Influence of the fly ash fraction after grinding process on the hydrothermal synthesis efficiency of Na-A, Na-P1, Na-X and sodalite zeolite types

Kunecki, Piotr; Panek, Rafał; Wdowin, Magdalena; Bień, Tomasz; Franus, Wojciech

doi:10.1007/s40789-020-00332-1

Cited by 38 publications

(30 citation statements)

References 63 publications

(48 reference statements)

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“…On the other hand, on the diffractogram of composite phases related to unreacted ash residue in the form of aluminosilicate glaze, mullite (d hkl = 5.38; 3.40; 2.79; 2.59 Å; reference code 01-089-2645), quartz (d hkl = 4.25; 3.34; 2.45; 2.28 Å; reference code 01-073-8320) and calcite (d hkl = 3.03; 2.49; 2.09; 1.88 Å; reference code 01-086-2334) were observed. Such phase characteristics is typical for fly ash-derived zeolites [ 37 ].…”

Section: Resultsmentioning

confidence: 99%

Simultaneous Removal of Pb2+ and Zn2+ Heavy Metals Using Fly Ash Na-X Zeolite and Its Carbon Na-X(C) Composite

et al. 2021

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Pure zeolite (Na-X) and a zeolite–carbon composite (Na-X(C)) were investigated as adsorbents of heavy metals—Pb2+ and Zn2+ from an aqueous solution. These materials were synthesized from fly ash—a waste from conventional hard coal combustion. Both solids were characterized using XRD, SEM-EDS, nitrogen adsorption/desorption, particle size and elemental composition analyses. The adsorption study was performed at pH 5 in the systems containing one or two adsorbates simultaneously. The obtained results showed that the pure zeolite was characterized by a more developed surface area (728 m2/g) than its carbon composite (272 m2/g), and the mean pore diameters were equal to 1.73 and 2.56 nm, respectively. The pure Na-X zeolite showed better adsorption properties towards heavy metals than its Na-X(C) composite, and Zn2+ adsorbed amounts were significantly higher than the Pb2+ ones (the highest experimental adsorption levels were: for Zn2+—656 and 600 mg/g, and for Pb2+—575 and 314 mg/g, on the Na-X and Na-X(C) surfaces, respectively). The zinc ions are exchanged with the cations inside the zeolite materials structure more effectively than lead ions with a considerably larger size. In the mixed systems, the competition between both heavy metals for access to the active sites on the adsorbent surface leads to the noticeable reduction in their adsorbed amounts. Moreover, the hydrochloric acid was a better desorbing agent for both heavy metals, especially Pb2+ one (desorption reached 78%), than sodium base (maximal desorption 25%).

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Section: Resultsmentioning

confidence: 99%

Simultaneous Removal of Pb2+ and Zn2+ Heavy Metals Using Fly Ash Na-X Zeolite and Its Carbon Na-X(C) Composite

et al. 2021

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“…Moreover, the diffractograms did not register a background line elevation in the angular range of 15–35° 2θ, which is a very characteristic phenomenon for zeolites obtained from fly ash, attributed to the presence of an amorphous phase [ 49 ]. Importantly, on the diffraction patterns of fly ash-derived zeolites, apart from the higher background level, characteristic reflexes of fly ash phases such as mullite, quartz, calcite, or hematite were also observed [ 50 ]. This phenomenon occurs because the hydrothermal conversion of the fly ash does not proceed with 100% efficiency.…”

Section: Resultsmentioning

confidence: 99%

“…terials 2021, 14, x FOR PEER REVIEW 8 of 16 ash phases such as mullite, quartz, calcite, or hematite were also observed [50]. This phenomenon occurs because the hydrothermal conversion of the fly ash does not proceed with 100% efficiency.…”

