High capacity cation exchanger by hydrothermal zeolitization of coal fly ash

Berkgaut, Vadim; Singer, Arieh

doi:10.1016/0169-1317(95)00033-x

Cited by 132 publications

(56 citation statements)

References 5 publications

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“…The fusion method contributes to the formation of more crystalline and higher purity zeolites due to facilitation of the dissolution of Si and Al present in the ash 4 . The zeolite P and zeolite X synthesized using hydrothermal treatments may show high cation exchange capacities 6 . The zeolite A and faujasites obtained by the conversion of the coal ash present an ion exchange capacity for Cs + ions of 19% (zeolite A) and 39% (zeolite faujasite), in relation to commercial zeolites that present greater ion exchange capacity 7 .…”

Section: Introductionmentioning

confidence: 99%

Zeolite A synthesis employing a brazilian coal ash as the silicon and aluminum source and its applications in adsorption and pigment formulation

2012

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Zeolite A was synthesized using the coal ash from Siderópolis/RS -Brazil. The synthesis was based on a standard IZA synthesis using coal ash as the Si and Al source. XRF analysis showed that the coal ash has a Si/Al ratio of 1.52, which is close to the Si/Al ratio required to produce zeolite A (1.0). The synthesized materials were analyzed by XRD, SEM and N 2 adsorption. More crystalline materials were obtained during synthesis when an additional treatment was applied at a temperature of 353 K at the dissolution of NaOH step. The product formed after 4 hours was the most crystalline, but even the product formed after 1 hour proved to be better than that formed using the standard 4 hours IZA synthesis. The zeolites synthesized by this method had an adsorption capacity of 120 mg.g -1 for Ca 2+ , half the capacity of commercial zeolite A (300 mg.g -1 ). It was not possible to obtain blue or green pigments using the synthesized zeolite A.

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Section: Introductionmentioning

confidence: 99%

Zeolite A synthesis employing a brazilian coal ash as the silicon and aluminum source and its applications in adsorption and pigment formulation

2012

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“…He noted that one ash formed sodalite octahydrate, whereas the other formed faujasite and phillipsite, and attributed this to variations in the chemical composition, nature and properties of the samples. Other authors 2,8,14,16,19 have also reported on the formation of zeolitic types such as zeolites X, A and P from different ash samples, depending on the treatment conditions. The surface areas, particle sizes and CEC values of the raw and treated Bayswater and Eraring ash samples are listed in Tables 2 and 3, respectively.…”

Section: Lead Ion Removalmentioning

confidence: 94%

“…Such a treatment process can lead to the formation of various types of zeolite including types P, A and X. 4,16,18,19 The type of zeolite formed is a function of the temperature, pressure, concentration, aging period, pH, Al, Si and cation sources used during preparation. 4,19 The high percentage of aluminosilicates in¯y ash (60±80%) 2 makes them a cheap and readily available source of Si and Al for zeolite synthesis.…”

Section: Introductionmentioning

confidence: 99%

Zeolite synthesis from coal fly ash for the removal of lead ions from aqueous solution

Scott

Guang

Naeramitmarnsuk

et al. 2001

J of Chemical Tech & Biotech

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Fly ash samples from the Bayswater and Eraring power plants, located in New South Wales, Australia, were used in a preliminary study on zeolite synthesis by hydrothermal treatment with sodium hydroxide under various conditions. The treated¯y ash was tested for the ability to remove lead ions from aqueous solution. Both¯y ashes were partially converted to zeolite. The zeolites formed under the experimental conditions were zeolite Na-P1 and sodalite octahydrate for the Bayswater ash and phillipsite, zeolite X, zeolite Na-P1 and sodalite octahydrate for the Eraring ash. The type of zeolite formed was dependent on the treatment time and sodium hydroxide concentration. In the case of the Bayswater ash, zeolite Na-P1 was formed by treatment with 4 mol dm À3 NaOH for 48 h while treatment with 5 mol dm À3 NaOH for 96 h produced sodalite octahydrate at the expense of zeolite Na-P1. In the case of the Eraring ash, phillipsite was formed following treatment with 3 mol dm À3 NaOH, zeolite X and zeolite Na-P1 were formed following treatment with 4 mol dm À3 NaOH and sodalite octahydrate was formed following treatment with 5 mol dm À3 NaOH. A maximum cation exchange capacity of $400 meq/100 g was achieved by both treated ash samples. Treatment of a solution with a lead ion concentration of 120 ppm using 0.5 g of both treated ash samples (S/L ratio = 0.25 g/100 cm 3 ) achieved complete removal in 5 min, whereas treatment with 0

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“…It leads to an assumption that a new mineral group (i.e. zeolites) was synthesized when Si reacted with hot NaOH as reported by some researchers previously [39] [40] [41]. Based on energy dispersive X-ray spectroscopy data the HCl-NaOH treated sample has mass composition of C (6.1%), O (55.4%), Na (29.3%), and Si (9.3%) with atomic distribution 9.1, 62.1, 22.9, and 6.0% of C, O, Na, and Si, respectively.…”

Section: Mineralogical Evidencesmentioning

confidence: 99%

Double Acid-Base Extraction of Silicic Acid from Quartz Sand

Santi¹,

Mulyanto²,

Goenadi³

2017

JMMCE

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Silica is becoming more attractive as plant nutrient for non-graminae crops particularly in relation with drought-stress tolerant. Many efforts have been conducted to obtain an efficient technique to produce silica fertilizer worldwide, but the results are varying considerably due to various factors including raw material and extraction technique. This study was carried out to develop an efficient extraction technique for ortho-silicic acid (OSA-H 4 SiO 4 ) from a Bangka-Belitung quartz sand by employing acid-base dissolution method. A 325-mesh size quartz sand was boiled in HCl solution at various concentrations. The optimum concentration was then used in the following experiment at several different volumes of solution. The sand obtained from optimum concentration and volume of HCl solution was then reacted with different amounts of NaOH (s), and heated until a wet mixture was obtained. As a reference the best extraction conditions were applied to a natural zeolite sample. All OSA analyses were done in triplicates with spectrophotometric method. Supporting evidences were collected from x-ray diffraction and scanning-electron-microscopy analyses of the treated samples. The yield of quartz sand-originated OSA was 183 g•kg −1 and significantly increased linearly with increasing weight of NaOH (R 2 = 0.99**), whereas that from zeolite was only 104.2 g•kg −1 at 80 g NaOH. XRD and SEM data confirmed the evidences that the acid-base extraction disrupted the quartz mineral structure and as a consequence releasing more water soluble OSA.

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High capacity cation exchanger by hydrothermal zeolitization of coal fly ash

Cited by 132 publications

References 5 publications

Zeolite A synthesis employing a brazilian coal ash as the silicon and aluminum source and its applications in adsorption and pigment formulation

Zeolite A synthesis employing a brazilian coal ash as the silicon and aluminum source and its applications in adsorption and pigment formulation

Zeolite synthesis from coal fly ash for the removal of lead ions from aqueous solution

Double Acid-Base Extraction of Silicic Acid from Quartz Sand

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