This work intends to critically review the data concerning the variations of reactivity of Ba-exchanged zeolite A precursor with Na+ and Li+ content originally present in the zeolite framework. The main results were the following: a) obtaining a fully monoclinic celsian from Ba-exchanged zeolite A bearing Na+ residual content ranging between 0.20 and 0.74 meq/g required a 5-22 h thermal treatment at 1300 °C; b) obtaining a fully monoclinic celsian from Ba-exchanged zeolite A bearing the not further reducible Na+ residual content (about 0.20 meq/g) and Li+ contents ranging from 0.11 to 0.37 meq/g required a 4-10 h thermal treatment at 1000e1100 °C. New insight into the mechanism through which Na+ and Li+ develop their mineralizing action on the thermal transformation of Ba-exchanged zeolite A was attained.
The role of the residual Na+ and Li+ on thermal transformations of Ba-exchanged zeolite A
MAROCCO, Antonello;DELL'AGLI, Gianfranco;ESPOSITO, Serena;PANSINI, Michele
2011-01-01
Abstract
This work intends to critically review the data concerning the variations of reactivity of Ba-exchanged zeolite A precursor with Na+ and Li+ content originally present in the zeolite framework. The main results were the following: a) obtaining a fully monoclinic celsian from Ba-exchanged zeolite A bearing Na+ residual content ranging between 0.20 and 0.74 meq/g required a 5-22 h thermal treatment at 1300 °C; b) obtaining a fully monoclinic celsian from Ba-exchanged zeolite A bearing the not further reducible Na+ residual content (about 0.20 meq/g) and Li+ contents ranging from 0.11 to 0.37 meq/g required a 4-10 h thermal treatment at 1000e1100 °C. New insight into the mechanism through which Na+ and Li+ develop their mineralizing action on the thermal transformation of Ba-exchanged zeolite A was attained.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
