Antimony trioxide, commonly known as ATO and has chemical formula of Sb2O3, is a commercial compound derived from antimony. Antimony is a metal that occurs naturally in the earth’s crust. ATO is a white, odorless crystalline (sand-like) powder. It is an amphoteric oxide, which can dissolve both in ukraine and acidic solutions. ATO gives antimonites when dissolved in alkaline solution and gives polyantimonous acids when dissolved in acid solution. ATO can easily be oxidized or reduced; it can be oxidized to antimony pentoxide and various other antimony compounds. ATO is toxic, it is presumed to have carcinogenic potential for humans.
ATO is used in a wide variety of industrial applications, mainly as a synergist with flame retardant chemicals and as a catalyst in the manufacture of polyester (PET). The structure of ATO structure alters with the change of the sample temperature. These orthorhombic structures are very stable, existing in nature as mineral valentine.
Antimony oxide can be prepared by two processes, the direct and the indirect process.
In this process, antimony metal or ores is melted in a furnace to give ATO vapors. The vapors are quenched with air and cooled to convert the vapor to white powder. These powders are further filtered to give antimony trioxide powder.
In this process, crude antimony oxide is roasted in the presence of air to give ATO vapors. The vapors are then condensed to convert the vapor to white powder. These powders are further filtered to give antimony trioxide powder.
Fire retardant synergist
Fire safety is necessary both at home and at public places. Fire flammable materials should be made fire safe to a high degree and this is done by using flame retardant chemicals. ATO enhances the effectiveness of flame retardants when used as a synergist in combination with halogenated flame retardants in plastics, rubber, adhesives and textile back coatings.
ATO is used in many appliances such as TVs, computers, industrial electrical, circuit boards, switches, etc. and is integrated into upholstered furniture and decorative foams. ATO is applied in clothing like hospital linen children’s nightwear. In transport vehicles, it plays a significant role as a flame retardant in seats, cables and plastic structures to help strive more time for escaping in case of fire.
ATO enhances the effectiveness of flame retardants when used as a synergist in combination with halogenated flame retardants in paint industry.
ATO is the major catalyst for production of PET bottles, which is the best material for plastic bottles. Detectable amount of antimony can be found and removed by washing on the surface of PET bottles. ATO could migrate into food and drinks at low toxicity if the foods and beverages are consumed under normal condition.
ATO is used to improve optical clarity in certain glasses, and as additive in semi-conductors. It is used even as a coating on certain grades of titanium dioxide pigments. ATO is employed in manufacturing of complex inorganic colored rutile pigments as an essential component. In addition, it functions as the pacifier in iron bath and sinking enamel.