Showing papers on "Aluminium hydroxide published in 2001"

Some catalytic properties of hydrothermally synthesised zinc aluminate spinel

Abstract: Two samples of zinc aluminate were hydrothermally synthesised from zinc acetate and different aluminium sources: basic aluminium nitrate or aluminium hydroxide. The textural properties of the prepared ZnAl2O4 samples are different from these one of the zinc aluminate prepared by conventional way. Powder XRD and TEM measurements reveal that samples are single-phase material or mixture of ZnAl2O4 with small amount of γ-Al2O3, with morphology of quasi-spherical shape. Catalytic properties of the hydrothermally obtained zinc aluminate and Pt (Pd) catalysts supported on them were investigated in the reactions of cyclohexene isomerisation and combustion of trichloroethylene, respectively. It was evidenced that activity and selectivity of the investigated materials could be qualitatively correlated with the part of the strong acid centres measured by TPD of NH3.

[Post-vaccination granuloma due to aluminium hydroxide].

Abstract: Post-vaccination granulomas a well-known reaction due to aluminium adsorbed vaccines. We report three cases of children who developed subcutaneous nodules at the site of a previous injection of Tetracoq*vaccine (tetanus, diphtheria, Bordetella pertussis, poliovirus). Histologically, the lesions were characterized by a necrotizing granulomatous reaction with eosinophilic crystalline material. This material stained positively with the solochrome cyanine stain and was pink-purple. This aluminium stain enabled diagnosis of post-immunization injection-site reaction due to aluminium.

Flow micro-calorimetry and FTIR studies on the adsorption of saturated and unsaturated carboxylic acids onto metal hydroxide flame-retardant fillers

Abstract: Carboxylic acids, particularly fatty acids, are by far the most important surface modification systems for inorganic fillers used in the plastics and rubber industries. However, relatively little is understood regarding factors that affect their adsorption behaviour, including the interplay between acid molecular structure, adsorption conditions, and substrate chemistry. In this study, the adsorption (from n-heptane and toluene) of a range of saturated and unsaturated fatty acids, together with acrylic acid, onto aluminium and magnesium hydroxides has been investigated using flow micro-calorimetry and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). With C18 saturated fatty acids, the overall heat of adsorption per unit surface area of substrate was found to be affected by the structure of the alkyl tail. The orientation of the adsorbed unsaturated fatty acids was found to be affected by the number of double bonds in the molecule. Acrylic acid was found to be very strongly adsorbing a...

Method for producing granulated sorbents and installation for carrying out the method

Abstract: The invention relates to a method for producing granulated sorbents, and to an installation for carrying out the method. The aim of the invention is to obtain the chloride form of the double hydroxide of aluminium and lithium as LiCL2AI/OH)3 nH2O (DHAL-CL) in a waste-free solid phase of aluminium hydroxide and lithium salts in a mixer, with subsequent continuous activation of crystalline DHAL-CI in a centrifugal mill activator in order to obtain a defectuous material structure. The product obtained is mixed with chlorinated polyvinyl chloride as a binding agent and with liquid methylene chloride. The granulation is carried out by extruding the paste produced and refining the same in the granulator. The methylene chloride produced is collected by an organic liquid absorbent having a high boiling point. The methylene chloride steam is guided out of the material flow in the carrier gas flow in the manner of an ideal displacement in the counter-current of the contact phases. The methylene chloride recuperation is carried out in two steps according to the thermal method, during the heating of the absorbent used. The inventive method is characterised by essentially reduced environmental impact in relation to prior art, due to the closed material circuits used. The granulated sorbent is especially suitable for the selective extraction of lithium from chloride salt lye of any mineralisation, with an extraction degree of 95 %.

Preparation process of alumina adsorbant

Abstract: The present invention relates to a preparation method of adsorbing agent, and is characterized by active aluminium hydroxide is used as raw material, and through the processes of drying and pulverizing to a certain mesh quickly dehydrating through the high-temp. air flow to obtain active aluminium oxide raw powder, placing the obtained raw powder in disk type pelletizer, and spraying aqueous solution of alkaline earth metal compound, rolling, forming and roasting so as to obtain finished product. Said product possesses higher adsorptivity, pore volume and specific surface area and crushing strength, and can obviously raise catalytic activity.

