Showing papers on "Aluminium hydroxide published in 1993"
TL;DR: Aluminium hydroxide (Al) and calcium phosphate (Ca) have been used for many years as immunological adjuvants for biologicals and Al-gel elicited vascular permeability-increasing and toxic effects to macrophages (M phi), while its haemolytic effect was weak.
84 citations
TL;DR: In this article, a simple fractionation procedure membrane filtration was successfully applied to the identification of the formation of hydroxyaluminosilicates and the mechanism of formation was shown to proceed through the inhibition of the nucleation of aluminium hydroxide.
70 citations
TL;DR: In this paper, a solid state reaction model for the formation of β″-Al 2 O 3 is proposed, and two aluminium hydroxides, bayerite and gibbsite, have been investigated as precursors for the synthesis of the solid electrolyte, beta alumina.
58 citations
TL;DR: In this article, a relationship between chemical compositions of geothermal waters and siliceous deposits was investigated, and the results indicated that iron and aluminium were concentrated into these silicerous deposits.
Abstract: In the deposition of siliceous material from geothermal water, a relationship between chemical compositions of geothermal waters and siliceous deposits was investigated. The results indicated that iron and aluminium were concentrated into these siliceous deposits. For the chemical state of the iron in the deposits, some oxides and oxyhydroxides, sulfide and amorphous iron silicate were identified by powder X-ray diffraction and 57Fe Mossbauer spectroscopy. For the aluminium, two states were detected by 27Al MAS NMR: 6-coordinate aluminium (such as aluminium hydroxide) and 4-coordinate aluminium substituting a Si atom site in the deposit. In some deposit samples, both 4 and 6-coordinate aluminium were detected, but in others only the former was found.
49 citations
TL;DR: The laser Raman microprobe spectrum of gibbsite displays four intense v (OH)- stretching bands at ~3365, 3435, 3525 and 3618 cm-1.
Abstract: The laser Raman microprobe spectrum of gibbsite displays four intense v (OH)- stretching bands at ~3365, 3435, 3525 and 3618 cm-1, bayerite shows three near 3425, 3545 and 3564 cm-1, nordstrandite has three near 3492, 3566 and 3623 cm-1, and doyleite one broad band centred at -3545 cm-1 with sometimes a prominent shoulder near 3615 cm-1. The four polymorphs also possess distinctly different Raman signatures of medium to strong bands in the region 100–1200 cm-1. These differences provide a non-destructive routine determinative procedure by direct microsampling of untreated crystals, fragments, and microcrystalline powders. Sample preparation is minimal. Excessive noise and non-quenchable fluorescence are the principle limitations of the technique.
37 citations
TL;DR: In this article, the effect of flame-retardant additives such as tributyl phosphate, tri(dibromopropyl) phosphate, aluminum hydroxide powder and aluminium hydroxides gel are used for acrylic fiber (acrylonitrile and vinyl acetate copolymer).
Abstract: In this study, flame-retardant additives such as tributyl phosphate, tri(dibromopropyl) phosphate, aluminium hydroxide powder and aluminium hydroxide gel are used for acrylic fibre (acrylonitrile and vinyl acetate copolymer), and calcium phosphate and antimony oxide are introduced into modacrylic fibre (acrylonitrile and vinylidene chloride copolymer). Investigations are carried out on the effect of these flame-retardants on the thermal properties, mechanical properties, morphology and flammability of acrylic and modacrylic fibres. The results show that the effect of additives on the rate of coagulation during spinning can be understood from the changee of morphology of the fibres. Tri(dibromopropyl) phosphate and antimony oxide are good flame-retardant and good synergistic flame retardant, respectively.
19 citations
Journal Article•
TL;DR: The dissolution of erythromycin was found to be markedly retarded in the presence of all the antacids studied except sodium hydrogen carbonate, and an attempt was made to elucidate the mechanism of this effect.
Abstract: The in vitro release of erythromycin stearate in the presence of aluminium hydroxide, aluminium trisilicate, magnesium oxide, magnesium trisilicate, sodium hydrogen carbonate and a combination of aluminium hydroxide gel, magnesium hydroxide and dimethyl polysiloxane has been studied by the USP XX dissolution method. The dissolution of erythromycin was found to be markedly retarded in the presence of all the antacids studied except sodium hydrogen carbonate. An attempt was made to elucidate the mechanism of this effect.
