Technical Memorandum 33
Stockwell DR, Bentley KW and Kerr CB
Supervising Scientist, 1991
ISBN 0 644 13771 1
About the report
Sixteen post-calcination uranium concentrate samples from two Australian uranium mills were analysed using the batch replacement method of Dennis et al. The samples were selected to represent a range of sulphate content. Results indicate that the degree of in vitro dissolution varies between samples and between solvents, and that the proportion of the most soluble fraction (class D) is linearly related to the sulphate content of the material. Results, using de-ionised water, physiological saline and a simulated lung fluid indicate that, following initial release of the soluble fraction, the extent and range of in vitro dissolution of the remaining material is comparable to values reported in the literature. Close examination of the in vitro dissolution results using the batch replacement method indicate, however, that the fraction of uranium released cannot be satisfactorily interpreted using a time-dependent exponential and a test appears to confirm this. Consequently, in vitro experimentation by the batch replacement method is of questionable value in prediction of in vitro behaviour in terms of dissolution halftimes. Dissolution of concentrate in a gastric juice simulant (0.1 M HCI) was also measured as a potential indicator of gastrointestinal absorption following ingestion.