Study of the wetting of coke by different pitches

Prebaked anodes are made of dry aggregates (coke, recycled butts and rejected green/baked anodes) and the binder pitch. During the mixing process, the wettability of coke by pitch influences the anode paste behavior. Coke particles (-125 +100 m) were prepared from the same source using two different procedures, and the wettability of cokes by five pitches with different properties was studied using a sessile-drop system at 170ºC. The contact angle results show that the wettability of coke by all pitches follows a similar trend for both cases, but the actual contact angles are different. The cokes and the pitch-coke interfaces were also investigated by the optical and scanning-electron microscopy (SEM) techniques. The image analysis results indicated that the coke particle size distribution depends on the coke preparation, which seems to influence its wettability

X-ray photoelectron study of the interaction of the uranyl group UO22+ with hydroxylapatite and fluoroapatite in aqueous solutions

The interaction of the uranyl group UO22+ in aqueous solutions with hydroxylapatite and fluoroapatite was studied by X-ray photoelectron spectroscopy. The apatite samples under study were found to contain CO32- groups. The reaction of uranyl nitrate with hydroxylapatite in aqueous solutions does not lend to U(IV)-containing compounds but forms U(VI)-containing uranyl compounds with equatorial hydroxyl or carbonate groups partly replaced by fluorine in the uranyl compounds in the case of fluoroapatite.. The interaction of the uranyl group with fluoroapatite in aqueous solutions is much more effective than the interaction with hydroxylapatite