17 citations
Patent•
31 Mar 1993
TL;DR: In this article, a synthetic method of KL type zeolite was proposed, which uses silica sol as the silica source and uses aluminium hydroxide or potassium meta-aluminate as the aluminium source, and a proper quantity of KL-type zeolites guiding agent is added under the condition of low silica-aluminium ratio and low alkali-silica ratio, and then the invented KL type Zeolite can be obtained.
Abstract: The present invention relates to a synthetic method of KL type zeolite. It uses silica sol as the silica source and uses aluminium hydroxide or potassium metaaluminate as the aluminium source, and a proper quantity of KL type zeolite guiding agent is added under the condition of low silica-aluminium ratio and low alkali-silica ratio, and then the invented KL type zeolite can be obtained. Its purity and crystallinity are high, and at least 50% of crystals are in the form cylinder, and its crystal grain size can be controlled.
11 citations
TL;DR: In this paper, the gelation of aluminium hydroxide sols from aluminium propoxide and aluminium sec-butoxide has been studied at high temperature and high molar ratio of water under acidic conditions, up to 1.1 molar ratios of nitric acid per aluminium alkoxide.
11 citations
TL;DR: Observations indicate that this new compound is likely to offer a prodrug for avoidance of interaction between new quinolone and metal cations.
Abstract: We newly synthesized a pivaloyloxymethyl ester of ofloxacin (OFLX-PVM) as prodrug in order to avoid the chelate formation between new quinolone and metal cations such as Al3+, Mg2+, Ca2+, or Fe2+ in the gastrointestinal tract. This compound was rapidly hydrolyzed in an incubation experiment by 43% in plasma, by 92% in small intestinal mucosal homogenates, and by 97% in liver homogenates during 0.5 h incubation, but was resistant to hydrolysis by pancreatic enzymes. In everted gut sac experiments, this compound was efficiently absorbed even in the presence of aluminium ion, whereas the absorption of ofloxacin (OFLX) was decreased significantly by the presence of aluminium ion. Minimal inhibitory concentration (MIC) values of OFLX-PVM were far higher than OFLX. Effects of aluminium hydroxide on the oral bioavailability of OFLX and OFLX-PVM were investigated in rabbits. The area under the plasma concentration-versus-time curve from zero to 24 h (AUC0-24h) following oral administration of OFLX was decreased significantly by 47.6% by combined administration with aluminium hydroxide, but AUC0-24h values of OFLX-PVM coadministered with and without aluminium hydroxide were similar to that of OFLX alone. These observations indicate that this new compound is likely to offer a prodrug for avoidance of interaction between new quinolone and metal cations.
11 citations
Patent•
18 Feb 1993
TL;DR: In this paper, an adsorbent for immobilising heavy metals, containing a complex of smectite, aluminium hydroxide and phosphate, is described, and a sealing layer containing a mixture of adsorbents, sand and clay is used for cleaning soil contaminated with heavy metals.
Abstract: The invention relates to an adsorbent for immobilising heavy metals, containing a complex of smectite, aluminium hydroxide and phosphate, to a sealing layer containing a mixture of this adsorbent, sand and clay, and to the use of this adsorbent for cleaning soil contaminated with heavy metals.
Patent•
05 Oct 1993TL;DR: In this paper, a process for the preparation of stabilised alumina from an alumina powder originating from the rapid dehydration of an aluminium hydroxide or oxyhydroxide, in which the said powder is rehydrated in the presence of a lanthanum compound and then subjected to a heat treatment.
Abstract: of EP0597738Alumina stabilised with lanthanum, retaining a high specific surface at high temperature, especially after calcination at 1200@C for 4 hours. Process for the preparation of this stabilised alumina from an alumina powder originating from the rapid dehydration of an aluminium hydroxide or oxyhydroxide, in which the said powder is rehydrated in the presence of a lanthanum compound and then subjected to a heat treatment. Use of this stabilised alumina as catalyst support.
Patent•
30 Jun 1993
TL;DR: In this article, a fire-retardant material in shaped form which retains its structural integrity after degradation of its organic content in a fire is made by curing a shaped mass of curable elastomer (eg an ethylene/vinyl acetate copolymer) in which are dispersed a mixture of glass-formers ("frits") melting progressively over a range of several hundred degrees C and containing components which devitrify in the upper part of the range.
