METHOD FOR PURIFYING NITROGEN TRIFLUORIDE FROM CARBON TETRAFLUORIDE IMPURITY Russian patent published in 2021 - IPC C01B21/83 F25J3/08 C07C17/38 

FIELD: chemistry.

SUBSTANCE: invention can be used to obtain nitrogen trifluoride NF₃ used in the production of liquid crystal displays, microprocessors. A method for purifying nitrogen trifluoride from carbon tetrafluoride CF₄ includes fractional condensation of nitrogen trifluoride and a sequence of cycles of equilibration in a cryostat at a temperature of the equilibrium pressure of carbon tetrafluoride exceeding the partial pressure of carbon tetrafluoride in the working mixture. The gas phase enriched in carbon tetrafluoride is evacuated, followed by cryogenic distillation of the condensate. The number of cleaning cycles is determined by the initial content of carbon tetrafluoride and the required purity of nitrogen trifluoride.

EFFECT: invention makes it possible to increase the degree of purification of nitrogen trifluoride up to 99.99% for large-scale production of NF₃, to minimize the loss of the target product, to exclude the regeneration of consumables and the need to use corrosion-resistant equipment.

1 cl, 2 dwg, 2 tbl, 2 ex