Process for preparing high-purity superfine alumina powder by aluminium alkoxide hydrolysis

Abstract: A process for preparing high-purity superfine alumina powder from aluminium alkoxide by hydrolysis includes such steps as reaction of aluminium with isopropanol in existance is catalyst to generate, aluminium alkoxide, hydrolysis to generate aluminium hydroxide and calcine. Its advantages include high purity (99.99-99.999%), sueperfine diameter less than 10 microns, high output rate (more than 92%) and smooth safety reaction.

Electrosurface Properties of Hydr(oxides) and Oxide Nanostructures in 1 : 1 Electrolyte Solutions: 2. Electrokinetic Characteristics of Boehmite, Goethite, and Silicon Dioxide

Abstract: The electrophoretic mobility of particles of silicon dioxide, aluminum hydroxide, and iron hydroxide was measured as a function of pH in NaCl and KCl background solutions. Isoelectric points for the investigated objects were determined. Electrokinetic potentials were calculated with allowances for the particle shape and the polarization of the electrical double layer within the framework of the Overbeek–Boes–Wiersema model.

Technological process for producing aluminium salt and silicate by using coal gangue

Abstract: the production process of aluminium salt and silicate by utilizing coal gangue is characterized by that is adopts the processes of alkali fusion, hydrolysis, carbonization, causticization and correspondent acid solving and alkali solving processes to obtain high-yield aluminium hydroxide and silicic acid, and can develop them into various aluminium salts and silicates with different specification. Said invented causticization process can recover and circularly use the caustic soda being in alkali fusion. Said invented technological line is reasonable, additional value of product is high, and said invented product can be used in the fields of environmental protection, paper-making, petroleum chemical and rubber and plastic industries.

Role of intermediate solid phase in the process of magnesium and lanthanum aluminates formation in sub- and supercritical water

Abstract: The synthesis of inorganic complicated powder oxides is of significant interest owing to wide application of these materials in modem engineering. In this paper the mechanism of fine crystalline magnesium and lanthanum aluminates formation in sub- and supercritical water was investigated. Mechanical mixtures of aluminium hydroxide and magnesia as well as lanthana were used as precursors. The synthesis was carried out in water steam atmosphere at P ≈ 20 MPa and temperature of 300-400° C in the presence of small amounts of Cr(VI) ions. It was found, that the mechanism of this process cannot be represented in the frameworks of the traditional approach dissolution of precursors in supercritical fluid and precipitation of the products. This approach assumes a complete homogenisation of reacting system at the intermediate stage of the process. By means of X-ray analysis of products of the intermediate stage of synthesis, the presence of a crystalline phase was revealed by us. This phase will be derived...

Encapsulation of aluminium hydroxide fillers with poly-methyl-methacrylate.

Abstract: A process was developed for the microencapsulation of inorganic filler particles with poly-methyl-methacrylate, to increase the interaction between the hydrophilic filler particles and a polymer matrix. The filler utilised was aluminium hydroxide with an average diameter of 1.9 microm and a specific surface area of 5 m2/g. The process comprised a surface modification, in which a monolayer of isopropoxy titanium isostearate was chemically bound to the surface to render it hydrophobic and to ensure a chemical bond between the filler and the organic phase. Then, an encapsulation reaction was carried out by means of an emulsion-like polymerization process at monomer starved conditions. The modified particles were stabilized in water with sodium-dodecyl-sulphate. A redox system consisting of cumene-hydroperoxide in combination with sodium-formaldehyde-sulphoxylate and iron(II) salt was applied for the initiation of the polymerization. Besides surface polymer, free polymer particles were also formed. The parameters which varied were the filler concentration, the concentration of the initiator components and the surfactant concentration. At optimum conditions, approximately 50% of the added monomer polymerized at the modified filler surface, thus forming encapsulated filler particles. SEM together with TGA analysis indicated that a smooth polymer layer had been formed on the filler surface. At high filler loading, however, coagulation occurred.

Prepn. of titanium-containing aluminium bydroxide

Abstract: The preparation method of aluminium hydroxide containing titanium is characterized by adding cheap titanium-contained compound in the course of preparing aluminium hydroxide. Said preparation processis simple, low in cost, at the same time the titanium oxide can be uniformly dispersed on the surface of aluminium oxide, so that the influence of the preparation process to aluminium oxide microstructure can be eliminated. Said aluminium hydroxide possesses good peptization property, when it is used for preparing catalyst carrier or catalyst, it can make catalyst easily form and can reduce its cost, and when it is used to prepare catalyst carrier and hydrogenation catalyst, it possesses good physical and chemical properties and application property.

