Uranium solutions

Chemical Precipitation. The product of the extraction processes, whether derived from acid or carbonate leach, is a purified uranium solution that may or may not have been upgraded by ion exchange or solvent extraction. The uranium ia such a solution is concentrated by precipitation and must be dried before shipment. Solutions resulting from carbonate leaching are usually precipitated directly from clarified leach Hquors with caustic soda without a concentration step, as shown ia equation 9. 

DATA nOUNDARY Dual-diaphragm pumps in uranium solution service. 

This paper describes a reliability analysis of dual - diaphragm pumps in uranium solution service. It is part of the output from a failure modes and effects analysis of the design for a system to be installed at the Oak Ridge Y-12 plant. The study involved collecting data on pumps with Viton and Teflon diaphragms at 10 gpm and 15 gpm. 

Langmuir D (1978) Uranium-solution-mineral equilibria at low temperatures with applications to sedimentaiy ore deposits. Geochim Cosmochim Acta 42 547-569. 

Langmuir D (1978) Uranium solution-mineral equilibria at low temperatures with applications to sedimentary ore deposits. Geochim Cosmochim Acta 42 547-569 Langmuir D, Herman JS (1980) The mobility of thorium in natural waters at low temperatures. Geochim Cosmochim Acta 44 1753-1766... 

Figure 9.51 Transient signal of238U+ using nanovolume flow injection of a lOngT1 uranium solution (sample loop =54nm). (D. Schaumloffel, P. Ciusti, M. Zoriy, C. Pickhardt, j. Szpunar, R. Lobinski and j. S. Becker, J. Anal. At. Spectrom., 20, 17(2005). Reproduced by permission of the Royal Society of chemistry.)...

Elsheimer, H. N., A. L. Johnston, and R. L. Kochen Microdistillation Technique for Separation of Micro Amounts of Chloride from Plutonium and Uranium Solutions. Anal. Chem. 38, 1684 (1966). 

The stoichiometry of the complexes between HDBP and U(VI) changes with the acidity, that is, at high nitric acidity, the presence of [U02(N03)2(HDBP)TBP] and [U02(N03)2(HDBP)2], and at low nitric acidity, the forms [U02(N03)(DBP)(HDBP)J, [U02(DBP)2(HDBP)J (where x = 1 or 2) dominate. The presence of such complexes can explain the difficulties in U(VI) recovery (114, 115, 120). Otherwise, various authors have indicated the presence of insoluble compounds for enriched uranium solutions (121-124). Recently, Powell identified the solid forms with various spectroscopic methods at lower acid concentrations, the well-characterized polymer U02(DBP)2 precipitates as a yellow powder, whereas a sticky solid or gels are formed at high acidity. The global formula is U02(N03)(H(DBP)2)(HDBP)2 (106). 

Langmuir, D. "Uranium"Solution-Mineral Equilibria at Low Temperatures with Applications to Sedimentary Ore Deposits, Geochimica et Cosmochimica Acta 1982, 42, 547-569. 

If the environmental condition of the ore zone changes as a result of either natural or manmade causes, the uranium can become very mobile. This is evidenced by the in situ mining process in which relatively minor modifications are made to the ground-water chemistry to produce a solution that can rapidly dissolve uranium and maintain uranium solution concentrations of hundreds of parts per million. We have shown in our laboratory experiments that when this uranium-rich solution contacts aquifer sediments containing minerals capable of reducing uranium from (VI) to (IV), large portions of the uranium are rapidly removed from solution and immobilized. 

Uranium solution Uranyl nitrate solution, 0.02 M U02+ Dissolve 10.0 g U02(N03)2.6H20 in water and dilute in a volumetric flask to 1 L. 

Step 5. Pipette 100 X of the uranium solution each onto the centers of two planchets and dry under a heat lamp. Count one with the proportional counter and then with the alpha-particle spectrometer. Save the second planchet for Part 1C, Step 8. 

Data Table 7.2 Uranium solution count rate... 

Step 8. Evaporate 10 ml 0.5 M oxalic acid to about 2 mL and pour onto the second planchet with dried 100-A. sample of the initial uranium solution (see Part 7A, Step 5). Evaporate to dryness under the heat lamp. Flame the planchet as in Step 6. Count three times for 3,000 s each with proportional counter for alpha and beta particles. Record in Data Table 7.5... 

Count the second dried aliquot of the initial uranium solution in Step 8 for both alpha particles and beta particles. 

Data Table 7.5 Count rate of uranium solution with oxalic acid ... 

Evaluate the effect of beta-particle absorption in residual oxalic acid on the count rates of the initial uranium solution. 

The first transition metal cation which is unstable in water but which can be generated as a stable entity in HF was U3+ [30]. It was formed by oxidation of the metal by protons in a BF3-HF solution which is non-oxidising and relatively weakly acidic. The UV-vis spectrum of the lilac-colored solution was virtually identical with that observed for an acidified aqueous solution in which the uranium solution was under continuous electrolytic reduction to maintain U(III) as the aquo-cation. 

Figure 9.51 Transient signal using nanovolume flow injection of a lOngP uranium solution...

The neptunium was purified by an anion column, and alpha pulse analysis revealed no other species than The uranium solutions... 

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