Product Name: Diantimony Trioxide

Cas: 1309-64-4

Molecular Formula: O3sb2

Einecs: 215-175-0

Antimony trioxide Chemical Properties

Physical and chemical properties

Antimony trioxide is a white crystalline powder, which turns yellow after heating and turns white after cooling. It has no odor. Its melting point is 655℃ and boiling point is 1425℃. It sublimates when heated to 400℃ in high vacuum. It is soluble in sodium hydroxide solution, hot tartaric acid solution, hydrogen tartrate solution and sodium sulfide solution, and slightly soluble in water, dilute nitric acid and dilute sulfuric acid. The relative density is 5.67. The median lethal dose (rat, oral) is >20g/Kg, which may cause cancer.

Antimony trioxide is the earliest flame retardant used. It is often used in combination with other flame retardants and smoke suppressants. The components can produce a synergistic effect. In the early stage of combustion, antimony trioxide first melts and forms a protective film on the surface of the material to isolate the air. Through internal endothermic reactions, the combustion temperature is reduced. Under high temperature conditions, antimony trioxide is vaporized, diluting the oxygen concentration in the air, thereby playing a flame retardant role. In fact, antimony trioxide is a commonly used flame retardant synergist.

Antimony oxide compounds

Antimony trioxide, antimony tetroxide and antimony pentoxide are three antimony and oxygen compounds with industrial uses. Antimony and oxygen can form a series of oxides, including Sb2O3, Sb2O4, Sb2O5, Sb6O13, Sb2O and gaseous SbO, but only the first three are meaningful in industrial production. The other oxides are mostly transition products in different production processes of antimony.

Antimony trioxide (Sb2O3, Mr291.50) is a binary substance, with two types: cubic and monoclinic. Different crystal forms have slightly different densities and refractive indices. The density and refractive index of the cubic crystal are 5.2 and 2.087, respectively, while those of the monoclinic crystal are 5.67 and 2.180, respectively. Sb2O3, which is usually generated by the hydrolysis of SbCl3, is an orthorhombic crystal. It is burned to red heat in an inert gas or vacuum, and sublimates to obtain square crystals. Antimony trioxide is a white powder with a density of 5.67g/cm3. It turns yellow when heated and turns white again after cooling. It melts into a light yellow or gray liquid at 656℃, and turns into a white asbestos-like substance with a mercerized luster after cooling. Antimony trioxide is slightly soluble in water, ethanol and dilute acid, easily soluble in concentrated hydrochloric acid, oxalic acid and tartaric acid solutions, and also soluble in fuming nitric acid and fuming sulfuric acid; it dissolves in alkali to form antimony salts. Antimony trioxide is not very toxic, but it has an irritating effect on organs such as the nose, eyes, throat and respiratory tract, and contact with the skin can induce dermatitis. There are two main preparation methods for antimony trioxide: dry method and wet method. The dry method is to reduce the crude antimony trioxide generated by calcining antimony ore to metallic antimony in the presence of coke using soda ash as a flux, and then oxidize it in air to obtain pure antimony trioxide. The wet method is to leach antimony ore with hydrochloric acid to generate antimony trichloride, and then hydrolyze it with caustic soda.

Chemical properties

White or gray orthorhombic or equiaxed crystal powder. Soluble in hydrochloric acid, potassium hydroxide, sodium sulfide, tartaric acid, concentrated sulfuric acid, concentrated nitric acid, insoluble in water, alcohol, dilute sulfuric acid.

Uses

1. Used as high-purity reagent, mordant and light-proof agent, also used in the preparation of pigments and potassium antimony tartrate

2. Widely used as flame retardant in plastics, rubber, textiles, chemical fibers, pigments, paints, electronics and other industries, also used as catalyst and production raw materials in the chemical industry

3. Used as white pigment, white glass, enamel, medicine, cement, filler, mordant and fire-retardant coating, etc.

4. Excellent inorganic white pigment, mainly used for paint coloring. Used as flame retardant for various resins, synthetic rubber, canvas, paper, coatings, etc., catalyst for petrochemicals and synthetic fibers. Used to make mordants and opacifiers, it is the raw material for synthetic antimony salts. The enamel industry is used to increase the opacity and surface gloss of enamel. The glass industry is used as a decolorizer to replace arsenic acid.

5. Used as flame retardant for various resins, synthetic rubber, canvas, paper, coatings, etc., catalyst for petrochemicals and synthetic fibers. Used to make mordants and opacifiers, it is the raw material for synthetic antimony salts. It is used as an additive in the enamel industry to increase the opacity and surface gloss of enamel. It is used as a decolorizing agent to replace arsenous acid in the glass industry. It is also used in medicine, metallurgy, military industry, etc.

Production method

It is divided into dry method and wet method. The dry method is a method of obtaining products by roasting and oxidizing stibnite or metallic antimony. The wet method is a method of obtaining products by reacting stibnite or metallic antimony with acid using a liquid phase method. Dry stibnite (Sb2S3) is calcined at 1000℃ in the presence of coke. The antimony trioxide vapor generated by oxidation is collected, condensed, and then heated and reduced with coke using soda ash as a flux to generate metallic antimony. The obtained metallic antimony is then oxidized in the air to obtain antimony trioxide. The wet antimony salt ammonolysis method reacts metallic antimony with chlorine to generate antimony trichloride, which is then distilled, hydrolyzed, ammonolyzed, washed, centrifuged, and dried to obtain the finished antimony trioxide product. The hydrochloric acid method uses stibnite as raw material: 2Sb+3C12→2SbC13SbCl3+H2O→SbOCl+2HCl4SbOCl+H2O→Sb2O3?2SbOCl+2HCl2SbOC1?Sb2O3+2NH4OH→2Sb2O3+2NH4CI+H2O. Stibnite reacts with hydrochloric acid in the presence of nitric acid, and the finished product is obtained after hydrolysis, precipitation and drying.

Team Presentation