Aluminum oxide Emery

Aluminum Oxide. Emery [57407-26-8] is a natural oxide of aluminum with various impurities. One of these impurities, iron oxide, also acts as an abrasive. Pure aluminum oxide is made from bauxite [1318-16-7] and has partially replaced emery. 

Extensive ranging of abrasive wheel geometries, abrasive materials (aluminum oxide, emery, corundum, diamond. Cubic Boron Nitride (CBN)), grain size, hardness grading and bond types (resin, vitrified glass, rubber, metal) are available. 

The compounds of greatest importance are aluminum oxide, the sulfate, and the soluble sulfate with potassium (alum). The oxide, alumina, occurs naturally as ruby, sapphire, corundum, and emery, and is used in glassmaking and refractories. Synthetic ruby and sapphire are used in lasers for producing coherent light. 

Aluminum oxide, A1203, is known almost universally as alumina. It exists with a variety of crystal structures, many of which form important ceramic materials (see Section 14.22). As a-alumina, it is the very hard, stable, crystalline substance corundum impure microcrystalline corundum is the purple-black abrasive known as emery. Some impure forms of alumina are beautiful, rare, and highly prized (Fig. 14.25). A less dense and more reactive form of the oxide is y-alumina. This form absorbs water and is used as the stationary phase in chromatography. 

Coated abrasives consist of a flexible backing on which films of adhesive hold a coating of abrasive grains. The backing may be paper, doth, open-mesh cloth, vulcanized fiber (a specially treated cotton rag base paper), or any combination of these materials. The abrasives most generally used are fused aluminum oxide, sol—gel alumina, alumina-zirconia, silicon carbide, garnet, emery, and flint... 

Aluminum is a constituent of many minerals, including clay (ka-olinite), mica, feldspar, sillimanite, and the zeolites. Some of these minerals are discussed under the chemistry of silicon, in Chapter 31. Aluminum oxide (alumina), occurs in nature as the mineral corundum. Corundum is the hardest of aU naturally occurring substances except diamond it scratches all other minerals, but is itself scratched by diamond, and also by the artificial substances boron carbide, and silicon carbide, SiC. Corundum and impure corundum (emery) are used as abrasives. 

Bauxite aluminum oxide (alumina, corundum, emery, ruby, sapphire) aluminum sulfate alum ammonium alum. Aluminum chloride aluminum acetate. Uses of aluminum compounds. 

CAS 1344-28-1. A Oj. The mineral corundum is natural aluminum oxide, and emery, ruby, and sapphire are impure crystalline varieties. The mixed mineral bauxite is a hydrated aluminum oxide. 

Aluminum oxide Al203 Adamantine span alumina alumina corundum emery. 

Aluminum oxide (AI2O3) is a widely used industrial abrasive (emery, corundum), for which the specific application depends on the hardness of the crystal. What does this hardness imply about the magnitude of the lattice energy Would you have predicted from the chemical formula that AI2O3 is hard Explain. 

Aluminum oxide is also widely used as an abrasive. An abrasive is a very hard material used to grind, polish, sand, scour, scrub, smooth or polish some other material. Among the products that include aluminum oxide as an abrasive are emery boards, sandpaper, grinding and polishing wheels and belts, lens grinding devices, and gem polishing wheels. 

PHYSICAL PROPERTIES mixture of aluminum oxide (AI2O3) and magnetite, with or without hematite varies in hardness according to iron oxide present solid medium brown color (corundum) or white crystalline powder (emery) odorless insoluble in water MP (2072°C, 3761.6T) BP (2980 C, 5396T) DN/SG (4.0) CP (79.0 J/K-mol crystal at 25 C)(corundum) VD (NA) VP (approximately 0 mmHg at 20°C, 0.750 mmHg at 2158°C). 

OTHER COMMENTS Emery is an impure variety of aluminum oxide (AI2O3), sometimes with small amounts of iron, magnesium, and silica. Corundum is natural aluminum oxide (AI2O3), which is a different and hard crystalline form of aluminum oxide. This material may be used in various polishing and abrasive operations may also be utilized during grinding and milling operations. 

Synonyms/Trade Names Alumina, Aluminum oxide, Aluminum trioxide [Note a-Alumina is the main component of technical grade alumina. Corundum is natural AI2O3. Emery is an impure crystalline variety ofAl203.] ... 

Natural aluminum oxide [Note Emery is an impure variety of AI2O3 which may contain small impurities of iron, magnesium silica Corundum is natural AI2O3.] ... 

Emery (corundum. Impure aluminum oxide [CAS 112-62-9]) An abrasive, nuisance dust causing physical Irritation to eyes, skin, and respiratory tract. 10 mg/m Solid crystals of aluminum oxide, Often used for Its abrasive properties (eg, emeiy oloth, emeiy wheel). 

Abrasive materials are usually classified into two groups, natural and manufactured ones. The natural abrasives are generally referred to as those that have been produced by the uncontrolled forces of nature and because of that, they can contain many impurities and vary in quality. Emery, corundum, quartz, flint, garnet, diamond, tripoli, diatomaceous earth, sandstone, pumice, and natural sharpening stones are some of them (Krar 1995 Jacobs 1928). On the other hand, artificial abrasives were first developed in the late nineteenth century and overcame the problems of impurities and inconsistencies, since their manufactore could be carefully controlled. Some manufactored abrasives are carbide of silicon, aluminum oxide, glass, and the metallic abrasives such as steel wool and steel shot and grit (Krar 1995 Jacobs 1928) (Table 1). 

Coated abrasive n. A flexible-type backing upon which a film of adhesive holds and supports a coating of abrasive grains. The backing may be paper, cloth, vulcanized fiber or a combination of these materials. Various types of resin and hide glues are used as adhesives. The abrasives used are flint, emery, crocus, garnet, aluminum oxide and silicon carbide. 

Crocus cloth n. An iron-oxide coated abrasive cloth, used as a polishing agent after most of the work has been done with emery or aluminum oxide, capable of giving a mirror-hke finish to metal. 

Emery cloth n. Coated abrasive cloth used for fight polishing of metal or for removing rust spots or similar fight work not recommended for large metal surfaces or tough metal, where aluminum oxide cloth is much more satisfactory. 

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