Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Alumina Aluminum Lithium Oxide

One gram of silver /3-alumina (see above) is placed into a fused quartz test tube about 2 cm in diameter and about 14 cm long. Five grams of lithium chloride is added. It is important that the lithium chloride used have a very low content of other alkali metal impurities, except Cs, since the ion exchange equilibria greatly favor the presence of the other alkali metals in the /3-alumina crystals over lithium. Essentially all of the impurity ends up in the crystals. The fused-quartz test tube is heated to 650° in a furnace. For crystals 1-cm in diameter the time to reach 99% equilibrium is approximately 16 hours. The molten salt is decanted and the crystals are allowed to cool to room temperature. Methyl alcohol containing about 10% propylamine or ethylenediamine is used to wash the product and thereby remove the silver chloride and residual lithium salts. The sample is dried at 400° and stored in a dessicator. The lithium /3-alumina crystals contain less than 0.05% Ag. If the lithium chloride used contains a trace of sodium or potassium, it can be prepurified by treatment with silver /3-alumina at 650°. Each gram of silver /3-alumina will remove about 30 mg of sodium from the melt. The molten lithium chloride, after decantation from the pretreatment silver /3-alumina, can be used to prepare the product, lithium 0-alumina. [Pg.54]

Lithium 0-alumina crystals are colorless and hygroscopic. They should be kept in a desiccator and dried at 400° before use. The lattice constants are a - 5.596 A, c= 22.570 A. [Pg.54]

The preparation of this compound from silver (3-alumina is similar to the preparation of lithium /3-alumina. The melt consists of 10 g of potassium chloride. The exchange temperature is 800°. For crystals with diameters of 1 cm it takes about 16 hours to reach 99% of equilibrium. The potassium salts used should contain less than 0.1 wt % sodium. After decantation of the melt the crystals are washed with water containing 2% propylamine or ethylenediamine to remove residual potassium salts and silver chloride. The sample is dried at 200°. The potassium 0-alumina contains less than 0.05% silver. [Pg.55]


The predominant process for manufacture of aniline is the catalytic reduction of nitrobenzene [98-95-3] with hydrogen. The reduction is carried out in the vapor phase (50—55) or liquid phase (56—60). A fixed-bed reactor is commonly used for the vapor-phase process and the reactor is operated under pressure. A number of catalysts have been cited and indude copper, copper on silica, copper oxide, sulfides of nickel, molybdenum, tungsten, and palladium—vanadium on alumina or lithium-aluminum spinds. Catalysts cited for the liquid-phase processes include nickel, copper or cobalt supported on a suitable inert carrier, and palladium or platinum or their mixtures supported on carbon. [Pg.231]

In general the reduction of a pyridine side-chain acid or ester using platinum oxide, Raney Nickel, rhodium-on-carbon, rhodium-on-alumina, or ruthenium oxide as the catalyst gives the piperidine acid or ester. Partial reduction of the pyridine ring to a tetrahydropyridine usually occurred when palladium-on-carbon was employed as the catalyst, although two exceptions were reported. Either a mixture of the piperidine and the tetrahydropyridine ester or the tetrahydropyridine ester alone was formed when sodium borohydride was used at room temperature in the reduction of pyridine side-chain ester salts. When the free bases were employed, reduction of the ester group occurred instead of nuclear reduction. The use of lithium aluminum hydride gave the same results (see Table XI-18). Many acetamides... [Pg.351]

In vacuum thermochemical reduction process, aluminum and silicon are suitable reduction agents [5, 6]. Vacuum aluminothermic reduction lithium is from a US patent about aluminum reduction of lithium oxide. Aluminum reduction of spodumene has been reported by Stauffer [7]. Lithium is difficultly reduced if not adding calcium oxide into spodumene. When the mass ratio of calcium oxide and spodumene is 3 2, the maximum productivity was 92.2% under the conditions of 1050 1150"C for 2 hours. Fedorov and Shamrai used aluminum to reduce lithium aluminate, and pointed out that the lithium productivity could reach 95% when the reduction temperature was 1200 C and the system pressure was below 0.0013 Pa [4]. The previous researches were focused on the production of lithium. But the recovery of reduction residue was not investigated. In present work, a novel vacuum aluminofliermic reduction lithium process is developed which used lithium carbonate, alumina and calcium oxide as raw materials. The products were metal lithium and high-whiteness aluminum hydroxide. [Pg.11]

Enamels - [BARIUMCOMPOUNDS] (Vol3) - [ALUMINUMCOMPOUNDS - ALUMINIUMOXIDE(ALUMINA) - CALCINED,TABULAR, AND ALUMINATE CEMENTS] (Vol2) - [TIN COMPOUNDS] (Vol 24) -aluminum fluoride in [FLUORINE COMPOUNDS,INORGANIC - ALUMINUM](Vol 11) -antimony compds in [ANTIMONY COMPOUNDS] (Vol 3) -borate in [BORON COMPOUNDS - BORON OXIDES, BORIC ACID AND BORATES] (Vol 4) -boric oxide in prepn of [BORON COMPOUNDS - BORON OXIDES, BORIC ACID AND BORATES] (Vo 14) -lithium for [LITHIUM AND LITHIUM COMPOUNDS] (Vol 15)... [Pg.361]

