Phase transformations during the zeolitization of fly ashes

J. D. MONZÓN; A. M. PEREYRA; M. S. CONCONI; E. I. BASALDELLA

Journal of Environmental Chemical Engineering

ELSEVIER SCIENCE BV

Año: 2017 vol. 5 p. 1548 - 1553

2213-3437

The reactivity of a fly ash discarded from a thermoelectric power station was evaluated in terms of its hydrothermal conversion into NaA-containing products. The influence of ash pretreatments and the effect of changes in the synthesis mixture composition on the evolution of the solid phase toward its conversion into zeolitic materials were studied. Activation by milling was not as effective as alkaline fusion. The highest levels of fly ash reactivity were obtained by applying an alkaline fusion treatment using sodium carbonate at 800 C. It was observed that this particular ash activatiorn induces a solid reordering that generates crystalline materials identified as NaAlSiO2 polymorphs that in turn are easily transformed into zeolite structures. Synthesis conditions for ash zeolitization as high as 60% were established.