Process for the production of aluminium hydroxide of improved thermal stability

Abstract: Aluminium hydroxide of improved thermal stability is produced by spray-drying of an aqueous slurry of aluminium hydroxide at 400 to 600 °C drying gas temperature. The resulting aluminium hydroxide is suitable as a flame retardant filler in polymeric systems with high processing temperatures. It has a low specific surface area and good rheological properties.

Process for preparing aluminium hydroxide

Abstract: A process for preparing aluminium hydroxide features that the continuous carbonating decomposition technology is used to decompose solution of sodium aluminate, and flash evaporation drying technology where gas is used as heat source is used to bake wet aluminium hydroxide. Its advantages include simple process, high output, low energy consumption, high purity and whiteness, and low content of ferric oxide, water and alkali.

Mineral-carbon sorbents based on aluminium hydroxide and atactic poly(propylene)

Abstract: The present work is an attempt to use the waste water stream, containing considerable amounts of aluminium chloride, for the manufacture of mineral-carbon sorbents. The use of the waste water has given a possibility of obtaining a suitable mineral matrix of aluminium hydroxide for the sorbents. Atactic poly(propylene) (APP) have been used as the necessary carbon raw material. The modification of aluminium hydroxide was attained by preliminary mixing with the organic component, followed by carbonisation. Optimum conditions for obtaining Al(OH) 3 have been determined and the effect of the amount of carbon matter on the properties of the materials obtained has been evaluated. The studies have enabled to trace the changes in the structure and properties of the sorbents obtained.

Method for removing sulfur dioxide from flue gas

Abstract: A method for removing sulfur dioxide from smoke uses aluminium hydroxide as catalyst, and includes the following steps: at 100-130 deg.C making the smoke pass through the urea, in the presence of aluminium hydroxide making sulfur dioxide in the smoke and urea produce reaction to form ammonium sulfate so as to remove it from smoke. Said invention has no secondary pollution, removing rate of sulfurdioxide can be up to above 97%, and its obtained product is a compound fertilizer containing high nitrogen content and several trace elements.

Process for preparing beta-aluminium hydroxide

Abstract: A process for preparing beta-type aluminium hydroxide includes such steps as introducing 35-40% CO2 gas to refined solution of sodium aluminate, which is obtained by sintering alkali and lime and has85-100 g/l of alumina content, at 40-70 degC and 100-150 cum/hcum for 60-90 min, liquid-solid separating, washing and baking The product has high purity (higher than 95%) Its advantages are simple process and easy control

Method for preparing super fine aluminium hydroxide

Abstract: The present invention relates to technology of producing superfine aluminium hydroxide and is characterized by the process including three subsequent procedures of using sodium aluminate solution to prepare active crystal seeds, decomposing superfine aluminium hydroxide slurry fluid and separating solid from liquid. The preparabon procedure of super fine crystal seeds from sodium aluminate solution includes diluting and cooling sodium aluminate solution, decomposing and forming aluminium hydroxide gel slurry fluid and the procedure of separating solid from liquid includes separating solid andliquid, adding water and washing and over drying to obtain superfine aluminium hydroxide.

Porosifying, solidification-accelerating additive for binding agent building materials, and process of producing same

Abstract: The invention relates to a porosifying, solidification-accelerating additive for binding agent building materials, consisting of Al2O3 50 - 90 % MgO 4 - 20 % SiO2 0.5 - 15 % AlN 0.1 - 5 % Fe2O3 0.1 - 5 % CaO 0.1 - 5 % F 0.1 - 5 % Na2O 0.1 - 5 % K2O 0.1 - 2 %as well as in the form of metallic particles A1 0.1 - 10 % Si 0.1 - 3 % Fe 0.1 - 3 %balance in total up to 5 %annealing losses 0.1 - 15 %and of mineral main constituents in the form of corumdum (.alpha.-Al2O3) and spinel (MgO × Al2O3) , wherein the metallic aluminium particles are enveloped by mineral transition modifications from aluminium hydroxide (Al2O3 × 3H2O) to .alpha.-aluminium oxide, wherein the powder comprises a particle size of at least 90%smaller than 500 µm and wherein the BET surface of the powder amounts to at least 10 m2/g. Furthermore, the invention relates to a process of producing a porosifying, solidification-accelerating additive for a binding agent building material by thermally treating the powder in a flue gas flow down to a residual moisture of 2 % maximum by shock drying at flue gas temperatures of 400 to 500 °C in a drying time of less than 10 seconds, and by thermally activating the powder by partially calcinating same within a temperature range of 400 to 1,000 °C, wherein the holding time is calculated in such a way that there is obtained a BET surface of the activated powder of at least 10 m2/g, and wherein the metallic aluminium particles are enveloped by mineral transition modifications from aluminium hydroxide (Al2O3 × 3H2) to .alpha.-aluminium oxide.

