing systems/devices.

 

US12129192 — TREATMENT OF TAILINGS — Extrakt Process Solutions, LLC (USA) — The management and sustainability of tailings ponds pose significant and growing problems, e.g., approximately 77 million tons of a highly alkaline waste product composed mainly of iron oxide and known as red sludge or red mud is generated every year, posing a significant disposal problem. Processes of consolidating tailings such as from metal and non-metal ore processes are disclosed. The processes include mixing tailings with a high concentration of a highly water-soluble salt or an aqueous solution thereof to destabilize and consolidate solids in the tailings and separating the consolidated solids from process water.

 

US12129400 — METHOD FOR PREPARING ALKALINE RED MUD COATING FOR PREVENTING MARINE ORGANISM ATTACHMENT — Taishan University (China) — Attaching organisms along the coast such as algae and mollusks, after these attaching organisms multiply on concrete surfaces, if they are not cleaned up in time, they will accelerate the corrosion of underwater buildings and hinder the inspection, maintenance and repair of underwater buildings. Provided is a method for preparing an alkaline red mud coating for preventing marine organism attachment, including: (1) mixing stearic acid and absolute ethanol by stirring to obtain a mixed solution; (2) mixing the mixed solution and a red mud powder to obtain a mixture, and drying the mixture to obtain a modified hydrophobic red mud powder; (3) adding benzyl glycidyl ether into an epoxy resin and conducting dispersion to be uniform to obtain a mixed system, adding the modified hydrophobic red mud powder into the mixed system, continuing the dispersion to be uniform to obtain a blend, and grinding the blend to obtain an antifouling coating material; and (4) during use, mixing the antifouling coating material with a polyamide curing agent to obtain a mixture system, and applying the mixture system onto a surface of building to form the alkaline red mud coating for preventing marine organism attachment.

 

US12122957 — POLYMERIC RED MUD-BASED KILLING FLUID AND USES THEREOF — Saudi Arabian Oil Company (Saudi Arabia) — A high-density red mud-based kill fluid composition includes a neutralized red mud slurry, a polymeric material, and an H2S capturing agent. A method of neutralizing red mud includes providing a red mud slurry, adding gypsum to the red mud slurry, and providing a neutralized red mud slurry, wherein the neutralized red mud slurry has a pH ranging from 7.5 to 9.0. A method of treating a sour well includes injecting a red mud-based kill fluid including a neutralized red mud slurry, a polymeric material, and an H2S capturing agent into the sour well, wherein the sour well comprises H2S gas and CO2 gas, solidifying the red mud-based kill fluid, and treating the H2S gas and the CO2 gas in the sour well.

 

US12116313 — NON-SINTERED HIGH-STRENGTH LIGHTWEIGHT AGGREGATE ONE-SHOT PREPARED FROM SULFUR-BASED AND ALKALINE-BASED SOLID WASTES BY STIRRING, GRANULATION, FOAMING, PREPARATION METHOD THEREFOR AND USE THEREOF — Shandong University and Hubei Changyao New Materials Co., Ltd. (China) — A non-sintered high-strength lightweight aggregate one-shot prepared from sulfur-based and alkaline-based solid wastes, such as red mud, by stirring, granulation, and foaming, and a preparation method therefor and use thereof. The non-sintered high-strength lightweight aggregate is prepared from a sulfur-based solid waste, an alkaline-based solid waste, an auxiliary cementing material, a ferro-aluminum-sulfur cementing material, water, and a foaming agent as raw materials. Based on the mass of the total solid, the total content of the sulfur-based solid waste, the alkaline-based solid waste, and the auxiliary cementing material is 80-90 wt %, and the content of the ferro-aluminum-sulfur cementing material is 10-20 wt %. The mass ratio of the water to the total solid is (15-20):(80-85). The foaming agent accounts for 0.3-0.7% of the mass of the total solid. The mass ratio between the sulfur-based solid waste, the alkaline-based solid waste, and the auxiliary cementing material is (27-33):(27-33):(18-25).

