| 摘要 |
The present invention provides a method for enriching an oxygen isotope which, when distilling a large amount of a nitric oxide raw material, enables the oxygen isotope to be enriched without requiring regular replenishment of large amounts of the nitric oxide raw material and with a small liquid NO hold-up volume, without reducing the separation efficiency for the oxygen isotope. By performing a chemical exchange between a water acquired by adding hydrogen to an oxygen having a crudely enriched oxygen isotope produced by a first distillation device (11), and a nitric oxide discharged from a second distillation device (12), a nitric oxide having an enriched concentration of the oxygen isotope and a water having a reduced concentration of the oxygen isotope are obtained, and the nitric oxide having an enriched concentration of the oxygen isotope is supplied to the second distillation device (12), while an oxygen obtained by electrolysis of the water having a reduced concentration of the oxygen isotope is returned to the first distillation device (11). |