Abstract: Fire-retardant material in shaped form which retains its structural integrity after degradation of its organic content in a fire is made by curing a shaped mass of curable elastomer (eg an ethylene/vinyl acetate copolymer) in which are dispersed (i) a mixture of glass-formers ("frits") melting progressively over a range of several hundred degrees C and containing components which devitrify in the upper part of the range, (ii) aluminium hydroxide and (iii) a magnesium compound (eg Mg(OH)2 endothermically decomposable to magnesium oxide. The mixture of frits preferably forms less than 15% by weight of the material.
Patent•
30 Jun 1993
TL;DR: In this article, a fire-retardant material in shaped form which retains its structural integrity after degradation of its organic content in a fire is made by curing a shaped mass of curable elastomer (e.g. an ethylene/vinyl acetate copolymer) in which are dispersed a mixture of glass-formers ('frits') melting progressively over a range of several hundred degrees C and containing components which devitrify in the upper part of the range.
Abstract: Fire-retardant material in shaped form which retains its structural integrity after degradation of its organic content in a fire is made by curing a shaped mass of curable elastomer (e.g. an ethylene/vinyl acetate copolymer) in which are dispersed (i) a mixture of glass-formers ('frits') melting progressively over a range of several hundred degrees C and containing components which devitrify in the upper part of the range, (ii) aluminium hydroxide and (iii) a magnesium compound (e.g. Mg(OH)2) endothermically decomposable to magnesium oxide. The mixture of frits preferably forms less than 15 % by weight of the material.
TL;DR: In this paper, the heavy metals in the chloroform layer were quantitatively extracted by electrothermal atomic absorption spectrometry, leaving the aluminium matrix in the aqueous phase as a bulky hydroxide precipitate.
Abstract: Milligram amounts of alumina powder were decomposed with 4 mol l–1 sulfuric acid and the pH of the solution was adjusted to 3 with 4.5 mol l–1 ammonia solution. After adding sodium diethyldithiocarbamate (DDTC) and chloroform, the pH of the solution was further increased to 7 with 1 mol l–1 ammonia solution, while the solution was mixed vigorously. Impurities present in the alumina sample, such as iron, copper, lead and cadmium, were quantitatively extracted into the chloroform, leaving the aluminium matrix in the aqueous phase as a bulky hydroxide precipitate. The DDTC and chloroform should be added before the formation of aluminium hydroxide, otherwise significant amounts of the desired heavy metals are lost because of coprecipitation. The heavy metals in the chloroform layer were directly determined by electrothermal atomic absorption spectrometry.
TL;DR: The similarity of the bleeding profiles of both lake dyes and the pH–solubility profile of aluminum hydroxide indicates that pH related bleeding, other than that occurring by competition with anions, is a result of dissolution of the aluminum hydoxide substrate.
Abstract: The effect of pH on the bleeding of FD&C yellow No. 5 aluminum lake and FD&C red No. 40 aluminum lake was investigated. The pH–bleeding profiles corresponded to the pH–solubility profile of aluminum hydroxide. The similarity of the bleeding profiles of both lake dyes and the pH–solubility profile of aluminum hydroxide indicates that pH related bleeding, other than that occurring by competition with anions, is a result of dissolution of the aluminum hydroxide substrate. This dissolution is related to the properties of the substrate rather than to the structure of adsorbed dye.
TL;DR: The reaction of an aqueous solution of AlCl3 on α'NaV2O5 allows separation of V(IV) and V(V) present in the vanadium oxide bronze as discussed by the authors.
Patent•
27 Apr 1993TL;DR: In this paper, the authors describe an insulation board having a waterproof coating made of mineral wool and having a coating based on waterglass and mineral additives, which contains, on a dry weight basis, from 10 to 30% of waterglass having a molar ratio SiO2/Me2O >/= 3.0, where Me is an alkali metal, from 40% of aluminium hydroxide, from 60% of inert fillers, from 3 to 15% of auxiliaries, and water.
Abstract: Insulation board having a waterproof coating, in particular made of mineral wool and having a coating based on waterglass and mineral additives, which contains, on a dry weight basis, from 10 to 30% of waterglass having a molar ratio SiO2/Me2O >/= 3.0, where Me is an alkali metal, from 10 to 40% of aluminium hydroxide, from 10 to 60% of inert fillers, from 3 to 15% of auxiliaries, and water.t
Patent•
30 Dec 1993
TL;DR: In this paper, a process for obtaining a granular zeolite from naturally occurring argillaceous material is described, in which the initial raw material is mixed with a neutral aluminium salt and caustic soda, aluminium hydroxide or silicon dioxide being introduced into the reaction mixture at the same time; the mixture is subjected to steam-heat treatment followed by thermal activation, and is then mixed with an alumino-silico-hydro gel until a homogenous slurry is formed.
