METHOD FOR SOLVENT REFINING OF NITRATE SOLUTIONS CONTAINING RARE-EARTH METALS Russian patent published in 2014 - IPC C22B59/00 C22B3/38 

FIELD: chemistry.

SUBSTANCE: method involves multi-step counter-current extraction of impurities from an aqueous nitrate solution with tributyl phosphate. Purification is carried out using a solution with rare-earth metal concentration of 100-150 g/l, while using 5 extraction steps with the ratio organic phase: aqueous phase=1:1.1, 3-5 washing steps with the ratio organic phase: aqueous phase=10:1 and 5 re-extraction steps in a system of 100% tributyl phosphate and aqueous nitrate solution. A solution with content of ballast impurities of less than 4% of the sum of rare-earth metals and total specific alpha activity of less than 1·10-8 Ku/(kg rare-earth metals) is obtained.

EFFECT: rare-earth metal solution satisfies consumer requirements for concentration and impurity content and sanitary requirements for content of radionuclides.

3 dwg, 9 tbl