What is tungstic acid?
Chinese name: 钨酸
English name: Tungstic Acid
Chemical formula: H2WO4
Molecular weight： 249
Melting point：698 °C(lit.)
Solubility: 730 g/L (20 ºC)
Customs Code : 28418000
Traits: colorless crystal or white crystalline powder. Weathered in dry air, 100 ℃, lost crystal water. Dissolved in water, insoluble in ethanol. The relative density of 3.23 ~ 3.25. The temperature of 698 ° C (anhydrous).
Storage: Sealed cool and dry seal.
Tungstic acid is a yellow shiny sheet crystal or crystalline powder, soluble in water, insoluble in ethanol, slightly soluble in ammonia. Weathered in the air. Heat to 100 ° C loss of water from the crystallization of anhydrous. Reacts with strong acid (except hydrofluoric acid) to form water-insoluble yellow tungstic acid, reacts with phosphoric acid or phosphate to form phosphotungstic acid heteropolyacid complex, reacts with organic acids such as tartaric acid, citric acid and oxalic acid to form the corresponding organic acid network Compound.
Tungsten oxide and sodium hydroxide reaction, or the use of tungsten concentrate and sodium hydroxide pressure cook to generate tungstic acid solution, the refining, filtration, ion exchange and other processes, separation of impurities, and then by evaporation of tungstic acid products.