Abstract: A process is disclosed for obtaining a granular zeolite from naturally occurring argillaceous material. The invention relates to the field of processing natural materials, in particular the production of granular synthetic zeolites. The invention permits the use of a wide range of natural clays, widens the raw material base for manufacturing granular synthetic zeolites, and boosts the active zeolite content in the granules. To these ends the initial raw material is mixed with a neutral aluminium salt and caustic soda, aluminium hydroxide or silicon dioxide being introduced into the reaction mixture at the same time; the mixture is subjected to steam-heat treatment followed by thermal activation, and is then mixed with an alumino-silico-hydro gel until a homogenous slurry is formed. The neutral aluminium salt used can be, for example, aluminium sulphate. The argillaceous raw material, neutral aluminium salt and sodium hydroxide are mixed in the following respective proportions: 100 : 0.05 : 0.02. The mixture is steam-heat treated for 10 to 60 minutes at a temperature of 110 to 250 °C.
Patent•
29 Apr 1993
TL;DR: In this article, a process for the production of basic magnesium aluminium carboxylates by reacting aqueous suspensions containing at least one magnesium compound and aluminium hydroxide at temperatures of 50 to 220 DEG C, with fatty acids and subsequently working up the reaction products.
Abstract: Proposed is a process for the production of basic magnesium aluminium carboxylates by reacting aqueous suspensions containing at least one magnesium compound and aluminium hydroxide at temperatures of 50 to 220 DEG C, optionally at elevated pressure, with fatty acids and subsequently working up the reaction products. These carboxylates are suitable for use as alkoxylation catalysts in the manufacture of non-ionic surfactants to give a narrow-range homologous distribution.
01 Jan 1993
TL;DR: In this paper, the authors described the energy consumption of aluminium production as high energy consumption and termed it an energy-hungry industry, which is why aluminium production is termed an ELECTRICITY HUNGRY INDUSTRY.
Abstract: High energy consumption is characteristic of the industrial production of aluminium. In the , initial, alumina production phase, THERMAL CONSUMPTION is predominant and becomes an important factor in the cost of production when the raw material used is a bauxite with a high diasporic content which, in the instance of existing bauxite reserves on our old continent, is the case. In the, second, aluminium production phase, a high consumption of ELECTRIC ENERGY is predominant. That is why aluminium production is termed an ELECTRICITY HUNGRY INDUSTRY. Successive energy crises therefore forced this industry to reduce, in both phases of production, its energy consumption. Our plant comprises both of these procedures, that is alumina and aluminium production.
Journal Article•
TL;DR: The in vitro antacid performance of dihydroxyaluminium sodium carbonate (DASC) powder was shown to be superior to that of DAA while aluminium hydroxide gave unsatisfactory results as mentioned in this paper.
Abstract: The in vitro antacid performance of dihydroxyaluminium sodium carbonate (DASC) powder was shown to be superior to that of dihydroxy aluminium aminoacetate (DAA) while aluminium hydroxide gave unsatisfactory results. Magnesium oxide improved the antacid effectiveness in all cases. Different formulations of DASC chewable tablets were prepared using various techniques for the inclusion of the binder. In general, the antacid properties of the tablets were quite good in presence of hydroxypropylmethylcellulose (HPMC) but the onset of action decreased somewhat when this binder was used in the form of a granulating solution. On the other hand, polyvinylpyrrolidone especially the higher molecular weight fraction (PVP K-90) had a detrimental effect on the performance of DASC when used intragranularly particularly as granulating solution
01 Jan 1993
TL;DR: In this article, the adsorption of zinc ions is measured in systems containing complexes of sodium clay (montmorillonite) with aluminium hydroxide polymers (indicated as CALHO) at pH 66 and pH 50.
Abstract: The adsorption of zinc ions is measured in systems containing complexes of sodium clay (montmorillonite) with aluminium hydroxide polymers (indicated as CALHO) at pH 66 and pH 50 Zinc adsorbs in such systems as well on the siloxane surface of the clay (Zn-CEC) as on the aluminium hydroxide polymers (Zn-ALHO) The total amount of zinc adsorbed on CALHO is several times higher than on the pure clay at pH 66 The higher adsorption capacity of CALHO is due to the adsorption of zinc ions on the aluminium hydroxide polymers (ALHO) At pH 50 the total amount of zinc adsorbed on CALHO is lower than on the pure sodium clay Zinc binding is surpressed due to competition with exchangeable Al3+ and less zinc is adsorbed to the ALHO
Patent•
16 Jun 1993
TL;DR: Aluminium oxide powders having a high alpha proportion, crystallite sizes of approximately 0.1 mu m and a narrow particle size distribution are prepared from ordinary Bayer aluminium hydroxide (Gibbsit) or aluminium oxide calcined at a low temperature.