Pinocarveol has been prepared by the autoxidation of a-pinene,5 by the oxidation of /S-pinene with lead tetraacetate,6 and by isomerization of a-pinene oxide with diisobutylalumi-num,7 lithium aluminum hydride,8 activated alumina,9 potassium ferf-butoxide in dimethylsulfoxide,10 and lithium diethylamide.11 The present method is preferred for the preparation of pinocarveol, since the others give mixtures of products. It also illustrates a general method for converting 1-methylcy-cloalkene oxides into the corresponding exocyclic methylene alcohols.11 The reaction is easy to perform, and the yields are generally high. [Pg.20]

Other raw materials such as aluminum oxide (calcined alumina), calcium-containing fluxes (marble, calcite, limestone, chalk) or lithium-containing fluxes (eucryptite, spodumene) are also added in small quantities. [Pg.447]

The ketolactam (233) was prepared from the lactamol (232) by heating in a mixture of methanol and concentrated hydrochloric acid. The ketolactam was reduced with lithium aluminum hydride in refluxing dioxane to afford the desired exoalcohol (234) and its epimer (235) in a 1 1 ratio. These epimers were separated by chromatography on alumina. The undesired epimer (235) was converted by Jones oxidation to the corresponding ketone (236), which was reduced with sodium in refluxing absolute alcohol to yield alcohols 234 and 235 in a more favorable 7 3 ratio. The exoalcohol 234 was acetylated with acetic anhydride in pyridine, and the product was hydrolyzed by heating with dilute methanolic potassium hydroxide to obtain the -acetate alcohol (237). The latter was... [Pg.67]

Recent patent disclosures by the Standard Oil Co. of Indiana indicate that their process for the polymerization of ethylene is also a relatively low-pressure process, and the following process information is based on these disclosures. The polymerization process is a fixed-bed process employing a prereduced catalyst, ethylene pressures of 809-1,000 psi, and temperatures somewhat greater than 200°C. The metal oxides (such as nickel, cobalt, and molybdenum) can be supported on either charcoal or alumina, and materials such as lithium aluminum hydride, boron, alkali metals, and alkaline-earth hydrides may be used as promotors. Variations of this process are reported to produce polyethylene resins with densities from 0.94-0.97. [Pg.994]

Another way to template thin films of nano-sized cylinders perpendicular to the surface is to start with a preformed membrane of track-etched polycarbonate or nanoporous alumina. A fiuid dispersion of a filler material can be drawn into the pores. Anodized aluminum oxide was the template for construction of lithium ion nanobatteries having many parallel cells filled with the solid state electrolyte PEO-LiOTf (poly(ethylene oxide)-lithium trifluoromethanesulfonate) and the electrodes coated on the top and bottom surfaces of the film (41). [Pg.384]

Regarding ceramic-containment materials," sihca, SiO, and alumina, Al O, are strongly attacked and hence readily dissolve in liquid lithium. By contrast, alkaline-earth oxides such as beryllia (BeO), magnesia (MgO), and calcia (CaO) and rare-earth oxides such as ceria (CeOJ, yttria (YfiJ, chromite spinel (FeCr OJ, and yttrium aluminum garnet (Y AljOj ) seem to be noncorroded below 500 C, while aluminum, titanium, and zirconium nitrides or... [Pg.218]

In vacuum reduction experiment, lithium carbonate(Li2COs a 99.0%), calcium oxide(CaO a 98%), alumina(Al203 a 98%) and aluminum power (A1 a 99%)are needed. In the leaching of reduchon residue, sodium carbonate and sodium hydroxide solution are needed. [Pg.12]


See other pages where Alumina Aluminum Lithium Oxide is mentioned: [Pg.54]    [Pg.237]    [Pg.54]    [Pg.237]    [Pg.11]    [Pg.97]    [Pg.95]    [Pg.175]    [Pg.100]    [Pg.58]    [Pg.359]    [Pg.45]    [Pg.1060]    [Pg.16]    [Pg.17]    [Pg.187]    [Pg.20]    [Pg.93]    [Pg.142]    [Pg.807]    [Pg.284]    [Pg.349]    [Pg.304]    [Pg.166]    [Pg.78]    [Pg.278]    [Pg.142]    [Pg.721]   


SEARCH



Aluminum alumina

Aluminum oxidation

Aluminum oxide

Aluminum oxidized

Lithium oxidation

Lithium) alumina

Oxide alumina

© 2024 chempedia.info