Quantification of Transitions Occurring in a Hydrothermally Activated Fly Ash

• Published in: Materials performance and characterization 2014-12, Vol.3 (1), p.239-254
• Main Authors: Jha, Bhagwanjee, Singh, D. N.
• Format: Article
• Language: English
• ISSN: 2165-3992; 2379-1365
• DOI: 10.1520/MPC20130033

Interaction of fly ash with NaOH results in formation of several transition compounds (viz., zeolites), which are polycrystalline in nature and their crystal wise quantification is a challenging task. In fact, various parameters (viz., oxides, minerals present in the fly ash, pH and EC of NaOH) control the outcome of such interaction at 100°C. Hence, extensive monitoring of these controlling parameters and the zeolites becomes essential. With this in view, a three-stage methodology to quantify transitions occurring in the fly ash has been proposed in this manuscript. Interestingly, it has been observed that Stage-3 of the fly ash-alkali interaction results in formation of 47 types of zeolite-crystals (viz., Na-P1, faujasite, chabazite, hydroxysodalite, and analcime), which exhibits polymerization of these zeolites and wide variation in their size (ranging from 30 to 2346 nm). This sort of transition encourages application of the residues in waste water treatment and other environmental cleanup projects.