The study of the interaction between cesium chloride and kaolinite by thermal methods.

The reaction occurring during the grinding of kaolinite with CsCl was studied by DTA and thermal weight losses. The thermographs were compared with those of kaolinite ground with KCl and of pure kaolinite. DTA curves show that the three endothermic peaks characteristic of the CsCl salt disappear when the kaolinite/CsCl ratio reaches 1:1. This shows that a separate phase of CsCl is no longer present in the CsCl-kaolinite complex. The exothermic peak of kaolinite at approx 1000oC does not appear in the presence of CsCl, possibly due to the fact that kaolinite is delaminated in the complex. Thermal weight-loss studies indicate different behaviour for kaolinite ground with KCl and that ground with CsCl. Differences were also observed between kaolinite ground in the presence of small amounts of Cs (kaolinite/CsCl wt. ratio = or > 1) and large amounts (<1). Thermal stability of kaolinite is observed when the kaolinite/CsCl wt. ratio fits the complex formation. Percentage weight losses suffered by pure KCl, CsCl, kaolinite, and mixtures of kaolinite and KCl or CsCl at various T between 105o and 1000oC are tabulated. -P.Br.