Adsorption of Eutectic LiCl−KCl into Zeolite 4A Using a Mechanically Fluidized Vacuum System

Abstract

A high-temperature mixer has been used to absorb LiCl−KCl eutectic salt powders into zeolite 4A. In situ sampling has been performed, allowing for a time-resolved view of the adsorption reaction. The weight percent free (nonabsorbed) chloride ions has been used as a measure of the effectiveness of the adsorption process. Using zeolite 4A powder with no binder, the free chloride concentration leveled off at 0.4−0.5 wt % in less than 5 h at 500 °C. Zeolite 4A granules (−60 + 200 mesh) containing binder yielded a free chloride concentration of 0.02 wt % after 5 h at 500 °C. It is concluded that the improved performance from the granulated zeolite can be attributed to better mixing within the retort. A 50% reduction in the free chloride concentration below the melting point of the salt suggests that solid-state adsorption of the salt into the zeolite is possible.