Алюминаты: состав, структура и применение.

Compound containing an oxyanion of aluminium
In chemistry, an aluminate is a compound containing an oxyanion of aluminium, such as sodium aluminate. In the naming of inorganic compounds, it is a suffix that indicates a polyatomic anion with a central aluminium atom.

There are many mixed oxides containing aluminium where there are no discrete or polymeric aluminate ions. The spinels with a generic formula that contain aluminium as Al3+, such as the mineral spinel itself, MgAl2O4 are mixed oxides with cubic close packed O atoms and aluminium Al3+ in octahedral positions. BeAl2O4, chrysoberyl, isomorphous with olivine, has hexagonal close packed oxygen atoms with aluminium in octahedral positions and beryllium in tetrahedral positions. Some oxides with the general formula of MAlO3 sometimes called aluminates or orthoaluminates such as YAlO3, Yttrium ortho aluminate are mixed oxides and have the perovskite structure. Some oxides such as Y3Al5O12, usually called YAG, have the garnet structure. Some materials that are known to form glass in binary combination with aluminium oxide are: rare earth oxides, alkaline earth oxides (CaO, SrO, BaO), lead oxide, and silicon dioxide. Also, the Al2O3 (aluminate) system has been discovered to form sapphire like glass ceramics. Often, this ability is based upon compositions in which interplay between glass forming ability and glass stability is approximately balanced.

Sodium aluminate, NaAlO2, is used industrially in dyeing to form a mordant and the hydrated forms are used in water purification, sizing of paper and in the manufacture of zeolites, ceramics and catalysts in the petrochemical industry. In the isomerization process of alkenes and amines Calcium aluminates are important ingredients of cements.