Light yellow powder,soluble in caustic soda, soda, ammonia generated tungstate solution.Tungstic acid refers to hydrated forms of tungsten trioxide, WO3. The simplest form, the tungstic acid monohydrate, is WO3.H2O, the tungstic acid dihydrate WO3.2H2O is also known. The solid state structure of WO3.H2O consists of layers of octahedrally coordinated WO5(H2O) units where 4 vertices are shared. the tungstic acid dihydrate has the same layer structure with the extra H2O molecule intercalated between the layers. The tungstic acid monohydrate is a yellow solid and insoluble in water. The classical name for this acid is ‘acid of wolfram’.
Tungstic acid, can exist in a variety of states, mostly yellow powder or crystal, etc. Soluble in hydrofluoric acid, slowly soluble in caustic solution, insoluble in water and other acids. The general formula is mWO3·nH2O. There are many kinds of known tungstic acid, which are all poly compounds formed by tungsten trioxide WO3 combined with water in different ratios and different forms. The known tungstic acids are yellow tungstic acid, white tungstic acid, metatungstic acid and so on.
Among them, flavotungstic acid is a common tungstic acid, referred to as tungstic acid, which is a light orange yellow powder; When the composition was WO3·H2O, the density was 5.5g/cm3, and it was dehydrated at 100℃. Insoluble in water, after dipping, gradually gelatinize, soluble in ammonia, alkaline solution and concentrated hydrochloric acid. Tungstic acid is burned and dehydrated to produce tungsten trioxide WO3, which is bright light yellow crystal or powder with a density of 7.16g/cm3 and a melting point of 1473℃. Flavotungstic acid is prepared by acidizing sodium tungstate Na2WO4·2H2O solution with hydrochloric acid to become sodium polytungstate solution, and then adding excessive concentrated hydrochloric acid to the hot solution. The flavotungstic acid obtained by this method contains sodium impurity, which has been changed to ion exchange method and solvent extraction method.
1, used for mordant, analytical reagents, catalysts, water treatment agents, manufacturing fire, waterproof materials, as well as phosphotungstate, borotungstate, etc.
2, used in the manufacture of metal tungsten, tungstic acid, tungstate, etc.
3, used for mordant, pigment, dye, ink.
4, textile workers used as fabric weighting agent, this product is used as fabric auxiliary, by tungstic acid, ammonium sulfate ammonium phosphate and other components of the mixture for fiber fire and waterproof. This kind of fiber can be made fireproof rayon and rayon. It can also be used for leather tanning.
5, used for anticorrosion of electroplating coating.
6, used as a cosolvent to introduce porcelain glaze color material can rise and fall low firing temperature and color complement effect.
7, used in petroleum industry and aviation, aerospace material manufacturing.