Product Description
Properties
Physical Properties
At room temperature, it is a white crystalline powder. It turns yellow when heated and reverts to white upon cooling. It exists in two crystalline forms: cubic and orthorhombic, which occur in nature as stibnite and valentinite respectively. Cubic antimony trioxide has a density of 5.2 g/cm³ and transforms into orthorhombic crystals when heated to 550 - 577 °C. Orthorhombic antimony trioxide has a density of 5.67 g/cm³, a melting point of 656 °C, and a boiling point of 1425 °C.
Chemical Properties
It belongs to amphoteric oxides, with a stronger basicity than arsenic trioxide. It is insoluble in water and alcohol, and also insoluble in dilute sulfuric acid or dilute nitric acid. However, it can dissolve in concentrated hydrochloric acid, concentrated sulfuric acid, concentrated nitric acid, concentrated sodium hydroxide solution, sodium sulfide solution, and tartaric acid solution. Fine - grained antimony trioxide is more readily soluble in the above - mentioned acids, alkalis, sodium sulfide solution, and tartaric acid solution. When it reacts with hydrogen sulfide, orange antimony trisulfide is formed.
Applications
Flame - Retardant Field
It is one of the earliest - used flame retardants and is often used as a flame - retardant synergist in combination with halogen - based flame retardants. It is widely applied in industries such as plastics (e.g., polyvinyl chloride, polystyrene, epoxy resin, polyurethane, etc.), rubber, textiles, chemical fibers, coatings, fire - resistant fabrics, and electronics. It achieves flame retardancy through methods such as forming a protective film by melting at the initial stage of combustion to isolate air, reducing the combustion temperature through endothermic reactions inside, and vaporizing at high temperatures to dilute the oxygen concentration.
Chemical Catalysis Field
It is used as a catalyst in the production processes of petrochemicals and synthetic fibers (such as polyester fibers, polyethylene terephthalate resin, etc.).
Glass and Ceramics Field
In the glass industry, it can serve as a fining agent and a decolorizing agent, which can remove bubbles and impurity colors in glass, improving the transparency and gloss of glass. In the enamel industry, it is used as an additive to increase the opacity and surface gloss of enamel.
Pigment and Coating Field
It can be used as a white pigment in the manufacture of white pigments, paints, coatings, etc., providing covering power and brightness.
Medical Field
Research has found that it has a certain inhibitory effect on some tumor cells (such as leukemia cells, human ovarian cancer SKOV3 cells), and has potential application prospects in medical research, especially in anti - cancer research. In addition, historically, antimony agents have also been used to treat parasitic diseases.
Other Applications
It is a raw material for synthesizing antimony salts; it can be used to manufacture mordants and opacifiers; and it can also be used to prepare compounds such as potassium antimonyl tartrate.
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