Antimony Trioxide 

Antimony trioxide 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. Like most polymeric oxides, Sb2O3 dissolves in aqueous solutions only with hydrolysis.


Antimony trioxide is an amphoteric oxide, dissolving in alkaline solution to give antimonites and in acid solution to given a range of polyantimonous acids. It can be readily oxidized to antimony pentoxide and related antimony (V) compounds, but it is also easily reduced to antimony, sometimes with production ofstibine.


The annual consumption of antimony trioxide in the United States and Europe is approximately 10,000 and 25,000 tonnes, respectively. The main application is for flame retardants in combination with halogenated materials. The combination of the halides and the antimony being key to the flame-retardant action for polymers, helping to form less flammable chars. Such flame retardants are found in electrical apparatus, textiles, Leather and coatings.

Other applications:

  • Antimony trioxide is an pacifying agent for glasses, ceramics and enamels.
  • Some specialty pigments contain antimony.
  • Antimony trioxide is a useful catalyst in the production of polyethylene terephthalate (PET plastic) and the vulcanization of rubber.
  • Flame retardant for textiles, leather, polymers, and coatings.

Grades of Antimony Trioxide

Gradde Sb2o399.90 Sb2o399.80 Sb2o399.50
Sb2o3 >= 99.90 99.80 99.50
Sb2o3 <= 0.02 0.05 0.06
Pbo <= 0.04 0.08 0.10
Fe2o3 <= 0.02 0.005 0.006
CuO <= 0.001 0.002 0.002
Se <= 0.002 0.004 0.005
Whiteness % >= 97.0 96.0 95.0
Coarse <= 2.5um
Fine level <= 1.6um
Ultra fine
Grain Size <=
Particulate level <= 0.4um

Back to Products