ChemicalBook CAS DataBase List Aluminum oxide

Aluminum oxide synthesis

5synthesis methods

Product Name:Aluminum oxide
CAS Number:1344-28-1
Molecular formula:Al2O3
Molecular Weight:101.96

Pure Aluminum oxide, needed to produce aluminum by the Hall process, is made by the Bayer process. The starting material is bauxite (Al2O3 • nH2O). The ore contains impurities, such as, SiO2, Fe2O3, TiO2, and Na2O. Most impurities are removed following treatment with caustic soda solution. Bauxite is dissolved in NaOH solution. Silica, iron oxides and other impurities are filtered out of the solution. CO2 is then bubbled through this solution. This precipitates are heated to remove water and produce Al2O3. These impurities are removed. Calcinations of bauxite produce Aluminum oxide of abrasive and refractory grades. Activated Aluminum oxide of amorphous type, as well as the transition Aluminum oxides of γ, η, χ, and ρ forms, are obtained from various aluminum hydroxides, such as, α- and β-trihydrates, α-monohydrate and Aluminum oxide gel. Such chemicals are also obtained from bauxite by the Bayer process.

7446-70-0 Synthesis