Abstract: A method for preparing high purity alumina (HPA) is provided.

Abstract: The present invention relates to a method for leaching precious metals contained in a waste denitrification catalyst by using a pressure leaching process, and more specifically, to a method for leaching precious metals contained in a waste denitrification catalyst by using a pressure leaching process, the method comprising the steps of: forming a mixture by mixing a waste denitrification catalyst with a sodium salt solution; and leaching vanadium and tungsten contained in the mixture by feeding the mixture into a sealed pressurized reactor, and then heating and stirring the mixture.

Abstract: This invention is directed to regeneration of solutions comprising metal ions, and production of valuable hydroxide compounds. Specifically, the invention is related to regeneration of spent electrolyte solutions comprising metal ions (e.g. Al ions), such as electrolyte solutions used in metal/air batteries. The invention is further related to production of layered double hydroxides, and, optionally aluminum tri-hydroxide from aluminate.

Abstract: A method for recovery of aluminum hydroxide Al(OH)3 from an aluminum enriched water/wastewater treatment sludge is disclosed. The method includes the steps of: adding a hydrated lime slurry to the aluminum enriched water/wastewater treatment sludge to form an alkaline sludge; adding sodium carbonate Na2CO3 to the alkaline sludge to form a Na2CO3 treated sludge; forming a first supernatant from the Na2CO3 treated sludge of step b) containing NaAl(OH)4; introducing CO2 to the first supernatant to form a precipitate of Al(OH)3 and a second supernatant containing NaHCO3; and recycling at least a portion of the NaHCO3 from the second supernatant back to the alkaline sludge of step a).

Abstract: The present invention relates to a process for isomerizing a C3-7 (hydro)(halo)fluoroalkene comprising (a) providing a reactor feed stream comprising the C3-7 (hydro)(halo)fluoroalkene; and (b) contacting the C3-7 (hydro)(halo)fluoroalkene with a catalyst comprising alumina to isomerize the C3-7 (hydro)(halo)fluoroalkene, wherein the catalyst has a sodium content of less than about 800 ppm.

Abstract: The invention provides methods and compositions for the addition of a CGM to precipitation liquor of a Bayer process. The CGM comprises a neopolyol, an ester derived from a neopolyol, and/or an ether derived from a neopolyol. Optionally the CGM may comprise water and/or an antifoaming agent and/or a hydrocarbon carrier liquid. The CGM is quite effective and results in a significant increase in mean particle size of produced alumina crystals.

Abstract: Disclosed herein are compounds, compositions, and methods for producing aluminum hydroxide crystals from a precipitation liquor. The precipitation liquor may be located in a Bayer process.

Abstract: A treatment process for processing raw liquor obtained from a tailings pond containing residue from an alumina production facility is disclosed where the raw liquor is first contacted with a gas containing carbon dioxide (CO2) to neutralize the raw liquor and to precipitate aluminum hydroxide Al(OH)3. The aluminum hydroxide is separated from the neutralized liquor, which is rich in bicarbonates and then concentrated using membrane separation technology to form a NaHCO3 (sodium bicarbonate) rich retentate. This NaHCO3 rich retentate is then subjected to a regeneration process to recover NaOH for recycle to the alumina production facility.

Abstract: The invention provides a method of inhibiting the accumulation of DSP scale in the liquor circuit of Bayer process equipment. The method includes adding one or more particular silane based small molecules to the liquor fluid circuit. These scale inhibitors reduce DSP scale formation and thereby increase fluid throughput, increase the amount of time Bayer process equipment can be operational and reduce the need for expensive and dangerous acid washes of Bayer process equipment. As a result, the invention provides a significant reduction in the total cost of operating a Bayer process.

Abstract: There are provided methods for separating iron ions from aluminum ions contained in an acidic composition. The methods comprise reacting the acidic composition with a basic aqueous composition having a pH of at least 10.5 so as to obtain a precipitation composition, maintaining the precipitation composition at a pH above 10.5 so as to cause precipitation of the iron ions, at least substantially preventing precipitation of the aluminum ions, and to obtain a mixture comprising a liquid portion and a solid portion; and separating the liquid portion from the solid portion. There are also provided methods for treating an acidic composition comprising iron ions and aluminum ions. Such methods can be useful for preparing products such as alumina, aluminum, hematite etc.

