Topic
Activated alumina
About: Activated alumina is a research topic. Over the lifetime, 1430 publications have been published within this topic receiving 31090 citations.
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Patent•
03 Jun 1981
TL;DR: In this paper, a fixed-bed reaction with activated alumina particles containing ferric chloride was proposed to remove the titled two ingredients simultaneously from a mixed gas comprising a gas containing ethylene and vinyl chloride and chloride gas.
Abstract: PURPOSE:To remove the titled two ingredients simultaneously from a mixed gas comprising a gas containing ethylene and vinyl chloride and chloride gas, by making the mixed gas flow through a fixed bed reactor packed with activated alumina particles containing ferric chloride, having a specific outer surface area. CONSTITUTION:In removing ethylene and vinyl chloride simultaneously from a mixed gas comprising the gases and chloride gas, the mixed gas is made to flow through a fixed bed reactor packed with activated alumina particles containing not less than 4wt% calculated as iron ferric oxide, having a corresponding diameter not more than 4.5mm.phi or an outer surface area of the catalyst per unit amount of the catalyst packed not less than 7.8cm /ml so that ethylene and vinyl chloride are converted to 1,2-dichloroethane and 1, 1, 2-tricholoroethane respectively to reduce ethylene content in the mixed gas to not more than 10ppm, and vinyl chloride content to not more than 20ppm. The reaction is carried out at average temperature 80-200 deg.C, at space velocity 100-5,000hr , and at a pressure 1-20atm.
3 citations
Patent•
31 May 1996
TL;DR: A method of making activated alumina including the steps of dissolving a double salt of aluminum in a solution of pure water at 85°C, recrystalizing the double salt at a pressure about 250 psi and temperature ranging from 200°C to 250°C as mentioned in this paper.
Abstract: A method of making activated alumina including the steps of dissolving a double salt of aluminum in a solution of pure water at 85°C, recrystalizing the double salt at a pressure about 250 psi and temperature ranging from 200°C to 250°C, precipitating out the purified basic double salt, drying the precipitated double salt to drive off water and roasting it at 850°C to 950°C to drive off the sulfate, washing to remove the potassium sulfate and then drying the remaining alumina to yield activated alumina for use as a high-grade catalyst.
3 citations
Patent•
29 Nov 2012
TL;DR: In this paper, a method of manufacturing an alumina-based abrasive grain using boehmite powder and activated alumina powder as starting materials is presented. But this method is not suitable for high hardness and high purity.
Abstract: Provided are a method of manufacturing an alumina-based abrasive grain, which includes preparing boehmite powder and activated alumina powder as starting materials, forming a sol by wet-blending and crushing the boehmite powder, the activated alumina powder, a solvent and a deflocculant, heating the sol at a first temperature which is higher than a room temperature and lower than a boiling point of the solvent and stirring the sol so as not to generate a precipitate, forming a gel by heating the sol at a second temperature higher than the first temperature at which a viscosity of the sol is increased and the sol becomes a paste, blending the gel with an organic solvent and performing wet crushing on the resulting mixture, preparing a powder by drying the wet-crushed gel, blending a binder and a solvent with the dried product, which is the powder, and molding the resulting mixture, calcining the molded product, performing dry crushing on the calcined product, and sintering the dry-crushed product to transform activated alumina and boehmite contained therein to an α-Al 2 O 3 crystal phase, and an alumina-based abrasive grain manufactured thereby. As a result, an alumina-based abrasive grain which is highly dense, has a high hardness, and exhibits a high purity may be manufactured using boehmite powder and activated alumina powder.
3 citations
Patent•
27 May 1960
TL;DR: A gallium-fluorine compound is prepared by treating with HF at least one gallium compound selected from a salt of an inorganic or carboxylic acid (such as GaCl3 or GaF3), an oxide or an organometallic derivative such as an alkyl- or chloroalkyl-gallium.
Abstract: A gallium-fluorine compound is prepared by treating with HF at least one gallium compound selected from a salt of an inorganic or carboxylic acid (such as GaCl3 or GaF3), an oxide or an organometallic derivative such as an alkyl- or chloroalkyl-gallium. ALSO:Another halogen in a halogenated aliphatic hydrocarbon is replaced by fluorine by treating the halohydrocarbon with HF in the presence of a catalyst containing at least one gallium-fluorine compound, e.g. one prepared by treating with HF one or more gallium compounds selected from a salt of an inorganic or carboxylic acid, (such as GaCl3 or GaF3), an oxide or an organometallic derivative such as an alkyl- or chloroalkyl-gallium. The halogenated aliphatic hydrocarbon may be a derivative of methane, ethane, ethylene or propane. The reaction temperature is preferably 175-450 DEG C. The catalyst may be supported. In examples, CCl4 gives CCl2F2 and CCl3F; CHCl3 gives CHF3, CHClF2 and CHCl2F; and perchloroethylene gives trifluorotrichloro- and tetrafluorodichloroethane.ALSO:Catalysts containing a gallium-fluorine compound for use in a hydrofluorination reaction (see Division C2) are prepared by treating with HF at least one gallium compound selected from a salt of an inorganic or carboxylic acid (such as GaCl3 or GaF3), an oxide or an organometallic derivative such as an alkyl- or chloroalkyl-gallium; the active material may be supported, e.g. on activated alumina or activated charcoal. The support may be impregnated with a gallium compound by treatment with an aqueous or organic solution of a gallium salt having volatile anions, or with an organo-germanium compound, and then treated with HF, e.g. at 150-250 DEG C. In preferred embodiments activated charcoal is heated with HF, impregnated with a gallium halide in an aliphatic halohydrocarbon, e.g. GaCl3 in CCl4, and again heated with HF vapour; or alumina is similarly impregnated and treated with HF.
3 citations
TL;DR: In this article, the adsorbed Sb(V) ions were desorbed easily by a 50 mM NaOH solution, and a 41-90 times concentrated SbV solution was yielded correspondingly.
Abstract: Adsorption rates of Sb(V) ions on an activated alumina (AA) were analyzed by batchwise experiments, while the continuous adsorption, desorption, regeneration of AA, and multiple reuse cycles were studied by flow column tests. The adsorption rates increased quickly with the increases of shaking speed and operation temperature. The adsorbed Sb(V) ions were desorbed easily by a 50 mM NaOH solution, and a 41–90 times concentrated Sb(V) solution was yielded correspondingly. AA was effectively regenerated by desorption operation and ca. 93% of the initial adsorption capacity was retained after six times adsorption/desorption cycles.
3 citations