 

US12054805 — METHODS FOR RECOVERING METALS USING OXALATE COMPOUNDS — University of Kansas (USA) — Methods for recovering a metal from a metal-containing material, including bauxite, are provided. In embodiments, such a method comprises exposing a metal-containing material to a leaching solution comprising a solvent and a binoxalate, a tetraoxalate, or a combination thereof, under conditions to provide a leachate comprising a soluble metal oxalate; inducing precipitation of a metal-containing precipitate comprising the metal of the soluble metal oxalate from the leachate; and recovering the metal-containing precipitate.

 

US12054389 — CATALYSTS CONTAINING RED MUD AND RHODIUM FOR DRY REFORMING — Saudi Arabian Oil Company (Saudi Arabia) — Catalyst compositions containing red mud, a by-product of alumina production for the Bayer process, and rhodium are provided. For each ton of alumina produced, 1 to 2 tons of red mud, also referred to as bauxite tailings, are generated, more than 100 million tons of red mud are generated annually, and billions of tons of red mud are stored worldwide. An exemplary catalyst composition used for dry reforming of methane includes about 50 wt % to about 99 wt % of a mixed-oxide material including iron oxide, aluminum oxide, and silicon oxide, and about 1 wt % to about 40 wt % of rhodium oxide, calculated as Rh2O3.

 

US12049683 — METHODS FOR RECOVERING METALS FROM METAL-CONTAINING MATERIALS — University of Kansas (USA) — Methods for recovering metals from metal-containing materials are provided. The metal-containing material comprises either Co and Li (e.g., an electrode material from a spent lithium-ion battery) or Fe and Al (e.g., bauxite). The metal-containing material is exposed to a leaching solution comprising ammonium hydrogen oxalate, oxalic acid, or both, to provide a solid composed of either cobalt oxalate or iron oxalate, and a solution of either lithium oxalate or aluminum oxalate. The solid is processed to provide either cobalt oxide or iron oxide; the solution is processed to provide either a lithium precipitate or an aluminum precipitate, and a filtrate comprising an oxalate; and the filtrate comprising the oxalate is processed to recover ammonium hydrogen oxalate, oxalic acid, or both. The method further comprises repeating the digestion step with the recovered ammonium hydrogen oxalate, the recovered oxalic acid, or both.

 

US12049409 — ACID WASH OF RED MUD (BAUXITE RESIDUE) — Worcester Polytechnic Institute (USA) — Bauxite residue recovery includes mixing a solution of hydrochloric acid (HCL) according to a predetermined concentration, and adding the HCL solution to a quantity of raw red mud recovered from industrial operations as waste material. The highly alkaline property of the bauxite residue, commonly known as red mud is at least partially neutralized from the HCL and makes the resulting washed red mud more amenable to subsequent uses in various applications in fields such as construction, wastewater treatment, and metal recovery processes. The process recovers washed red mud from the red mud and HCL solution by filtering the raw red mud and HCL solution for generating a stream of leach liquor from the filtrate and the recovered washed red mud from the residue.

 

US12006225 — BAYER PROCESS — Rio Tinto Alcan International Limited (Canada) — A Bayer process increases oxalate removal in the red side of the Bayer process and at least substantially minimizes, for example by at least substantially suppressing, precipitation of oxalates in the white side of the Bayer process, including feed materials to the process, at least substantially suppressing, oxalate precipitation in the white side and to achieve a workable balance of white and red side oxalate removal. The Bayer process of the invention is based on trials at the Yarwun refinery of a related company of the applicant that has found that reagents known in the industry to have oxalate modifying properties, such as carboxylic acids, quaternary ammonium compounds and crystal growth modifiers can be effective to at least substantially minimize, for example by at least substantially suppressing, oxalate precipitation in the precipitation step.