Abstract: Disclosed herein are compounds, compositions, and methods for producing aluminum hydroxide crystals from a precipitation liquor. The precipitation liquor may be located in a Bayer process.

Abstract: The present invention relates to a method for preparing high-purity aluminum, the method comprising: a mother liquor preparing step for preparing a mother liquor by dissolving and aging ordinary aluminum hydroxide; a refining step for adding pulp to absorb impurities from the prepared mother liquor after the mother liquor preparing step; and an obtaining step for obtaining high-purity alumina by adding a seed into the mother liquor and precipitating a precipitate, and filtering, washing, and recrystallizing the precipitate, and calcining the precipitate. Thus, the present invention enables an environmentally-friendly and low-cost preparation of high-purity alumina.

Abstract: A process for neutralization is provided which can maintain a high solid content of a bauxite dissolution residual substance slurry even after a neutralization treatment is completed and the stabilize pH within a short time of the neutralization treatment. Such a process for neutralizing a bauxite dissolution residual substance containing a desiliconizing product which is generated in the production process of aluminum hydroxide using Bayer process, includes: mixing a bauxite dissolution residual substance or a bauxite dissolution residual substance slurry with sulfuric acid in an amount ranging from 0.6 to 1.2 equivalence to the total amount of sodium contained in the bauxite dissolution residual substance or a bauxite dissolution residual substance slurry, such that the solid content after mixing becomes 400 to 700 g/l to gelate the mixture, and thereafter obtaining a bauxite dissolution residual substance neutralized slurry.

Abstract: A process for neutralization is provided which can maintain a high solid content of a bauxite dissolution residual substance slurry even after a neutralization treatment is completed and the stabilize pH within a short time of the neutralization treatment. Such a process for neutralizing a bauxite dissolution residual substance containing a desiliconizing product which is generated in the production process of aluminum hydroxide using Bayer process, includes: mixing a bauxite dissolution residual substance or a bauxite dissolution residual substance slurry with sulfuric acid in an amount ranging from 0.6 to 1.2 equivalence to the total amount of sodium contained in the bauxite dissolution residual substance or a bauxite dissolution residual substance slurry, such that the solid content after mixing becomes 400 to 700 g/l to gelate the mixture, and thereafter obtaining a bauxite dissolution residual substance neutralized slurry.

Abstract: Process for manufacturing alumina trihydrate by alkaline attack of bauxite, following the general steps of the Bayer process, and during which, after settling and before decomposition, the aluminate liquor undergoes a filtration, known as security filtration, so that at the end of the filtration it contains less than 10 mg/l of insoluble particles, characterized in that, during said security filtration, a filtration device is used that comprises a zone in which the liquor is subjected, after passing through said filtration media, to a pressure greater than 2 bar, preferably greater than 3 bar. Preferably, this device also comprises a zone in which the liquor is subjected, before passing through the filtration media, to a pressure greater than 5 bar, preferably greater than 6, typically in the vicinity of 7 bar. In this way, the aluminate liquor can be kept at a high temperature during the security filtration, typically greater than 130° C., preferably greater than 140° C.

Abstract: The invention provides methods and compositions for inhibiting the accumulation of DSP scale in the liquor circuit of Bayer process equipment. The method includes adding one or more particular silane based small molecules to the liquor fluid circuit. These scale inhibitors reduce DSP scale formation and thereby increase fluid throughput, increase the amount of time Bayer process equipment can be operational and reduce the need for expensive and dangerous acid washes of Bayer process equipment. As a result, the invention provides a significant reduction in the total cost of operating a Bayer process.

Abstract: A method for co-producing alumina and activated calcium silicate from high-alumina fly ash, comprising the steps that: high-alumina fly ash reacts with sodium hydroxide solution to obtain desiliconized solution and desiliconized fly ash; lime cream is added to the desiliconized solution to obtain activated calcium silicate; limestone and sodium carbonate solution are added to the desiliconized fly ash to blend raw slurry, the raw slurry is baked into clinker, and sodium aluminate crude solution is obtained from dissolution of the clinker; the sodium aluminate crude solution is subjected to the processes of first-stage deep desiliconization, second-stage deep desiliconization, carbonization decomposition, seed precipitation and etc to obtain alumina.

