Meta-schoepite

Fig. 6. SEM images of meta-schoepite (a) Precipitation of meta-schoepite after 1 y of reaction (b) After 2 y, preferential corrosion of the U64 phase occurred along specific crystallographic directions.

Fig. 7. SEM image of studtite from corroded SNF. Studtite replaces meta-schoepite, which is not visible in the image.

Salbu et al. (2003) used micro-XAS to examine oxidation of depleted uranium (DU) munitions. Interestingly, these studies revealed the presence of U02 and U3Os but no U6+ oxide hydrate phases. Brock et al. (2003) examined the corrosion of DU penetrators in an arid environment. Using SEM, they observed aggregates of tabular, hexagonal schoepite and meta-schoepite crystals with clay/silt particles that were coated with amorphous silica. Brock et al. (2003) suggested that as the schoepite/meta-schoepite phases were coated with amorphous silica/clays, further dissolution was inhibited. 

Figure 7. The fourmaiieiite sheet anion-topology generated by stacking chains (a), and the sheet of uranyl pentagonal bipyramids that occurs in fourmarierite, schoepite and meta-schoepite (b).

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