 

US11981615 — METHOD FOR CHEMICALLY REDUCING CARBON DIOXIDE WITH RED MUD CATALYST COMPOSITION — King Fahd University of Petroleum and Minerals (Saudi Arabia) — A method for chemically reducing carbon dioxide (CO2) with a red mud catalyst composition is provided includes introducing a gaseous mixture of CO2 and H2 into a reactor containing particles of the red mud catalyst composition. The method further includes reacting at least a portion of the CO2 and H2 in the gaseous mixture in the presence of the red mud catalyst composition at a temperature of 200 to 800? C., and under a pressure ranging from 5 to 100 bar to form a gaseous product including a chemical reduction product of the CO2. The volume ratio of the CO2 to the H2 in the gaseous mixture is in a range of 1:10 to 10:1. In some embodiments, the red mud catalyst composition is a waste product from an aluminum extraction process.

 

US11964914 — INDUSTRIAL SOLID WASTE BASED CONSTRUCTION AND TECHNICAL CERAMICS — Seramic Materials Limited (Arab Emirates) — A ceramic for construction or technical applications, composed of at least one of Municipal Solid Waste Incinerator Bottom Ash (MSWIBA) and other recycled industrial solid waste and different methods of forming such ceramics. These wastes include but are not limited to alumina and aluminum red muds and dross, quarrying mining and ceramic wastes and residues, combustion ashes (biomass or fossil fuels such as coal), and ashes from municipal waste incineration. Various techniques illustrate how ceramics are formed using extrusion shaping or dry powder compaction and agglomeration, any of which can be preceded by a pre-treatment process of received feedstock.

 

US11958788 — METHOD OF PREPARING ALKALI ACTIVATION MATERIAL BY USING RED MUD-BASED WET GRINDING AND CARBON SEQUESTRATION AND APPLICATION THEREOF — Hubei University of Technology (China) — The present invention discloses a method of preparing an alkali activation material by using red mud-based wet grinding and carbon sequestration and an application thereof. The preparation method includes: (1) adding water, red mud, a crystalline control agent, and a grinding aid into a wet grinding carbon sequestration apparatus to perform wet grinding, and simultaneously introducing CO2 until a slurry pH reaches 7 to 7.5; and removing wet grinding balls by a sieve to obtain a slurry A; (2) adding carbide slag (an industrial solid waste produced after production of polyvinyl chloride), water and a water reducer to a wet planetary ball grinder tank for wet grinding, and removing wet grinding balls by a sieve to obtain a slurry B; (3) taking 50 to 80 parts of the slurry A and 20 to 50 parts of the slurry B and mixing them to obtain an alkali activation material. The present invention can realize permanent CO2 sequestration and at the same time increase the utilization rate of carbide slag and red mud, avoiding the environmental impact caused by solid waste stockpiling.

 

US11946343 — GEOMASS MEDIATED CARBON SEQUESTRATION MATERIAL PRODUCTION METHODS AND SYSTEMS FOR PRACTICING THE SAME — Blue Planet Systems Corporation (USA) — Geomass mediated carbon dioxide (CO2) sequestering methods and systems are provided. Aspects of the methods include contacting a gaseous source of CO2 and an aqueous capture ammonia to produce a CO2 sequestering carbonate composition produced by methods of the invention and an aqueous ammonium salt, and then contacting the aqueous ammonium salt liquid with a geomass, e.g., alkaline waste product, to regenerate the aqueous capture ammonia. Also provided are systems configured for carrying out the methods. The seed structure, that describes any object upon which carbonate material forms, may be made up of any convenient material or materials, including red mud.