Abstract: The invention is directed towards methods and compositions for treating slurry to better dewater alumina trihydrate precipitated from the Bayer process. The method comprises using a product comprising the combination of at least two surfactants together with an optional coupling agent to treat the alkaline slurry with certain amount of alumina trihydrate present. Synergistic effects between binary combinations of nonionic and anionic surfactants result in more efficient dewatering aids for alumina trihydrate slurry when combinations of such surfactants are applied. A coupling agent may be used in formulations to reduce viscosity of such surfactant combinations, allowing the practical application of such products.

Abstract: The invention provides a method of inhibiting the accumulation of DSP scale in the liquor circuit of Bayer process equipment. The method includes adding one or more particular silane based small molecules to the liquor fluid circuit. These scale inhibitors reduce DSP scale formation and thereby increase fluid throughput, increase the amount of time Bayer process equipment can be operational and reduce the need for expensive and dangerous acid washes of Bayer process equipment. As a result, the invention provides a significant reduction in the total cost of operating a Bayer process.

Abstract: There is provided a method for extracting aluminum ions from argillite. The process comprises leaching the argillite with an acid such as HCl so as to obtain a composition comprising the aluminum ions and iron ions; at least partially removing the iron ions from the composition by substantially selectively precipitating the iron ions by adding a base and at least partially removing the precipitated iron ions so as to obtain an Al-rich composition; and optionally purifying the Al-rich composition by adding a base for substantially selectively precipitating the aluminum ions, by means of a hollow fiber membrane, or by a liquid-liquid extraction.

Abstract: An aluminum hydroxide gel particle having high purity and extremely high acid reactivity and a production method thereof. The aluminum hydroxide gel particle has an iron (Fe) content of 1 to 10 ppm.

Abstract: A heap leach process for the recovery of nickel and/or cobalt from a laterite ore, said process including the steps of: a) providing one or more heaps of a nickeliferous laterite ore; b) leaching the ore in a heap leach step by applying acid to one or more heaps to provide a pregnant leach solution; c) neutralizing the pregnant leach solution with ground saprolite ore; and d) recovering the nickel and/or cobalt from the neutralized pregnant leach solution.

Abstract: The invention provides methods and compositions for improving the production of alumina hydrate. The invention involves adding one or more polysaccharides to liquor or slurry in the fluid circuit of the production process. The one or more polysaccharides can be a cross-linked polysaccharide (such as cross-linked dextran or cross-linked dihydroxypropyl cellulose). The various polysaccharides can impart a number of advantages including at least some of: greater flocculation effectiveness, increasing the maximum effective dosage, faster settling rate. The production process can be a Bayer process.

Abstract: A method of purifying an aluminum source includes dissolving an aluminum ion source to provide a first solution including aluminum ions having a pH of not greater than 4.0, adjusting the pH of the first solution with a tetraalkylammonium hydroxide solution to a pH in range of 4.1 to 8.4 thereby forming an aluminum hydroxide precipitate, separating the aluminum hydroxide precipitate from the first solution, washing the separated aluminum hydroxide precipitate with an aqueous solution having a pH in a range of 4.1 to 8.4, dissolving the washed aluminum hydroxide precipitate using an acid to provide a second solution having a pH of not greater than 4.0, and forming an aluminum salt from the second solution.

Abstract: A process for the recovery of high purity boehmite with controlled pore size from spent hydroprocessing catalyst includes the step of treating the spent hydroprocessing catalyst composition in order to get recovery of the aluminas after extracting the valuable metals. The process permits easy and resourceful recovery of high quality boehmite from waste catalyst, which can be further used as hydroprocessing catalyst carrier having a pore structure almost identical or better than that used in heavy oil hydroprocessing catalysts. Such catalyst carrier is required to have high pore volume, macro-porosity, high strength and optimum surface area for active metal dispersion. The treating steps include process steps such as decoking, roasting, leaching, dissolving, digestion, precipitation, washing, stripping, and the like. The recovery steps include digestion, hydrothermal treatment, flocculation or precipitation, filtration, drying, calcination and the like.

