Extraction process

摘要

The invention relates to a method for the selective recovery of uranium from a sulphate-based acidic aqueous solution of uranium containing iron and other metals by means of solvent extraction, in which the extractant used in the organic extraction solution is bis(2-ethylhexyl) phosphate and a liquid branched trialkyl phosphine oxide is the modifying agent. It is typical of the method that the uranium concentration in the feed solution is less than 50 mg/l and a reducing agent is introduced into the aqueous and/or extraction solution to prevent the permanent oxidation of iron to trivalent. In the method the majority of the extraction solution is circulated in a circuit consisting of the extraction stage and the storage tank and only a small part of the uranium-loaded extraction solution is routed to scrubbing and stripping.