Patent ID: 8182773

Claim:
A process for separating a chemical element from uranium(VI) starting from a nitric acid aqueous phase A 1 , in an extraction cycle for the uranium comprising: a) a uranium(VI) extraction step, in which an aqueous phase flows, with a flow rate D 1 , in a first extractor, in counter-flow to an organic phase, immiscible with water and containing an extractant, and b) a step for washing the organic phase obtained after step a) with a nitric acid aqueous phase A 2 , in which the organic phase flows in a second extractor in counter-flow to nitric acid aqueous phase A 2 ; in which the first and second extractors are connected to one another in such a manner that the aqueous phase flowing in the first extractor is formed by nitric acid aqueous phase A 1 and by nitric acid aqueous phase A 2 obtained after step b); and in which the chemical element is present in nitric acid aqueous phase A 1 at a concentration lower than that of the uranium(VI) and is less extractable by said extractant than is the uranium(VI), and the chemical element accumulates in the organic phase in the course of step a); said process being characterized in that step a) comprises drawing-off a part of the aqueous phase flowing in the first extractor, at the accumulation peak of the chemical element in the organic phase, or upstream, relative to the direction of flow of the organic phase, of said accumulation peak.