Abstract: As population density increases, the transportation of hazardous chemicals, including acids and disinfectants, lead to an increased incidence of spills while the consequences of spills become more serious. While solutions of halide acids, hypohalites and halites are safer disinfectants for transportation, handling, storage and use than traditional gaseous chlorine, the manufacturing cost of these disinfectants has here-to-fore limited their use. Economical processes are presented for the manufacture of O2, halogen oxides, halide acids, hypohalites, and halates; as well as polynucleate metal compounds, metal hydroxides and calcium sulfate hydrate (gypsum). The instant invention presents methods and processes that incorporate the use of sulfur. This is while environmental regulators, such as the US EPA, require an increased removal of sulfur from hydrocarbon fuels, thereby creating an abundance of sulfur, such that the refining industry is in need of a way to dispose of said abundance of sulfur.

Abstract: A method for producing boehmite particles includes subjecting powder of aluminum hydroxide to hydrothermal reaction together with a nucleation agent, thereby obtaining boehmite particles having an average primary particle size of 0.6 ?m or less and including primary particles each having a hexahedral shape. A method for producing alumina particles includes: drying the boehmite particles produced by the above described method; calcining the boehmite particles, which have been dried, to obtain alumina particles; and disintegrating the obtained alumina particles.

Abstract: The invention provides a method of inhibiting the accumulation of DSP scale in the liquor circuit of Bayer process equipment. The method includes adding one or more particular silane based small molecules to the liquor fluid circuit. These scale inhibitors reduce DSP scale formation and thereby increase fluid throughput, increase the amount of time Bayer process equipment can be operational and reduce the need for expensive and dangerous acid washes of Bayer process equipment. As a result, the invention provides a significant reduction in the total cost of operating a Bayer process.

Abstract: The present invention concerns a process for the instantaneous control of the precipitation of nickel and cobalt present in a leach liquor by adjustment of the pH-value. Said leach liquor is obtained by pressurized acidic leaching of laterite ores and additionally contains aluminium, ferric and ferrous iron and chromium among others. The process comprises the following steps: precipitation of aluminium, ferric and ferrous iron, chromium etc. by increasing the pH-value by adding a suitable reagent such as lime and/or limestone, following precipitation of nickel and cobalt by further increasing the pH-value of the liquor, finally separating the precipitate from the low-content nickel and cobalt solution. The nickel and cobalt precipitate can be used for further refinement. In order to keep the process conditions constant, the steps of increasing the pH-value are controlled simultaneously.

Abstract: A process for the recovery of high purity boehmite with controlled pore size from spent hydroprocessing catalyst includes the step of treating the spent hydroprocessing catalyst composition in order to get recovery of the aluminas after extracting the valuable metals. The process permits easy and resourceful recovery of high quality boehmite from waste catalyst, which can be further used as hydroprocessing catalyst carrier having a pore structure almost identical or better than that used in heavy oil hydroprocessing catalysts. Such catalyst carrier is required to have high pore volume, macro-porosity, high strength and optimum surface area for active metal dispersion. The treating steps include process steps such as decoking, roasting, leaching, dissolving, digestion, precipitation, washing, stripping, and the like. The recovery steps include digestion, hydrothermal treatment, flocculation or precipitation, filtration, drying, calcination and the like.

Abstract: The invention relates to a method for hydrolyzing hydrolyzable solid metallic salts, wherein the metallic salts are reacted with aqueous saline solutions.

Abstract: An improved process for producing alumina from bauxite is disclosed comprising the steps of: a) wet grinding of the bauxite in the presence of an agent capable of reducing the viscosity of the semiliquid paste obtained; b) caustic etching of the bauxite ground in step a) with a concentrated solution of sodium hydroxide until a liquid phase is obtained comprising aluminium hydroxide and a solid phase; c) removal of the solid phase formed in step b) from the liquid phase; d) precipitation of the aluminium hydroxide from the liquid phase of step c); e) filtration of the aluminium hydroxide precipitated in step d); and f) calcination of the aluminium hydroxide of step e).

