Silicate, soluble manufacture

Orthopedic devices, 3 721-735 joint replacement, 3 727-735 Orthopedic marrow needles, 3 743-744 Orthophosphate (PO4), in soil, 11 112 Orthophosphates, 18 830-841 20 637 magnesium, 18 839 manufacture of, 18 853-855 Orthophosphate salts, 18 836 Orthophosphoric acid, 18 815, 817-826 condensation of, 18 826 properties of, 18 817-819 solubility of boron halides in, 4 140t orf/zo-phthalic resins, 20 101, 113 formulation of, 20 102 Orthorhombic crystal system, 8 114t Orthorhombic phosphorus pentoxide, 19 49 Orthorhombic structure, of ferroelectric crystals, 11 95, 96 Orthorhombic symmetry, 8 114t Orthosilicate monomers, in silicate glasses, 22 453... 

Aluininatcs Sodium aluminate NaAlOi, white solid, soluble, (1) by reaction of aluminum hydroxide and NaOH solution. (2) by fusion of aluminum oxide and sodium carbonate the solution of sodium aluminate is reactive with CO2 to form aluminum hydroxide. Used as a mordant in the textile industry, in the manufacture of artificial zeolites, and in the hardening of budding stones. See silicates below and calcium aluminates. 

Examples of known phosphazene polymer blends are those in which phosphazenes with methylamino, trifluoroethoxy, phenoxy, or oligo-ethyleneoxy side groups form blends with poly(vinyl chloride), polystyrene, poly(methyl methacrylate), or polyethylene oxide).97 100 IPNs have been produced from [NP(OCH2CH2OCH2CH2OCH3)2] (MEEP) and poly(methyl methacrylate).101-103 In addition, a special type of IPN has been reported in which a water-soluble polyphosphazene such as MEEP forms an IPN with a silicate or titanate network generated by hydrolysis of tetraethoxysilane or tetraalkoxytitanane.104 These materials are polyphosphazene/ceramic composites, which have been described as suitable materials for the preparation of antistatic layers in the manufacture of photographic film. 

Aluminium is the third most abundant element in the earth s crust and is used widely in the manufacture of construction materials, wiring, packaging materials and cookware. The metal and its compounds are used in the paper, glass and textile industries as well as in food additives. Despite the abundance of the metal, its chemical nature effectively excludes it from normal metabolic processes. This is due largely to the low solubility of aluminium silicates, phosphates and oxides that result in the aluminium being chemically unavailable. However, it can cause toxic effects when there are raised concentrations of aluminium in water used for renal dialysis. These effects are not seen when aluminium is at the concentrations usually present in drinking water. There is currently much activity to examine the factors that influence uptake of aluminium from the diet. 

The chemistries of phosphates and silicates are similar, but the morphology of the crystals of the sparingly soluble phosphates are unsuited for fiber applications. Amorphous phosphate glasses can be easily spun into fibers in a process similar to the manufacture of fiberglass. Unfortunately, amorphous phosphates lack both strength and hydrolytic stability. 

Calcium oxide is the main ingredient in conventional portland cements. Since limestone is the most abundant mineral in nature, it has been easy to produce portland cement at a low cost. The high solubility of calcium oxide makes it difficult to produce phosphate-based cements. However, calcium oxide can be converted to compounds such as silicates, aluminates, or even hydrophosphates, which then can be used in an acid-base reaction with phosphate, forming CBPCs. The cost of phosphates and conversion to the correct mineral forms add to the manufacturing cost, and hence calcium phosphate cements are more expensive than conventional cements. For this reason, their use has been largely limited to dental and other biomedical applications. Calcium phosphate cements have found application as structural materials, but only when wollastonite is used as an admixture in magnesium phosphate cements. Because calcium phosphates are also bone minerals, they are indispensable in biomaterial applications and hence form a class of useful CBPCs that cannot be substituted by any other. 

Potassium-silicate water glass is manufactured for special purposes (e.g. binder for acid-resistant cements, fresco paintings, etc.). The application of soluble silicates in industry is dealt with in the monograph by Vail (1952). 

Sodium and potassium hexafluorosilicate are manufactured by reacting alkali salts (e.g. chlorides) with hexafluoro-silicic acid and subsequent separation of the poorly soluble alkali hexafluorosilicates. 

Deflocculation. Soluble silicates suppress the formation of ordered structures within clay slurries, thus increasing the solids which can be incorporated into a clay water system. This interesting surface phenomenon finds practical expression in the manufacture of bricks and cement. 

Soluble sodium silicate glass sobd and Uquid (anhydrous). Excludes quantities consumed in the manufacture of meta-, ortho-, and sesquisiUcates. Includes quantities consumed in the manufacture of glass powder, hydrated glasses, and precipitated products. Shipment figures include unspecified amounts shipped to other plants for the manufacture of meta-, ortho-, or sesquisiUcates. 

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