515 results about "Hydrated alumina" patented technology

A method for producing a substantially desulfurized hydrocarbon fuel stream at temperatures less than 100° C. including providing a nondesulfurized fuel cell hydrocarbon fuel stream and passing the fuel stream through a sequential sulfur adsorbent system containing calcium exchanged zeolite, hydrated alumina and a selective sulfur adsorbent placed in sequence to produce a substantially desulfurized hydrocarbon fuel stream.

The invention discloses a preparation method for aluminum oxide by a direct forming method. The method is characterized in that the aluminum oxide is directly formed by a wet filter cake, wherein pore volume is 0.3-0.8ml/g; a specific surface area is 150-300 m<2>/g; and crushing strength is 30-120 N/particle; the preparation process comprises the steps: a) meta-aluminate containing aluminum or a strong acid salt compound is neutralized with a precipitator solution at a temperature of 30-80 DEG C and pH of 6-9; accessory ingredient is added in a neutralizing process; mixture is aged for at least 10min after neutralizing; b) prepared aluminium hydroxide gel is washed by de-ionized water for 4-10 times; dosage of the de-ionized water for each time is 10-40 times of mass of a dried substrate of prepared aluminium hydroxide; a hydrated alumina filter cake is obtained after washing and filtering; content of the aluminium hydroxide in the filter cake is controlled to be 5-50%; and c) the accessory ingredient is added into one or various liquid in the step a) and step b); the filter cake after washing is formed by a normal forming method; and the formed filter cake is dried at a temperature of 80-120 DEG C and calcined at a temperature of 450-1000 DEG C to obtain a finished product of the aluminum oxide.

A plasterboard composition includes from 55 to 92% of hydratable calcium sulphate; from 0.1 to 5% of mineral and/or refractory fibres; from 3 to 25% of a mineral additive; from 1 to 5% of unexpanded vermiculite; and from 3 to 15% of hydrated alumina.

The invention belongs to the field of refractory materials and discloses a preparation method of a fused silica refractory casting material unwetted by an aluminum liquid, which comprises the following step of: enhancing a ground substance by adopting 10-20wt% of white alundum powder, 4-8wt% of calcium aluminate cement, 3-5wt% of hydrated alumina compound binding agent, 4-10wt% of silicon oxide micropowder and 3-6wt% of alumina micropowder, wherein 60-70wt% of fused silica is used as a main material, BaSO4 and Na3AlF6 is adopted as a compound aluminum liquid anti-wetting agent with the addition of 1-6wt%, and additional 0.12wt% of trimeric sodium phosphate and additional 0.03wt% of sodium hexametahposphate are adopted as dispensing agents. The casting material prepared by using the method has high strength, is unwetted by the aluminum liquid, has the highest use temperature of 1000 DEG C and can be used as the refractory materials, such as an aluminum flowing groove of an aluminum smelting furnace and the like.

A hydrated alumina containing additive (0.5-40 Wt %) and with alpha-AlO (OH) structure for preparing the catalyst used for catalytic cracking reaction. Said additive is chosen from RE metal, La-family metal, Si, Ga, B and P. Its preparing process includes such steps as mixing alpha-AlO (OH) with H2O and acid while stirring, ageing, and mixing with additive.

The invention discloses a pouring material for a steel ladle. The pouring material consists of the following components in part by weight: 40 to 75 parts of alumina-magnesia spinel (between 25 and 0.074 mm), 10 to 20 parts of alumina fine powder, 3 to 7 parts of magnesia powder of which the magnesia content is over 95 percent, 1 to 5 parts of pure calcium aluminate cement, 0.5 to 1.5 parts of silicon dioxide fine powder, 0.05 to 0.5 part of water reducing agent, 1 to 35 parts of corundum (between 25 and 0.074 mm) and 0.5 to 5 parts of hydrated alumina powder. The pouring material for the steel ladle has the advantages of extremely high molten steel corrosion resistance, slag corrosion resistance, slag penetration resistance, no pollution to molten steel when taken as a refractory material for the liner of a molten steel accommodating container for smelting pure steel, slag bonding resistance and very long service life.

A flame retardant polymer composition having acceptable char strength and optionally also drip resistance comprises a polymer and a particulate clay mineral distributed in the polymer composition at a particle number per unit volume of at least about 1 particle per 100 μm³, provided that the clay mineral present at the said particle number per unit volume is not an organomontmorillonite. The composition preferably further contains alumina trihydrate (ATH) and/or another flame retardant.

