Dissolution studies of CsA1Si5O12

CsAlSi5O12 was exposed to a variety of aqueous media, with most of the experiments being conducted at 70 0C. The Cs extraction was approximately proportional to the square root of the dissolution time. As found previously at 25 0C the Cs extraction at 70 0C varied as (H+) /SUP 1/4/ 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 μ CaC12, as against deionized water, a possible slight increase was observed in 0.01 μ NaHCO3 relative to KOH of about the same pH, and a sixfold increase was observed at neutral pH in 1 μ NaCl relative to deionized water. The dissolution rate increased by a factor of about 10 on heating from 25 to 70-100 0C, 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 0C was found to be about 1 g.m-2.day-1 in a Soxhlet test