Abstract: A method for fabricating a high specific surface area mesoporous alumina is disclosed, which includes the following steps: (a) providing a water solution containing an aluminum salt and a fluoro-surfactant; (b) adding concentrated hydrochloric acid to adjust the PH value of the solution to about 6.0 to 8.0; (c) aging the solution at 70° C. to 110° C. for 12 to 20 hours; (d) washing the precipitate with water; (e) washing the precipitate with an organic solvent; (f) drying the precipitate; and (g) sintering the precipitate in a furnace of 500° C. to 1000° C.

Abstract: Disclosed is a method of manufacturing a metal oxide nano powder comprising preparing a first dispersed solution by adding a nano-sized metal powder to water and dispersing the metal powder within the water, performing a hydration reaction of the first dispersed solution at a temperature of about 30 to about 70° C. to generate a precipitation, and filtering and drying the precipitation to prepare a metal oxide powder. Also, disclosed is a metal oxide nano powder manufactured by the method described above, and having any one of a bar-form, a cube-form, and a fiber-form.

Abstract: The invention provides a method of inhibiting the accumulation of DSP scale in the liquor circuit of Bayer process equipment. The method includes adding one or more particular silane based small molecules to the liquor fluid circuit. These scale inhibitors reduce DSP scale formation and thereby increase fluid throughput, increase the amount of time Bayer process equipment can be operational and reduce the need for expensive and dangerous acid washes of Bayer process equipment. As a result, the invention provides a significant reduction in the total cost of operating a Bayer process.

Abstract: An improved method and composition for producing aluminum hydroxide crystals in a Bayer process pregnant liquor, involve the addition of an emulsified crystallization modifier comprising a C8-C10 fatty acid, precursors, salts or blends thereof. The alkyl chain of the fatty acid crystallization modifier is free of functional groups. The modifier yields a commercially viable product in the presence and absence of a hydrocarbon oil which dissolves the fatty acid. Further, the modifier, prepared in either an emulsified form or as a fatty acid neat, facilitates formation of oxalate aggregates greater than 200 ?m which may be readily screened out with minimum trihydrate loss.

Abstract: An improved method and composition for producing aluminum hydroxide crystals from precipitation liquor, involves the addition of an emulsified crystal growth modifier comprising a C8-C10 fatty acid, precursors, salts or blends thereof. The emulsified crystal growth modifier also facilitates an upward shift in particle size distribution of aluminum hydroxide and an upward shift in oxalate ball size.

Abstract: Process for manufacturing alumina trihydrate by alkaline attack of bauxite, following the general steps of the Bayer process, and during which, after settling and before decomposition, the aluminate liquor undergoes a filtration, known as security filtration, so that at the end of the filtration it contains less than 10 mg/l of insoluble particles, characterized in that, during said security filtration, a filtration device is used that comprises a zone in which the liquor is subjected, after passing through said filtration media, to a pressure greater than 2 bar, preferably greater than 3 bar. Preferably, this device also comprises a zone in which the liquor is subjected, before passing through the filtration media, to a pressure greater than 5 bar, preferably greater than 6, typically in the vicinity of 7 bar. In this way, the aluminate liquor can be kept at a high temperature during the security filtration, typically greater than 130° C., preferably greater than 140° C.

Abstract: An improved method and composition for producing aluminum hydroxide crystals in a Bayer process pregnant liquor, involve the addition of a crystallization modifier comprising a C8-C10 fatty acid, precursors, salts or blends thereof. The alkyl chain of the fatty acid crystallization modifier is free of functional groups. The modifier yields a commercially in the presence and absence of an hydrocarbon oil which dissolves the fatty acid.

Abstract: A method of treating alkaline industrial by-products, such as red mud generated by Bayer process bauxite refining, is described. Embodiments of the method comprise treating the alkaline industrial by-products with salts of divalent and/or polyvalent cations, thereby lowering pH of the alkaline industrial by-products. The method involves replacement reactions in which relatively insoluble hydroxide salts form precipitates, thereby removing hydroxide ions from solution.

Abstract: A method of purifying an aluminum source includes dissolving an aluminum ion source to provide a first solution including aluminum ions having a pH of not greater than 4.0, adjusting the pH of the first solution with a tetraalkylammonium hydroxide solution to a pH in range of 4.1 to 8.4 thereby forming an aluminum hydroxide precipitate, separating the aluminum hydroxide precipitate from the first solution, washing the separated aluminum hydroxide precipitate with an aqueous solution having a pH in a range of 4.1 to 8.4, dissolving the washed aluminum hydroxide precipitate using an acid to provide a second solution having a pH of not greater than 4.0, and forming an aluminum salt from the second solution.

