FTIR spectroscopic investigation of alkali-activated fly ash: Atest study

Abstract

Fly ash is byproduct of thermal power plants. Millions tons of fly ash is produced globally. Fly ash is disposed partly in landfills but it could also be released into the atmosphere in the past. Fly ash is composed of silica, alumina, iron oxide, magnesia and activated carbon. Due to large surface area, fly ash is very suitable for catalysis application. It is well known and well reported that fly ash can be converted into efficient adsorptive material such as zeolites. In the present work, the transformation of fly ash into zeolite was carried out by alkali activation process of aluminosilicates material. The alkali solution releases silicon and aluminum ion into solution, which form afterwards Si-OH and Al-OH groups. FTIR spectroscopy was applied to characterize fly ash chemical activation, in order to conduct a study making intensive use of infrared spectroscopy and further to provide information on chemical bond vibrations in the molecular units of fly ash. The FTIR spectrum of solid base fly ash (SBFA) after chemical activation shows a significant increase in peak intensity of the band for -OH group.