METHOD FOR SELECTIVE EXTRACTION OF RADIONUCLIDES FROM RADIOACTIVE NITRATE SOLUTIONS Russian patent published in 2019 - IPC G21F9/04 

FIELD: technological processes.

SUBSTANCE: invention relates to radiochemical technology. Method of selective extraction of radionuclides from nitric acid solutions involves reduction treatment of initial solution, contacting with extractant consisting of solution of aliphatic hydroxamic acid C₈-C₁₀ in hydrophobic liquid alcohols, combined extraction of molybdenum and zirconium nuclides with extract thereof with their purification from uranium, washing of the extract with a solution of nitric acid and separation of radionuclides jointly or separately from the extract during its thermal treatment or by re-extraction into an alkaline solution. Extraction into solutions of aliphatic alcohols C₈-C₁₀ with saturated hydrocarbons and extract washing is carried out with addition of a strong reducing agent. Re-extraction of Mo with Zr is carried out in solution of nitric acid by thermochemical oxidation of hydroxamic acid in extract. Destructible complexing agent concentrate is added to the re-extract, and phosphoric acid is washed out with an alkaline solution in proportions providing washing the zirconium alkylphosphate complex from the aqueous solution of molybdenum.

EFFECT: invention enables to develop a universal method of selective removal of zirconium and molybdenum at the re-extraction step with their deep purification from alpha and gamma-emitting nuclides.

10 cl, 1 ex