Purification of Fly Ash Zeolites

1 Monitoring Relative Variations Between Two Steps ofTSA 

6 Major Findings of the Three-Step Activation Technique 

which can he opined to he a superior reagent than 0.5 M NaOH. These outcomes are in full agreement to Kolay and Singh [20] and can he attributed to various effects of ash-alkali interaction in Step-1 (the PT) such as (i) etching at fewer areas on interacting surface of the ash and (ii) creation of surface pores, visible in the micrographs, as discussed in the following section. 

Incidentally, a decrease in G of the residues may be attributed to (i) enhanced formation of porous compounds and (ii) polymerization of Si and A1 tetrahedra, which also corresponds to increased volume of a zeolitic framework stmcture, present in the residues. Based on variations of G and SSA it can be inferred that Steps-2 and 3 (the R2), are indicative of better zeolitic characteristics of the residues (i.e., purified form of residues of Step-1). 

Note A number under parenthesis represents percentage increase or decrease, as designated by + or - sign, respectively due to its stage in comparison to immediate previous stage of the treatment 

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Abstract Though, naturally occurring and chemically synthesized (pure grade) zeolites have been used for various industrial applications in the past, their increasing demand for several novel applications (viz., as adsorbent or absorbent for waste water decontamination, soil remediation as fertilizers, aqua-culture purification, etc.) warrants their enhanced production. With this in view, several researchers have attempted to synthesize zeolites from the fly ash, an abundantly available industrial by-product, as described in this chapter. Furthermore, different methods employed for synthesis of fly ash zeolites, the mechanism of zeolites formation and potential fields of their appUcations have also been included herein. 

In this context, a thorough review of state-of-the-art on the fly ash utilization and various innovative efforts made by the researchers, in the recent past, for synthesis of zeolites (popularly known as fly ash zeolites) from the fly ash are presented in this handbook. These zeolites are being used for various industrial applications such as catalysts and adsorbents for the contaminated soils and sludge. In addition, a novel methodology for purification of some low grade fly ash zeolites is presented in this book. Attempts have also been made to provide a single source of the literature on the fly ash and its recycled products (the polycrystalline fly ash zeolites) as an easy and quick reference for the researchers and industrialists. 

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