Dissolution studies of CsAISi 5O 12

Abstract

CsAlSi 5O 12 was exposed to a variety of aqueous media, with most of the experiments being conducted at 70°C. The Cs extraction was approximately proportional to the square root of the dissolution time. As found previously at 25°C the Cs extraction at 70°C varied as [H +] 0.4 in the pH = 1–4 range and increased with increasing alkalinity beyond pH = 7. No substantial change in the Cs dissolution rate at neutral pH was found in 1 M CaCl 2, as against deionized water, a possible slight increase was observed in 0.01 M NaHCO 3 relative to KOH of about the same pH, and a sixfold increase was observed at neutral pH in 1 M NaCl relative to deionized water. The dissolution rate increased by a factor of ∼ 10 on heating from 25 to 70–100°C, but not with further increase of temperature. The Cs dissolution rate of Cs-loaded Na mordenite which was rendered X-ray amorphous by subsolidus heating at 1000°C was found to be ∼ 1 g·m −2·day −1 in a Soxhlet test.