Lithium isotopes separation methods

The classical method for lithium isotope separation employed chemical exchange between lithium amalgam and an aqueous solution of lithium hydroxide. 

The present work has been the first application of extraction chromatography to isotope separation. This technique proved to be a simple and convenient laboratory-scale method for studying lithium isotope separation by liquid-liquid extraction. The method may have even more interesting possibilities for isotopes of elements which form a variety of complexes which are soluble in organic solvents. 

The alkali elution curves of the displacement chromatography are shown in Fig. 17, the ratio Li/ Li dependent on the effluent volume is given in Fig. 18. As one can see from Fig. 18, an increase of the Li/ Li ratio from 0.07 to 0.09 is found within the lithium elution band which corresponds to a column length of 91 cm. The relative enrichment of the heavy lithium isotope Li in the first fractions — that is in the methanolic phase — agrees with isotopic separations of calcium using a condensation resin with dibenzo(18]crown-6 and [2b.2.2], respectively (Chap. 4.3.2.3 and Chap. 4.3.2.4). Fujine and coworkers have also carried out one breakthrough experiment with methanolic solutions of cesium chloride and lithium acetate The evaluation of the front analysis with Spedding and coworkers method resulted in an isotopic separation factor of a = 1.014. 

This chapter gives a brief account of the nuclear fission reaction and the most important fissile fuels. It continues with a short description of a typical nuclear power plant and outlines the characteristics of the principal reactor types proposed for nuclear power generation. It sketches the principal fuel cycles for nuclear power plants and points out the chemical engineering processes needed to make these fuel cycles feasible and economical. The chapter concludes with an outline of another process that may some day become of practical importance for the production of power the controlled fusion of light elements. The fusion process makes use of rare isotopes of hydrogen and lithium, which may be produced by isotop>e separation methods analogous to those used for materials for fission reactors. As isotope separation processes are of such importance in nuclear chemical engineering, they are discussed briefly in this chapter and in some detail in the last three chapters of this book. 

Many methods have been used to achieve partial separation of lithium isotopes on a small scale. Examples of processes and reported separations are listed in Table 12.4. A process somewhat similar to the last one listed in this table, involving countercurrent exchange of lithium isotopes between aqueous lithium hydroxide and lithium amalgam, is to be used in a plant being built... 

Table 12.4 Methods tested for separating lithium isotopes... 

The method was tested by Kobayashi, Fujii, and Okamoto in 1982 for the separation of X = calcium isotopes on a cation-exchange column with Y = lithium ions. The heavier calcium isotopes, " Ca, " Ca, and " Ca, were enriched at the... 

There were various methods for separating the isotopes, one being molecular distillation and another being a chemical process involving an amalgam with mercury. A distillation programme was started but with disappointing results. Eventually a conversion plant was set up at the Royal Ordnance Factory at Chorley in Lancashire. There was also another source of lithium the United States. 

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