Single stage enrichment

The primed or unprimed symbols refer to isotope fractions. The single stage separation factor for infinitesimal product removal (yi/zj 0), (rj)0, is given the symbol a . The i s index the stage number. Most often a is close to unity and it is convenient to define the isotope enrichment factor (the single stage enrichment factor), e, between the i th and (i + l) th stage... 

Along the gradient of the breakthrough curve, the lithium samples were isotopically assayed by mass spectrometry. The single stage enrichment factor was determined as follows (24) ... 

Other oxides of nitrogen are present in these systems, and they affect the single stage enrichment factor a = ( N/ N)iiquid/( N/ N)gas as well as the interphase transfer rate as measured by the height of the column equivalent to a theoretical plate (HETP). 

Table I. Effect of Non-donor Solvents on the Single Stage Enrichment Factor exp for Solutions with an Initial Mole Fraction of N2O4 of Approximately 0.5 to which NO was Added until the Total Pressure in the Equilibration Vessel (146cc.) was 1 atm.

Table II. Single Stage Enrichment Factors aexp for Solutions of Com< ...

It may be seen that partial vaporisation of the liquid gives a vapour richer in the more volatile component than the liquid. If the vapour initially formed, as for instance at point E, is at once removed by condensation, then a liquid of composition x3 is obtained, represented by point C. The step BEC may be regarded as representing an ideal stage, since the liquid passes from composition x2 to a liquid of composition x3, which represents a greater enrichment in the more volatile component than can be obtained by any other single stage of vaporisation. 

We now appreciate the reasons for the high cost of enriched uranium. The single stage separation factors are low, as is the natural abundance. This leads inexorably... 

Table 3. Single Stage 13C Isotope Enrichment Parameters for Photolysis of Dibenzyl Ketone Under Various Conditions...

To attain a sufficiently high degree of separation, multiplication of the single stage separation factor is needed. This can only be accomplished by providing circulation of the separated substances. With this approach most of the enriched mixture is returned to the column. 

The output solutions contain only enriched products without auxiliary ion impurities. At the same time that the ion separation takes place concentration of the mixture components occurs. The product concentration in column I equals the total concentration of the ion mbmire put into the column and the product concentration in column II, that is, the ion-displacer concentration. This is riiy, other conditions being equal, the use of more concentrated solutions is beneficial. However, it should be taken into account that increase in the total concentration of the mixture of ions separated may result in a decrease in the sorbability differences between the separated and auxiliary ions. Moreover, the resultant decrease in the single-stage separation coefficient reduces the efficiency of the column operation. 

The relationship between the separation hictor and the enrichment ratio was calculated (Figure-6). As the CO separation factor of Na-LSX at 2I3K is 1.1, it is predicted that the enrichment ratio for a single stage of this VPSA will be 2.5. 

The characteristic value for a single-stage separation system is the isotopic separation factor a which is defined by Eq. (12). Because a deviates not very much from one, a number of separation stages must be connected in series for a sufficient total isotopic enrichment. The total isotopic separation factor S, using N equilibrium stages, is given by ... 

Single-stage batch experiments without monactin showed no isotopic separation, which does not agree with the comparable investigations of Knochel and Wilken (Table 13). In contrast to that, Rade and Wagener found an enrichment of Na in the monactin complex. The average of two independent investigations was aK( Na/ Na) = 1.038. 

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