The invention relates to a chemical mechanical polishing composite of stainless steel surface polishing; the polishing composite is composed of grinding material, oxidizer, polishing accelerant, metalchelator, penetrant, and surfactant; the invention is characterized in that: aluminum oxide sol, namely hydrated alumina dispersed in acidic aqueous solution in sol state, is added, the hydrated alumina can be boehmite, fake boehmite, diaspore or gibbsite.

The invention relates to a method for preparing aluminum oxide with bimodal pore distribution, which comprises the following steps of: preparing two types of hydrated alumina raw materials under different process conditions; and then mixing, molding and calcinating the two hydrated alumina raw materials in a ratio of 1:0.5-4, wherein the calcination temperature is between 450 and 1,000 DEG C, and the calcination time is between 1 and 12 hours. The aluminum oxide provided by the invention has the bimodal pore distribution, has no pore-forming agent in the preparation process, has the pore diameter smaller than the pore volume of pores and not more than 5 percent of the total pore volume, and can be used as a catalyst and a carrier or an adsorbent thereof.

The invention provides a hydrogenating deasphaltenizing catalyst and preparation and application thereof. The hydrogenating deasphaltenizing catalyst comprises a supporter and a hydrogenating active metallic compound, wherein the supporter is a doublet-hole alumina supporter which has the pore volume of 0.9 to 1.2ml/g and specific surface area of 50 to 300m<2>/g under the representation in a mercury intrusion method, and the pore volume of a hole being 10 to 30nm in diameter accounts for 55 to 80% of the total pore volume, and the pore volume of a hole being 300 to 500nm in diameter accounts for 10 to 35% of the total pore volume. The preparation method of the supporter comprises the following steps of: mixing, molding, drying and roasting hydrated alumina P1 containing pseudo-boehmite and a modifying substance P2 of the P1, wherein the mixing ratio in weight of the P1 to P2 is (20-95): (5-80; ); the k value of P2 ranges from 0 to 0.9, and the k is DI2/DI1, wherein DI1 represents the acid peptizing index of the hydrated alumina P1 containing the pseudo-boehmite; and DI2 represents the acid peptizing index of the modifying substance P2 of the P1. Compared with the prior art, the catalyst provided by the invention shows greater performance on hydrogenating deasphaltenizing and demetalizing after being applied to hydroprocessing of residual oil.

The invention discloses a method for preparing a high water dispersibility titanium dioxide. The method comprises the following steps sequentially: a, adding a dispersing agent into a titanium dioxide slurry, and stirring uniformly; b, adding a phosphorus-containing solution, and curing; c, adding an aluminum sulfate solution to control the pH value of the titanium dioxide slurry to be 1.5 to 4.5, and curing; d, adding a sodium metaaluminate solution to control the pH value of the titanium dioxide slurry to be 8.5 to 10.5, and curing; e, adjusting the pH value of the titanium dioxide slurry to be 7.0 to 7.8, and curing; f, filtering, washing, drying, and pulverizing to obtain the high water dispersibility titanium dioxide. According to the method, before coating, the dispersing agent is added to improve a dispersing condition of the titanium dioxide slurry, then the phosphorus-containing solution and the aluminum-containing solution are used as a coating agent, and then the coating agent is deposited on the surface of titanium dioxide in forms of aluminum phosphate and hydrated alumina, so that the water dispersibility of a product is effectively improved, and the titanium dioxide product with the high water dispersibility is obtained.

The invention discloses silicon nitride and corundum combined breathable bricks and a preparation method. The silicon nitride and corundum combined breathable bricks are characterized by being prepared by the following steps: adding water into corundum particles and fine powder, hydrated alumina, alumina micro powder and monomer silicon powder, which serve as raw materials, mixing to obtain a sludge material; pouring in molds to form breathable brick bodies; demolding, curing and drying; removing pre-buried organic burning-out material by pre-burning to form slits; and preparing by high-temperature nitridation treatment. The bricks comprise: 70 to 80 parts of corundum particles and fine powder, 3 to 12 parts of active alumina micro powder, 1 to 6 parts of hydrated alumina, 4 to 15 parts of monomer silicon powder and organic water reducer serving as a dispersant in an amount which is 0.05 to 0.30 percent based on the total weight parts of the previous raw materials. The bricks overcomethe drawbacks of low thermal-shock resistance and low stripping resistance of the conventional corundum-spinel breathable brick material, are expected to replace conventional chromium corundum and corundum-spinel breathable brick materials for making steel and have the characteristics of high blow-off rate, high stripping resistance, long service life and the like.

