METHOD OF REGENERATING NITRIC ACID Russian patent published in 2009 - IPC C01B21/46 G21F9/08 

FIELD: chemistry.

SUBSTANCE: invention relates to radiochemical engineering, particularly to methods of regenerating nitric acid from tail solutions from nuclear reprocessing with its purification from impurities of more volatile acids during fractionation. The method of regenerating nitric acid from tail solutions from nuclear reprocessing involves evaporation and fractionation with feeding the aqueous condensate to the top tray of the fractionation column, outlet of condensate backflow into the column still, feeding water for absorption of nitric acid with outlet of regenerated nitric acid from the tray over the still of the column and inlet of an additional stream of water into the column still. Outlet of the condensate backflow into the column still is done from one of the trays lying below the inlet of the supply vapour stream in form of secondary vapour from evaporation of the initial solution of nitric acid with impurities of volatile acids, including acetic, hydrofluoric and hydrochloric acid, inlet of water for absorption of nitric acid is done at one tray below the outlet of the condensate backflow into the column still, and impurities of volatile acids are discharged with the distillate. Improved purification from impurities enables to maintain concentration of nitric acid in the distillate between 0.03 and 0.1 mol/l, as well as in the regenerated nitric acid - from 10 to 13 mol/l.

EFFECT: method allows for regeneration of nitric acid from acetic, hydrofluoric and/or hydrochloric acid.

2 cl, 1 tbl, 5 dwg, 11 ex