Exchange Processes for Other Elements

First-stage molal flow rate per mole 99.8% Dj 0 product  

To give an example of one of the most successful applications of chemical exchange to separation of isotopes of an element heavier than hydrogen that may have industrial application, a brief description will be given of the process and equipment used by Taylor and Spindel [T2] to product 99.8 percent pure. This separation depends on the exchange reaction 

Taylor and Spindel found that the optimum conditions for operating this process on the laboratory scale were 8 to QM HNO3, 25 to 50°C, and atmospheric pressure. Although a hi er temperature speeds up attaiiunent of exchange equilibrium, a is lower, and more NO2 is present with a lower exchange equilibrium constant. 

The process used by Taylor and Spindel is illustrated in Fig. 13.41. liquid aqueous HNO3 flows downward through a packed column countercurrent to an upflowing gas stream consisting largely of NO with lesser amounts of other nitrogen compounds. Nitric acid containing the 

The HNO3 flowing down through the smaller column, no. 2, countercurrent to NO is enriched further in N to 99.8 percent at the foot of the column. At this point some of the downflowing HNO3 is withdrawn as plant product, and the remainder of the HNO3 is reduced to NO with SO2 in reflux generator no. 2. This NO is used to reboil column no. 2. 

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