Tungsten Trioxide, also known as tungsten anhydride (WO3), is a yellow powder, insoluble in water and alkali, and slightly soluble in acid. Because of its good optical, electrical and gas sensitive properties, it is widely used in life, chemical industry, medical treatment and military affairs.
I. Physical Properties
Appearance and properties: yellow or yellow-green powder
Melting point (°C): 1472
Relative density (moisture = 1): 7.1
Boiling point (°C): 1837
Relative density (water = 1): 7.16 g/cm 3
Molecular formula:WO3
Molecular weight: 231.85
Solubility: insoluble in water, soluble in alkali and slightly soluble in acid.
II. Chemical Properties
At 850 degrees, Tungsten Trioxide sublimes significantly, the sublimation heat is 459.8 k/mol, and it is green when melted. Except hydrofluoric acid, it hardly reacts with inorganic acids, and can be slowly dissolved in ammonia or concentrated alkali solution. It reacts with chlorine by heating to produce oxychloride compounds, but can not react with bromine and iodine.
III. Function & Use
Tungsten Trioxide can be calcined and reduced to produce tungsten powder and tungsten carbide powder, which can then be used to produce cemented carbide products, such as tools and molds; It can also be used to manufacture pure tungsten products, tungsten rods, tungsten wires and tungsten electrodes; In addition, it can also be used in the fields of new battery materials, ceramic colorants, smart glass electrochromic films, etc.
IV. Use Precautions
Precautions for operators:
1. Close operation and exhaust air locally to prevent dust from being released into the air of the workshop;
2. Operators must receive special training and strictly abide by operating procedures;
3. Operators are advised to wear self-priming filter dust masks, chemical safety glasses, rubber acid and alkali resistant clothing and rubber acid alkali resistant gloves;
4. Avoid exposure to bromine pentafluoride and chlorine trifluoride;
5. Equipped with emergency equipment for leakage. Empty containers may leave harmful substances behind.
