Nomenclature
CAS number: 17099-70-6
Hexafluorosilicate(2) aluminum (3:2); aluminum fluosilicate; aluminum silicofluoride.
Al
2F
18Si
3; mol wt 480.19.
Al 11.24%, F 71.22%, Si 17.55%.
Al
2(SiF
6)
3.
Description and references
Occurs in nature as topaz, Al2SiO4(OH,F)2. Prepn:
Sanfourche, Krapivine, Compt. Rend. 208, 2080 (1939).
Derivative
Nonahydrate.
Properties
Hexagonal prisms. Easily sol in water; aq soln
decomposes on heating or neutralization. Solid loses water on heating
to temperatures below 500°, leaving a hexahydrate form; decomposes
completely on heating to 1000°.Use
Protection and preservation of construction materials;
manuf of glass.