摘要 |
<p>An improved multistage method for reextracting uranium from an organic extractant comprising a dialkylphosphoric acid and a trialkylphosphine oxide with the aid of an aqueous solution of phosphoric acid containing ferrous ions, each stage comprising the following steps: (a) bringing the organic extractant into contact with the aqueous phase, (b) separating the organic phase depleted in uranium from the uraniferous aqueous phase, (c) recycling a fraction of the aqueous phase resulting from step (b) towards step (a), and (d) adjusting the ferrous ion content of the fraction which is recycled. The ferrous ion content of the recycled fraction is adjusted by placing the aqueous phase resulting from step (b) in contact with metallic iron each time the ferrous ion content of the said fraction falls below a predetermined value.</p> |