METHOD OF PRODUCING ESPECIALLY PURE SELENIUM Russian patent published in 2019 - IPC C01B19/02 C22B9/02 C22B9/04 C22B9/05 

FIELD: chemistry.

SUBSTANCE: invention relates to inorganic chemistry and can be used in fiber-optic infrared optics, semiconductor instrument-making for production of extremely pure chalcogenide glass and fiber-optic guides on their basis, as well as in semiconductor engineering. To obtain an especially pure product, the selenium to be purified is successively subjected to high-vacuum degassing of its melt at temperature of 250–270 °C, high-vacuum distillation and thermal treatment of selenium vapors at temperature of 600–650 °C. Method includes chemical-thermal treatment of selenium melt and vapors at temperature 600–650 °C in atmosphere of helium inert gas with oxygen addition at pressure 400–650 mm Hg with subsequent freezing of volatile reaction products. Three-stage high-vacuum distillation is carried out with low (2-1)10^-4 cm³/cm²⋅with and decreasing from stage to stage to (2-1)10^-5 cm³/cm²⋅with specific rate of evaporation. Selenium is obtained with high degree of purity in terms of hydrogen-containing impurities, water (H₂O), hydrogene selenide (H₂Se), hydrogen sulphide (H₂S), impurities of carbon- and oxygen-containing substances, heterophase impurity inclusions from silicon dioxide, carbon and metals.

EFFECT: production of extremely pure chalcogenide glass and fiber-optic guides based thereon.

4 cl, 1 dwg