Radiochemical Separations by Ion Exchange

Abstract

During the past few years ion exchange has become firmly entrenched as a separations tool. Its great popularity stems from its theoretical and practical simplicity, its insensitivity to concentration, its versatility and broad applicability, its rapidity for obtaining materials of extremely high purity and, of course, from the ready availability of reasonably stable ion exchange materials. Ion exchange is ideally suited for separations at the trace concentration so typical for radiochemical work and, indeed, ion exchange and radiochemical developments have been closely allied. Further, because ion exchange columns are simple to operate, easily shielded and adaptable to remote control, their use is attractive, even at relatively high activity levels.The war-time work on the Manhattan project on the separation of rare earth and other fission products is generally considered the starting point of the present great interest in the use of ion exchangers for inorganic and radio chemical separations. Since then, application of ion exchangers to radio chemical problems has increased enormously and now includes such widely different fields as analysis, process control, isolation of tracers from target materials, discovery, identification and study of new elements, separation of activities in neutron activation analysis, general investigations of the chemistry of solutions, "hot atom" chemistry, production of radioisotopes, and waste disposal. The isolation of uranium from low grade ores is, in principle, also a radiochemical separation and has become the largest appli cation of ion exchangers outside the water conditioning field.The flood of ion exchange papers originating in many laboratories throughout the world is now so large as to preclude adequate coverage in the limited space of this review, even if attention is confined, as will be done here, to inorganic separations. Complete restriction of the paper to radio chemical applications, although implied by the title, seemed inappropriate since except at highest radiation densities, there is essentially no difference between separations of active or inactive materials. The field to be covered is thus extremely large and, in order to stay within bounds, citation of references had to be severely restricted, and selections often be made on an arbitrary basis. Fortunately, the field is frequently reviewed and a number of recent books (e.g., refs. 1 to 9) and review articles (e.g., refs. 10 to 21) are available. In addition, it is hoped that sufficient individual citations have been made to provide an adequate introduction to recent developments in the field.

An anion exchange radiochemical experiment: Separation of manganese, zinc, and iron

“…This separation is based on distribution coefficients reported for tartrate complexes (5). Clean separations are obtained with almost no tailing, very little resin is used (a column of resin 4 X 0.8 cm is sufficient), and the separation can be accomplished in one 4-hour laboratory period. Three readily available, long-lived isotopes (54Mn, 66Zn, and S9Fe) are employed.…”

Sequential ion exchange separation scheme for the identification of metallic radioelements

“…This method becomes onerous or time-consuming when many activities are present in the sample, or when the nature of the activities is unknown. Examples of such cases are the determination of impurities by activation analysis (11, IS) and the determination of the composition of fission products (17).…”

Rapid Chemical Separations

“…Online isotope separation is discussed in detail by Klapisch (15). Since many rapid separa tions are based on standard radiochemical procedures or make use of certain nuclear phenomena like recoil effects, the consultation of review articles on radiochemical separations (16)(17)(18), solvent extraction (19), ion exchange (20), distillation (21), recoil (22), and recoil reactions (23,24) is recom mended.…”