Section: Xrd Mineralogy Characterizationmentioning

confidence: 99%

Recycling of Waste Solution after Hydrothermal Conversion of Fly Ash on a Semi-Technical Scale for Zeolite Synthesis

et al. 2021

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Nowadays, using fly ash for zeolites production has become a well-known strategy aimed on sustainable development. During zeolite synthesis in a hydrothermal conversion large amount of post-reaction solution is generated. In this work, the solution was used as a substrate for Na-A and Na-X zeolites synthesis at laboratory and technical scale. Obtained materials were characterized using particle size analysis, X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), transmission electron microscopy (TEM), Fourier transformed infrared spectroscopy (FTIR), and nitrogen adsorption/desorption isotherm. Produced zeolites revealed high purity (>98%) and monomineral zeolitic phase composition. The SiO2 content was in the range 39–42% and 40–38%, whereas Al2O3 content was 23–22% and 25–26% for Na-X and Na-A, respectively. TEM and BET analyses revealed Na-X zeolite pores were almost identical to commercial 13X with SBET in the range 671–734 m2/g. FTIR indicated slight differences between materials obtained at laboratory and technical scale in Si-O-(Si/Al) bridges of the zeolitic skeleton. The results showed good replicability of the laboratory process in the larger scale. The proposed method allows for waste solution reusability with a view to highly pure zeolites production in line with circular economy assumptions.

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“…Natural clinoptilolite came from Sokyrnytsya deposit (Transcarpathian region, Ukraine) [ 43 ] and has particles diameter <0.2 mm. The Na-X and Na-A (both <0.2 mm) are the synthetic zeolites which were produced in the hydrothermal conversion of fly ash after coal combustion [ 44 , 45 ].…”

Section: Methodsmentioning

confidence: 99%

Sorption of Heavy Metal Ions of Chromium, Manganese, Selenium, Nickel, Cobalt, Iron from Aqueous Acidic Solutions in Batch and Dynamic Conditions on Natural and Synthetic Aluminosilicate Sorbents

et al. 2020

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Zeolites are materials with known sorption properties. The sorption is thought to progress mainly by ion exchange with Na+, K+, Mg2+, Ca2+ or H+ from the zeolite exchange sites. The aim of the study was to compare the sorption properties of natural and synthetic zeolites on the example of the removal of selected metals from aqueous acidic solutions. Uptake experiments for selected ions of chromium, manganese, selenium, nickel, cobalt, and iron were performed using the batch and kinetic column methods. The sorption of the individual metal ions in mg per 1g of sorbent was determined for each sorbent. The relative affinity sequence of the examined cations toward the various sorbent was presented. The Langmuir model was used to model the adsorption equilibrium. Vermiculite under 1 mm of diameter (SF), Na-X, and Na-A were proved to be the most suitable for the individual uptake of studied metal ions. It was observed that the behavior of selenium ions differed from the remaining ones which was interpreted that selenium undergoes adsorption in the anionic form. The fixed-bed column studies were performed using Na-A, ensuring the sorption of selenium in the presence of iron(III) ions. The experiments were conducted using Na-X zeolite pre-loaded by Fe(III) as well as unmodified sorbent eluted by an equimolar mixture containing 100 ppm of Fe and Se. Obtained results prove that selenium sorption improves if other metal ions such as iron appear in the acidic solution. That efficient selenium sorption conditions can be applied to remove selenium which was recognized as toxic at higher levels.

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Influence of the fly ash fraction after grinding process on the hydrothermal synthesis efficiency of Na-A, Na-P1, Na-X and sodalite zeolite types

Cited by 38 publications

References 63 publications

Simultaneous Removal of Pb2+ and Zn2+ Heavy Metals Using Fly Ash Na-X Zeolite and Its Carbon Na-X(C) Composite

Simultaneous Removal of Pb2+ and Zn2+ Heavy Metals Using Fly Ash Na-X Zeolite and Its Carbon Na-X(C) Composite

Recycling of Waste Solution after Hydrothermal Conversion of Fly Ash on a Semi-Technical Scale for Zeolite Synthesis

Sorption of Heavy Metal Ions of Chromium, Manganese, Selenium, Nickel, Cobalt, Iron from Aqueous Acidic Solutions in Batch and Dynamic Conditions on Natural and Synthetic Aluminosilicate Sorbents

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