Aluminum oxide

 

Aluminum oxide

Chemical formula	Al2O3
OTP appearance	white solid
Molar Mass(g/mol)	101.96
Density(g/cc)	3.95-4.1
Melting Point(°C)	2072
Boiling Point(°C)	2977
Solubility in water(g/L)	insoluble
NFPA 704	0 1 0

Aluminum oxide is a mineral form of aluminum oxide, Al₂O₃. It is a minor constituent of sand and clay. It rarely occurs in pure form.

Uses

• Primary feedstock for aluminum
• Refractory: melting point 2072°C

Natural Occurrence

• Aluminum oxide does occur naturally as bauxite

Hazards

• GRAS
• Inhalation danger for fine particles / fibers

Production

Bauxite is 30-55% aluminum oxide, with the remainder being silicon and iron oxides. To produce pure aluminum oxide, it must be processed into aluminum hydroxide.

Synthesis

from aluminum hydroxide

1. Calcine aluminum hydroxide, producing aluminum oxide and water:

   2  Al(OH)₃

   {

   →

   1100°C}

   Al₂O₃ + 3  H₂O