Araucaria bidwillii

Antimony Trioxide

Antimony trioxide powder

Antimony trioxide is a chemical compound with the formula Sb₂O₃. It is the most important commercial compound of antimony. The compound is found in nature as the minerals senarmontite and valentinite.

Structure

Antimony trioxide exists in two crystalline forms: cubic and orthorhombic. The cubic form is known as senarmontite, while the orthorhombic form is known as valentinite. In both forms, the antimony atoms are in a +3 oxidation state, and the oxygen atoms are in a -2 oxidation state.

Senarmontite

Molecular structure of senarmontite

Senarmontite has a cubic crystal structure. In this form, the antimony atoms are coordinated to three oxygen atoms, forming a pyramidal shape. This structure is similar to that of arsenic trioxide.

Valentinite

Molecular structure of valentinite

Valentinite has an orthorhombic crystal structure. In this form, the antimony atoms are also coordinated to three oxygen atoms, but the arrangement is different from that in senarmontite, leading to a different crystal symmetry.

Production

Antimony trioxide is produced by roasting antimony sulfide ores or by oxidizing antimony metal. The process involves the reaction of antimony with oxygen to form the trioxide:

4 Sb + 3 O₂ _ 2 Sb₂O₃

The product is then purified by sublimation.

Applications

Antimony trioxide is used as a flame retardant in plastics, textiles, and electronics. It is also used as a catalyst in the production of polyethylene terephthalate (PET) and as an opacifying agent in the manufacture of glass and ceramics.

Health and Safety

Antimony trioxide is considered a potential occupational carcinogen. Exposure to antimony trioxide can occur in industrial settings, and it is important to follow safety guidelines to minimize exposure.

Related Pages

• Antimony
• Senarmontite
• Valentinite
• Flame retardant

Gallery

• 
  3D structure of senarmontite
• 
  3D structure of valentinite