Abstract: The present invention relates ways to increase the output of a high quality product from the precipitation liquor crystallization process exemplified through the aluminum hydroxide recovery processes such as the Bayer process. The invention is a method of increasing the size of precipitated of a liquor. The invention in one embodiment relates to the use of a crystal growth modifier compositions added to the precipitation process to increase the particle size distribution of the precipitated alumina trihydrate.

Abstract: A Bayer process is disclosed. The Bayer process includes a step of treating any one or more of: (a) Bayer liquor or liquors produced in the process, (b) precipitated aluminium trihydrate particles produced in the process, and (c) other solids added to or produced in the process, with ultrasonic energy and destroying organics in the liquor or liquors, on the precipitated aluminium trihydrate particles, and on the other solids.

Abstract: The present invention relates ways to increase the output of a high quality product from the aluminum hydroxide recovery processes such as the Bayer process. The invention is a method of increasing the size of precipitated aluminum hydroxide while not reducing the total production amounts. The invention relates to the use of a crystal growth modifier compositions added to the precipitation liquor to increase the particle size distribution of the precipitated alumina trihydrate.

Abstract: An improved process for the causticisation of Bayer liquors in an alumina refinery, the process including the steps of reacting lime with aluminate ions in a Bayer liquor within a primary reactor under controlled conditions of low to moderate temperature (between 70-80° C.) and agitation, to form substantially only a hydrocalumite species and hydroxyl ions; and a secondary reactor wherein the hydrocalumite species formed is subjected to heating in contact with a Bayer liquor under controlled conditions so as to cause the hydrocalumite species to react with the liquor to form calcium carbonate, aluminate ions and hydroxyl ions, whereby a causticised Bayer liquor is obtained and wherein the efficiency of lime utilization is substantially increased and/or alumina losses are minimized.

Abstract: A method for making a composite includes combining a strengthening agent and an aluminum compound to form a first solution; precipitating an Al(OH)3 gel from the first solution, wherein strengthening agent particles are dispersed within the gel; washing the Al(OH)3 gel with an alcohol; contacting the Al(OH)3 gel with a salt; drying the Al(OH)3 gel to form a powder; calcining the powder to convert Al(OH)3 to Al2O3; and sintering the powder to form a composite article comprising beta double prime alumina.

Abstract: A reinforcing aluminum-based filler which can be used for reinforcing diene rubber compositions intended for the manufacture of tires, comprising an aluminum (oxide-)hydroxide corresponding, with the exception of any impurities and the water of hydration, to the general formula (a and b being real numbers): Al(OH)aOb, with 0<a?3 and b=(3?a)/2, ??(I) the specific BET surface area of which is between 30 and 400 m2/g, the average particle size (by mass) dw of which is between 20 and 400 nm and the disagglomeration rate, ?, of which, measured via an ultrasound disagglomeration test at 100% power of a 600-watt ultrasonic probe, is greater than 5×10?3 ?m?1/s is provided. A rubber composition suitable for the manufacture of tires comprising said aluminum-based filler as reinforcing filler.

Abstract: A Bayer process is disclosed. The Bayer process includes a step of treating any one or more of: (a) Bayer liquor or liquors produced in the process, (b) precipitated aluminium trihydrate particles produced in the process, and (c) other solids added to or produced in the process, with ultrasonic energy and destroying organics in the liquor or liquors, on the precipitated aluminium trihydrate particles, and on the other solids.

Abstract: A method for producing aluminum hydroxide includes a step of elevating a temperature of a slurry of aluminum hydroxide suspended in a sodium aluminate solution from 70° C. or lower to 85° C. or higher, and a step of applying a centrifugal force to the slurry. The aluminum hydroxide constituting the slurry is obtained beforehand through the Bayer's process.

Abstract: A composition of matter which is aluminum hydroxide, produced using the Bayer Process, wherein the aluminum hydroxide produced has a Total Organic Carbon of less than about 0.5 milligrams Total Organic Carbon/gram aluminum hydroxide.