Abstract
Zeolites are porous solids composed mainly of aluminum and silicon in the form of hydrated crystalline aluminosilicates; they have special properties inherent to their structural characteristics that make them useful in many industrial applications. The synthesis of zeolites from natural and residual sources of silicon and aluminum has become more important due to both environmental and economic benefits. In this work fly ash from power plants were converted to zeolite by alkaline activation with sodium hydroxide (NaOH). The technique is characterized by low cost, and great value added; a technological alternative that transforms existing materials on a large scale into an innovative material for applications relevant to the industrial sector. This work aimed to study the sodalite and cancrinite (zeolites) synthesis process from fly ash using phase quantification and rational chemical analysis, in order to highlight the influence of process conditions. The samples were characterized by X-ray diffraction with phase quantification by Rietveld method, X-ray fluorescence method with rational analysis of crystalline phases, and scanning electron microscopy. Sodalite and cancrinite zeolites from fly ash were obtained by synthesis with concentrations of 3.5, 5.25 and 7.0 M NaOH for 24, 36 and 48 h.
Keywords:
fly ash; synthesis of zeolites; sodalite; cancrinite; crystalline phases