 

US11981615 — METHOD FOR CHEMICALLY REDUCING CARBON DIOXIDE WITH RED MUD CATALYST COMPOSITION — King Fahd University of Petroleum and Minerals (Saudi Arabia) — The present disclosure is directed to a method for carbon dioxide reduction, and particularly, to a method for chemically reducing carbon dioxide using red mud and modified red mud as catalyst. A method for chemically reducing carbon dioxide (CO2) with a red mud catalyst composition is provided includes introducing a gaseous mixture of CO2 and H2 into a reactor containing particles of the red mud catalyst composition. The method further includes reacting at least a portion of the CO2 and H2 in the gaseous mixture in the presence of the red mud catalyst composition at a temperature of 200 to 800oC, and under a pressure ranging from 5 to 100 bar to form a gaseous product including a chemical reduction product of the CO2. The volume ratio of the CO2 to the H2 in the gaseous mixture is in a range of 1:10 to 10:1.

 

US11773025 — RED MUD-BASED COMPOSITE CALCIUM FERRITE AND PREPARATION METHOD AND USE THEREOF — University of Science and Technology Beijing (China) — Provided is a red mud-based composite calcium ferrite and a preparation method and use thereof. The preparation method of the red mud-based composite calcium ferrite includes the following steps: mixing red mud and a calcium source, and roasting an obtained mixture in an oxygen-containing atmosphere to obtain the red mud-based composite calcium ferrite; where the calcium source is selected from the group consisting of lime and calcium carbonate. In the present disclosure, the composite calcium ferrite is prepared using a solid waste red mud, with a greatly reduced cost of raw materials; on the other hand, compared with traditional calcium ferrite, the composite calcium ferrite mainly has phase structures of CaFe2O4, Ca2FeAlO5, and Ca2Fe2O5. Therefore, the composite calcium ferrite has a lower melting point, a higher lime dissolution efficiency, and better fluxing and dephosphorization effects during primary smelting and refining of molten steel and has broad prospects for use in industry.

 

US11766705 — SYNTHETIC SOIL AND METHODS FOR PRODUCING SAME FROM WASTE — HK Brothers America LLC (USA) — The present disclosure provides efficient and cost-effective methods for producing synthetic soil and synthetic stone from waste, including inorganic waste and organic waste, through a hydrolysis-polycondensation process. Organic waste can be hydrolyzed/extracted by, e.g., activated red mud, to form a biomaterial (e.g., a biosolid sludge), before being mixed with the activated inorganic waste (e.g., a reactive zeolite gel). The ingredients react, set and harden to form a synthetic soil, which is a new complex having geotechnical properties and nutritional values equal, or superior, to existing natural fertile soil. The present methods efficiently convert a large amount of industrial, agricultural and residential waste into synthetic soil that could help lessen acute environmental pollution and global warming. Synthetic soil is extremely important to a sustainable future for all mankind.

 

US11753580 — INVERSE EMULSION COMPOSITIONS — Kemira OYJ (Finland) — An inverse emulsion composition comprising: one or more hydrophobic liquids having a boiling point at least about 100oC; up to about 38% by weight of one or more acrylamide-(co)polymers; one or more emulsifier surfactants; and one or more inverting surfactants; wherein, when the composition is inverted in an aqueous solution, it provides an inverted solution having a filter ratio using a 1.2 micron filter (FR1.2) of about 1.5 or less. The exemplary inverse emulsion compositions and inverted polymer solutions can be used in clarification and settling of industrial waste, including treatment of Bayer process applications such as red mud settling, red mud washing, Bayer process filtration, hydrate flocculation, and precipitation.

 

US11739167 — PROCESS FOR PRODUCING AQUEOUS POLYACRYLAMIDE SOLUTIONS — BASF SE (Germany) — Process for producing aqueous polyacrylamide solutions by polymerizing an aqueous solution comprising at least acrylamide thereby obtaining an aqueous polyacrylamide gel and dissolving said aqueous polyacrylamide gel in water, wherein the manufacturing steps are allocated to two different locations A and B and the process comprises the step of transporting an aqueous polyacrylamide gel from a location A to a location B. Modular, relocatable plant for manufacturing aqueous polyacrylamide solutions wherein the units of the plant are located at two different locations A and B. In the field of mining, location B may be a location at or close to tailings ponds in which mineral tailings are dewatered using aqueous polyacrylamide solutions. In one embodiment location B may be a location for the treatment of red mud, a by-product of the Bayer process for manufacturing aluminum.

