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Stripping nitric acid

The method of separation results in the Am being diverted to the aqueous waste stream of the second plutonium solvent extraction cycle (2 AW). The calculated predicted volume of this stream for the full campaign was 2.2 x 10 L. Physical limitations of equipment required that the solution be evaporated in two steps instead of one. The first step could result in a concentration factor of 25 to 50. The second step included nitric acid stripping and evaporation to the final volume. [Pg.101]

After scrubbing, the coextracted actinides and lanthanides are removed from the organic phase by two separate strip columns (a reductant and dilute nitric acid strip, followed by a dilute oxalic acid strip). After destruction of the excess oxalic acid, the two strips are combined with other recycle streams that are... [Pg.367]

In the uranium stripping contactor, uranyl nitrate was transferred back to the aqueous phase by 0.1 M nitric acid strip solution. Fission products were separated from the impure uranyl nitrate by additional cycles of solvent extraction and by adsorption on silica gel, not shown. [Pg.459]

Calkins and Bohlmann describe this route or a similar one, in more detail. They used 50 per cent TBP in pure kerosene, a feed 7 5N in nitric acid and a 6N nitric acid strip, with volume ratios of feed solvent strip equal to 1 0 1 5 0 5. This system extracts thorium and uranium and they are separated by a first backwash of the thorium with 0 5N nitric acid. [Pg.179]

The urea produced is normally either prilled or granulated. In some countries there is a market for Hquid urea—ammonium nitrate solutions (32% N). In this case, a partial-recycle stripping process is the best and cheapest system. The unconverted NH coming from the stripped urea solution and the reactor off-gas is neutralized with nitric acid. The ammonium nitrate solution formed and the urea solution from the stripper bottom are mixed, resulting in a 32—35 wt % solution. This system drastically reduces investment costs as evaporation, finishing (priQ or granulation), and wastewater treatment are not required. [Pg.300]

The vapor-phase process of SocifitH Chemique de la Grande Paroisse for production of nitroparaffins employs propane, nitrogen dioxide, and air as feedstocks (34). The yields of nitroparaffins based on both propane and nitrogen dioxide are relatively high. Nitric oxide produced during nitration is oxidized to nitrogen dioxide, which is adsorbed in nitric acid. Next, the nitric dioxide is stripped from the acid and recirculated. [Pg.36]

The distribution of highly extractable solutes such as and Pu between the aqueous and organic phases is strongly dependent upon the nitrate anion concentration in the aqueous phase. This salting effect permits extraction or reextraction (stripping) of the solute by controlling the nitric acid concentration in the aqueous phase. The distribution coefficient, D, of the solute is expressed as... [Pg.204]

In view of the foregoing remarks, it is clear that all glassware used in the preliminary treatment of samples to be subjected to stripping voltammetry, as well as the apparatus to be used in the actual determination, must be scrupulously cleaned. It is usually recommended that glassware be soaked for some hours in pure nitric acid (6 M), or in a 10 per cent solution of pure 70 per cent perchloric acid, followed by washing with de-ionised water. [Pg.624]

Conceptual Flowsheet for the Extraction of Actinides from HLLW. Figure 5 shows a conceptual flowsheet for the extraction of all the actinides (U, Np, Pu, Am, and Cm) from HLLW using 0.4 M 0< >D[IB]CMP0 in DEB. The CMPO compound was selected for this process because of the high D m values attainable with a small concentration of extractant and because of the absence of macro-concentrations of uranyl ion. Distribution ratios relevant to the flowsheet are shown in previous tables, IV, V, VI, and VII and figures 1 and 2. One of the key features of the flowsheet is that plutonium is extracted from the feed solution and stripped from the organic phase without the addition of any nitric acid or use of ferrous sulfamate. However, oxalic acid is added to complex Zr and Mo (see Table IV). The presence of oxalic acid reduces any Np(VI) to Np(IV) (15). The presence of ferrous ion, which is... [Pg.439]

Insert each metal strip into the corresponding well. Place the graphite rod in the well with the nitric acid. The metal strips and the graphite rod are your electrodes. [Pg.511]

Clean off any tarnish on the copper strip by sanding it gently. Dip the bottom of the copper strip in the nitric acid for a few seconds, and then rinse off the strip carefully with deionized water. Avoid touching the section that has been cleaned by the acid. [Pg.542]

Stripping of cobalt from the loaded extract is accomplished by various acids, such as nitric acid ... [Pg.285]

The leach liquor is first treated with a DEHPA solution to extract the heavy lanthanides, leaving the light elements in the raffinate. The loaded reagent is then stripped first with l.Smoldm nitric acid to remove the elements from neodymium to terbium, followed by 6moldm acid to separate yttrium and remaining heavy elements. Ytterbium and lutetium are only partially removed hence, a final strip with stronger acid, as mentioned earlier, or with 10% alkali is required before organic phase recycle. The main product from this flow sheet was yttrium, and the yttrium nitrate product was further extracted with a quaternary amine to produce a 99.999% product. [Pg.502]

Cadmium in acidified aqueous solution may be analyzed at trace levels by various instrumental techniques such as flame and furnace atomic absorption, and ICP emission spectrophotometry. Cadmium in solid matrices is extracted into aqueous phase by digestion with nitric acid prior to analysis. A much lower detection level may be obtained by ICP-mass spectrometry. Other instrumental techniques to analyze this metal include neutron activation analysis and anodic stripping voltammetry. Cadmium also may be measured in aqueous matrices by colorimetry. Cadmium ions react with dithizone to form a pink-red color that can be extracted with chloroform. The absorbance of the solution is measured by a spectrophotometer and the concentration is determined from a standard calibration curve (APHA, AWWA and WEF. 1999. Standard Methods for the Examination of Water and Wastewater, 20th ed. Washington, DC American Public Health Association). The metal in the solid phase may be determined nondestructively by x-ray fluorescence or diffraction techniques. [Pg.143]

The technique of differential pulse stripping voltammetry has been developed for the determination of plutonium in nitric acid solutions [117]. The successful determination of plutonium was demonstrated... [Pg.1071]

In the process using sulfuric acid (see Figure 1) this acid was, and in many instances still is, added to the weak nitric acid produced by an AOP before the mixed acid was fed to the top of a distillation column. The feed has been preheated in some processes to minimize the vapor load in the distillation column. Enough sulfuric acid was added to the feed so that the vapor leaving the top of the column was at least 98% nitric acid. Live steam was added to the base of the column to provide the heat for the column and the stripping vapor required to... [Pg.149]


See other pages where Stripping nitric acid is mentioned: [Pg.341]    [Pg.495]    [Pg.393]    [Pg.113]    [Pg.317]    [Pg.341]    [Pg.495]    [Pg.393]    [Pg.113]    [Pg.317]    [Pg.418]    [Pg.80]    [Pg.246]    [Pg.43]    [Pg.44]    [Pg.44]    [Pg.44]    [Pg.64]    [Pg.205]    [Pg.266]    [Pg.294]    [Pg.294]    [Pg.239]    [Pg.441]    [Pg.443]    [Pg.530]    [Pg.214]    [Pg.448]    [Pg.455]    [Pg.1361]    [Pg.146]    [Pg.195]    [Pg.498]    [Pg.504]    [Pg.641]    [Pg.1477]    [Pg.599]    [Pg.12]    [Pg.255]    [Pg.143]   
See also in sourсe #XX -- [ Pg.97 ]




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