Microwave assisted two-step process for rapid synthesis of Na-A zeolite from coal fly ash

Journal Article · Tue Jan 15 04:00:00 EST 2008 · Industrial and Engineering Chemistry Research

DOI:https://doi.org/10.1021/ie070603k· OSTI ID:21004833

Tanaka, H; Fujimoto, S; Fujii, A; Hino, R; Kawazoe, T ^[1]

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1. Shimane University, Shimane (Japan). Faculty of Science & Engineering

Using the amorphous aluminosilicate of coal fly ash (FA), Na-A zeolite was synthesized. The FA particles mechanically treated with ball mill were added into a tube made of cellulose filter paper, and they were pretreated with a NaOH solution by refluxing under microwave (MW) irradiation for 60 min. The amorphous aluminosilicate of FA was dissolved during the pretreatment. After pretreatment, the tube was removed and NaAlO{sub 2} solution was added to the residual solution to control the SiO{sub 2}/Al{sub 2}O{sub 3} molar ratio of the solution ranging from 0.5 to 4.0. The precipitates thus formed were aged by refluxing under MW irradiation for 60 min. After aging, white precipitates were yielded over the whole SiO{sub 2}/Al{sub 2}O{sub 3} range. At SiO{sub 2}/Al{sub 2}O{sub 3} = 0.51.0, the materials were identified as Na-A zeolite with a little amount of hydroxysodalite. The amorphous aluminosilicate emerged slightly at SiO{sub 2}/Al{sub 2}O{sub 3} = 2.0. The diffraction peaks of Na-A zeolite and hydroxysodalite disappeared at SiO{sub 2}/Al{sub 2}O{sub 3} = 4.0. The cation exchange capacity of Na-A zeolite formed at SiO{sub 2}/Al{sub 2}O{sub 3} = 0.5 and 1.0 was 4.32 and 4.70 meq.gP{sup -1}, respectively. The results obtained led to the conclusion that Na-A zeolite can be synthesized from milled FA for 120 min under MW irradiation.

• OSTI ID: 21004833
• Journal Information: Industrial and Engineering Chemistry Research, Journal Name: Industrial and Engineering Chemistry Research Journal Issue: 1 Vol. 47; ISSN IECRED; ISSN 0888-5885
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
ALUMINIUM SILICATES
FLY ASH
IRRADIATION
MICROWAVE RADIATION
PRECIPITATION
SODIUM HYDROXIDES
SYNTHESIS
WASTE PROCESSING
ZEOLITES