Abstract: Aluminium oxide powders having a high alpha proportion, crystallite sizes of approximately 0.1 mu m and a narrow particle size distribution are prepared from ordinary Bayer aluminium hydroxide (Gibbsit) or aluminium oxide calcined at a low temperature. The starting material is wet-disagglomerated, mixed with alpha aluminium oxide nuclei, dried and calcined. Calcination produces agglomerates which already have the crystallite size required and which only have to be disagglomerated to the particle size required. … The alpha aluminium oxide powders prepared according to the invention are particularly suitable as starting materials for producing high-performance ceramics, for example of blanking dies. … …
Patent•
24 Jul 1993TL;DR: In this paper, the authors proposed casting resin suspensions comprising from 40 to 80% by weight of an inorganic filler, from 60 to 20% of a liquid, polymerisable, organic precursor and from 0 to 5 parts by weight, based on the sum of a polymerisable organosilicon compound as adhesion promoter (coupling agent).
Abstract: The invention relates to casting resin suspensions comprising A) from 40 to 80% by weight of an inorganic filler, B) from 60 to 20% by weight of a liquid, polymerisable, organic precursor and C) from 0 to 5 parts by weight, based on the sum of A) and B), of a polymerisable organosilicon compound as adhesion promoter (coupling agent), where the inorganic filler is a mixture of at least two filler particle fractions of different average particle size, and the size ratio between the average particle sizes of the large and small filler particles is between 10 : 1 and 2 : 1, and the weight ratio between the proportions of the large and small filler particles is between 4 : 1 and 1 : 4. The filler particles preferably comprise aluminium hydroxide and/or aluminium oxide hydrate, and component B) preferably comprises at least 50 parts by weight of (meth)acrylates.
Patent•
22 Sep 1993
TL;DR: In this article, a new process for preparing an aluminium hydroxide having a rounded grain surface was described, in which a liquor derived from the Bayer process and having a particular composition is seeded with an aluminium hydride having particular particle size distribution and is stirred out.
Abstract: A new process is described for preparing an aluminium hydroxide having a rounded grain surface, in which a liquor derived from the Bayer process and having a particular composition is seeded with an aluminium hydroxide having a particular particle size distribution and is stirred out. The aluminium hydroxide obtained by the new process is particularly suitable for flame-proofing plastics.
Patent•
27 May 1993
TL;DR: Aluminium oxide powders having a high alpha proportion, crystallite sizes of approximately 0.1 mu m and a narrow particle size distribution are prepared from ordinary Bayer aluminium hydroxide (Gibbsit) or aluminium oxide calcined at a low temperature as discussed by the authors.
Abstract: Aluminium oxide powders having a high alpha proportion, crystallite sizes of approximately 0.1 mu m and a narrow particle size distribution are prepared from ordinary Bayer aluminium hydroxide (Gibbsit) or aluminium oxide calcined at a low temperature. The starting material is wet-disagglomerated, mixed with alpha aluminium oxide nuclei, dried and calcined. Calcination produces agglomerates which already have the crystallite size required and which only have to be disagglomerated to the particle size required. … The alpha aluminium oxide powders prepared according to the invention are particularly suitable as starting materials for producing high-performance ceramics, for example of blanking dies. … …
Patent•
27 Jan 1993
TL;DR: The product of this invention, which is a flame-inhibitor, consists of aluminium hydroxides, magnesium hydroxide, antimony trioxide, aluminate coupling agent and condensed polymer of ammonium chloride.
Abstract: The product of this invention, which is a flame-inhibitor, consists of aluminium hydroxide, magnesium hydroxide, antimony trioxide, aluminate coupling agent and condensed polymer of ammonium chloride. By ratio of 1:1 of above compounds being used in glass-plastics, the oxygen index of product may be secured by above 40, and the centipoise of viscosity may be under 1500. Its brightness is fine, it is nondeliquecent, its physical and chemical properties are significantly improved.