The invention discloses a preparation method for high-purity flaky alumina, belonging to the technical field of preparation of special powder. The preparation method comprises the following steps: with high-purity aluminum isopropoxide with a purity of 99.999%, pure water and isopropanol as main raw materials and ammonium bifluoride or ammonium fluoride as a crystal morphology controlling agent, dissolving the high-purity aluminum isopropoxide in isopropanol to prepare a solution A; preparing a solution B from pure water, isopropanol and ammonium bifluoride; then gradually adding the solution A into the solution B drop by drop at a certain addition speed; carrying out a reaction under the conditions of heating and stirring so as to produce hydrated alumina; and then successively carrying out filtering, drying and roasting so as to obtain the high-purity flaky alumina. The high-purity flaky alumina prepared by using the method has crystal grain thickness of no more than 1.0 [mu]m, a radial size of 5 to 20 [mu]m, a smooth surface, a flaky shape, no agglomeration and crystal twinning, and good dispersibility, and can be used in fields like cosmetics, pearlescent pigment, high-grade coatings and fine ceramics.

Producing high purity lithium solution from a lithium source containing dissolved Na⁺, Ca²⁺, and Mg²⁺, by: passing the source into and out of a bed of sorbent composed of hydrated alumina intercalated with LiX, preferably LiCl, to extract lithium from the lithium source into the sorbent; washing the bed of sorbent with dilute aqueous LiCl to remove lithium from the sorbent to obtain a lithium eluent of increased Li⁺ concentration; subjecting this eluent to nanofiltration to produce a lithium permeate from which Ca2+, Mg2+, and other nanofilterable components are concurrently removed, yielding a permeate solution with 25% or less, and a retentate solution with 75% or more Ca²⁺ and Mg²⁺, as compared to the eluent from washing; and subjecting the permeate solution to a particular forward osmosis yielding a solution having 13,000-25,000 ppm dissolved lithium. Specified optional steps and new features can be used to increase lithium concentrations and purity.

The invention relates to a magnesium aluminate spinel light refractory castable and a production method thereof. According to the magnesium aluminate spinel light refractory castable and the production method thereof, the purpose of improving the porosity of the refractory castable is achieved by using magnesium aluminate spinel light aggregate and introducing air bubbles during the production of the castable. According to the magnesium aluminate spinel light refractory castable and the production method thereof, a foaming method and castable are combined, not only is the characteristic of large raw critical particle size in the castable ensured but also the porosity of the castable is improved. According to the magnesium aluminate spinel light refractory castable and the production method thereof, 50-65 wt% of light magnesium aluminate spinel particles which serve as the aggregate and 10-15 wt% of sintered magnesium aluminate spinel fine powder, 10-15 wt% of aluminum oxide micro powder and one of 15-20 wt% of pure calcium aluminate cement or hydrated alumina which serve as the matrix are mixed; and a water reducing agent, a foaming agent and a foam stabilizer are added. The magnesium aluminate spinel light refractory castable produced according to the method provided by the invention has high porosity, low thermal conductivity and good thermal shock resistance, and the serviceability temperature reaches 1700 DEG C.

The present invention discloses a heat-resistant and high-strength concrete having a gradient enclosing structure. The heat-resistant and high-strength concrete comprises an inner layer high-strength and heat-resistant concrete and an outer layer high heat-resistant concrete from inside to outside, wherein the inner layer high-strength and heat-resistant concrete adopts a silicate-based cement, fly ash, mineral powder, river sand, basalt graded gravel, toughening fiber, a polycarboxylic acid water reducing agent, an inner curing light aggregate and water as raw materials, and the outer layer high heat-resistant concrete adopts an aluminum-based cement, aluminum sand, aluminum stone, hollow fiber, a polycarboxylic acid water reducing agent, an inner curing light aggregate and water as raw materials. According to the present invention, the gradient enclosing structure is designed, such that the generated calcium aluminate and the generated dicalcium aluminate in the outer layer high heat-resistant concrete in the high temperature environment can be converted into the non-hydrated alumina ceramic phase at the high temperature, and the non-hydrated alumina ceramic phase is firmly bonded with the aluminum stone, the aluminum sand and the like so as to significantly increase the high-temperature resistance; and the large doping amount of the fly ash and the mineral powder are used in the inner layer high-strength and heat-resistant concrete, such that the durability is ensured, and the disadvantages of rapid strength loss in the high temperature environment and the like of the existing ordinary silicate heat-resistant concrete can be effectively solved.