MOSSBAUER SPECTROSCOPIC STUDIES ON 3 DIFFERENT TYPES OF CROCIDOLITE FIBERS

Mossbauer spectroscopic studies have shown that the M1 cationic site in native UICC crocidolite is populated by both ferric and ferrous ions, whereas the M2 and the M3 sites are exclusively occupied by ferric and ferrous ions, respectively. The detoxification of these fibres increased the ferric ion content al the M1 sites and formed a layer of ferric ions on the surface of the fibres. The activation process on the other hand, increased the ferrous ion content of these sites. Activation also converted some of the ferric ions at the M2 sites into ferrous ions and produced some metallic iron on the surface of the fibres.