Formation of Na-A and -X zeolites from waste solutions in conversion of coal fly ash to zeolites

Tanaka, Hidekazu; Sakai, Yasuhiko; Hino, Ryozi

doi:10.1016/s0025-5408(02)00861-9

Cited by 103 publications

(71 citation statements)

References 15 publications

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“…Literature and data show that by using appropriate synthesis conditions, coal fly ash can be converted into different zeolite structures such as analcime (Adamczyk and Bialecka 2005;Querol et al 1997;Wang et al 2003), chabazite (Wang et al 2003), cancrinite, gmelinite, Na-P1 (Adamczyk and Białecka 2005;Hollman et al 1999;Wang et al 2003), ZSM-5 (Mohamed et al 2008), ZSM-28 (Wang et al 1998), Na-X (Derkowski et al 2006(Derkowski et al , 2007Querol et al 1997;Tanaka et al 2002), Na-Y (Ojha et al 2004), philipsite (Querol et al 1997), and sodalite (Musyoka et al 2011).…”

Section: Introductionmentioning

confidence: 99%

The conversion technology of fly ash into zeolites

Wdowin

Franus

Panek

et al. 2014

Clean Techn Environ Policy

199

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This paper presents a sub-pilot scale process of synthesis of Na-P1 zeolite from the coal fly ash. After establishing the appropriate synthesis conditions (20 kg of fly ash, 12 kg of NaOH, 90 dm 3 of water, the reaction temperature: 80°C and reaction time: 36 h), the highpurity (81 wt%) Na-P1 zeolite product was obtained. Its chemical, mineralogical, and textural properties were determined (by means of XRD, XRF, SEM-EDS and ASAP 2020). The synthesized material has a specific BET surface area (88 m 2 /g) c.a. six times higher than the fly ash from which it has been derived (15 m 2 /g). The pore-size distribution indicates a mesoporous character of the obtained zeolite, with the following pores size contents: micropores (2.76 %), mesopores (61.81 %), and macropores (35.43 %). The presented technological/production line is fully automated and allows to regulate the conditions of the synthesis process, therefore different types of zeolite materials (including: Na-X, Linde-A, and Na-P1) can be obtained using the same equipment.

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Section: Introductionmentioning

confidence: 99%

The conversion technology of fly ash into zeolites

Wdowin

Franus

Panek

et al. 2014

Clean Techn Environ Policy

199

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show abstract

“…Many studies [7][8][9][10][11] on the synthesis of zeolite-type materials by hydrothermal treatment using fly ash have been reported. However, the synthesized product is zeolite with high Si/Al ratio and there are only a few reports on the synthesis of zeolite A as a main product.…”

Section: Introductionmentioning

confidence: 99%

Alkali Hydrothermal Synthesis of Zeolite A Using Oxide By-products

et al. 2011

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The alkali hydrothermal synthesis of zeolite A using oxide by-products such as blast furnace (BF) slag and aluminum dross was investigated. Na-P1 (Na 6 Al 6 Si 6 O 32 · 12H 2 O) was synthesized directly in NaOH aqueous solution for 86.4 ks at 373 K using BF slag, Al 2 O 3 , and SiO 2 . On the other hand, zeolite A was successfully synthesized by a two-step method including an elution treatment of Al 2 O 3 . Under optimal conditions, the formation ratio of zeolite A in various compounds contained in the product was 56 %. The utilization of dross residue squeezed out from the aluminum dross as a raw material to synthesis of zeolite A let this ratio increase to 60 %. The heat of water adsorption of the product synthesized by the two-step method using BF slag, SiO 2 , and aluminum dross residue was measured, and it was 184 J/g, being higher than that of commercial zeolite A.

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“…On taking account of substitutability Ca and Mg for Na in zeolite A, water-quenched slag may possibly become one of the available raw materials for synthesis of zeolite. There have been many reports of the synthesis of zeolite-type materials by hydrothermal treatment in use of fly ash, [7][8][9] but there was no report on synthesis of zeolite A in use of fly ash except the report by Holloman et al They studied zeolite A synthesis using the solution including Si and Al ion by two step synthesis process. There has been no report on alkali hydrothermal synthesis of hydrophilic zeolite in use of BF slag.…”

Section: Introductionmentioning

confidence: 99%

“…It was suggested by studies on alkali hydrothermal treatment for synthesis of zeolite A using fly ash that the compositional control of raw material powders was needed to be the molar ratio Si/Al of 1. [7][8][9][10] However, its ratio in the compositions of water-quenched slag is 1.95 as shown in Table 1. Consequently, three kinds of experiments for zeolite A synthesis were carried out in this study.…”

Section: Introductionmentioning

confidence: 99%

Hydrothermal Synthesis of Zeolite A Using Blast Furnace Slag

et al. 2005

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Alkali hydrothermal synthesis of zeolite A using blast furnace (BF) slag was investigated. The preliminary experiment was conducted in use of synthetic slag consisting of SiO 2 , Al 2 O 3 , and CaO powders, and it was made clear that the most optimum slag compositions to synthesize zeolite A were the molar ratio of Si to Al (Si/Al) of 1 and reduction of CaO content down to 15 mass%, and that hydrothermal treating conditions were the temperature range from 328 to 358 K, NaOH solution of 1 M (ϭmol/L) and the ratio of the volume of NaOH solution to total mass of slag (V sol /W slag ) of 15 (mL/g). It was also found that synthetic slag with such a higher content of CaO as 40 % resulted in formation of tobermorite and hydrogarnet. In the experiment using BF slag, zeolite A could be successfully synthesized by optimizing both conditions of the compositions of raw material powders and hydrothermal treatment as noted above, where optimization of the compositions of raw material powders such as Si or Al content were performed by the suitable amount of addition of SiO 2 powder or NaAlO 2 powder as a source of Si and Al. The ball milling type reaction vessel containing numerous small SiC balls which was first adopted in this hydrothermal treating study was confirmed to be very effective for acceleration of synthetic reaction rate, shortening markedly the time period needed for fully synthesis of zeolite A. Temperature dependence of heat capacity of zeolite A powder synthesized in use of BF slag was measured after absorption of vapor at the ambient temperature, showing endothermic behavior with the peak at the temperature of around 473 K.

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Formation of Na-A and -X zeolites from waste solutions in conversion of coal fly ash to zeolites

Cited by 103 publications

References 15 publications

The conversion technology of fly ash into zeolites

The conversion technology of fly ash into zeolites

Alkali Hydrothermal Synthesis of Zeolite A Using Oxide By-products

Hydrothermal Synthesis of Zeolite A Using Blast Furnace Slag

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