Alumina and other related products

タイトルまたは説明

Alumina, chemical symbol: Al2O3, molecular weight **2, pure alumina is white amorphous powder, commonly known as bauxite, density 3.**4.0g/cm3, melting point ***0 ℃, boiling point ***0 ℃, insoluble in water, amphoteric oxide, soluble in inorganic acid and alkaline solution, there are four isomorphic β - alumina δ - alumina v-alumina a-alumina, mainly α and γ type Varieties, commercially available from bauxite.

Properties: insoluble white solid, odorless, tasteless, extremely hard, easy to absorb moisture without deliquescence (non hygroscopic after burning). Amphoteric oxide, soluble in inorganic acid and alkaline solution, almost insoluble in water and non-polar organic solvent; relative density (d**4) 4.0; melting point ***0 ℃.

Storage: sealed and dry. SCRC*****9

Uses: used as analytical reagent, dehydration of organic solvent, adsorbent, organic reaction catalyst, abrasive, polishing agent, aluminum smelting material, refractory.

In the lattice of A-type alumina, oxygen ions are tightly packed in six directions, and Al3 + is symmetrically distributed in the octahedral coordination center surrounded by oxygen ions. The lattice energy is very large, so the melting point and boiling point are very high. α - alumina is insoluble in water and acid, also known as aluminum oxide in industry, and it is the basic material for making metal aluminum; it is also used for making various refractory bricks, refractory crucibles, refractory pipes, high-temperature test instruments; it can also be used as abrasives, flame retardants, fillers, etc.; high-purity α - alumina is still the material for producing artificial corundum, artificial Ruby and sapphire; it is also used for producing modern large-scale integrated electricity Slab foundation of road.

γ - alumina is produced by dehydration of aluminum hydroxide at ******0 ℃, which is also called active alumina and aluminum glue in industry. In the structure, the oxygen ions are closely packed in the cubic center, and Al3 + is irregularly distributed in the octahedral and tetrahedral open spaces surrounded by oxygen ions. γ - alumina is insoluble in water and soluble in strong acid or alkali solution. When heated to ***0 ℃, it will be transformed into α - alumina. γ - alumina is a kind of porous material, with an inner surface area of hundreds of square meters per gram, which can be strongly adsorbed with high activity. Industrial products are usually colourless or slightly pink cylindrical particles with good pressure resistance. In petroleum refining and petrochemical industry, it is commonly used as adsorbent, catalyst and catalyst carrier; in industry, it is the deacidification agent of transformer oil and turbine oil, and it is also used for color layer analysis; in laboratory, it is a neutral strong dull agent, its dull ability is no less than that of phosphorus pentoxide, and it can be regenerated and reused after being heated under **5 ℃ for **8h.

At present, alumina produced by Bayer process accounts for more than *0% of the total output in the world. Most of alumina is used to produce aluminum metal and less than *0% is used for other purposes.