METHOD OF OBTAINING HIGH-PURITY TUNGSTEN OXIDE (IV) Russian patent published in 2008 - IPC C01G41/02 

FIELD: chemistry.

SUBSTANCE: proposed method of obtaining high-purity tungsten oxide (IV) involves hydrolysis of pure tungsten hexafluoride with subsequent separation of tungsten oxide from the solution of hydrolysis products and baking of the latter. Tungsten hexafluoride is purified by distillation with subsequent filtering of the tungsten hexafluoride stream through a fluoroplastic fibrous filter. Distillation of tungsten hexafluoride is carried out with rate of evaporation not exceeding 5·10^-4 g/(cm²·s), and filtration is carried out when the stream of gaseous tungsten hexafluoride passes through a filter at linear speed of 0.3-1 cm/s. The separated tungsten oxide is baked in a stream of oxygen at 400-900°C.

EFFECT: obtaining a compound with high metal purity of ≤ 1·10^-5%, suitable for use in making tellurite glass.

3 cl, 2 ex, 1 tbl