Ti-contained aluminium hydroxide and its preparing process and application

Abstract: A Ti-contained aluminium hydroxide and its prepared process and application are disclosed When titanium oxide is introduced to monohydrated aluminium hydroxide, the uniform dispersion of titanium oxide on surface of alumina is ensured and the influence to microstructure of alumina is prevented Said product can be used as catalyst carrier or hydrogenation catalyst with better physical and chemical properties

Effect of Al2O3 Raw Materials on Fluidity of Al2O3-Coated Graphite Powder Slurry

Abstract: Al2O3-coated graphite powder was prepared using ethyl acetoacetate aluminium diisopropoxide, aluminium tri-sec-butoxide and aluminium hydroxide lactate according to the sol-gel method. The effect of Al2O3 raw materials on fluidity of the Al2O3-coated graphite powder slurry was studied. The apparent viscosity of the Al2O3-coated graphite powder slurry depended on the selected Al2O3 raw material. The apparent viscosity of the Al2O3-coated graphite powder slurry prepared using aluminium hydroxide lactate was lower than that of other Al2O3-coated graphite powder slurries.

Improved mesoporous catalysts

Abstract: A method of preparing activated alumina catalysts, which have large pore size and greater resistance to the effects of high temperature. The method includes the steps of; forming an aqueous aluminium hydroxide precipitate from mixing an acidic solution and a basic solution; mixing it with a low molecular weight, water dispersable surfactant; forming a homogeneous composite of aluminium hydroxide and surfactant through keeping the aluminium hydroxide and surfactant in a closed environment at approximately 100 °C; and calcining the aluminium hydroxide alumina precipitate and surfactant mixture at greater than 100 °C to eliminate the surfactant and form the activated alumina (AI2O3).An alumina catalyst having a mesoporous structure, formed from nanometer particles of alumina arranged so as to create interstices.

Resin composition for inhibiting generation of chloride and method for inhibiting generation of chloride using the composition

Abstract: PROBLEM TO BE SOLVED: To provide a resin composition, which is able to efficiently inhibit generation of chlorides such as dioxins when combusted along with a chlorine- bearing polymer by adding a reducing agent to a resin base selected from a polyethylene resin, a polypropylene resin, a polystyrene resin and a polyester resin. SOLUTION: The resin composition for inhibiting generation of chlorides by adding 0.01 to 60 wt.% of a reducing agent to one or more resin bases selected from a resin base selected from a polyethylene resin, a polypropylene resin, a polystyrene resin and a polyester resin. An aluminium compound may be used in combination with the reducing agent. The reducing agent preferably includes hypophoshites or phosphites, and the aluminium compound preferably includes one or more members selected from aluminium phosphate, aluminium sulfate, aluminium hydroxide, aluminium oxide and activated alumina. The resin composition is added to a refuse in an amount of 1.0 to 90 wt.% and incinerated to inhibit generation of chlorides.

Process for producing aluminium-hydroxide powder

Abstract: The present invention provides a method for manufacturing aluminum hydroxide powder highly fillable in a resin as a filler, comprising the step of grinding raw aluminum hydroxide using a kneader mixer

Method of preparing corundum ceramic material

Abstract: manufacture of products from constructional ceramic material, more particularly wear- and chemically- resistant equipment components that withstand high static loads. SUBSTANCE: in order to prepare blend of corundum ceramic material with lower sintering temperature of 1450 C, method comprises using aluminium hydroxide or alumina calculated for aluminium oxide (88-92 wt %) which is mixed with mineralize glass additive presintered at 900-1000 C. Glass additive comprises MgO, CaO, SiO2,B2O3 at 0.5:0.5:1:1 weight ratio. EFFECT: lower sintering temperature with main strength characteristics unchanged of constructional corundum ceramic material. 2 tbl