 

US11697594 — METHOD FOR RECYCLING SPENT CARBON CATHODE OF ALUMINUM ELECTROLYSIS — Central South University (China) — A method for recycling spent carbon cathode of aluminum electrolysis includes the following steps: (1) crushing and sieving spent carbon cathode, to obtain carbon particles; (2) mixing the carbon particles with a sulfuric acid solution, to obtain a slurry A, and then performing pressure leaching, to obtain a slurry B; (3) evaporating and concentrating the slurry B until a mass percentage of water is lower than 8%, to obtain a slurry C; (4) adding concentrated sulfuric acid to the slurry C to obtain a slurry D, then roasting the slurry D at 150-300°C for 0.5-10 h, and then roasting at 300-600°C for 0.5-8 h, to obtain the roasted carbon; and calcining the roasted carbon at a high temperature, to obtain the purified carbon, or mixing the roasted carbon with a leaching agent, and performing leaching, filtering, and washing, to obtain the purified carbon.

 

US11691922 — CERAMIC COMPOSITE AND METHOD OF PREPARING THE SAME — Industrial Technology Research Institute (Taiwan) — A ceramic composite and a method of preparing the same are provided. The method of preparing the ceramic composite includes mixing an aluminum smelting slag and a carbon accelerator to obtain a mixture and reacting the mixture at a temperature equal to or greater than 1600°C in a nitrogen atmosphere to obtain a ceramic composite. The aluminum slag includes aluminum, oxygen, nitrogen, and magnesium. The weight ratio of the oxygen to the aluminum is 0.6 to 2. The weight ratio of nitrogen to aluminum is 0.1 to 1.2. The weight ratio of magnesium to aluminum is 0.04 to 0.2. The ceramic composite includes aluminum nitride accounting for at least 90 wt. % of the ceramic composite.

 

US11691888 — PROCESS FOR THE PREPARATION OF HIGH PURITY ALUMINA — Scandium International Mining Corporation (USA) — A method for preparing high purity alumina (HPA), a high-value, high margin product which is in significant demand and has many uses, is provided. The method includes subjecting an aluminum feedstock to acid leaching, thereby yielding an aluminum bearing leachate; subjecting the aluminum bearing leachate to solvent extraction, thereby yielding an organic phase which is loaded with aluminum; stripping the aluminum from the loaded organic phase with a stripping solution containing an acid, thereby yielding an aluminum bearing extract; crystallizing an aluminum salt from the aluminum bearing extract; dissolving the aluminum salt in an ammoniacal solution, thereby generating a boehmite precursor compound and an ammonium salt; calcining the boehmite precursor compound to yield HPA; subjecting the ammonium salt to electro-dialysis, thereby yielding ammonia and the acid; and performing at least one step of (a) utilizing the ammonia in preparing the ammoniacal solution used in a subsequent iteration of the method, or (b) utilizing the acid in preparing the stripping solution used in a subsequent iteration of the method. Smelter grade alumina or Al(OH)3 is preferably refined if utilized as a feedstock in the processes described herein. In some embodiments, other aluminum containing resources and wastes (including, for example, red mud, or sulfuric acid leach solutions from processing base metal containing ores) may also be employed as a source of aluminum units.

 

US11584657 — SYSTEMS AND METHODS FOR ALUMINA PRODUCTION — Solenis Technologies, L.P. (USA) — A method for isolating a humic substance (soluble red mud material) from alumina process liquor is provided herein. Separate from or within the method, bauxite is processed to form the alumina process liquor. The method includes providing a diallyldimethylammonium chloride-containing polymer. The method further includes providing an amine-containing polymer. The method further includes combining the diallyl dimethyl ammonium chloride, the amine-containing polymer, and the alumina process liquor, to isolate the humic substance from the alumina process liquor.

