Barium carbonate, chemical formula BaCO3, molecular weight 197.35. Hexagonal fine crystals or white powder. Insoluble in water, density 4.43 g/cm3, melting point 1740 ℃ (8820 kPa-Chemicalbook90 atmospheric pressure). 1450 ℃ decomposition, release carbon dioxide. Slightly soluble in water containing carbon dioxide, also soluble in ammonium chloride or ammonium nitrate solution to form a complex, soluble in hydrochloric acid and nitric acid to release carbon dioxide. poisonous. Barium carbonate is an important inorganic salt product, which can be used as an auxiliary material for ceramic coatings and optical glass for the manufacture of electronic ceramics, PTC thermistors, capacitors and other electronic components. Analysis of iron in calcium, magnesium, manganese and zinc. Identification and determination of halogens in organic compounds. It is used to make barium salts, pigments, fireworks, rodenticide pottery, and used as fillers and clearing agents for water clarification. for catalysts. The production of electronic ceramics and purified water, the production of pigments, coatings or other barium salts for making optical glass, barium magnetic materials, etc. are important chemical raw materials for the production of picture tube glass bulbs, magnetic materials and advanced optical glass. It can also be used in the treatment of excess sulfate in the chrome-plating electrolyte, in the white passivation solution of the zinc coating, and in the treatment of waste water.