DETERMINATION OF DENSITY AND DIELECTRIC PERMITTIVITY OF SOLUTIONS OF MEDIUM-HEAVY RARE EARTH ELEMENTS IN AQUEOUS SOLUTIONS AND IN EXTRACTS OF ACIDIC ORGANOPHOSPHORUS EXTRACTANTS

Co-extraction of rare-earth elements from chloride solutions containing total rare-earth elements by a mixture of extractants mono-2-ethylhexyl ester of 2-ethylhexylphosphonic acid (P507) + di(2,2,4-trimethylpentyl)phosphinic acid (Cyanex 272) + 10 about. % TBP in isopar-l with a mass concentration of P507 + Cyanex 272 - 15%. The density and permittivity of solutions of rare-earth elements of the medium-heavy group in aqueous solutions and in extracts of acidic organophosphorus extractants have been determined. Initial concentrations in REE GH solutions ranged from 0.15 to 1.7 mol/dm3. The features of complex formation in a mixture of praseodymium metal and P507 extractant were studied. The initial concentrations in praseodymium solutions ranged from 0.014 to 0.149 mol/dm3.