 

US11535790 — MULTIVALENT IRON BIO-INHIBITOR FROM WASTE BAUXITE RESIDUE TO CONTROL RESERVOIR SOURING — Saudi Arabian Oil Company (Saudi Arabia) — Reservoir souring (or bio-souring) due to the activity of sulfur-reducing bacteria (SRB) that produces hydrogen sulfide (H2S) in oil reservoirs has a major impact on the quality and efficient recovery of oil and gas. This document relates to a method of fabricating a multivalent iron bio-inhibitor from waste bauxite residue and methods of controlling reservoir souring in oilfields and wastewater treatment using the bio-inhibitor. The bio-inhibitor is made by treating iron-containing bauxite with an acid solution (perchloric acid), treating this mixture with a reducing agent (sodium borohydride), and obtaining the multivalent iron bio-inhibitor. This bio-inhibitor inhibits or terminates the growth, activity, or both, of SRB present in the reservoir.

 

US11534746 — RED MUD COMPOSITIONS AND METHODS RELATED THERETO — Utah State University (USA) — Red mud compositions may be useful in a variety of catalytic processes. A need exists for alternative red mud compositions that can be used with existing catalytic processes and give rise to additional catalytic processes. Red mud compositions are disclosed herein, such as compositions comprising dried and calcined catalytic particles including red mud and one or more additives, wherein the particles comprise at least about 50% red mud by weight. Methods of making red mud compositions are also disclosed herein, such as methods comprising mixing a slurry of red mud and one or more additives, drying the mixture at a first temperature, and calcining the dried mixture at a second temperature higher than the first temperature to form dried and calcined catalytic particles comprising red mud and the one or more additives. Methods of using red mud compositions are also disclosed herein, such as methods of hydrotreating or pyrolyzing a material with the compositions disclosed herein.

 

US11498053 — NICKEL-CONTAINING CATALYST COMPOSITION HAVING ENHANCED ACIDITY FOR DRY REFORMING PROCESSES — Saudi Arabian Oil Company (Saudi Arabia) — Dry reforming simultaneously utilizes two greenhouse gases, CH4 and CO2, to produce synthesis (syn) gas (CO and H2). Present catalyst technology is insufficient in some processes to provide cost-effective and reliable means for dry reforming. Red mud generally includes a mixture of transition metals such as Ti, Fe, and Al, which make it an advantageous catalyst for dry reforming processes, for example once modified with nickel. Modified red mud catalyst compositions, methods for production, and methods of use in dry reforming, the composition comprising: red mud material produced from an alumina extraction process from bauxite ore; and nickel oxide, the nickel oxide present at between about 5 wt. % to about 40 wt. % of the modified red mud catalyst composition.

 

US11478777 — CATALYST COMPOSITIONS HAVING ENHANCED ACIDITY FOR DRY REFORMING PROCESSES — Saudi Arabian Oil Company (Saudi Arabia) — Dry reforming simultaneously utilizes two greenhouse gases, CH4 and CO2, to produce synthesis (syn) gas (CO and H2). Present catalyst technology is insufficient in some processes to provide cost-effective and reliable means for dry reforming. In embodiments of the present disclosure, red mud acts as a catalyst in addition to or alternative to a catalyst carrier. Utilization of red mud in dry reforming processes provides the concurrent advantages of utilizing a waste material (red mud), converting CO2 (a greenhouse gas), and producing H2. Modified red mud catalyst compositions, methods for production, and methods for use, a composition including red mud material produced from an alumina extraction process from bauxite ore; nickel oxide, the nickel oxide present at between about 5 wt. % to about 40 wt. % of the modified red mud catalyst composition; and a Periodic Table Group VIB metal oxide, the Group VIB metal oxide present at between about 1 wt. % and about 30 wt. % of the modified red mud catalyst composition.

