Bench scale studies have been made of the recovery of uranium from acid leach liquors (and slurries) by solvent extracting with di (2-ethylhexyl) phosphoric acid in an organic diluent. Uranium may be stripped from the organic solvent by either alkaline or acidic reagents, the former having been studied in greater detail. On the basis of these tests, a recovery process may be considered which shows promise both from the standpoint of operation and chemical costs. Under proper conditions, vanadium can also be extracted by the di (2-ethylhexyl) phosphoric acid and stripping again may be accomplished with either acidic or alkaline reagents. Preliminary studies have been made of these possibilities. In addition to di (2-ethylhexyl) phosphoric acid, some other organophosphorus acids, have been cursorily examined in respect to their extraction and/or stripping performance.

A satisfactory ion-exchange-polarographic method was developed for the determination of either chromium(VI) or total chromium in Homogeneous Reactor fuels. Total chromium is determined as chromium (VI) , i.e., chromate, and in the same way as is chromium(VI), after chromium in the lower valence states is oxidized to chromate by potassium permanganate. Chromate is separated from all interfering metal ions in the fuel by ion exchange on a Dowex 50 resin column. The Chromate in the effluent is determined polarographically in approximately 0.75 M sodium hydroxide solution as supporting electrolyte. A well polarographic wave is obtained for the chromium (VI) chromium (III) reduction at a half-wave potential of -0.85 volt vs. the S.C.E. The relative standard deviation of the data for 2 μg of chromium (VI) per ml was 2%; for 4 μg of total chromium per ml, it was 3%. An ion-exchange-polarographic method was developed also for the determination of chromium(III). Chromium (III) is separated from all interfering ions in the fuel by ion exchange on a Dowex 1 resin column. The chromium (III) in the effluent is determined polarographically in a 1M ammonia-1M ammonium chloride supporting electrolyte. The wave obtained at a half-wave potential of -1.42 volt vs. the …