Silicates aluminum/silicate ratios

No aluminum silicates of alkali metals are known in which the A1+3 R+1 ratio is less than 1 1. 

Sodium Aluminosilicate occurs as a fine, white, amorphous powder, or as beads. It is a series of hydrated sodium aluminum silicates having Na20 Al203 Si02 molar ratios of approximately 1 1 13, respectively. It is insoluble in water and in alcohol and other organic solvents, but at 80° to 100°, it is partially soluble in strong acids and solutions of alkali hydroxides. 

Heating a phenol ester in the presence of Nafion-H gave good yields of the hydroxy phenyl ketone.This Fries rearrangement gave a mixture of the ortho and para hydroxy compounds in a 1 2-2.5 ratio (Eqn. 22.19). A study of the rearrangement of phenyl benzoate over a number of solid acid catalysts indicated that Nafion-H was more effective than montmorilIonite or amorphous aluminum silicate for this reaction. " ... 

The USPNF 23 describes magnesium aluminum silicate as a blend of colloidal montmorillonite and saponite that has been processed to remove grit and nonswellable ore components. Four types of magnesium aluminum silicate are defined types lA, IB, IC, and IIA. These types differ according to their viscosity and ratio of aluminum and magnesium content, see Table II. 

A special-purpose photo-structured glass called FOTURAN (available from Mik-roglas Chemtech GmbH - www.mikroglas.com), which is based on lithium aluminum silicate and is especially useful for creating microchannels and related structures with high aspect ratios. 

Indeed, the H2(ext/obs) ratio which is a measure of the reduction degree and therefore indicates if there is an interaction with the zeolite or between cerium and vanadium, exhibited different values, depending on the way of introduction and species formation. The catalyst treated with steam, EXV, presented a low H2 (ext/obs) ratio, which indicates a better reduction. On the other hand, the impregnated catalyst (IMPV) presented a high H2 (ext/obs) ratio, and thus low reduction. This could explain the indication that an interaction occurred during the treatment, with the formation of bimetallic or alloys or even the formation of aluminum silicate-metal interaction. 

There are basically only three types of platelet-type fillers which can be considered for use in thin barrier films. These are aluminum flake, mica and talc (Table II). Other types of platelets, such as glass, stainless steel or brass flakes and certain aluminum silicate minerals, such as kaolin clay, are either too large in particle size or have too low an aspect ratio to be useful. With these three... 

Reforming catalysts usually involve both transition metals, often platinum, and minerals, particularly zeolites modified with various metals the zeolites are aluminum silicates. Depending on the exact structure, there are a number of anionic sites, which must be neutralized by metal cations or protons. The protonic forms are strongly acidic. The zeolites have distinctive pore sizes and are selective for certain molecular sizes or shapes. For example, pore size can be a factor in determining the ratio of the 0-, m-, and /i-isomers of xylenes, with narrower pores favoring the last. Under normal... 

Synonyms Aluminosilicic acid, sodium salt Aluminum sodium silicate Silicic acid, aluminum sodium salt Sodium aluminosilicate Sodium aluminum silicate Sodium feldspar Zeolite Zeolites Definition Series of hydrated sodium aluminum silicates produced by reaction of sodium silicate and kaolinite clay Formula NajO AI2O3 SiOa with mole ratio = 1 1 13.2 Properties Wh. fine amorphous powd. or beads, odorless and tasteless insol. in water, alcohol, org. soivs. partly sol. in strong acids and alkali hydroxides 80-100 C pH 6.5-10.5 (20% slurry)... 

Mica. Mica is a potassium aluminum silicate mineral that occurs as flakes with aspect ratio up to 50/1. The best grades offer good processability, reinforcement, and impermeability. 

The word "mica" is a generic teirm used to describe a group of complex hydrous potassium aluminum silicate minerals. They differ in chemical composition but share a unique laminar crystalline structure. Mica develops in a book-like form. Individual platelets have perfect basal cleavage which permits delaminating into extremely thin, high aspect ratio particles. These particles are tough and flexible. 

Magnesium alumimun silicate is insoluble in water or alcohol, but swells to many times its original volume to form colloidal dispersions. It is practically insoluble in organic solvents. Dispersions in water at the 1% to 2% level are thin colloidal dispersions. At 3% or above the dispersions are opaque, and as the concentration is increased above 3% the viscosity of the dispersions increases rapidly and exhibits thixotropic behavior. Magnesium aluminum silicate forms a gel at levels of 10% and above. Several different grades are available differentiated by Al Mg ratio (montmorillonite saponite ratio), particle size, dispersion viscosity, and degree of chemical activity. 

The term mica includes a whole family of aluminum silicates. Commercial grades differ in the ratio of aluminum to magnesium found (with potassium) in the cationic portion of the mineral crystal. The two prevalent commercial types are... 

When the ratio of percentages of aluminum oxide to ferric oxide is 0.64 or more, the percentages of tricalcium silicate, dicakium silicate, tricalcium aluminate, and tetracalcium aluminoferrite shall be calculated from the chemical analysis as follows ... 

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