 

US11459272 — METHOD FOR PREPARING IRON ALLOY AND CEMENT MATERIAL — Tsinghua University (China) — A method for preparing iron alloy and a cement material, in the field of solid waste recycling, provides an efficient, synergistic effect between main components of carbon, calcium and heavy metal in municipal solid waste incineration (MSWI) fly ash and main components of iron, aluminum and silicon in red mud, so that the iron alloy and cement material can be readily obtained. By using waste to treat waste and using the complementarity of the components of two waste streams, carbon in the MSWI fly ash may provide a reductant to accelerate an iron mineral in the red mud to reduce into metal iron. With the formation of the metal iron, a siderophile heavy metal element in the MSWI fly ash is also accelerated to enter an iron phase. Meanwhile, the cement material is formed by Al2O3 and SiO2 in the red mud and CaO in the MSWI fly ash.

 

US11447420 — METHOD OF TREATMENT OF BAUXITE RESIDUE, SOLID OBTAINED BY THIS METHOD AND BAUXITE TREATMENT PROCESS INCLUDING THIS METHOD OF TREATMENT OF THE BAUXITE RESIDUE — Purgonpl Group Limited (Great Britain) — A method of treatment of bauxite residue resulting from a Bayer process of bauxite treatment in order to produce a solid product. The present invention also relates to the manufacture of building products such as bricks, tiles, building panels and other materials such as high-performance aggregates, aggregates, railway ballast etc. from the treatment of bauxite residue. The method comprises mixing a quantity of the bauxite residue (1) with a quantity of a glass material (2) to form a mixture. Then, compressing the mixture (4) to form a green body, and sintering (5) the green body. After cooling, the sintered green body thereby provides the solid product.

 

US11427519 — ACID MODIFIED RED MUD AS A CATALYST FOR OLEFIN ISOMERIZATION — Saudi Arabian Oil Company (Saudi Arabia) — A system and a method for isomerizing a 2-butene feed stream to form a 1-butene product stream are provided. An exemplary method includes calcining the red mud, flowing a butene feedstock over the red mud in an isomerization reactor, and separating 1-butene from a reactor effluent. An embodiment described in examples herein provides a method for using an acid modified red mud (AMRM) catalyst for olefin isomerization. The method includes forming the AMRM catalyst by dissolving red mud in water to form a red mud solution, neutralizing the red mud solution with an acid, and forming a precipitant by adding a base to the red mud solution. The precipitant is filtered from the red mud solution, dried, and ground to form particles of less than 100 μm. The particles are calcined to form the AMRM catalyst. A butene feedstock flows over the AMRM catalyst in an isomerization reactor. 1-Butene is separated from a reactor effluent.

 

US11426708 — POTASSIUM-PROMOTED RED MUD AS A CATALYST FOR FORMING HYDROCARBONS FROM CARBON DIOXIDE — King Abdullah University of Science and Technology and Saudi Arabian Oil Company (Saudi Arabia) — The presence of different metals in red mud may enhance its use as a catalyst. The use of red mud (RM), or bauxite tailings, for reactions to fix CO2 to form higher value products is described herein. A method and catalyst for forming higher carbon number products from carbon dioxide is provided. An exemplary catalyst includes red mud including iron and aluminum, and impregnated potassium.

 

US11420915 — RED MUD AS A CATALYST FOR THE ISOMERIZATION OF OLEFINS — Saudi Arabian Oil Company (Saudi Arabia) — A system and a method for isomerizing a feedstock to form an alpha-olefin product stream are provided. An exemplary method includes calcining the red mud, flowing an olefin feedstock over the red mud in an isomerization reactor, and separating the alpha-olefin from a reactor effluent. The complex mixture of metals indicates that red mud may be an effective catalyst for the isomerization of olefins, such as 2-butene to 1-butene described in examples herein.

