PROGRESS REPORT ON RAW MATERIALS FOR DECEMBER 1957
; > 8 9 8 7 8 9 < 8 < 6 9 7 kerosene sdiutions of N-benzylheptadecylumine (NBHA) from 1 M sulfate at pH 1, the extraction coefficient varied with a power between 1 and 1.5, and in extraction from 2 M sulfuric acid solution with the first power of the uncomplexed amine concentration. Extraction decreased with increasing sulfate concentration, but extraction coefficients were still high (>300 with 0.1 M NBHA) from 4 M sub 2/SO/ sub 4/ content was 0.5 M or less, dropping to ~1 at 3 M. With 4 M H/sub 2/SO/sub 4/ the amine solutions separated into two phases. In continued tests of strontium-sodium exchange between di(2ethyinexyl)phosphate and aqueous solutions, the strontium extraction enhancement at pH ~ 5 over that at higher or lower pH's previously reported from nitrate solutions was also found from acetate solutions. Am extraction isotherm from acetate buffer solution was consistent with the previously postulated complex formation, and showed that the enhancement is not limited to trace strontium. Tracer cesium extractions confirmed the preferential extraction of sodium over cesium by D2EHP from nitrate solution at pH 4 to 11. Process Development. In a continuous Amex run demonstrating the ammonium nitrate stripping flowsheet,>99.9% of the uranium and ~96% of the molybdenum were recovered from a synthetic leach iiquor containing 3.5 g of uranium and 0.12 g of molybdenum per liter. Stripping of uranium was 99.9% complete, yielding a strip solution containing 30 g of uranium and 0.1 g of molybdenum per liter. Consumption of nitrate was 0.25 lb/lb of U/sub 3/O/sub 8/. Molybdenum, which tended to accumulate in the regeneration system, was sorbed from the uranium- barren ammonium nitrate solution (produced by regenerating the amine with ammonium hydroxide) on an ion exchange resin column; it was eluted with dilute caustic with difficulty. Control and physical operation of the regeneration system was satisfactory, although high entrainment of ammonium nitrate solution in the organic recycle stream is a potential process problem. Molybdenum was recovered effectively from Amex nitrate strip solutions by adsorption on activated carbon, which was still far from saturation at a molybdenum loading of 220 g/kg of carbon. The molybdenum was readily eluted with dilute ammonum hydroxide, using 0.4 lb NH/sub 3/ per pound of molybdenum. Evaporation of the eluate and caicination gave a molybdenum product containing>99.9% MoO/sub 3/. The rate of phase separation of a amine solutions when contacted with leach liquors containing dissolved silica was dependent on a number of variables, including silica concentration, amine-diluent choice, amine concentration, liquor pH, temperature, and the type of mixing. When mixing was with the organic as the continuous phase, separation times were not appreciably affected by silica, but with aqueous-continuous mixing, separations slowed with increase in silica concentration, the effect being much more pronounced for some aminediluent combinations than for others. Of the amines tested, ditridecyl amine was affected least by the presence of silica. With 9D-178 amine (aqueous-continuous mixing), separation times decreased markediy with increase in temperature or decrease in solution pH but were not greatly affected by change in amine concentration in the range 0.0 to 0.1 M. Engineering Studies. Phase separation in the extraction step of the Amex process (0.1 M Rohm and Haas Aanberlite LA-1 in kerosene) was evaluated in 6and 48-in.-diam- gravity settlers. The flow capacity based on cross-sectional areas was the same for both sizes, demonstrating the feasibility of simple scaleup. The nominal aqueous flow capacity for oil-in-water type dispersions was 0.8 gpm/ft/sup 2/ at a phase ratio of 1/1 and 2.9 gpm/ft/sup 2/ at 4/1. For water-in-oil type dispersions the aqueous flow capacity was 0.4 gpm/sq ft at at.% phase ratio of 1/1 and 1/2. Modification of the kerosene diluent with
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Chemical Technology Div.
- DOE Contract Number:
- W-7405-ENG-26
- NSA Number:
- NSA-12-009071
- OSTI ID:
- 4321425
- Report Number(s):
- ORNL-2486
- Resource Relation:
- Other Information: Orig. Receipt Date: 31-DEC-58
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ABSORPTION- ACTIVATION- ADSORPTION- ALKALI METALS- BUFFERS- CARBON- CESIUM- CONTROL- DECOMPOSITION- EVAPORATION- HYDROXIDES- ION EXCHANGE MATERIALS- LEACHING- LIQUIDS- MOLYBDENUM- REACTION KINETICS- RECOVERY- RESINS- STABILITY- TEMPERATURE- TRACE AMOUNTS- TRACER TECHNIQUES
ACETATES- ACIDITY- ALKYL RADICALS- AMINES- AMMONIUM COMPOUNDS- ARYL RADICALS- BENZYL RADICALS- COMPLEXES- EFFICIENCY- ION EXCHANGE- KEROSENE- NITRATES- ORGANIC COMPOUNDS- PHOSPHATES- QUANTITY RATIO- SODIUM- SOLUTIONS- SOLVENT EXTRACTION- STRONTIUM- SULFATES- SULFURIC ACID- URANYL COMPOUNDS- WATER
ALCOHOLS- AMBERLITE- CROSS SECT