Calcium-aluminum silicate

Several different possible zeolite structures may result, and if the sodium content is too high, calcium and magnesium are excluded and a hard zeolite scale of sodium-aluminum silicate preferentially forms. If only calcium is present, calcium-aluminum silicate zeolite forms, also as a hard scale. If only magnesium is present in solution, it forms the flocculant magnesium aluminate, MgAl204. 

Cooper A.R. and Kingery W.D. (1963) Dissolution in ceramic systems, 1 molecular diffusion, natural convection, and forced convection studies of sapphire dissolution in calcium aluminum silicate. /. Am. Ceram. Soc. 47, 37-43. 

Beryl had also been analyzed by T. Bergman, F. K. Achard, J. J. Bindheim, and N.-L. Vauquelin, and was supposed to be a calcium aluminum silicate (23). The identity of beryl and the emerald was not suspected until the famous French mineralogist the Abb6 R.-J. Hauy made a careful study of their crystal forms and physical properties and was so struck by the similarity of the two minerals that he asked Vauquelin to analyze them chemically. 

Mo03 in a calcium aluminum silicate melt (CaO, 23% A1203, 15% and Si02, 62% by weight). At 1400°C. they report a diffusion constant of 3.0 X 10"7 cm.2/sec. which exceeds the value of D used here by a factor of about 31. 

The diffusion constant of Mo03 in the calcium aluminum silicate (CAS) melt may differ appreciably from that in the clay loam melt. However, Norman et al have also compared the diffusivities of cesium in CAS and in a melt of soil from the Nevada Test Site and found that the difference in diffusivities in the two matrices was smaller than the experimental uncertainties (12). They concluded that the CAS melt was a fair model of the Nevada soil with respect to the diffusion of most radionuclides of interest in fallout. 

This group of minerals consists of three silicates a potassium-aluminum silicate, a sodium-aluminum silicate, and a calcium-aluminum silicate (KAIShOj. NaAISiiO. and CaAKSriOs) and their isontorphous mixtures. 

Plagioclase A sodium and calcium aluminum silicate mineral that commonly forms in igneous and metamorphic rocks, and occasionally survives weathering to occur in sediments, soils, and sedimentary rocks. A solid solution exists in plagioclase, where (CaAl)5+ and (NaSi)5+ may substitute for each other to produce a composition that ranges from NaAISisOg to CaAUSiiOg. 

Grossular (Garnet) Simple calcium aluminum silicate Massive green (a.k.a. transvaal j ade ) 1.54-1.55 7 2.6-2.7... 

Vesuvian (Idocrase) Complex calcium aluminum silicate Opaque to translucent green or brown (a.k.a. Happy Camp jade ) 1.49-1.69 3 2.7... 

Composition A binding material consisting essentially of calcium aluminum silicate. 

Hydrogenation of nitiobenzoic acid (T=35-96oQ Pd Calcium- aluminum silicate (disk) Gas-liquid reactor De Vos and Hamrin, 1982 De Vos etal., 1982... 

A membrane can be used in the so-called phase transfer catalysis as a separator between two immiscible liquids or a liquid and a gas. It serves as a well controlled contact surface. An interesting type of membrane reactor has been suggested in which a ceramic membrane is applied to regulate the contact between a gas and a liquid stream on the opposites of the membrane [De Vos, 1982 De Vos et al., 1982]. Hydrogenation of nitrobenzoic acid can be effectively performed with a porous calcium-aluminum silicate membrane reactor which essentially becomes a gas-liquid reactor. 

Molecular sieve zeolites constitute a class of stationary phase that combines exclusion with specific adsorption properties. These materials, which are crystalline aluminum silicates (commonly sodium or calcium aluminum silicates), have rigid, highly uniform three-dimensional porous structures containing up to 0.5ml/g of free pore volume, resulting when water of crystallization is removed by heating. Although munerous natural zeolites are known, most practical work is done with... 

Catalytic cross-flow reactor Calcium aluminum silicate H2 diffusion in liquid-filled pores Hydrogenation of p-nitrobcnzoic acid Pd-coated monolith wall 60 ... 

Sand, preferably fine particulate, is used as the source of Si02 in the manufacture of silicate glasses. Raw materials for the standard network-modifiers are lime, dolomite (CaC03 MgC03) for the alkaline earth oxides, sodium carbonate for sodium oxide, feldspar (sodium potassium calcium aluminum silicate), or other naturally occurring aluminum silicates, for aluminum oxide. Boron is used in the form of boric acid, borax and other boron minerals, e.g. ulexite (NaCa[B505(0H)6] 5H2O) or colemanite... 

Synonyms Calcium aluminosilicate Calcium aluminum silicate... 

Calcium aluminum silicate. See Aluminum calcium silicate Calcium ascorbate CAS 5743-27-1 5743-28-2 (dihydrate) EINECS/ELINCS 227-261-5 INS302 E302... 

Lesser Gemstones. Many other gemstones of lesser importance are commonly used. For example, spodumene (lithium aluminum silicate) can occur as transparent yellow, green, and colorless specimens. Turquoise (calcium aluminum silicate) is a blue to green, opaque mineral that is usually mixed with other dark impurities or some copper minerals it has a hardness less than quartz and a good cleavage, so care must be taken not to damage it. 

Figure 25.24 See (i) Cooper, A.R. and Kingery, W.D. (1964) Dissolution in ceramic systems I. Molecular diffusion, natural convection, and forced convection studies of sapphire dissolution in calcium aluminum silicate, /. Am. Ceram. Soc. 47,37. (ii) Samaddar, B.N., Kingery, W.D., and Cooper, A.R. (1964) Dissolution in ceramic systems II. Dissolution of alumina, mullite, anorthite, and silica in a calcium-aluminum-silicate slag, J. Am. Ceram. Soc. 47, 249. (iii) Oishi, Y., Cooper, A.R., and Kingery, W.D. (1964) Dissolution in ceramic systems III. Boundary layer concentration gradients, J. Am. Ceram. Soc. 48,88. (A classic series of papers all on-line for ACerS members.)...

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