 

US11299409 — POLYMER COMPOSITIONS AND METHODS OF USE — Kemira OYJ (Finland) and Chevron U.S.A. Inc. (USA) — Provided herein are liquid polymer (LP) compositions comprising an acrylamide (co)polymer, as well as methods for preparing inverted polymer solutions by inverting these LP compositions in an aqueous fluid. The resulting inverted polymer solutions can have a concentration of acrylamide (co)polymer of from about 50 to about 15,000 ppm, and a filter ratio of 1.5 or less at 15 psi using a 1.2μm filter. Also provided are methods of using these inverted polymer solutions in dewatering, clarification, flocculation and/or thickening applications, and the like, including treatment of various mineral slurries in Bayer process applications such as red mud settling, red mud washing, Bayer process filtration, hydrate flocculation, and precipitation.

 

US11293077 — METHOD FOR RECOVERING SCANDIUM FROM RED MUD LEFT FROM ALUMINA PRODUCTION — United Company RUSAL Eng. and Tech. Centre LLC (Russia) — The present invention relates to rare earth metallurgy, in particular a method for recovering scandium from the red mud byproduct of alumina production. The method includes repulping red mud, sorption leaching scandium therefrom with the use of an ion-exchange sorbing agent to obtain a rich-in-scandium ion exchanger and depleted-in-scandium pulp, desorbing scandium with a solution of sodium hydrocarbonate to obtain a desorbed ion exchanger which is returned to the sorption leaching stage and a solution of industrial reclaim scandium which is transferred to obtain a deposited concentrated scandium, wherein scandium is continuously sorption-leached from red mud pulp in the phosphorous-containing ion exchanger in a countercurrent mode upon direct contact of the pulp with the ion exchanger, scandium is desorbed from the organic phase of the ion exchanger by a solution with a concentration of Na2CO3 of 200-450 g/dm3 to obtain industrial reclaim scandium, from which a scandium concentrate is recovered.

 

US11161784 — MATERIAL AND PRODUCTION THEREOF FOR USE AS A STORAGE MEDIUM IN A SENSITIVE ENERGY STORAGE SYSTEM IN THE LOW-, MEDIUM- OR HIGH-TEMPERATURE RANGE — Fluorchemie GmbH Frankfurt (Germany) — The present invention relates to a modified red mud/a modified bauxite residue and also to processes for the production thereof and to a storage medium comprising a modified red mud, to a heat storage means comprising a storage medium and to numerous uses of a modified red mud as storage medium, in particular in a heat storage means. The modified red mud contains the following components: haematite (Fe2O3), corundum (Al2O3), rutile (TiO2) and/or anatase (TiO2), quartz (SiO2), optionally perowskite (CaTiO ), and optionally pseudobrookite ((Fe3+,Fe2+)2(Ti,Fe3+)O5), nepheline ((Na,K)[AlSiO4]) and/or hauynite ((Na,Ca)4-8[Al6Si6O24(SO4)]), wherein the modified red mud is substantially free from Na2O and/or glass. A novel material is thus provided, and the production thereof for use as a storage medium in a sensitive energy storage system in the low-, medium- or high-temperature range is described.

 

US11111179 — NON-FIRED MONOLITHS — Katholieke Universiteit Leuven (Belgium) — The present invention describes a process to convert inter alia a formulation containing bauxite residue (BR), also known as red mud, into a monolithic, water insoluble, material. The invention relates to methods for manufacturing an inorganic polymer (geopolymer) object from a precursor wherein the precursor consists of one or more or comprises one or more selected from the group consisting of gibbsite-containing bauxite, gibbsite containing residue of the Bayer process, thermally processed gibbsite-containing bauxite, and thermally processed gibbsite-containing residue of the Bayer process, the method comprising the steps of alkaline-activating said precursor, mixing the precursor, shaping the mixed precursor and hydrothermally curing the shaped precursor at a temperature between 70°C and 350°C.

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