Abstract
Na-A and -X zeolites were synthesized from waste solutions in conversion of coal fly ash (Fa) to zeolite. The amorphous SiO 2 and Al 2O 3 of Fa were completely dissolved to form Po, Pt, and Pc type zeolites in NaOH solutions at 85°C. Only 24% of Si 4+ eluted from Fa were converted to the zeolites and the remaining waste solutions contained high Si 4+ concentrations. When molar ratio SiO 2/Al 2O 3 of the waste solutions was modified at 1.0≤SiO 2/Al 2O 3≤2.0 by addition of NaOH–NaAlO 2 solutions and the solutions were agied at 85°C, a single phase of Na-A zeolite was formed. The Na-X zeolite was formed at SiO 2/Al 2O 3≥2.5 and its crystallinity was increased with increasing the SiO 2/Al 2O 3 ratio, whereas the crystallinity of Na-A zeolite was decreased. At SiO 2/Al 2O 3=7.3, a single phase of Na-X zeolite was produced.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
