Antimony trioxide

Antimony trioxide or Antimony (III) oxide is the inorganic compound with the formula Sb2O3. It is the most important commercial compound of antimony. It is found in nature as the minerals valentinite and senarmontite.
Other applications:
Antimony (III) oxide is used as an opacifying agent for glasses, ceramics and enamels. It is also used in some specialty pigments contain antimony. Antimony(III) oxide is a useful catalyst in the production of polyethylene terephthalate (PET plastic) and the vulcanization of rubber.

Specifications of Antimony Trioxideor Antimony (III) oxide:
Molecular Formula: Sb2O3
Appearance: White Powder
Assay: 99.5%
pH: 2 to 12
Odor: Odorless
Density: 5.2 g/cm3, α-form; 67 g/cm3 β-form
Melting Point: 656C
Boiling Point: 1425C to 1550C reported in literature.
Solubility: Soluble in acid.
Solubility in Water: Dissolves.
Arsenic (As): 0.05% maximum
Lead (Pb): 0.05% maximum
Iron (Fe): 50 ppm