抄録
The fact that the enrichment of rubidium and cesium in carnallite has been pointed out by many workers.
The behaviour of trace amount of rubidium and cesium was studied during the crystallisation of halite, sylvite, bischoffite and carnallite, by isothermal evaporation of each of the saturatued solution by use of137Cs and86Rb as tracer.
Logarithmic distribution coefficients of rubidium and cesium between the crystal and the solution have been determined as follows : Logarithmic distribution coefficient of rubidium in halite was 0.14, in sylvite was 0.4, in bischoffite was 0.3, and in carnallite was 2.4, and that of cesium in halite was 0.02, in sylvite was 0.03, in bischoffite was 0.3 and in carnallite was 1.3.
Those results suggest that rubidium and cesium will be selectively concentrated in carnallite among the oceanic salts.
The actual samples of carnallite originated from the oceanic salt deposit in Stassfurt were analysed for chemical composition and X-ray diffraction pattern.
The results indicated that one of the samples was the mixture of carnallite, halite and kainite, and the other was perfect carnallite ; cesium contained 1 ppm. in the former and 2 ppm. in the latter, but the Rb/Cs ratio of the former was 90 and that of the latter was 85.
The similarity of the ratios and results of the above described experiment suggest that the rubidium and the cesium in the former impure carnallite sample are concentrated only in the carnallite.
